A study of the action of amlodipine on adrenergically regulated sodium handling by the kidney in normotensive and hypertensive rats.

PubMed Central

Johns, E. J.

1988-01-01

1. An investigation was undertaken to examine the effect of calcium channel blockade, induced by amlodipine, on the ability of the renal sympathetic nerves to cause an antidiuresis and anti-natriuresis in normotensive Sprague Dawley and spontaneously hypertensive rats anaesthetized with pentobarbitone. 2. Low frequency renal nerve stimulation in normotensive rats, which did not change renal blood flow, caused a 15% reduction in glomerular filtration rate and was associated with falls in urine flow of 37%, absolute sodium excretion of 47%, and fractional sodium excretion of 38%. The magnitude of these renal excretory changes was unaffected by prior administration of amlodipine at either 200 micrograms kg-1 plus 50 micrograms kg-1 h-1 or 400 micrograms kg-1 plus 100 micrograms kg-1 h-1. Amlodipine given in the higher dose, decreased basal levels of blood pressure and increased basal urine flow and sodium excretion. 3. In spontaneously hypertensive rats, renal nerve stimulation minimally affected renal haemodynamics but decreased urine flow, absolute and fractional sodium excretion by 29%, 31% and 24%, respectively. 4. Similar renal nerve stimulation in spontaneously hypertensive rats given amlodipine at 200 micrograms kg-1 plus 50 micrograms kg-1 h-1 or 400 micrograms kg-1 plus 100 micrograms kg-1 h-1 caused minimal changes in renal haemodynamics and in the excretion of water and sodium. The higher dose of drug resulted in decreased blood pressure and increased basal rates of urine flow and sodium excretion.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2967097

Urine sodium excretion increased slightly among U.S. adults between 1988 and 2010.

PubMed

Pfeiffer, Christine M; Hughes, Jeffery P; Cogswell, Mary E; Burt, Vicki L; Lacher, David A; Lavoie, Donna J; Rabinowitz, Daniel J; Johnson, Clifford L; Pirkle, James L

2014-05-01

Little information is available on temporal trends in sodium intake in the U.S. population using urine sodium excretion as a biomarker. Our aim was to assess 1988-2010 trends in estimated 24-h urine sodium (24hUNa) excretion among U.S. adults (age 20-59 y) participating in the cross-sectional NHANES. We used subsamples from a 1988-1994 convenience sample, a 2003-2006 one-third random sample, and a 2010 one-third random sample to comply with resource constraints. We estimated 24hUNa excretion from measured sodium concentrations in spot urine samples by use of calibration equations (for men and women) derived from the International Cooperative Study on Salt, Other Factors, and Blood Pressure study. Estimated 24hUNa excretion increased over the 20-y period [1988-1994, 2003-2006, and 2010; means ± SEMs (n): 3160 ± 38.4 mg/d (1249), 3290 ± 29.4 mg/d (1235), and 3290 ± 44.4 mg/d (525), respectively; P-trend = 0.022]. We observed significantly higher mean estimated 24hUNa excretion in each survey period (P < 0.001) for men compared with women (31-33%) and for persons with a higher body mass index (BMI; 32-35% for obese vs. normal weight) or blood pressure (17-26% for hypertensive vs. normal blood pressure). After adjusting for age, sex, and race-ethnicity, temporal trends in mean estimated 24hUNa excretion remained significant (P-trend = 0.004). We observed no temporal trends in mean estimated 24hUNa excretion among BMI subgroups, nor after adjusting for BMI. Although several limitations apply to this analysis (the use of a convenience sample in 1988-1994 and using estimated 24hUNa excretion as a biomarker of sodium intake), these first NHANES data suggest that mean estimated 24hUNa excretion increased slightly in U.S. adults over the past 2 decades, and this increase may be explained by a shift in the distribution of BMI.

Estimation of Daily Sodium and Potassium Excretion Using Spot Urine and 24-Hour Urine Samples in a Black Population (Benin).

PubMed

Mizéhoun-Adissoda, Carmelle; Houehanou, Corine; Chianéa, Thierry; Dalmay, François; Bigot, André; Preux, Pierre-Marie; Bovet, Pascal; Houinato, Dismand; Desport, Jean-Claude

2016-07-01

The 24-hour urine collection method is considered the gold standard for the estimation of ingested potassium and sodium. Because of the impracticalities of collecting all urine over a 24-hour period, spot urine is often used for epidemiological investigations. This study aims to assess the agreement between spot urine and 24-hour urine measurements to determine sodium and potassium intake. A total of 402 participants aged 25 to 64 years were randomly selected in South Benin. Spot urine was taken during the second urination of the day. Twenty-four-hour urine was also collected. Samples (2-mL) were taken and then stored at -20°C. The analysis was carried out using potentiometric dosage. The agreement between spot urine and 24-hour urine measurements was established using Bland-Altman plots. A total of 354 results were analyzed. Daily sodium chloride and potassium chloride urinary excretion means were 10.2±4.9 g/24 h and 2.9±1.4 g/24 h, respectively. Estimated daily sodium chloride and potassium chloride means from the spot urine were 10.7±7.0 g/24 h and 3.9±2.1 g/24 h, respectively. Concordance coefficients were 0.61 at d=-0.5 g, (d±2SD=-11 g and 10.1 g) for sodium chloride and 0.61 at d=-1 g, (d±2SD=-3.8 g and 1.8 g) for potassium chloride. Spot urine method is acceptable for estimating 24-hour urinary sodium and potassium excretion to assess sodium and potassium intake in a black population. However, the confidence interval for the mean difference, which is too large, makes the sodium chloride results inadmissible at a clinical level. © 2015 Wiley Periodicals, Inc.

Feasibility of collecting 24-h urine to monitor sodium intake in the National Health and Nutrition Examination Survey123

PubMed Central

Terry, Ana L; Cogswell, Mary E; Wang, Chia-Yih; Chen, Te-Ching; Loria, Catherine M; Wright, Jacqueline D; Zhang, Xinli; Lacher, David A; Merritt, Robert K; Bowman, Barbara A

2016-01-01

Background: Twenty-four–hour urine sodium excretion is recommended for monitoring population sodium intake. Because of concerns about participation and completion, sodium excretion has not been collected previously in US nationally representative surveys. Objective: We assessed the feasibility of implementing 24-h urine collections as part of a nationally representative survey. Design: We selected a random half sample of nonpregnant US adults aged 20–69 y in 3 geographic locations of the 2013 NHANES. Participants received explicit instructions, started and ended the urine collection in a urine study mobile examination center, and answered questions about their collection. Among those with a complete 24-h urine collection, a random one-half were asked to collect a second 24-h urine sample. Sodium, potassium, chloride, and creatinine excretion were analyzed. Results: The final NHANES examination response rate for adults aged 20–69 y in these 3 study locations was 71%. Of those examined (n = 476), 282 (59%) were randomly selected to participate in the 24-h urine collection. Of these, 212 persons [75% of those selected for 24-h urine collection; 53% (equal to 71% × 75% of those selected for the NHANES)] collected a complete initial 24-h specimen and 92 persons (85% of 108 selected) collected a second complete 24-h urine sample. More men than women completed an initial collection (P = 0.04); otherwise, completion did not vary by sociodemographic characteristics, body mass index, education, or employment status for either collection. Mean 24-h urine volume and sodium excretion were 1964 ± 1228 mL and 3657 ± 2003 mg, respectively, for the first 24-h urine sample, and 2048 ± 1288 mL and 3773 ± 1891 mg, respectively, for the second collection. Conclusion: Given the 53% final component response rate and 75% completion rate, 24-h urine collections were deemed feasible and implemented in the NHANES 2014 on a subsample of adults aged 20–69 y to assess population sodium intake. This study was registered at clinicaltrials.gov as NCT02723682. PMID:27413136

Association between 24-h urinary sodium excretion and obesity in Korean adults: A multicenter study.

PubMed

Nam, Ga Eun; Kim, Seon Mee; Choi, Mi-Kyeong; Heo, Young-Ran; Hyun, Tai-Sun; Lyu, Eun-Soon; Oh, Se-Young; Park, Hae-Ryun; Ro, Hee-Kyong; Han, Kyungdo; Lee, Yeon Kyung

2017-09-01

The aim of this study was to explore the association between sodium intake, as assessed by 24-h urinary sodium excretion, and various obesity parameters among South Korean adults. The associations of 24-h urinary sodium excretion and sodium intake calculated from the dietary questionnaire with obesity parameters also were compared. This multicenter, cross-sectional study analyzed data of 640 healthy adults from eight provinces in South Korea. Obesity was assessed by body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR). Mean 24-h urinary sodium excretion was calculated from repeatedly collected 24-h urine samples. Participants' dietary intake was assessed by 24-h dietary recall interview on the days before 24-h urine collection. In both sexes, the means of all anthropometric measurements tended to increase proportionally with 24-h urinary sodium excretion quartiles, regardless of adjustment. Men in the highest quartile (Q4) of 24-h urinary sodium excretion had increased odds of obesity (as assessed by BMI, WC, WHR, and WHtR) compared with men in the three lower quartiles (Q1-Q3) of 24-h urinary sodium excretion. Women in Q4 of 24-h urinary sodium excretion exhibited a higher chance of general obesity and abdominal obesity. Sodium intake calculated from the dietary questionnaire was not significantly associated with obesity in either sex. In Korean adults, there was a positive association between higher sodium intake as assessed by 24-h urinary sodium excretion and obesity independent of energy intake. Copyright © 2017 Elsevier Inc. All rights reserved.

The relationship between sodium excretion and blood pressure, urine albumin, central retinal arteriolar equivalent.

PubMed

Huang, Feng; Yu, Peng; Yuan, Yin; Li, Qiaowei; Lin, Fan; Gao, Zhonghai; Chen, Falin; Zhu, Pengli

2016-10-11

Many studies showed an association between dietary salt intake, blood pressure and increased CVD risk. The potential reason may be related to vascular structural and functional changes, through alterations in endothelial function. The central retinal arteriolar equivalent and urinary albumin reflected vascular endothelial dysfunction in different part of the body. The urinary sodium-creatinine ratio of causal urine specimens could represent the 24-h urinary sodium intake to estimate sodium intake. The 24-h sodium excretion was estimated by urinary sodium-creatinine ratio. Urinary albumin-creatinine ratio (UACR), reflecting renal arterial damage, was also determined. The central retinal arteriolar equivalent (CRAE) was detected by fundus photography and was further analyzed by semi-quantitative software. Participants included 951 hypertensive patients with the average sodium excretion of 11.62 ± 3.01 g. The sodium excretion was significantly higher (P < 0.01) in the hypertensive as compared to that of the non-hypertensive participants. Prevalence of hypertension was increased with increasing sodium excretion. The sodium excretion was positively correlated with systolic blood pressure (SBP) and diastolic blood pressure (DBP), respectively (r = 0.20 and 0.14; P < 0.01). Furthermore, UACR and CRAE were significantly (P < 0.01) different within the sodium excretion quartiles (Q1-Q4). After adjusting the confounding variables, such as age and sex, the binary logistic regression analysis showed that sodium excretion was an independent factor of UACR and CRAE (P < 0.01). Our results suggest that sodium excretion in the hypertensive participants were higher. The high sodium excretion was related with the renal arterial damage as well as retinal arteriolar changes.

Influence of hypernatraemia and urea excretion on the ability to excrete a maximally hypertonic urine in the rat

PubMed Central

Cheema-Dhadli, Surinder; Halperin, Mitchell L

2002-01-01

Rats normally excrete 20-25 mmol of sodium (Na+) + potassium (K+) per kilogram per day. To minimize the need for a large water intake, they must excrete urine with a very high electrolyte concentration (tonicity). Our objective was to evaluate two potential factors that could influence the maximum urine tonicity, hypernatraemia and the rate of urea excretion. Balance studies were carried out in vasopressin-treated rats fed a low-electrolyte diet. In the first series, the drinking solution contained an equivalent sodium chloride (NaCl) load at 150 or 600 mmol l−1. In the second series, the maximum urine tonicity was evaluated in rats consuming 600 mmol l−1 NaCl with an 8-fold range of urea excretion. Hypernatraemia (148 ± 1 mmol l−1) developed in all rats that drank 600 mmol l−1 saline. Although the rate of Na+ + K+ excretion was similar in both saline groups, the maximum urine total cation concentration was significantly higher in the hypernatraemic group (731 ± 31 vs. 412 ± 37 mmol l−1). Only when the rate of excretion of urea was very low, was there a further increase in the maximum urine total cation concentration (1099 ± 118 mmol l−1). Thus hypernatraemia was the most important factor associated with a higher urine tonicity. PMID:12068051

DIETARY SODIUM ADHERENCE IS POOR IN CHRONIC HEART FAILURE PATIENTS

PubMed Central

Basuray, Anupam; Dolansky, Mary; Josephson, Richard; Sattar, Abdus; Grady, Ellen M.; Vehovec, Anton; Gunstad, John; Redle, Joseph; Fang, James; Hughes, Joel W.

2015-01-01

Background We sought to determine the rates and predictors of dietary sodium restriction, while evaluating the reliability of the 24-hour urine collection as a tool to estimate dietary sodium intake in heart failure (HF) patients. Methods and Results We evaluated the 24-hour urinary sodium excretion of 305 outpatients with HF and reduced ejection fraction who were educated on following a <2 gm sodium diet. The mean sodium excretion using a single sample from each participant was 3.15 ± 1.58 grams, and 23% were adherent to the <2 gm recommendation. 168 participants provided two samples with urinary creatinine excretion within normative range. Averaging both resulted in a mean sodium excretion of 3.21 ± 1.20 grams and lower adherence rates to the <2-gram diet: 14% versus 23% (p=0.019). Multivariate logistic regression showed only male sex and higher BMI was associated with non-adherence (OR male: 2.20, 95% CI: 1.25-3.88, OR one unit BMI: 1.05, 95% CI: 1.01-1.10). Bland-Altman plots of urinary sodium and creatinine showed poor reproducibility between samples. Conclusions In this chronic HF population, sodium consumption probably exceeds recommended amounts, particularly in men and those with higher BMI. Urine analyses were not highly reproducible, suggesting variation in both diet and urine collection. PMID:25576680

Evaluation of Equations for Predicting 24-Hour Urinary Sodium Excretion from Casual Urine Samples in Asian Adults.

PubMed

Whitton, Clare; Gay, Gibson Ming Wei; Lim, Raymond Boon Tar; Tan, Linda Wei Lin; Lim, Wei-Yen; van Dam, Rob M

2016-08-01

The collection of 24-h urine samples for the estimation of sodium intake is burdensome, and the utility of spot urine samples in Southeast Asian populations is unclear. We aimed to assess the validity of prediction equations with the use of spot urine concentrations. A sample of 144 Singapore residents of Chinese, Malay, and Indian ethnicity aged 18-79 y were recruited from the Singapore Health 2 Study conducted in 2014. Participants collected urine for 24 h in multiple small bottles on a single day. To determine the optimal collection time for a spot urine sample, a 1-mL sample was taken from a random bottle collected in the morning, afternoon, and evening. Published equations and a newly derived equation were used to predict 24-h sodium excretion from spot urine samples. The mean ± SD concentration of sodium from the 24-h urine sample was 125 ± 53.4 mmol/d, which is equivalent to 7.2 ± 3.1 g salt. Bland-Altman plots showed good agreement at the group level between estimated and actual 24-h sodium excretion, with biases for the morning period of -3.5 mmol (95% CI: -14.8, 7.8 mmol; new equation) and 1.46 mmol (95% CI: -10.0, 13.0 mmol; Intersalt equation). A larger bias of 25.7 mmol (95% CI: 12.2, 39.3 mmol) was observed for the Tanaka equation in the morning period. The prediction accuracy did not differ significantly for spot urine samples collected at different times of the day or at a random time of day (P = 0.11-0.76). This study suggests that the application of both our own newly derived equation and the Intersalt equation to spot urine concentrations may be useful in predicting group means for 24-h sodium excretion in urban Asian populations. © 2016 American Society for Nutrition.

5C.07: A METHOD TO ESTIMATE 24-HOUR SODIUM EXCRETION THROUGH SPOT URINE SAMPLES AND ITS APPLICATION VALUE FOR TARGET-ORGAN DAMAGE ASSESSMENT.

PubMed

Wang, H; Zhao, L; Xi, Y; Sun, N

2015-06-01

24-h urine sodium excretion is considered the most reliable method to evaluate the salt intakes. However, this method is cumbersome. So we want to develop formulas to estimate 24-h urinary sodium excretion using spot urinary samples in Chinese hypertensive population and explore the application value of this method in salt intake assessment and target organ damage. 1. We enrolled 510 cases of hospitalized patients with hypertension, 2/3 of them were arranged randomly to formula group to develop a new formula and the remainings were used to test the performance of the formula. All participants were instructed to collect a 24-h urine sample, a second morning voiding urine sample (SMU), and a post-meridiem urine sample in the late afternoon or early evening, prior to the evening meal (PMU). All samples were sent to measure sodium and creatinine concentration.2. We compared the differences of office blood pressure, 24-hour ambulatory blood pressure and left ventricular hypertrophy, vascular stiffness and urine protein among groups of different sodium intake. 24hour sodium excretion formulas was obtained using SMU and PMU respectively, which have good cosistency. The difference between the estimated and measured values in sodium excretion is 12.66mmol/day (SMU) and 9.41mmol/day (PM), to be equal to 0.7 g (SMU) and 0.6 g (PM) salt intake. Comparing with Kawasaki and Tanaka method, the new formula shows the lower degree of deviation, and higher accuracy and precision. Blood pressure of high urinary sodium group is higher than that in low urinary sodium group (P < 0.05). Left ventricular hypertrophy and urinary albumin/creatinine aggravated with the salt intake increase, this has eliminated the influence of other factors. All of morphologies of the relationship between ambulatory arterial stiffness index, pulse wave velocity and carotid intima-media thickness with quartiles of sodium intake resembled a J-shaped curve. In Chinese hypertensive population, the formulas to estimate 24-h urinary sodium using spot urinary samples spot urine are considered useful for estimating the mean level of population salt intake, and have a role in evaluating target organ damage.

Validity of predictive equations for 24-h urinary sodium excretion in adults aged 18–39 y12345

PubMed Central

Wang, Chia-Yih; Chen, Te-Ching; Pfeiffer, Christine M; Elliott, Paul; Gillespie, Cathleen D; Carriquiry, Alicia L; Sempos, Christopher T; Liu, Kiang; Perrine, Cria G; Swanson, Christine A; Caldwell, Kathleen L; Loria, Catherine M

2013-01-01

Background: Collecting a 24-h urine sample is recommended for monitoring the mean population sodium intake, but implementation can be difficult. Objective: The objective was to assess the validity of published equations by using spot urinary sodium concentrations to predict 24-h sodium excretion. Design: This was a cross-sectional study, conducted from June to August 2011 in metropolitan Washington, DC, of 407 adults aged 18–39 y, 48% black, who collected each urine void in a separate container for 24 h. Four timed voids (morning, afternoon, evening, and overnight) were selected from each 24-h collection. Published equations were used to predict 24-h sodium excretion with spot urine by specimen timing and race-sex subgroups. We examined mean differences with measured 24-h sodium excretion (bias) and individual differences with the use of Bland-Altman plots. Results: Across equations and specimens, mean bias in predicting 24-h sodium excretion for all participants ranged from −267 to 1300 mg (Kawasaki equation). Bias was least with International Cooperative Study on Salt, Other Factors, and Blood Pressure (INTERSALT) equations with morning (−165 mg; 95% CI: −295, 36 mg), afternoon (−90 mg; −208, 28 mg), and evening (−120 mg; −230, −11 mg) specimens. With overnight specimens, mean bias was least when the Tanaka (−23 mg; 95% CI: −141, 95 mg) or Mage (−145 mg; −314, 25 mg) equations were used but was statistically significant when using the Tanaka equations among females (216 to 243 mg) and the Mage equations among races other than black (−554 to −372 mg). Significant over- and underprediction occurred across individual sodium excretion concentrations. Conclusions: Using a single spot urine, INTERSALT equations may provide the least biased information about population mean sodium intakes among young US adults. None of the equations evaluated provided unbiased estimates of individual 24-h sodium excretion. This trial was registered at clinicaltrials.gov as NCT01631240. PMID:24047921

Spot urine and 24-h diet recall estimates of dietary sodium intake from the 2008/09 New Zealand Adult Nutrition Survey: a comparison.

PubMed

McLean, Rachael M; Williams, Sheila M; Te Morenga, Lisa A; Mann, Jim I

2018-05-22

We aimed to test the difference between estimates of dietary sodium intake using 24-h diet recall and spot urine collection in a large sample of New Zealand adults. We analysed spot urine results, 24-h diet recall, dietary habits questionnaire and anthropometry from a representative sample of 3312 adults aged 15 years and older who participated in the 2008/09 New Zealand Adult Nutrition Survey. Estimates of adult population sodium intake were derived from 24-h diet recall and spot urine sodium using a formula derived from analysis of INTERSALT data. Correlations, limits of agreement and mean difference were calculated for the total sample, and for population subgroups. Estimated total population 24-h urinary sodium excretion (mean (95% CI)) from spot urine samples was 3035 mg (2990, 3079); 3612 mg (3549, 3674) for men and 2507 mg (2466, 2548) for women. Estimated mean usual daily sodium intake from 24-h diet recall data (excluding salt added at the table) was 2564 mg (2519, 2608); 2849 mg (2779, 2920) for men and 2304 mg (2258, 2350) for women. Correlations between estimates were poor, especially for men, and limits of agreement using Bland-Altman mean difference analysis were wide. There is a poor agreement between estimates of individual sodium intake from spot urine collection and those from 24-hour diet recall. Although, both 24-hour dietary recall and estimated urinary excretion based on spot urine indicate mean population sodium intake is greater than 2 g, significant differences in mean intake by method deserve further investigation in relation to the gold standard, 24-hour urinary sodium excretion.

Dietary sodium adherence is poor in chronic heart failure patients.

PubMed

Basuray, Anupam; Dolansky, Mary; Josephson, Richard; Sattar, Abdus; Grady, Ellen M; Vehovec, Anton; Gunstad, John; Redle, Joseph; Fang, James; Hughes, Joel W

2015-04-01

We sought to determine the rates and predictors of dietary sodium restriction and to evaluate the reliability of 24-hour urine collection as a tool to estimate dietary sodium intake in heart failure (HF) patients. We evaluated the 24-hour urinary sodium excretion of 305 outpatients with HF and reduced ejection fraction who were educated on following a <2 g sodium diet. The mean sodium excretion according to a single sample from each participant was 3.15 ± 1.58 g, and 23% were adherent to the <2 g recommendation. One hundred sixty-eight participants provided 2 samples with urinary creatinine excretion within normative range. Averaging both resulted in a mean sodium excretion of 3.21 ± 1.20 g and lower adherence rates to the <2-gram diet: 14% versus 23% (P = .019). Multivariate logistic regression showed only male sex and higher body mass index (BMI) to be associated with nonadherence (male: odds ratio [OR] 2.20, 95% confidence interval [CI] 1.25-3.88; 1 unit BMI: OR 1.05, 95% CI 1.01-1.10). Bland-Altman plots of urinary sodium and creatinine showed poor reproducibility between samples. In this chronic HF population, sodium consumption probably exceeds recommended amounts, particularly in men and those with higher BMI. Urine analyses were not highly reproducible, suggesting variation in both diet and urine collection. Copyright © 2015 Elsevier Inc. All rights reserved.

Assessment of dietary sodium intake using a food frequency questionnaire and 24-hour urinary sodium excretion: a systematic literature review.

PubMed

McLean, Rachael M; Farmer, Victoria L; Nettleton, Alice; Cameron, Claire M; Cook, Nancy R; Campbell, Norman R C

2017-12-01

Food frequency questionnaires (FFQs) are often used to assess dietary sodium intake, although 24-hour urinary excretion is the most accurate measure of intake. The authors conducted a systematic review to investigate whether FFQs are a reliable and valid way of measuring usual dietary sodium intake. Results from 18 studies are described in this review, including 16 validation studies. The methods of study design and analysis varied widely with respect to FFQ instrument, number of 24-hour urine collections collected per participant, methods used to assess completeness of urine collections, and statistical analysis. Overall, there was poor agreement between estimates from FFQ and 24-hour urine. The authors suggest a framework for validation and reporting based on a consensus statement (2004), and recommend that all FFQs used to estimate dietary sodium intake undergo validation against multiple 24-hour urine collections. ©2017 Wiley Periodicals, Inc.

Sodium and water metabolism under the influence of prolactin, aldosterone, and antidiuretic hormone.

PubMed Central

Burstyn, P G

1978-01-01

1. Rabbits were placed in metabolism cages in order to measure their intakes of food, water, and sodium chloride (as 1% saline solution), and to measure urinary and faecal excretion of sodium, potassium, and water. 2. Antidiuretic hormone (0.2 i.u./day) caused a reduction in urine volume and no change in sodium excretion. There was full compensatory reduction in water intake so that no accumulation of water occurred. 3. Aldosterone (4 mg/da) caused a reduction in renal sodium excretion for 1--2 days. The saline intake was reduced, though this was insufficient to prevent some sodium accumulation. 4. Renal mineralocorticoid 'escape' resulted in a large increase in sodium excretion at the end of the aldosterone treatment period. This was fully compensated through increased saline intake, and balance was maintained. 5. Prolactin (200 i.u./day) caused a reduction in urine volume and in renal sodium excretion and since there were no compensatory changes in water and sodium intake, this led to substantial accumulation of both water and sodium. 6. The effects of smaller doses of both aldosterone and prolactin were investigated and found to be similar but smaller. 7. It is suggested that whereas prolactin may have little or no role to play in the sodium homoeostasis of the normal animal, the hormone may well be responsible for the substantial increase in body fluids in pregnancy. PMID:633132

Assessment of Dietary Sodium and Potassium in Canadians Using 24-Hour Urinary Collection.

PubMed

Mente, Andrew; Dagenais, Gilles; Wielgosz, Andreas; Lear, Scott A; McQueen, Matthew J; Zeidler, Johannes; Fu, Lily; DeJesus, Jane; Rangarajan, Sumathy; Bourlaud, Anne-Sophie; De Bluts, Anne Leblanc; Corber, Erica; de Jong, Veronica; Boomgaardt, Jacob; Shane, Alexandra; Jiang, Ying; de Groh, Margaret; O'Donnell, Martin J; Yusuf, Salim; Teo, Koon

2016-03-01

Although salt intake derived from data on urinary sodium excretion in free-living populations has been used in public policy, a population study on urinary sodium excretion has not been done in Canada. We assessed dietary sodium and potassium intake using a 24-hour urine collection in a large survey of urban and rural communities from 4 Canadian cities and determined the association of these electrolytes with blood pressure (BP). One thousand seven hundred consecutive individuals, aged 37-72 years, attending their annual follow-up visits of the ongoing Prospective and Urban Rural Epidemiology (PURE) study in Vancouver, Hamilton, Ottawa, and Quebec City, Canada, collected a 24-hour urine sample using standardized procedures. Mean sodium excretion was 3325 mg/d and mean potassium excretion was 2935 mg/d. Sodium excretion ranged from 3093 mg/d in Vancouver to 3642 mg/d in Quebec City, after adjusting for covariates. Potassium excretion ranged from 2844 mg/d in Ottawa to 3082 mg/d in Quebec City. Both electrolytes were higher in men than in women and in rural populations than in urban settings (P < 0.001 for all). Sodium excretion was between 3000 and 6000 mg/d in 48.3% of the participants, < 3000 mg/d in 46.7%, and > 6000 mg/d in only 5%. No significant association between sodium or potassium excretion and BP was found. Sodium consumption in these Canadians is within a range comparable to other Western countries, and intake in most individuals is < 6000 mg/d, with only 5% at higher levels. Within this range, sodium or potassium levels were not associated with BP. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Validation of spot urine in predicting 24-h sodium excretion at the individual level.

PubMed

Zhou, Long; Tian, Yu; Fu, Jun-Jie; Jiang, Ying-Ying; Bai, Ya-Min; Zhang, Zi-Hua; Hu, Xiao-He; Lian, Hong-Wu; Guo, Min; Yang, Zheng-Xiong; Zhao, Lian-Cheng

2017-06-01

Background: Evidence for the effect of dietary sodium intake on the risk of cardiovascular disease has been controversial. One of the main explanations for the conflicting results lies in the great variability associated with measurement methods for sodium intake. Spot urine collection is a convenient method commonly used for sodium estimation, but its validity for predicting 24-h urinary sodium excretion at the individual level has not been well evaluated among the general population. Objective: The aim of this study was to evaluate the validity of the Kawasaki, the International Cooperative Study on Salt, Other Factors, and Blood Pressure (INTERSALT), and the Tanaka formulas in predicting 24-h urinary sodium excretion by using spot urine samples in Chinese adults. Design: We analyzed the relative and absolute differences and misclassification at the individual level from 3 commonly used methods for estimating sodium intake among 141 Chinese community residents. Results: The mean measured 24-h sodium excretion was 220.8 mmol/d. The median (95% CIs) differences between measured sodium and those estimated from the Kawasaki, INTERSALT, and Tanaka methods were 6.4 mmol/d (-17.5, 36.8 mmol/d), -67.3 mmol/d (-96.5, -46.9 mmol/d), and -42.9 mmol/d (-59.1, -24.8 mmol/d), respectively. The proportions of relative differences >40% with the Kawasaki, INTERSALT, and Tanaka methods were 31.2%, 41.1%, and 22.0%, respectively; and the absolute difference for the 3 methods was >51.3 mmol/d (3 g salt) in approximately half of the participants. The misclassification rate was 63.1% for the Kawasaki method, 78.7% for the INTERSALT method, and 66.0% for the Tanaka method at the individual level. Conclusion: The results from our study do not support the use of spot urine to estimate 24-h urinary sodium excretion at the individual level because of its poor performance with respect to misclassification. This trial was registered at www.chictr.org.cn as ChiCTR-IOR-16010278. © 2017 American Society for Nutrition.

Relationship between Sodium Intake and Water Intake: The False and the True.

PubMed

Bankir, Lise; Perucca, Julie; Norsk, Peter; Bouby, Nadine; Damgaard, Morten

2017-01-01

Generally, eating salty food items increases thirst. Thirst is also stimulated by the experimental infusion of hypertonic saline. But, in steady state, does the kidney need a higher amount of water to excrete sodium on a high than on a low sodium intake? This issue is still controversial. The purpose of this review is to provide examples of how the kidney handles water in relation to salt intake/output. It is based on re-analysis of previously published studies in which salt intake was adjusted to several different levels in the same subjects, and in databases of epidemiologic studies in populations on an ad libitum diet. Summary and Key Messages: These re-analyses allow us to draw the following conclusions: (1) In a steady state situation, the urine volume (and thus the fluid intake) remains unchanged over a large range of sodium intakes. The adaptation to a higher sodium excretion rests only on changes in urinary sodium concentration. However, above a certain limit, this concentration cannot increase further and the urine volume may then increase. (2) In population studies, it is not legitimate to assume that sodium is responsible for changes in urine volume, since people who eat more sodium also eat more of other nutrients leading to an increase in the excretion of potassium, urea and other solutes, besides sodium. (3) After an abrupt increase in sodium intake, fluid intake is increased in the first few days, but urine volume does not change. The extra fluid drunk is responsible for an increase in body weight. © 2017 The Author(s) Published by S. Karger AG, Basel.

Renal function in sheep during infusion of alkali metal ions into the renal artery.

PubMed Central

Beal, A M; Harrison, F A

1975-01-01

1. The effect on renal function of 1 M solutions of LiCl, NaCl, KCl, RbCl and CsCl and 3 M-NaCl infused close-arterially to the kidney for 10 min at 0-7ml./min has been studied in nine experiments on four unilaterally nephrectomized sheep. The levels of flow, electrolyte concentration and electrolyte excretion in the urine were measured before, during and for 50 min after the infusions. 2. The infusion of 1-M-NaCl produced little change in urine flow and composition whereas 3 M-NaCl resulted in relatively small increases in urine flow and sodium excretion. 3. The infusion of lithium, potassium, rubidium and caesium resulted in marked increases in urine flow, urinary sodium concentration and excretion, urinary potassium excretion and osmolal clearance while the urinary potassium concentration decreased. 4. Changes in urine flow and urinary pH during the infusions of all the alkali ions except sodium were consistent with increased urinary bicarbonate excretion. 5. The osmolal clearance was increased by the infusion of lithium, potassium, rubidium and caesium, but equivalent increases in the rate of solutefree water reabsorption did not occur. 6. The infusion of caesium resulted in a depression of the glomerular filtration rate (G.F.R.) which was not observed when the other alkali ions were infused. 7. The effects of lithium, potassium and rubidium on urine flow and composition were rapid in onset and the residual effects on these ions, on cessation of infusion, were relatively short. The effects on caesium were slow in onset and prolonged in duration. 8. It was concluded that lithium, potassium, rubidium, and caesium altered urine flow and electrolyte excretion by acting upon common mechanisms which were predominantly intra-renal and located in the proximal segment of the nephron. PMID:236381

The relationship between sodium concentrations in spot urine and blood pressure increases: a prospective study of Japanese general population: the Circulatory Risk in Communities Study (CIRCS).

PubMed

Umesawa, Mitsumasa; Yamagishi, Kazumasa; Noda, Hiroyuki; Ikeda, Ai; Sawachi, Shinobu; Muraki, Isao; Chei, Choy-Lye; Cui, Renzhe; Nagao, Masanori; Ohira, Tetsuya; Sankai, Tomoko; Tanigawa, Takeshi; Kitamura, Akihiko; Kiyama, Masahiko; Iso, Hiroyasu

2016-03-05

Although several cross-sectional and intervention studies showed that sodium intake or excretion was associated with blood pressure levels, no prospective study has examined the long-term association between sodium excretion in spot urine and blood pressure changes. We conducted a prospective study of 889 normotensive subjects (295 men and 594 women, mean age 57.3 years) who underwent the baseline survey including spot urine test in 2005 and the follow-up survey in 2009 to 2011 (mean follow-up period: 5.8 years). We examined the association between sodium concentration in spot urine, a validated index of sodium excretion occurring over 24-h, and blood pressure changes between baseline and follow-up survey in all, non-overweight (body mass index(BMI) ≤ 25 kg/m(2)) and overweight normotensives. For all subjects, sodium concentrations in spot urine were not associated with either systolic or diastolic blood pressure changes. When stratified by BMI at baseline survey, sodium concentrations were positively associated with systolic blood pressure changes in non-overweight subjects, but not in overweight subjects. After adjustment for age, sex, BMI, alcohol intake status, current smoking and estimated glomerular filtration rate, the multivariable-adjusted mean values of the systolic blood pressure change among non-overweight subjects was +7.3 mmHg in the highest quartiles of sodium concentrations, while it was +3.9 mmHg in the lowest quartile (P for difference = 0.021, P for trend = 0.040). After further adjustment of baseline blood pressure levels, the association was slightly weakened; the multivariable-adjusted mean values of the systolic blood pressure changes were +7.0 mmHg and +4.2 mmHg (P for difference = 0.047, P for trend = 0.071). High sodium concentrations in spot urine were associated with subsequent systolic blood pressure increases among non-overweight normotensive individuals. (272 words).

Ultra-long–term human salt balance studies reveal interrelations between sodium, potassium, and chloride intake and excretion12

PubMed Central

Birukov, Anna; Rakova, Natalia; Lerchl, Kathrin; Engberink, Rik HG Olde; Johannes, Bernd; Wabel, Peter; Moissl, Ulrich; Rauh, Manfred; Luft, Friedrich C; Titze, Jens

2016-01-01

Background: The intake of sodium, chloride, and potassium is considered important to healthy nutrition and cardiovascular disease risk. Estimating the intake of these electrolytes is difficult and usually predicated on urine collections, commonly for 24 h, which are considered the gold standard. We reported on data earlier for sodium but not for potassium or chloride. Objective: We were able to test the value of 24-h urine collections in a unique, ultra-long–term balance study conducted during a simulated trip to Mars. Design: Four healthy men were observed while ingesting 12 g salt/d, 9 g salt/d, and 6 g salt/d, while their potassium intake was maintained at 4 g/d for 105 d. Six healthy men were studied while ingesting 12 g salt/d, 9 g salt/d, and 6 g salt/d, with a re-exposure of 12 g/d, while their potassium intake was maintained at 4 g/d for 205 d. Food intake and other constituents were recorded every day for each subject. All urine output was collected daily. Results: Long-term urine recovery rates for all 3 electrolytes were very high. Rather than the expected constant daily excretion related to daily intake, we observed remarkable daily variation in excretion, with a 7-d infradian rhythm at a relatively constant intake. We monitored 24-h aldosterone excretion in these studies and found that aldosterone appeared to be the regulator for all 3 electrolytes. We report Bland–Altman analyses on the value of urine collections to estimate intake. Conclusions: A single 24-h urine collection cannot predict sodium, potassium, or chloride intake; thus, multiple collections are necessary. This information is important when assessing electrolyte intake in individuals. PMID:27225435

Estimating 24-Hour Urinary Sodium Excretion From Casual Urinary Sodium Concentrations in Western Populations

PubMed Central

Brown, Ian J.; Dyer, Alan R.; Chan, Queenie; Cogswell, Mary E.; Ueshima, Hirotsugu; Stamler, Jeremiah; Elliott, Paul

2013-01-01

High intakes of dietary sodium are associated with elevated blood pressure levels and an increased risk of cardiovascular disease. National and international guidelines recommend reduced sodium intake in the general population, which necessitates population-wide surveillance. We assessed the utility of casual (spot) urine specimens in estimating 24-hour urinary sodium excretion as a marker of sodium intake in the International Cooperative Study on Salt, Other Factors, and Blood Pressure. There were 5,693 participants recruited in 1984–1987 at the ages of 20–59 years from 29 North American and European samples. Participants were randomly assigned to test or validation data sets. Equations derived from casual urinary sodium concentration and other variables in the test data were applied to the validation data set. Correlations between observed and estimated 24-hour sodium excretion were 0.50 for individual men and 0.51 for individual women; the values were 0.79 and 0.71, respectively, for population samples. Bias in mean values (observed minus estimated) was small; for men and women, the values were −1.6 mmol per 24 hours and 2.3 mmol per 24 hours, respectively, at the individual level and −1.8 mmol per 24 hours and 2.2 mmol per 24 hours, respectively, at the population level. Proportions of individuals with urinary 24-hour sodium excretion above the recommended levels were slightly overestimated by the models. Casual urine specimens may be a useful, low-burden, low-cost alternative to 24-hour urine collections for estimation of population sodium intakes; ongoing calibration with study-specific 24-hour urinary collections is recommended to increase validity. PMID:23673246

High Dietary Sodium Intake Assessed by Estimated 24-h Urinary Sodium Excretion Is Associated with NAFLD and Hepatic Fibrosis

PubMed Central

Huh, Ji Hye; Lee, Kyong Joo; Lim, Jung Soo; Lee, Mi Young; Park, Hong Jun; Kim, Moon Young; Kim, Jae Woo; Chung, Choon Hee; Shin, Jang Yel; Kim, Hyun-Soo; Kwon, Sang Ok; Baik, Soon Koo

2015-01-01

Background Although high sodium intake is associated with obesity and hypertension, few studies have investigated the relationship between sodium intake and non-alcoholic fatty liver disease (NAFLD). We evaluated the association between sodium intake assessed by estimated 24-h urinary sodium excretion and NAFLD in healthy Koreans. Methods We analyzed data from 27,433 participants in the Korea National Health and Nutrition Examination Surveys (2008–2010). The total amount of sodium excretion in 24-h urine was estimated using Tanaka’s equations from spot urine specimens. Subjects were defined as having NAFLD when they had high scores in previously validated NAFLD prediction models such as the hepatic steatosis index (HSI) and fatty liver index (FLI). BARD scores and FIB-4 were used to define advanced fibrosis in subjects with NAFLD. Results The participants were classified into three groups according to estimated 24-h urinary excretion tertiles. The prevalence of NAFLD as assessed by both FLI and HSI was significantly higher in the highest estimated 24-h urinary sodium excretion tertile group. Even after adjustment for confounding factors including body fat and hypertension, the association between higher estimated 24-h urinary sodium excretion and NAFLD remained significant (Odds ratios (OR) 1.39, 95% confidence interval (CI) 1.26–1.55, in HSI; OR 1.75, CI 1.39–2.20, in FLI, both P < 0.001). Further, subjects with hepatic fibrosis as assessed by BARD score and FIB-4 in NAFLD patients had higher estimated 24-h urinary sodium values. Conclusions High sodium intake was independently associated with an increased risk of NAFLD and advanced liver fibrosis. PMID:26571018

High Dietary Sodium Intake Assessed by Estimated 24-h Urinary Sodium Excretion Is Associated with NAFLD and Hepatic Fibrosis.

PubMed

Huh, Ji Hye; Lee, Kyong Joo; Lim, Jung Soo; Lee, Mi Young; Park, Hong Jun; Kim, Moon Young; Kim, Jae Woo; Chung, Choon Hee; Shin, Jang Yel; Kim, Hyun-Soo; Kwon, Sang Ok; Baik, Soon Koo

2015-01-01

Although high sodium intake is associated with obesity and hypertension, few studies have investigated the relationship between sodium intake and non-alcoholic fatty liver disease (NAFLD). We evaluated the association between sodium intake assessed by estimated 24-h urinary sodium excretion and NAFLD in healthy Koreans. We analyzed data from 27,433 participants in the Korea National Health and Nutrition Examination Surveys (2008-2010). The total amount of sodium excretion in 24-h urine was estimated using Tanaka's equations from spot urine specimens. Subjects were defined as having NAFLD when they had high scores in previously validated NAFLD prediction models such as the hepatic steatosis index (HSI) and fatty liver index (FLI). BARD scores and FIB-4 were used to define advanced fibrosis in subjects with NAFLD. The participants were classified into three groups according to estimated 24-h urinary excretion tertiles. The prevalence of NAFLD as assessed by both FLI and HSI was significantly higher in the highest estimated 24-h urinary sodium excretion tertile group. Even after adjustment for confounding factors including body fat and hypertension, the association between higher estimated 24-h urinary sodium excretion and NAFLD remained significant (Odds ratios (OR) 1.39, 95% confidence interval (CI) 1.26-1.55, in HSI; OR 1.75, CI 1.39-2.20, in FLI, both P < 0.001). Further, subjects with hepatic fibrosis as assessed by BARD score and FIB-4 in NAFLD patients had higher estimated 24-h urinary sodium values. High sodium intake was independently associated with an increased risk of NAFLD and advanced liver fibrosis.

The subtype of alpha-adrenoceptor involved in the neural control of renal tubular sodium reabsorption in the rabbit.

PubMed Central

Hesse, I F; Johns, E J

1984-01-01

A study was undertaken in pentobarbitone anaesthetized rabbits, undergoing a saline diuresis, to determine the subtype of alpha-adrenoceptor mediating renal tubular sodium reabsorption. Stimulation of the renal nerves at low rates, to cause an 11% fall in renal blood flow, did not change glomerular filtration rate but significantly reduced urine flow rate, and absolute and fractional sodium excretions by approximately 40%. These responses were reproducible in different groups of animals and with time. Renal nerve stimulation during an intra-renal arterial infusion of prazosin, to block alpha 1-adrenoceptors, had no effect on the renal haemodynamic response but completely abolished the reductions in urine flow rate, and absolute and fractional sodium excretion. During intra-renal arterial infusion of yohimbine, to block renal alpha 2-adrenoceptors, stimulation of the renal nerves to cause similar renal haemodynamic changes resulted in significantly larger reductions in urine flow rate, and absolute and fractional sodium excretion of about 52-58%. These results indicate that in the rabbit alpha 1-adrenoceptors are present on the renal tubules, which mediate the increase in sodium reabsorption caused by renal nerve stimulation. They further suggest the presence of presynaptic alpha 2-adrenoceptors on those nerves innervating the renal tubules. PMID:6086915

Effects of sodium intake and diet on racial differences in urinary potassium excretion: results from the Dietary Approaches to Stop Hypertension (DASH)-Sodium trial.

PubMed

Turban, Sharon; Thompson, Carol B; Parekh, Rulan S; Appel, Lawrence J

2013-01-01

We previously showed that African Americans excreted less urinary potassium than whites, even while consuming similar diets in the Dietary Approaches to Stop Hypertension (DASH) trial. We hypothesized that a low-sodium diet may eliminate these differences. Data from the DASH-Sodium randomized controlled feeding trial were analyzed. 412 adults with prehypertension or stage 1 hypertension. Random assignment to either a typical American "control" diet (1.7 g [43 mEq] potassium/2,100 kcal/d) or the DASH diet (4.1 g [105 mEq] potassium/2,100 kcal/d). Within each diet, participants received 3 levels of sodium intake in random order for 30 days. 24-hour urine samples were analyzed at the end of each period. The primary outcome was urinary potassium excretion. On the DASH diet, African Americans consistently excreted significantly less urinary potassium (mean 24-hour urinary potassium excretion, 2,594 ± 961 mg [66 ± 25 mEq]) than whites (3,412 ± 1,016 mg [87 ± 26 mEq]) at the highest sodium level; adjusted (P < 0.001); this difference was not altered by sodium level (P = 0.6 comparing white to African American difference in urinary potassium excretion on high- vs low-sodium diet). In contrast, there was a smaller but significant white-African American difference in mean daily urinary potassium excretion in participants fed the control/high-sodium diet that was not present in the control/low-sodium diet (adjusted differences of 281 mg [7 mEq]/d vs 20 mg [0.5 mEq]/d, respectively; P = 0.007). Significant interactions were found between race and diet (P < 0.001) and between race and sodium (P = 0.02). Single rather than multiple urine collections were available at each time. Lack of stool potassium and sweat potassium values. Racial differences in urinary potassium excretion depend on sodium intake and diet. Our results may help explain the previously documented large variability in urinary potassium excretion. Copyright © 2012 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Role of atrial receptors in the control of sodium excretion. [pressure breathing and antinatiuretic effects in dogs

NASA Technical Reports Server (NTRS)

Meehan, J. R.; Henry, J. P.

1973-01-01

Responses of an innervated and a contralateral chronically denervated kidney to mild positive pressure breathing are compared for saline volume expansions in chloralose anesthetized dogs. It is shown that mild pressure breathing significantly reduces sodium excretion, urine flow, free water clearance, and PAH clearance. After 20 minutes of positive pressure breathing, both kidney responses are identical suggesting the release of natriuretic hormone which reduces renal function in addition to the demonstrated change in renal nerve activity. Increase of the left atrial pressure through balloon obstruction of the mitral orifice increases urine flow, sodium excretion and PAH clearance; inflation of the balloon and positive pressure breathing again depresses renal function. Preliminary evidence indicates that receptors in the right atrium are more severely affected by pressure breathing than those in the left atrium.

Urinary 24-h creatinine excretion in adults and its use as a simple tool for the estimation of daily urinary analyte excretion from analyte/creatinine ratios in populations.

PubMed

Johner, S A; Boeing, H; Thamm, M; Remer, T

2015-12-01

The assessment of urinary excretion of specific nutrients (e.g. iodine, sodium) is frequently used to monitor a population's nutrient status. However, when only spot urines are available, always a risk of hydration-status-dependent dilution effects and related misinterpretations exists. The aim of the present study was to establish mean values of 24-h creatinine excretion widely applicable for an appropriate estimation of 24-h excretion rates of analytes from spot urines in adults. Twenty-four-hour creatinine excretion from the formerly representative cross-sectional German VERA Study (n=1463, 20-79 years old) was analysed. Linear regression analysis was performed to identify the most important influencing factors of creatinine excretion. In a subsample of the German DONALD Study (n=176, 20-29 years old), the applicability of the 24-h creatinine excretion values of VERA for the estimation of 24-h sodium and iodine excretion from urinary concentration measurements was tested. In the VERA Study, mean 24-h creatinine excretion was 15.4 mmol per day in men and 11.1 mmol per day in women, significantly dependent on sex, age, body weight and body mass index. Based on the established 24-h creatinine excretion values, mean 24-h iodine and sodium excretions could be estimated from respective analyte/creatinine concentrations, with average deviations <10% compared with the actual 24-h means. The present mean values of 24-h creatinine excretion are suggested as a useful tool to derive realistic hydration-status-independent average 24-h excretion rates from urinary analyte/creatinine ratios. We propose to apply these creatinine reference means routinely in biomarker-based studies aiming at characterizing the nutrient or metabolite status of adult populations by simply measuring metabolite/creatinine ratios in spot urines.

Effectiveness of a Communication for Behavioral Impact (COMBI) Intervention to Reduce Salt Intake in a Vietnamese Province Based on Estimations From Spot Urine Samples.

PubMed

Do, Ha Thi Phuong; Santos, Joseph Alvin; Trieu, Kathy; Petersen, Kristina; Le, Mai Bach; Lai, Duc Truong; Bauman, Adrian; Webster, Jacqui

2016-11-01

This study evaluated the effectiveness of the Communication for Behavioral Impact (COMBI)-Eat Less Salt intervention conducted in Viet Tri, Vietnam. The behavior change intervention was implemented in four wards and four communes for one year, which included mass media communication, school interventions, community programs, and focus on high-risk groups. Mean sodium excretion was estimated from spot urine samples using different equations. A subsample provided 24-hour urine to validate estimates from spot urine. Information about salt-related knowledge and behaviors was also collected. There were 513 participants at both baseline and follow-up. Mean sodium excretion estimated from spot urines fell significantly from 8.48 g/d at baseline to 8.05 g/d at follow-up (P=.001). All spot equations demonstrated a significant reduction in sodium levels; however, the change was smaller than the measured 24-hour urine. Participants showed improved knowledge and behaviors following the intervention. The COMBI intervention was effective in lowering average population salt intake and improving knowledge and behaviors. ©2016 Wiley Periodicals, Inc.

Influence of injected caffeine on the metabolism of calcium and the retention and excretion of sodium, potassium, phosphorus, magnesium, zinc and copper in rats.

PubMed

Yeh, J K; Aloia, J F; Semla, H M; Chen, S Y

1986-02-01

Mineral metabolism was studied by the metabolic balance technique in rats with and without administration of caffeine. Caffeine was injected subcutaneously each day at either 2.5 mg or 10 mg/100 g body weight for 2 wk before the balance studies. Urinary volume excretion was higher in the group given caffeine than in the control group, but the creatinine clearance was not different. Urinary excretion of potassium, sodium, inorganic phosphate, magnesium and calcium, but not of zinc and copper, was also higher in the rats given caffeine. The rank order of the difference was the same as the percent of ingested mineral excreted in urine in the absence of caffeine. Caffeine caused a negative balance of potassium, sodium and inorganic phosphate. There was no significant difference from the control levels and in the apparent metabolic balance of calcium and magnesium. The urinary and fecal excretion of zinc and copper were found to be unaffected by caffeine. It is suggested that chronic administration of caffeine may lead to a tendency toward deficiency of those minerals that are excreted primarily in urine.

Validation study of the Tanaka and Kawasaki equations to estimate the daily sodium excretion by a spot urine sample.

PubMed

Mill, José Geraldo; Rodrigues, Sérgio Lamêgo; Baldo, Marcelo Perim; Malta, Deborah Carvalho; Szwarcwald, Celia Landmann

2015-12-01

To validate Tanaka and Kawasaki's formulas to calculate the salt intake by the sodium/creatinine ratio in spot of urine. Two hundred and seventy two adults (20 - 69 years old; 52.6% women) with 24 h urine collection and two urinary spots collected on the same day (while fasting - spot 1 - or not fasting - spot 2). Anthropometry, blood pressure and fasting blood were measured on the same day. The analysis of agreement between salt consumption measured in the 24 h urine test and urinary spots were determined by the Pearson's correlation (r) and the Bland & Altman method. The mean salt consumption measured by the 24 h sodium excretion was 10.4 ± 5.3 g/day. The correlation between the measured 24 h sodium excretion and the estimation based on spots 1 and 2, respectively, was only moderated according to Tanaka (r = 0.51 and r = 0.55; p < 0.001) and to Kawasaki (r = 0.52 and r = 0.54; p < 0.001). We observed an increasing underestimation of salt consumption by Tanaka to increasing salt consumption and conversely, an overestimation of consumption by the Kawasaki formula. The estimation of salt consumption (difference between measured and calculated salt consumption lower than 1 g/day) was adequate only when the consumption was between 9 - 12 g/day (Tanaka) and 12 - 18 g/day (Kawasaki). Spot urine sampling is adequate to estimate salt consumption only among individuals with an actual consumption near the population mean.

Use of Urine Biomarkers to Assess Sodium Intake: Challenges and Opportunities

PubMed Central

Maalouf, Joyce; Elliott, Paul; Loria, Catherine M.; Patel, Sheena; Bowman, Barbara A.

2017-01-01

This article summarizes current data and approaches to assess sodium intake in individuals and populations. A review of the literature on sodium excretion and intake estimation supports the continued use of 24-h urine collections for assessing population and individual sodium intake. Since 2000, 29 studies used urine biomarkers to estimate population sodium intake, primarily among adults. More than half used 24-h urine; the rest used a spot/casual, overnight, or 12-h specimen. Associations between individual sodium intake and health outcomes were investigated in 13 prospective cohort studies published since 2000. Only three included an indicator of long-term individual sodium intake, i.e., multiple 24-h urine specimens collected several days apart. Although not insurmountable, logistic challenges of 24-h urine collection remain a barrier for research on the relationship of sodium intake and chronic disease. Newer approaches, including modeling based on shorter collections, offer promise for estimating population sodium intake in some groups. PMID:25974702

21 CFR 862.1665 - Sodium test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment... excretion of large amounts of dilute urine, accompanied by extreme thirst), adrenal hypertension, Addison's...

21 CFR 862.1665 - Sodium test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment... excretion of large amounts of dilute urine, accompanied by extreme thirst), adrenal hypertension, Addison's...

Placing Salt/Soy Sauce at Dining Tables and Out-Of-Home Behavior Are Related to Urinary Sodium Excretion in Japanese Secondary School Students.

PubMed

Okuda, Masayuki; Asakura, Keiko; Sasaki, Satoshi

2017-11-28

We investigated whether home environment, salt knowledge, and salt-use behavior were associated with urinary sodium (Na) excretion in Japanese secondary school students. Students (267; mean age, 14.2 years) from Suo-Oshima, Japan, collected three overnight urine samples and completed a salt environment/knowledge/behavior questionnaire. A subset of students ( n = 66) collected, on non-consecutive days, two 24 h urine samples, and this subset was used to derive a formula for estimating 24 h Na excretion. Generalized linear models were used to examine the association between salt environment/knowledge/behavior and Na excretions. Students that had salt or soy sauce placed on the dining table during meals excreted more Na than those that did not ( p for trend < 0.05). A number of foods to which the students added seasonings were positively associated with Na excretion ( p for trend = 0.005). The students who frequently bought foods at convenience stores or visited restaurants excreted more Na in urine than those who seldom bought foods ( p for trend < 0.05). Knowledge about salt or discretionary seasoning use was not significantly associated with Na excretion. The associations found in this study indicate that home environment and salt-use behavior may be a target for a public health intervention to reduce salt intake of secondary school students.

Placing Salt/Soy Sauce at Dining Tables and Out-Of-Home Behavior Are Related to Urinary Sodium Excretion in Japanese Secondary School Students

PubMed Central

Okuda, Masayuki; Asakura, Keiko; Sasaki, Satoshi

2017-01-01

We investigated whether home environment, salt knowledge, and salt-use behavior were associated with urinary sodium (Na) excretion in Japanese secondary school students. Students (267; mean age, 14.2 years) from Suo-Oshima, Japan, collected three overnight urine samples and completed a salt environment/knowledge/behavior questionnaire. A subset of students (n = 66) collected, on non-consecutive days, two 24 h urine samples, and this subset was used to derive a formula for estimating 24 h Na excretion. Generalized linear models were used to examine the association between salt environment/knowledge/behavior and Na excretions. Students that had salt or soy sauce placed on the dining table during meals excreted more Na than those that did not (pfor trend < 0.05). A number of foods to which the students added seasonings were positively associated with Na excretion (pfor trend = 0.005). The students who frequently bought foods at convenience stores or visited restaurants excreted more Na in urine than those who seldom bought foods (pfor trend < 0.05). Knowledge about salt or discretionary seasoning use was not significantly associated with Na excretion. The associations found in this study indicate that home environment and salt-use behavior may be a target for a public health intervention to reduce salt intake of secondary school students. PMID:29182529

Pathophysiology of Intense Physical Conditioning in a Hot Climate. I. MECHANISMS OF POTASSIUM DEPLETION

PubMed Central

Knochel, James P.; Dotin, Larry N.; Hamburger, Richard J.

1972-01-01

Serial estimations of exchangeable 42K showed that six volunteer subjects undergoing intensive physical conditioning in a hot climate sustained a mean deficit of 517 mEq. This deficit occurred despite a daily potassium intake of 100 mEq. Simultaneous values for lean body mass rose suggesting that potassium deficiency was not the result of catabolism. Although sweating was the major avenue by which the deficit occurred, daily excretion of potassium into the urine when each subject was maximally deficient ranged from 46 to 75 mEq and thus was inappropriately high for potassium-depleted subjects. Despite high intakes of sodium and excretion of corresponding quantities into the urine, Na/K ratios in sweat were low thus indicating unsuppressed activity of aldosterone on sweat glands. Moreover, excretion and secretion of aldosterone and in many instances, plasma renin activity, appeared to be high with respect to sodium intake. These findings suggest that intense physical work in the heat stimulates higher production of aldosterone than would occur in nonexercising subjects on similar sodium intakes. Similar to the phenomenon of mineralocorticoid escape, such overproduction of aldosterone in the presence of conditions permitting excretion of sodium into the urine could facilitate continued excretion of potassium by the kidney despite serious potassium depletion. As a consequence, the kidney played a role in the genesis of potassium depletion in these subjects. In contrast to subjects undergoing conditioning in the summer months, potassium depletion did not occur in 16 subjects during identical training under cooler environmental conditions. Images PMID:5009112

A multiregional Italian cohort of 24-hour urine metabolic evaluation in renal stone formers.

PubMed

Esperto, Francesco; Marangella, Martino; Trinchieri, Alberto; Petrarulo, Michele; Miano, Roberto

2018-02-01

Nephrolithiasis is a common condition with several studies documenting an increased prevalence over the past four decades. EAU and AUA guidelines recommend 24-hour urine metabolic evaluation in high-risk stone formers. Aim of this study is to retrospectively evaluate the first three years of experience with LithoTest® (Biohealth Italia Srl, Turin, Italy) through the analysis of demographic, clinical and biochemical data collected from a large cohort of patients with kidney stones. We retrospectively analyzed data from the LithoCenter database, including data from outpatient consultations, between January 2007 and December 2009 from all over Italy. LithoTest® was performed through a 24-hour urine collection and included measurements of urine volume and pH, 24-hour excretion of creatinine as well as main cations and anions, including calcium, magnesium sodium potassium, ammonium, uric acid, oxalate, citrate, phosphate, inorganic sulphate and chloride. Urine state of saturation for calcium oxalate (βCaOx), calcium hydrogen phosphate or brushite (βbsh) and uric acid (βUA) were also calculated by means of the computer program LithoRisk. Brand's test for cystinuria was also carried out. Statistical analysis was performed using the S-PSS software v. 22.0. The number of patients with data available for analysis was 435, of whom 236 were male (54%) and 199 female (46%). Complete 24-hour urine measurements were available for all 435 patients. Compared to men, women had significantly lower values for creatinine, urate, oxalate, phosphate, sodium, potassium, magnesium and chloride excretion, whereas 24-hour pH and citrate excretion were higher. No significant differences were found for the other examined variables. βCaOx and βUA were significantly higher in men than women, whereas no significant difference was found for βbsh. There was a direct relationship between calcium and sodium urine excretion. Excessive sodium excretion was recorded in 191 patients (44%) and low urine volumes in 201 (46.2%). Hyperoxaluria was observed in 118 patients (27.3%), hypercalciuria in 115 (26.6%), hyperuricosuria in 153 (35.4%), hypomagnesuria in 96 (22.2%), and hypocitraturia in 134 patients (31%). Hyperexcretion of sodium, hypocitraturia and hyperoxaluria were most frequent in males. βCaOx was significantly higher in the setting of hypercalciuria, hypocitraturia, hyperoxaluria and urine pH below 5.5. Our findings in a large cohort of high-risk stone-forming patients show significant differences in urinary metabolic profiles between men and women. Carrying on the collection and analysis of data by LithoTest® from 2009 to 2015 and matching urinary and dietary data could eventually improve our understanding on the metabolic profile of stone-formers in Italy.

The Impact of Using Different Methods to Assess Completeness of 24-Hour Urine Collection on Estimating Dietary Sodium.

PubMed

Wielgosz, Andreas; Robinson, Christopher; Mao, Yang; Jiang, Ying; Campbell, Norm R C; Muthuri, Stella; Morrison, Howard

2016-06-01

The standard for population-based surveillance of dietary sodium intake is 24-hour urine testing; however, this may be affected by incomplete urine collection. The impact of different indirect methods of assessing completeness of collection on estimated sodium ingestion has not been established. The authors enlisted 507 participants from an existing community study in 2009 to collect 24-hour urine samples. Several methods of assessing completeness of urine collection were tested. Mean sodium intake varied between 3648 mg/24 h and 7210 mg/24 h depending on the method used. Excluding urine samples collected for longer or shorter than 24 hours increased the estimated urine sodium excretion, even when corrections for the variation in timed collections were applied. Until an accurate method of indirectly assessing completeness of urine collection is identified, the gold standard of administering para-aminobenzoic acid is recommended. Efforts to ensure participants collect complete urine samples are also warranted. ©2015 Wiley Periodicals, Inc.

Urinary Sodium Excretion and Dietary Sources of Sodium Intake in Chinese Postmenopausal Women with Prehypertension

PubMed Central

Liu, Zhao-min; Ho, Suzanne C.; Tang, Nelson; Chan, Ruth; Chen, Yu-ming; Woo, Jean

2014-01-01

Background Reducing salt intake in communities is one of the most effective and affordable public health strategies to prevent hypertension, stroke and renal disease. The present study aimed to determine the sodium intake in Hong Kong Chinese postmenopausal women and identify the major food sources contributing to sodium intake and urine excretion. Methods This was a cross-sectional study among 655 Chinese postmenopausal women with prehypertension who were screened for a randomized controlled trial. Data collection included 24 h urine collection for the measurement of sodium, potassium and creatinine, 3-day dietary records, anthropometric measures and questionnaire survey on demographic data and dietary habits. Results The average salt intake estimated from urinary excretion was 7.8±3.2 g/d with 82.1% women above WHO recommendation of 5 g/day. Food groups as soup (21.6%), rice and noodles (13.5%), baked cereals (12.3%), salted/preserved foods (10.8%), Chinese dim sum (10.2%) and sea foods (10.1%) were the major contributors of non-discretionary salt. Discretionary salt use in cooking made a modest contribution to overall intake. Vegetable and fruit intake, age, sodium intake from salted foods, sea foods and soup were the independent determinants of urinary sodium excretion. Conclusions Our data revealed a significant room for reduction of the sodium intake. Efforts to reduce sodium from diets in Hong Kong Chinese postmenopausal women should focus on both processed foods and discretionary salt during cooking. Sodium reduction in soup and increase in fruit intake would be potentially effective strategy for reducing sodium. PMID:25083775

Diuretic effects of KW-3902 (8-(noradamantan-3-yl)-1,3-dipropylxanthine), a novel adenosine A1 receptor antagonist, in conscious dogs.

PubMed

Kobayashi, T; Mizumoto, H; Karasawa, A

1993-12-01

The diuretic effects of KW-3902 (8-(noradamantan-3-yl)-1,3-dipropylxanthine), a novel adenosine A1 receptor antagonist, were determined and compared with those of trichlormethiazide (TCM) and furosemide in saline-loaded conscious dogs. KW-3902, at doses higher than 0.1 mg/kg (p.o.), produced dose-dependent increases of urine volume and sodium excretion and these effects were statistically significant at doses of 1-100 mg/kg. The increase in potassium excretion was lower than that of sodium, and the ratio of sodium to potassium excretion (Na/K) tended to be elevated. TCM (0.3 mg/kg) and furosemide (3 mg/kg) also induced increases in urine volume and sodium excretion. The diuretic effects of KW-3902 lasted for 4 h after administration, whereas TCM and furosemide caused significant natriuresis for 2 h after administration. Thus, KW-3902 exhibited a longer lasting natriuresis than TCM and furosemide. These results indicate that adenosine A1 receptor blockade by KW-3902 causes consistent diuresis and natriuresis in dogs and suggest that adenosine A1 receptor blockade is a promising approach to diuretic therapy.

The relationship between cognitive function, depressive behaviour and sleep quality with 24-h urinary sodium excretion in patients with essential hypertension.

PubMed

Afsar, Baris

2013-03-01

Various studies have shown that sodium intake is related to increased blood pressure. However, the relationship between sodium intake and cognitive function and depression has not previously been studied. The objective of this study was to investigate the relationship between 24-h sodium excretion with cognitive function, depression and sleep quality in patients newly diagnosed with essential hypertension. All patients underwent history taking, physical examination, blood pressure measurement, 12-lead ECG evaluation, routine urine analysis, biochemical analysis and 24-h urine collection to measure urinary sodium and protein excretion and creatinine clearance, evaluation of cognitive function, depressive behaviour and sleep quality. In total, 119 patients newly diagnosed with essential hypertension (50 men and 69 women aged 54.2 ± 16.1 years) were enrolled. The 24-h urinary sodium excretion of the patients was 204.0 ± 240.4 mEq/day. The Standardized Mini Mental State Examination (SMMSE), Pittsburgh Sleep Quality Index and Beck Depression Inventory scores of the patients were 26.0 ± 2.7, 5.6 ± 3.1 and 21.6 ± 13.5, respectively. Spearman correlation analysis revealed that 24-h urinary sodium excretion was correlated with age (rho -0.258, p = 0.005), systolic blood pressure (rho 0.219, p = 0.017), diastolic blood pressure (rho 0.195, p = 0.034), creatinine clearance (rho 0.414, p < 0.0001) and SMMSE score (rho -0.257, p = 0.005). Stepwise linear regression of independent factors revealed that gender (p < 0.0001), creatinine clearance (p < 0.0001), systolic blood pressure (p = 0.031) and SMMSE score (p < 0.0001) were independently related to logarithmically converted 24-h sodium excretion. The current study demonstrated that better cognitive function, but not depressive behaviour and sleep disturbance, is related to decreased sodium intake as evaluated by 24-h urinary sodium excretion. Studies are needed to highlight the mechanisms regarding the relationship between cognitive function and sodium intake.

Low urine pH and acid excretion do not predict bone fractures or the loss of bone mineral density: a prospective cohort study.

PubMed

Fenton, Tanis R; Eliasziw, Misha; Tough, Suzanne C; Lyon, Andrew W; Brown, Jacques P; Hanley, David A

2010-05-10

The acid-ash hypothesis, the alkaline diet, and related products are marketed to the general public. Websites, lay literature, and direct mail marketing encourage people to measure their urine pH to assess their health status and their risk of osteoporosis.The objectives of this study were to determine whether 1) low urine pH, or 2) acid excretion in urine [sulfate + chloride + 1.8x phosphate + organic acids] minus [sodium + potassium + 2x calcium + 2x magnesium mEq] in fasting morning urine predict: a) fragility fractures; and b) five-year change of bone mineral density (BMD) in adults. Cohort study: the prospective population-based Canadian Multicentre Osteoporosis Study. Multiple logistic regression was used to examine associations between acid excretion (urine pH and urine acid excretion) in fasting morning with the incidence of fractures (6804 person years). Multiple linear regression was used to examine associations between acid excretion with changes in BMD over 5-years at three sites: lumbar spine, femoral neck, and total hip (n = 651). Potential confounders controlled included: age, gender, family history of osteoporosis, physical activity, smoking, calcium intake, vitamin D status, estrogen status, medications, renal function, urine creatinine, body mass index, and change of body mass index. There were no associations between either urine pH or acid excretion and either the incidence of fractures or change of BMD after adjustment for confounders. Urine pH and urine acid excretion do not predict osteoporosis risk.

Role of vasopressin in regulation of renal kinin excretion in Long-Evans and diabetes insipidus rats.

PubMed Central

Kauker, M L; Crofton, J T; Share, L; Nasjletti, A

1984-01-01

To study the relationship between vasopressin and the renal kallikrein-kinin system we measured the rate of excretion of kinins into the urine of anesthetized rats during conditions of increased and decreased vasopressin level. The excretion of immunoreactive kinins in Brattleboro rats with hereditary diabetes insipidus (DI) (24 +/- 3 pg min-1 kg-1) was lower than in the control Long Evans (LE) rats (182 +/- 22 pg min-1 kg-1; P less than 0.05). The DI rats also exhibited negligible urinary excretion of immunoreactive vasopressin, reduced urine osmolality, and increased urine flow and kininogenase excretion. In LE rats, volume expansion by infusion of 0.45% NaCl-2.5% dextrose to lower vasopressin secretion reduced (P less than 0.05) kinin excretion, vasopressin excretion, and urine osmolality to 41, 26, and 15% of their respective control values, while increasing (P less than 0.05) urine flow and kininogenase excretion. On the other hand, the infusion of 5% NaCl, which promotes vasopressin secretion, increased (P less than 0.05) the urinary excretion of kinins and vasopressin to 165 and 396% of control, while increasing (P less than 0.05) urine flow and kininogenase excretion. Infusion of vasopressin (1.2 mU/h, intravenous) enhanced (P less than 0.05) kinin excretion by two to threefold in DI rats and in LE rats during volume expansion with 0.45% NaCl-2.5% dextrose, while decreasing urine flow and increasing urine osmolality. This study demonstrates that the urinary excretion of immunoreactive kinins varies in relation to the urinary level of vasopressin, irrespective of urine volume and osmolality and of the urinary excretions of sodium and kininogenase. The study suggests a role for vasopressin in promoting the activity of the renal kallikrein-kinin system in the rat. PMID:6561201

Calciuric effects of short-term dietary loading of protein, sodium chloride and potassium citrate in prepubescent girls.

PubMed

Duff, T L; Whiting, S J

1998-04-01

Studies using adult human subjects indicate that dietary protein and sodium chloride have negative effects on the retention of calcium by increasing urinary calcium excretion, while alkaline potassium improves calcium retention along with decreasing urinary calcium losses. This study investigated the effect of these dietary factors on acute urinary calcium excretion in 14 prepubescent girls age 6.7 to 10.0 years. Subjects provided a fasting urine sample then consumed a meal containing one of five treatments: moderate protein (MP) providing 11.8 g protein, moderate protein plus 26 mmol sodium chloride (MP+Na), high protein (HP) providing 28.8 g protein, high protein plus 26 mmol sodium chloride (HP+Na), or high protein plus 32 mmol potassium as tripotassium citrate (HP+K). Urine was collected at 1.5 and 3.0 hours after the meal. Supplemental protein was given as 80:20 casein:lactalbumin. Test meals were isocaloric, and unless intentionally altered, components of interest except phosphate were equal between treatments. Each subject completed all five treatments. Urinary calcium excretion rose after the meal, peaking at 1.5 hours. There were no significant differences in calcium excretion between treatments at any time point. The high protein treatments did not result in a significant increase in either net acid or sulfate excretion at 1.5 hours compared to moderate protein. Dietary sodium chloride had no effect on urinary sodium or calcium excretion over the 3 hours. After the potassium treatment, sodium excretion increased (p< or =0.002) and net acid excretion decreased (p<0.001) compared to other treatments at 1.5 hours. In children, a simultaneous increase in protein and phosphorus due to increased milk protein intake did not increase acute urinary calcium excretion. An effect of dietary sodium chloride on acute urinary calcium excretion was not observed. Both these findings were similar to those of adult studies previously conducted in the same laboratory using similar format and treatments. Potassium citrate was not hypocalciuric in children, a response differing from that for adults, who have shown a decrease in acute urinary calcium excretion in response to alkaline potassium treatment. Further characterization of calciuric responses to dietary factors is required for children, who may differ from adults in many respects.

Effect of indomethacin on desmopressin resistant nocturnal polyuria and nocturnal enuresis.

PubMed

Kamperis, Konstantinos; Rittig, Søren; Bower, Wendy F; Djurhuus, Jens C

2012-11-01

We evaluated the acute effect of indomethacin on renal water and solute handling in children with coexisting monosymptomatic nocturnal enuresis and desmopressin resistant nocturnal polyuria, and in healthy controls. A total of 23 subjects were recruited, consisting of 12 children with monosymptomatic nocturnal enuresis and nocturnal polyuria with partial or no response to desmopressin, and 11 age matched controls. Children completed a 48-hour inpatient study protocol consisting of fractional urine collections and blood samples. Sodium and water intake were standardized. During the second night a dose of 50 mg indomethacin was administered orally before bedtime. Diuresis, urine osmolalities, clearances and fractional excretions were calculated for sodium, potassium, urea, osmoles and solute-free water. Renin, angiotensin II, aldosterone and atrial natriuretic peptide were measured in plasma. Prostaglandin E(2) was measured in urine. Indomethacin markedly decreased the nocturnal sodium, urea and osmotic excretion in children with enuresis and controls. The overall effect on nocturnal urine output was inconsistent in the group with enuresis. Subjects in whom nocturnal diuresis was decreased following administration of indomethacin remained dry. Prostaglandin inhibition leads to antidiuresis, reducing the amount of sodium, urea and osmotic excretion in children with monosymptomatic nocturnal enuresis and desmopressin resistant nocturnal polyuria. The sodium regulating hormones do not seem to mediate these processes. The overall effect in desmopressin nonresponders with nocturnal polyuria is variable. The extent to which indomethacin can be applied in the treatment of enuresis needs further evaluation. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Alterations in acid-base homeostasis during water immersion in normal man

NASA Technical Reports Server (NTRS)

Epstein, M.; Schneider, N. S.; Vaamonde, C. A.

1974-01-01

The effects of water immersion on renal bicarbonate and acid excretion were assessed in 10 normal male subjects. Immersion resulted in a highly significant progressive increase in the rate of sodium and bicarbonate excretion, and in urine pH. Immersion was also associated with a significant increase in urine P-CO2; this increase presupposes a maintained rate of hydrogen secretion in the distal tubular segment. The rapidity of onset of the bicarbonaturia (2 hrs of immersion) and the concomitant increase in urinary P-CO2 suggest that enhanced bicarbonate excretion of immersion cannot be completely accounted for by immersion-induced suppression of aldosterone, and that the natriuresis and bicarbonaturia of immersion is mediated in part by an increased proximal rejection of sodium and bicarbonate.

Comparison of the excretion of sodium and meglumine diatrizoate at urography with simulated compression: an experimental study in the rat.

PubMed

Owman, T

1981-07-01

In the experimental model in the rabbit the excretion of sodium and meglumine diatrizoate, respectively, have been compared. Urographic density which was estimated through renal pelvic volume as calculated according to previous experiments (Owman 1978; Owman & Olin 1980) and urinary iodine concentration, is suggested to be more accurate than mere determination of urine iodine concentration and diuresis when evaluating and comparing urographic contrast media experimentally. More reliable dose optima are probably found when calculating density rather than determining urine concentrations. Of the examined media in this investigation, the sodium salt of diatrizoate was not superior to the meglumine salt in dose ranges up to 320 mg I/kg body weight, while at higher doses sodium diatrizoate gave higher urinary iodine concentrations and higher estimated density.

Effect of high dietary sodium on bone turnover markers and urinary calcium excretion in Korean postmenopausal women with low bone mass.

PubMed

Park, S M; Joung, J Y; Cho, Y Y; Sohn, S Y; Hur, K Y; Kim, J H; Kim, S W; Chung, J H; Lee, M K; Min, Y-K

2015-03-01

High salt intake is a well-recognized risk factor of osteoporosis for its modulating effect on calcium metabolism. To understand the effect of dietary sodium on bone turnover, we evaluated the association between urinary sodium excretion and bone turnover markers in Korean postmenopausal women with low bone mass. A retrospective review of medical records at a single institution identified 537 postmenopausal women who were first diagnosed with osteopenia or osteoporosis between 2008 and 2013. Subjects were stratified by low (<2 g/day, n=77), moderate (2-4.4 g/day, n=354) and high (⩾4.4 g/day, n=106) sodium excretion. A 24-h urine was collected to estimate sodium, calcium and creatinine. Bone turnover markers and calciotropic hormones were measured in serum. Bone mineral density (BMD) was assessed using dual-energy X-ray absorptiometry. Sodium intake was positively associated with urinary sodium excretion (P=0.006, r=0.29). Bone turnover markers were significantly higher in the moderate-to-high urinary sodium excretion group (⩾2 g/day) than in the low urinary sodium excretion group (<2 g/day); CTX-I (C-telopeptides of type I collagen) was 21.3% higher (P=0.001) and osteocalcin (OC) was 15.7% higher (P=0.004). Calciotropic hormones and BMD were not significantly different across the sodium excretion groups. High urinary sodium excretion (⩾2 g/day) increased bone turnover markers in Korean postmenopausal women, suggesting that excessive sodium intake might accelerate bone turnover.

Sodium and potassium excretion are related to bone mineral density in women with coeliac disease.

PubMed

Turner, Kirsty M; Clifton, Peter M; Keogh, Jennifer B

2015-04-01

Women with coeliac disease may have a lower bone mineral density due to the malabsorption of calcium before diagnosis. A high sodium excretion is associated with increased calcium and bone loss. Our aim was to describe the bone mineral density (BMD) and sodium excretion in women with coeliac disease. In a cross-sectional study BMD of the lumbar spine and hip was assessed by dual energy X-ray absorptiometry. Sodium, potassium and calcium excretion were measured from a 24 h urine collection. In 33 women (51 ± 16 yr) BMD was 1.14 ± 0.19 g/cm(2) and 0.94 ± 0.14 g/cm(2) at the lumbar spine and hip respectively. Age matched Z-scores were -0.1 ± 1.2 and -0.3 ± 1.1 at lumbar spine and hip respectively. Sodium excretion was 107 ± 51 mmol/d; 14 (42%) had a sodium excretion >100 mmol Na/d (145 ± 45 mmol/d). Potassium and calcium excretion were 87 ± 25 mmol/d and 4.1 ± 2.0 mmol/d respectively. In women with Na excretion >100 mmol Na/d, Ca excretion was significantly greater than those with <100 mmol/d (4.9 ± 2.0 vs 3.4 ± 1.8, p < 0.05). Sodium excretion and BMI were positively correlated (r = 0.61, p < 0.001) as were sodium and calcium excretion (r = 0.43, p < 0.05). Sodium excretion was inversely related to femoral neck BMD (t = -2.4 p = 0.023) after adjustment for weight, age, years since diagnosis and potassium excretion. Weight, but no other variable, was a predictor of BMD at the lumbar spine (t = 2.58 p = 0.018). Sodium excretion was inversely related and potassium excretion positively related to femoral neck density which was similar to age matched women without coeliac disease. Copyright © 2014 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Renal haemodynamics and natriuretic responses to intravenous administration of diadenosine tetraphosphate (Ap4A) and nicotinamide adenine dinucleotide (NAD) in rat.

PubMed

Szczepańska-Konkel, M; Langner, G; Bednarczuk, G; Stiepanow-Trzeciak, A; Jankowski, M; Angielski, S

2003-06-01

Effects of Ap4A and NAD--precursor of adenosine, on renal plasma flow (RPF), glomerular filtration rate (GFR) and urine excretion were determined in the anaesthetised rats. Infusion of Ap4A or NAD (i.v., bolus--1 micromol/kg followed by 10 nmol/min/kg) decreased RPF and GFR (by 30 and 40%, respectively). In spite of GFR reduction during Ap4A infusion, the significant increase in sodium excretion and urine flow was noticed: fractional sodium (FENa) and urine excretion (FEurine) rose 15-fold and 2.5-fold in comparison with the control value, respectively. In contrast to Ap4A, NAD-induced decrease in GFR was associated with parallel decrease in sodium and urine excretion, thus the FENa and FEurine did not significantly change. Pretreatment with adenosine deaminase (adenosine degrading enzyme, 2 U/min/kg) or theophylline (P1-receptors antagonist, 0.2 mmol/min/kg) ceased responses to NAD, whereas Ap4A-induced changes were not affected. Pre-treatment with suramin (P2-receptors antagonist, (i.v., bolus--12 mg/kg followed by 1.2 mg/min/kg) completely abolished the renal effects of Ap4A. We conclude that Ap4A may exert specific action on renal function. It acts different from NAD that modified renal function through its hydrolysis product--adenosine. Ap4A might reduce glomerular filtration rate and evoke natriuresis and diuresis, and its effects are probably mediated through stimulation of P2-receptors.

Population-based association between urinary excretion of sodium, potassium and its ratio with albuminuria in Chinese.

PubMed

Yan, Liuxia; Guo, Xiaolei; Wang, Huicheng; Zhang, Jiyu; Tang, Junli; Lu, Zilong; Cai, Xiaoning; Liu, Longjian; Gracely, Edward J; Ma, Jixiang

2016-12-01

Albuminuria is a risk factor for cardiovascular and renal disease. However, little is known about the association of 24 h urinary sodium and potassium excretion with albuminuria in China. The aim of this study was to examine this association by analyzing the data from 1,975 Chinese adults living in north China. Excretion of urinary sodium, potassium and albumin was assessed in a single 24-h urine sample for each participant. Height, weight, waist circumference and blood pressure were measured and body mass index was determined as weight divided by square height. Fasting blood sample was collected and fasting glucose was measured. The average 24-h urinary sodium and potassium excretion were 232 mmol and 40.8 mmol, resulting a mean sodium to potassium ratio of 6.7. The median (Q1-Q3) 24-h urinary albuminuria excretion was 6.1 mg (4.5-8.7 mg). Overall, urinary sodium excretion was positively associated with albumin excretion (β=0.029, p<0.001). This association was independent of major cardiovascular risk factors including age, gender, systolic blood pressure, body mass index, fasting glucose, waist circumference, hypertensive drug treatment, and smoking. Moreover, the relation of sodium and albumin was similar in the subgroups stratified by gender, adiposity and diabetic status. No significant associations of potassium excretion or sodium to potassium ratio with urinary albumin excretion were observed. In cross-sectional analyses, high sodium intake was shown to be associated with increased urinary albuminuria in the general Chinese adult population, supporting salt restriction for renal and cardiovascular health benefit.

Thiazide-induced hyponatraemia is associated with increased water intake and impaired urea-mediated water excretion at low plasma antidiuretic hormone and urine aquaporin-2.

PubMed

Frenkel, Nanne J; Vogt, Liffert; De Rooij, Sophia E; Trimpert, Christiane; Levi, Marcel M; Deen, Peter M T; van den Born, Bert-Jan H

2015-03-01

Hyponatraemia is a common, potentially life-threatening, complication of thiazide diuretics. The mechanism of thiazide-induced hyponatraemia is incompletely understood. Previous experiments have suggested a direct effect of thiazide diuretics on the plasma membrane expression of aquaporin (AQP)2. We examined the effects of a single re-exposure to hydrochlorothiazide (HCTZ) 50 mg on water balance, renal sodium handling and osmoregulation in 15 elderly hypertensive patients with a history of thiazide-induced hyponatraemia and 15 matched hypertensive controls using thiazide diuretics without previous hyponatraemia. Patients with thiazide-induced hyponatraemia had significantly lower body weight and lower plasma sodium and osmolality at baseline. After HCTZ administration, plasma sodium and osmolality significantly decreased and remained lower in patients compared with controls (P < 0.001). Plasma antidiuretic hormone (ADH) and urine AQP2 were low or suppressed in patients, whereas solute and electrolyte-free water clearance was significantly increased compared with controls. Ad libitum water intake was significantly higher in patients (2543 ± 925 ml) than in controls (1828 ± 624 ml, P < 0.05), whereas urinary sodium excretion did not differ. In contrast, urea excretion remained significantly lower in patients (263 ± 69 mmol per 24 h) compared with controls (333 ± 97 mmol per 24 h, P < 0.05) and predicted the decrease in plasma sodium following HCTZ administration. Thiazide diuretics are associated with markedly impaired free water excretion at low ADH and AQP2 in elderly patients. The higher water intake and lower urea excretion in patients points to an important role for polydipsia and urea-mediated water excretion in the pathogenesis of thiazide-induced hyponatraemia.

Agreement between 24-hour salt ingestion and sodium excretion in a controlled environment.

PubMed

Lerchl, Kathrin; Rakova, Natalia; Dahlmann, Anke; Rauh, Manfred; Goller, Ulrike; Basner, Mathias; Dinges, David F; Beck, Luis; Agureev, Alexander; Larina, Irina; Baranov, Victor; Morukov, Boris; Eckardt, Kai-Uwe; Vassilieva, Galina; Wabel, Peter; Vienken, Jörg; Kirsch, Karl; Johannes, Bernd; Krannich, Alexander; Luft, Friedrich C; Titze, Jens

2015-10-01

Accurately collected 24-hour urine collections are presumed to be valid for estimating salt intake in individuals. We performed 2 independent ultralong-term salt balance studies lasting 105 (4 men) and 205 (6 men) days in 10 men simulating a flight to Mars. We controlled dietary intake of all constituents for months at salt intakes of 12, 9, and 6 g/d and collected all urine. The subjects' daily menus consisted of 27 279 individual servings, of which 83.0% were completely consumed, 16.5% completely rejected, and 0.5% incompletely consumed. Urinary recovery of dietary salt was 92% of recorded intake, indicating long-term steady-state sodium balance in both studies. Even at fixed salt intake, 24-hour urine collection for sodium excretion (UNaV) showed infradian rhythmicity. We defined a ±25 mmol deviation from the average difference between recorded sodium intake and UNaV as the prediction interval to accurately classify a 3-g difference in salt intake. Because of the biological variability in UNaV, only every other daily urine sample correctly classified a 3-g difference in salt intake (49%). By increasing the observations to 3 consecutive 24-hour collections and sodium intakes, classification accuracy improved to 75%. Collecting seven 24-hour urines and sodium intake samples improved classification accuracy to 92%. We conclude that single 24-hour urine collections at intakes ranging from 6 to 12 g salt per day were not suitable to detect a 3-g difference in individual salt intake. Repeated measurements of 24-hour UNaV improve precision. This knowledge could be relevant to patient care and the conduct of intervention trials. © 2015 American Heart Association, Inc.

Lithium evokes a more pronounced natriuresis when administered orally than when given intravenously to salt-depleted rats.

PubMed

Mu, J; Johansson, M; Hansson, G C; Lundgren, O

1999-07-01

The effects on renal sodium excretion of giving lithium chloride (LiCl; 0.75 mmol per kg body mass) by gavage or intravenously were investigated. The experiments were carried out on Wistar-Kyoto (WKY) or spontaneously hypertensive (SHR) rats in metabolic cages. The rats had been on a low-salt diet for 4 days. Urine excretion of water, sodium and potassium was followed before and for 24 h after giving LiCl. An oral dose of LiCl evoked a more pronounced renal sodium excretion in either strain of rat as compared to that following intravenous administration, in agreement with previous observations of the effects of giving sodium chloride. Choline chloride (1.5 mmol per kg body mass) given by gavage to WKY rats or SHR evoked no change in the renal excretion of sodium. Based on the results of the present study and on observations reported in the literature, we propose that the intestinal tract contains a sodium "sensor", which upon activation releases a natriuretic factor to cause renal sodium excretion. The present results indicate that the proposed "sensor" is sensitive to lithium but not chloride ions.

Urinary sodium and potassium excretion, mortality, and cardiovascular events.

PubMed

O'Donnell, Martin; Mente, Andrew; Rangarajan, Sumathy; McQueen, Matthew J; Wang, Xingyu; Liu, Lisheng; Yan, Hou; Lee, Shun Fu; Mony, Prem; Devanath, Anitha; Rosengren, Annika; Lopez-Jaramillo, Patricio; Diaz, Rafael; Avezum, Alvaro; Lanas, Fernando; Yusoff, Khalid; Iqbal, Romaina; Ilow, Rafal; Mohammadifard, Noushin; Gulec, Sadi; Yusufali, Afzal Hussein; Kruger, Lanthe; Yusuf, Rita; Chifamba, Jephat; Kabali, Conrad; Dagenais, Gilles; Lear, Scott A; Teo, Koon; Yusuf, Salim

2014-08-14

The optimal range of sodium intake for cardiovascular health is controversial. We obtained morning fasting urine samples from 101,945 persons in 17 countries and estimated 24-hour sodium and potassium excretion (used as a surrogate for intake). We examined the association between estimated urinary sodium and potassium excretion and the composite outcome of death and major cardiovascular events. The mean estimated sodium and potassium excretion was 4.93 g per day and 2.12 g per day, respectively. With a mean follow-up of 3.7 years, the composite outcome occurred in 3317 participants (3.3%). As compared with an estimated sodium excretion of 4.00 to 5.99 g per day (reference range), a higher estimated sodium excretion (≥ 7.00 g per day) was associated with an increased risk of the composite outcome (odds ratio, 1.15; 95% confidence interval [CI], 1.02 to 1.30), as well as increased risks of death and major cardiovascular events considered separately. The association between a high estimated sodium excretion and the composite outcome was strongest among participants with hypertension (P=0.02 for interaction), with an increased risk at an estimated sodium excretion of 6.00 g or more per day. As compared with the reference range, an estimated sodium excretion that was below 3.00 g per day was also associated with an increased risk of the composite outcome (odds ratio, 1.27; 95% CI, 1.12 to 1.44). As compared with an estimated potassium excretion that was less than 1.50 g per day, higher potassium excretion was associated with a reduced risk of the composite outcome. In this study in which sodium intake was estimated on the basis of measured urinary excretion, an estimated sodium intake between 3 g per day and 6 g per day was associated with a lower risk of death and cardiovascular events than was either a higher or lower estimated level of intake. As compared with an estimated potassium excretion that was less than 1.50 g per day, higher potassium excretion was associated with a lower risk of death and cardiovascular events. (Funded by the Population Health Research Institute and others.).

The polyuria of paroxysmal atrial tachycardia

NASA Technical Reports Server (NTRS)

Kinney, M. J.; Stein, R. M.; Discala, V. A.

1974-01-01

Two patients with paroxysmal atrial fibrillation and an associated polyuria were studied to delineate the mechanism of the increase in urine flow. A striking saluresis was noted in both patients. The increased sodium excretion was probably due to decreased sodium reabsorption, perhaps at proximal tubular nephron sites. This inhibition of sodium reabsorption could explain both the saluresis and some part or all of the polyuria. Re-evaluation of earlier case reports reveals patterns of concomitant salt and water excretion consistent with this mechanism. The saluresis cannot be explained by the previously favored hypothesis of antidiuretic hormone inhibition.

Dietary intake and sources of sodium and potassium among Australian schoolchildren: results from the cross-sectional Salt and Other Nutrients in Children (SONIC) study.

PubMed

Grimes, Carley A; Riddell, Lynn J; Campbell, Karen J; Beckford, Kelsey; Baxter, Janet R; He, Feng J; Nowson, Caryl A

2017-10-30

To examine sodium and potassium urinary excretion by socioeconomic status (SES), discretionary salt use habits and dietary sources of sodium and potassium in a sample of Australian schoolchildren. Cross-sectional study. Primary schools located in Victoria, Australia. 666 of 780 children aged 4-12 years who participated in the Salt and Other Nutrients in Children study returned a complete 24-hour urine collection. 24-hour urine collection for the measurement of sodium and potassium excretion and 24-hour dietary recall for the assessment of food sources. Parent and child reported use of discretionary salt. SES defined by parental highest level of education. Participants were 9.3 years (95% CI 9.0 to 9.6) of age and 55% were boys. Mean urinary sodium and potassium excretion was 103 (95% CI 99 to 108) mmol/day (salt equivalent 6.1 g/day) and 47 (95% CI 45 to 49) mmol/day, respectively. Mean molar Na:K ratio was 2.4 (95% CI 2.3 to 2.5). 72% of children exceeded the age-specific upper level for sodium intake. After adjustment for age, sex and day of urine collection, children from a low socioeconomic background excreted 10.0 (95% CI 17.8 to 2.1) mmol/day more sodium than those of high socioeconomic background (p=0.04). The major sources of sodium were bread (14.8%), mixed cereal-based dishes (9.9%) and processed meat (8.5%). The major sources of potassium were dairy milk (11.5%), potatoes (7.1%) and fruit/vegetable juice (5.4%). Core foods provided 55.3% of dietary sodium and 75.5% of potassium while discretionary foods provided 44.7% and 24.5%, respectively. For most children, sodium intake exceeds dietary recommendations and there is some indication that children of lower socioeconomic background have the highest intakes. Children are consuming about two times more sodium than potassium. To improve sodium and potassium intakes in schoolchildren, product reformulation of lower salt core foods combined with strategies that seek to reduce the consumption of discretionary foods are required. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Dietary intake and sources of sodium and potassium among Australian schoolchildren: results from the cross-sectional Salt and Other Nutrients in Children (SONIC) study

PubMed Central

Grimes, Carley A; Riddell, Lynn J; Campbell, Karen J; Beckford, Kelsey; Baxter, Janet R; He, Feng J; Nowson, Caryl A

2017-01-01

Objectives To examine sodium and potassium urinary excretion by socioeconomic status (SES), discretionary salt use habits and dietary sources of sodium and potassium in a sample of Australian schoolchildren. Design Cross-sectional study. Setting Primary schools located in Victoria, Australia. Participants 666 of 780 children aged 4–12 years who participated in the Salt and Other Nutrients in Children study returned a complete 24-hour urine collection. Primary and secondary outcome measures 24-hour urine collection for the measurement of sodium and potassium excretion and 24-hour dietary recall for the assessment of food sources. Parent and child reported use of discretionary salt. SES defined by parental highest level of education. Results Participants were 9.3 years (95% CI 9.0 to 9.6) of age and 55% were boys. Mean urinary sodium and potassium excretion was 103 (95% CI 99 to 108) mmol/day (salt equivalent 6.1 g/day) and 47 (95% CI 45 to 49) mmol/day, respectively. Mean molar Na:K ratio was 2.4 (95% CI 2.3 to 2.5). 72% of children exceeded the age-specific upper level for sodium intake. After adjustment for age, sex and day of urine collection, children from a low socioeconomic background excreted 10.0 (95% CI 17.8 to 2.1) mmol/day more sodium than those of high socioeconomic background (p=0.04). The major sources of sodium were bread (14.8%), mixed cereal-based dishes (9.9%) and processed meat (8.5%). The major sources of potassium were dairy milk (11.5%), potatoes (7.1%) and fruit/vegetable juice (5.4%). Core foods provided 55.3% of dietary sodium and 75.5% of potassium while discretionary foods provided 44.7% and 24.5%, respectively. Conclusions For most children, sodium intake exceeds dietary recommendations and there is some indication that children of lower socioeconomic background have the highest intakes. Children are consuming about two times more sodium than potassium. To improve sodium and potassium intakes in schoolchildren, product reformulation of lower salt core foods combined with strategies that seek to reduce the consumption of discretionary foods are required. PMID:29084791

Renal Regulation of Acid-Base Balance: Ammonia Excretion.

ERIC Educational Resources Information Center

Tanner, George A.

1984-01-01

Describes an experiment which demonstrates changes in ammonia excretion and urine pH that occur in response to metabolic acidosis (induced by ammonium chloride ingestion) or metabolic alkalosis (produced by sodium bicarbonate ingestion). List of materials needed and background information are included. Typical results are provided and discussed.…

Changes in urinary risk profile after short-term low sodium and low calcium diet in recurrent Swiss kidney stone formers.

PubMed

Seeger, Harald; Kaelin, Andrea; Ferraro, Pietro M; Weber, Damian; Jaeger, Philippe; Ambuehl, Patrice; Robertson, William G; Unwin, Robert; Wagner, Carsten A; Mohebbi, Nilufar

2017-12-04

Kidney stone disease is common in industrialized countries. Recently, it has attracted growing attention, because of its significant association with adverse renal outcomes, including end stage renal disease. Calcium-containing kidney stones are frequent with high recurrence rates. While hypercalciuria is a well-known risk factor, restricted intake of animal protein and sodium, combined with normal dietary calcium, has been shown to be more effective in stone prevention compared with a low-calcium diet. Notably, the average sodium intake in Switzerland is twice as high as the WHO recommendation, while the intake of milk and dairy products is low. We retrospectively analyzed Swiss recurrent kidney stone formers (rKSF) to test the impact of a low-sodium in combination with a low-calcium diet on the urinary risk profile. In patients with recurrent calcium oxalate containing stones, we investigated both, the consequence of a low-sodium diet on urinary volume and calcium excretion, and the influence of a low-sodium low-calcium diet on urinary oxalate excretion. Of the 169 patients with CaOx stones, 49 presented with hypercalciuria at baseline. The diet resulted in a highly significant reduction in 24-h urinary sodium and calcium excretion: from 201 ± 89 at baseline to 128 ± 88 mmol/d for sodium (p < 0.0001), and from 5.67 ± 3.01 to 4.06 ± 2.46 mmol/d (p < 0.0001) for calcium, respectively. Urine volume remained unchanged. Notably, no increase in oxalate excretion occurred on the restricted diet (0.39 ± 0.26 vs 0.39 ± 0.19 mmol/d, p = 0.277). Calculated Psf (probability of stone formation) values were only predictive for the risk of calcium phosphate stones. A diet low in sodium and calcium in recurrent calcium oxalate stone formers resulted in a significant reduction of urinary calcium excretion, but no change in urine volume. In this population with apparently low intake of dairy products, calcium restriction does not necessarily result in increased urinary oxalate excretion. However, based on previous studies, we recommend a normal dietary calcium intake to avoid a potential increase in urinary oxalate excretion and unfavorable effects on bone metabolism in hypercalciuric KSFs.

Difference between 24-h diet recall and urine excretion for assessing population sodium and potassium intake in adults aged 18–39 y12345

PubMed Central

Cogswell, Mary E; Valderrama, Amy L; Wang, Chia-Yih; Loria, Catherine M; Moshfegh, Alanna J; Rhodes, Donna G; Carriquiry, Alicia L

2015-01-01

Background: Limited data are available on the accuracy of 24-h dietary recalls used to monitor US sodium and potassium intakes. Objective: We examined the difference in usual sodium and potassium intakes estimated from 24-h dietary recalls and urine collections. Design: We used data from a cross-sectional study in 402 participants aged 18–39 y (∼50% African American) in the Washington, DC, metropolitan area in 2011. We estimated means and percentiles of usual intakes of daily dietary sodium (dNa) and potassium (dK) and 24-h urine excretion of sodium (uNa) and potassium (uK). We examined Spearman's correlations and differences between estimates from dietary and urine measures. Multiple linear regressions were used to evaluate the factors associated with the difference between dietary and urine measures. Results: Mean differences between diet and urine estimates were higher in men [dNa – uNa (95% CI) = 936.8 (787.1, 1086.5) mg/d and dK – uK = 571.3 (448.3, 694.3) mg/d] than in women [dNa – uNa (95% CI) = 108.3 (11.1, 205.4) mg/d and dK – uK = 163.4 (85.3, 241.5 mg/d)]. Percentile distributions of diet and urine estimates for sodium and potassium differed for men. Spearman's correlations between measures were 0.16 for men and 0.25 for women for sodium and 0.39 for men and 0.29 for women for potassium. Urinary creatinine, total caloric intake, and percentages of nutrient intake from mixed dishes were independently and consistently associated with the differences between diet and urine estimates of sodium and potassium intake. For men, body mass index was also associated. Race was associated with differences in estimates of potassium intake. Conclusions: Low correlations and differences between dietary and urinary sodium or potassium may be due to measurement error in one or both estimates. Future analyses using these methods to assess sodium and potassium intake in relation to health outcomes may consider stratifying by factors associated with the differences in estimates from these methods. This trial was registered at clinicaltrials.gov as NCT01631240. PMID:25646336

Difference between 24-h diet recall and urine excretion for assessing population sodium and potassium intake in adults aged 18-39 y.

PubMed

Mercado, Carla I; Cogswell, Mary E; Valderrama, Amy L; Wang, Chia-Yih; Loria, Catherine M; Moshfegh, Alanna J; Rhodes, Donna G; Carriquiry, Alicia L

2015-02-01

Limited data are available on the accuracy of 24-h dietary recalls used to monitor US sodium and potassium intakes. We examined the difference in usual sodium and potassium intakes estimated from 24-h dietary recalls and urine collections. We used data from a cross-sectional study in 402 participants aged 18-39 y (∼50% African American) in the Washington, DC, metropolitan area in 2011. We estimated means and percentiles of usual intakes of daily dietary sodium (dNa) and potassium (dK) and 24-h urine excretion of sodium (uNa) and potassium (uK). We examined Spearman's correlations and differences between estimates from dietary and urine measures. Multiple linear regressions were used to evaluate the factors associated with the difference between dietary and urine measures. Mean differences between diet and urine estimates were higher in men [dNa - uNa (95% CI) = 936.8 (787.1, 1086.5) mg/d and dK - uK = 571.3 (448.3, 694.3) mg/d] than in women [dNa - uNa (95% CI) = 108.3 (11.1, 205.4) mg/d and dK - uK = 163.4 (85.3, 241.5 mg/d)]. Percentile distributions of diet and urine estimates for sodium and potassium differed for men. Spearman's correlations between measures were 0.16 for men and 0.25 for women for sodium and 0.39 for men and 0.29 for women for potassium. Urinary creatinine, total caloric intake, and percentages of nutrient intake from mixed dishes were independently and consistently associated with the differences between diet and urine estimates of sodium and potassium intake. For men, body mass index was also associated. Race was associated with differences in estimates of potassium intake. Low correlations and differences between dietary and urinary sodium or potassium may be due to measurement error in one or both estimates. Future analyses using these methods to assess sodium and potassium intake in relation to health outcomes may consider stratifying by factors associated with the differences in estimates from these methods. This trial was registered at clinicaltrials.gov as NCT01631240. © 2015 American Society for Nutrition.

Physiological Adaptations of Arctic Mammals.

DTIC Science & Technology

1975-01-01

photometry for sodium and potassium concentration. Data for the first 30 minute period of severe cold exposure is summarized in Table 1. All the urine...exception of the slope of potassium concentration of unacclimated brown lemmings (which increased), slopes of ion concentrations were not different from...between 5:00 AN and 9:00 AM. Interpretation of the sodium and potassium excretion ..n the urine is difficult as long as there are no specific data on

The effect of puberty on diurnal sodium regulation.

PubMed

Mahler, B; Kamperis, K; Ankarberg-Lindgren, C; Djurhuus, J C; Rittig, S

2015-11-15

The aim of this study was to investigate the impact of sex and puberty stage on circadian changes in sodium excretion, sodium-regulating hormones, and hemodynamics. Thirty-nine healthy volunteers (9 prepuberty boys, 10 prepuberty girls, 10 puberty boys, and 10 puberty girls) were included. They all underwent a 24-h circadian in-patient study under standardized conditions regarding activity, diet, and fluid intake. Blood samples were drawn every 4 h, and the urine was collected in fractions. Blood pressure and heart rate were noninvasively monitored. Atrial natriuretic peptide (ANP), angiotensin II, aldosterone, and renin were measured in blood. Children in puberty had lower plasma levels of renin (P<0.05) and angiotensin II (P<0.05) and a 26% reduction in filtered sodium without changes in sodium excretion compared with prepuberty children. A circadian rhythm in sodium excretion, the renin-angiotensin system, ANP, and blood pressure was found with a midnight ANP peak (P<0.001), a nighttime decrease in hemodynamic parameters (P<0.001), an increase in plasma renin (P<0.001) and angiotensin II (P<0.001), and a decrease in sodium excretion (P<0.001) mainly on the basis of increased sodium reabsorption (P<0.001). The timing of the changes did not depend on sex or puberty group. There is a circadian rhythm of sodium excretion and sodium regulation in 7- to 15-yr-old children. This rhythm is similar in boys and girls. As an important new finding, puberty changes the plasma levels of renin and angiotensin II without changing the amount of sodium excreted or the day to night sodium excretion ratio. Copyright © 2015 the American Physiological Society.

Urinary excretion of adrenal steroids, catecholamines and electrolytes in man, before and after acclimatization to cold in Antarctica

PubMed Central

Budd, G. M.; Warhaft, N.

1970-01-01

1. Urine samples were collected from four men before and during test cold exposures in Melbourne, Australia, and Mawson, Antarctica. Changes in the response of body temperature to the test exposures showed that the men had acclimatized to cold at Mawson. 2. Excretion rates of 17-hydroxycorticosteroids and 17-ketosteroids were significantly greater at Mawson than in Melbourne, in both the pre-exposure and exposure periods. 3. Excretion rates of noradrenaline, adrenaline, sodium, potassium and creatinine did not differ significantly between Mawson and Melbourne, nor did urine flow rates. 4. During the cold exposure significant increases occurred, to the same extent at Mawson as in Melbourne, in urine flow rate and in all measured urinary constituents except creatinine. PMID:5501486

Agreement between twenty-four hour salt ingestion and sodium excretion in a controlled environment

PubMed Central

Lerchl, Kathrin; Rakova, Natalia; Dahlmann, Anke; Rauh, Manfred; Goller, Ulrike; Basner, Mathias; Dinges, David F.; Beck, Luis; Agureev, Alexander; Larina, Irina; Baranov, Victor; Morukov, Boris; Eckardt, Kai-Uwe; Vassilieva, Galina; Wabel, Peter; Vienken, Jörg; Kirsch, Karl; Johannes, Bernd; Krannich, Alexander; Luft, Friedrich C.; Titze, Jens

2015-01-01

Accurately collected 24-hour urine collections are presumed to be valid for estimating salt intake in individuals. We performed two independent ultra-long-term salt balance studies lasting 105 (4 men) and 205 (6 men) days in 10 men simulating a flight to Mars. We controlled dietary intake of all constituents for months at salt intakes of 12, 9, and 6 grams per day and collected all urine. The subjects’ daily menus consisted of 27,279 individual servings, out of which 83.0% were completely consumed, 16.5% completely rejected, and 0.5% incompletely consumed. Urinary recovery of dietary salt was 92% of recorded intake, indicating long-term steady state sodium balance in both studies. Even at fixed salt intake, 24-hour sodium excretion (UNaV) showed infradian rhythmicity. We defined a ±25 mmol deviation from the average difference between recorded sodium intake and UNaV as the prediction interval to accurately classify a 3-gram difference in salt intake. Due to the biological variability in UNaV, only every-other daily urine sample correctly classified a 3-gram difference in salt intake (49%). By increasing the observations to three consecutive 24-hour collections and sodium intakes, classification accuracy improved to 75%. Collecting seven 24-hour urines and sodium intake samples improved classification accuracy to 92%. We conclude that single 24-hour urine collections at intakes ranging from 6–12 grams salt per day were not suitable to detect a 3-gram difference in individual salt intake. Repeated measurements of 24-hour UNaV improve precision. This knowledge could be relevant to patient care and the conduct of intervention trials. PMID:26259596

Effect of sodium chloride intake on urine volume, urinary urea excretion, and milk urea concentration in lactating dairy cattle.

PubMed

Spek, J W; Bannink, A; Gort, G; Hendriks, W H; Dijkstra, J

2012-12-01

Milk urea nitrogen (MUN; mg of N/dL) has been shown to be related to excretion of urinary urea N (UUN; g of N/d) and total excretion of urinary N (UN; g of N/d) in dairy cows. In the present experiment, it was hypothesized that MUN and the relationship between MUN and UUN or UN is affected by urine volume as a result of dietary sodium chloride intake. Twelve lactating Holstein-Friesian dairy cows (mean ± SD: milk production 28.1±3.23 kg/d and 190±41 d in milk), of which 4 were fitted with catheters in the urine bladder and jugular vein, were randomly assigned to 4 dietary levels of sodium chloride (3, 9, 14, and 19 g of Na/kg of DM) according to a triple 4×4 Latin square design. Cows were fed at 95% of ad libitum intake, excluding salt addition. Milk was analyzed for MUN and protein content; urine was analyzed for total N, urea, and creatinine content; feces were analyzed for total N and DM content; and blood plasma was analyzed for urea and creatinine content. Creatinine clearance rate (CCR; L/min) and renal urea reabsorption ratio were estimated based on plasma concentrations of urea and creatinine, and total excretion of urea and creatinine in urine. Intake of DM and N, milk production, and milk protein content were (mean ± SD), on average, 21.4±1.24 kg/d, 522±32.0 g/d, 25.4±2.53 kg/d, and 3.64±0.186%, respectively. A linear relationship was found between Na intake and urine production [urine (kg/d; mean ± SE)=7.5±4.33+0.136±0.0143 × Na intake (g/d)] and between Na intake and MUN [MUN (mg/dL; mean ± SE)=13.5±0.35-0.0068±0.00104 × Na intake (g/d)]. Despite the decrease in MUN with increased Na intake, UN excretion increased linearly with Na intake. Excretion of UUN was not affected by dietary Na content. A linear plateau relationship was observed between CCR and renal urea reabsorption. An increase in CCR coincided with an increase in calculated renal urea reabsorption until a CCR breakpoint value (mean ± SD) of 1.56±0.063 L/min was reached. We conclude that Na intake is negatively related to MUN, whereas UUN is not affected. Variation in mineral intake levels that affect urine volume should, therefore, be taken into account when using MUN as an indicator of UUN in dairy cattle. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Urinary Excretion of N-Nitroso Compounds in Rats Fed Sodium Nitrite and/or Hot Dogs

PubMed Central

2015-01-01

Nitrite-treated meat is a reported risk factor for colon cancer. Mice that ingested sodium nitrite (NaNO2) or hot dogs (a nitrite-treated product) showed increased fecal excretion of apparent N-nitroso compounds (ANC). Here, we investigated for the first time whether rats excrete increased amounts of ANC in their urine after they are fed NaNO2 and/or hot dogs. Rats were treated for 7 days with NaNO2 in drinking water or were fed hot dogs. Their 24 h urine samples were analyzed for ANC by thermal energy analysis on days 1–4 after nitrite or hot dog treatment was stopped. For two rats fed 480 mg NaNO2/L drinking water, mean urinary ANC excretion on days 1–4 was 30, 5.2, 2.5, and 0.8 nmol/day, respectively. For two to eight rats/dose given varied NaNO2 doses, mean urinary ANC output on day 1 increased from 0.9 (for no nitrite) to 37 (for 1000 mg NaNO2/L drinking water) nmol ANC/day. Urine samples of four rats fed 40–60% hot dogs contained 12–13 nmol ANC on day 1. Linear regression analysis showed highly significant correlations between urinary ANC excretion on day 1 after stopping treatment and varied (a) NaNO2 level in drinking water for rats fed semipurified or commercials diet and (b) hot dog levels in the diet. Some correlations remained significant up to 4 days after nitrite treatment was stopped. Urinary output of ANC precursors (compounds that yield ANC after mild nitrosation) for rats fed semipurified or commercial diet was 11–17 or 23–48 μmol/day, respectively. Nitrosothiols and iron nitrosyls were not detected in urinary ANC and ANCP. Excretion of urinary ANC was about 60% of fecal ANC excretion for 1 to 2 days after NaNO2 was fed. Administered NaNO2 was not excreted unchanged in rat urine. We conclude that urinary ANC excretion in humans could usefully be surveyed to indicate exposure to N-nitroso compounds. PMID:25183213

The distribution of lithium and its effects on the distribution and excretion of other ions in the rat

PubMed Central

Birch, N. J.; Jenner, F. A.

1973-01-01

1. In rats, lithium (ca 1 mEquiv/kg body weight) decreased brain sodium and magnesium, bone sodium and calcium and increased muscle calcium, plasma magnesium, urinary calcium and urine volume. 2. Lithium was particularly concentrated in bone. PMID:4730833

Urinary sodium excretion after gastric bypass surgery.

PubMed

Docherty, Neil G; Fändriks, Lars; le Roux, Carel W; Hallersund, Peter; Werling, Malin

2017-09-01

Gut-kidney signaling is implicated in sodium homeostasis and thus blood pressure regulation. Roux-en-Y gastric bypass (RYGB) surgery for morbid obesity confers a pronounced and long-lasting blood pressure lowering effect in addition to significant weight loss. We set out to establish whether RYGB is associated with an intrinsic change in urinary sodium excretion that may contribute to the reported blood pressure lowering effects of the procedure. University hospital METHODS: Five female patients (age range: 28-50 yr) without metabolic or hypertensive co-morbidities were included in a study involving four 24-hour residential visits: once before surgery and 10 days, 3 months, and 20 months after surgery. Creatinine and sodium were measured in fasting plasma samples and 24-hour urine samples and creatinine clearance, estimated glomerular filtration rate, and indices of urinary sodium excretion were calculated. Fasting and 60-minute postprandial blood samples from each study day were assayed for pro-B-type natriuretic peptide (NT-proBNP). Increases in weight-normalized urinary sodium excretion of up to 2.3-fold in magnitude occurred at 20 months after surgery. Median fractional excretion of sodium at 20 months was double that seen before surgery. Fasting NT-proBNP levels were stable or increased (1.5- to 5-fold). Moreover, a small postprandial increase in NT-proBNP was observed after surgery. Renal fractional excretion of sodium is increased after RYGB. A shift toward increased postoperative basal and meal associated levels of NT-proBNP coincides with increased urinary sodium excretion. The data support a working hypothesis that an enhanced natriuretic gut-kidney signal after RYGB may be of mechanistic importance in the blood pressure lowering effects of this procedure. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Blood volume reduction counteracts fluid shifts in water immersion

NASA Technical Reports Server (NTRS)

Simanonok, Karl E.; Bernauer, Edmund

1993-01-01

Six healthy men were bled by 15 percent of their total blood volume (TBV) before 7 h of seated water immersion, to test the hypothesis that some of the major physiological responses to an expansion of central blood volume can be counteracted by prior reduction of TBV. Subjects were their own controls under two conditions: seated dry in air and seated immersed to the suprasternal notch in water. Immersion without prior reduction of TBV Wet Control (WC) caused a statistically significant 22-percent increase in cardiac output (CO), 368-percent increase in urine production, and 200-percent increase in sodium excretion relative to dry control (DC) sessions. When TBV was reduced before immersion, CO was the same as during DC sessions; however there were significant increases above DC in urine flow (+73 percent) and sodium excretion (+120 percent), although they were significantly reduced from WC values. Potassium excretion was similar during DC and WC sessions, but was significantly increased (+75 percent) when subjects were immersed after 15-percent reduction of TBV.

Sodium in the Finnish diet: 20-year trends in urinary sodium excretion among the adult population.

PubMed

Laatikainen, T; Pietinen, P; Valsta, L; Sundvall, J; Reinivuo, H; Tuomilehto, J

2006-08-01

High sodium intake increases the risk of cardiovascular diseases and may also be associated with higher rates of stomach cancer, asthma disorders and infections. In Finland, cross-sectional population surveys to monitor cardiovascular risk factors have been carried out since the 1970s. The main aim of this paper is to present trends in urinary sodium and potassium excretion from 1979 to 2002. Cross-sectional population surveys on cardiovascular risk factors. Surveys were carried out in Finland in 1979, 1982, 1987 and 2002 in four geographical areas: North Karelia, the Kuopio area, Southwestern Finland and the Helsinki area. For each survey a random sample stratified by age and sex was drawn from the population register. In this analysis, participants of urine collection subsamples aged 25-64 years (n = 4648) were included. A 24-h urinary collection was carried out in subsamples (n = 2218-2487) in connection with population risk factor surveys. Urinary sodium and potassium concentrations were analyzed in the same laboratory throughout, using a flame photometer in 1979, 1982 and 1987 and an ion-selective electrode in 2002. Between 1979 and 2002 urinary sodium excretion in Finland decreased from over 220 to less than 170 mmol/day among men and from nearly 180 to less than 130 mmol/day among women. Although potassium excretion decreased somewhat as well, the decrease in sodium-potassium molar ratio was also significant. The 24-h urinary sodium excretion in Finland has decreased significantly during the last 20 years. However, excretion levels are still considerably higher than recommendations. A further decrease in sodium intake remains a goal for the Finnish food industry and consumers. All surveys were funded by the National Public Health Institute in Finland.

Seasonal variations in urinary risk factors among patients with nephrolithiasis

NASA Technical Reports Server (NTRS)

Hill, K.; Poindexter, J.; Pak, C. Y.

1991-01-01

Twenty-four hour urine specimens from 5,677 stone-forming patients throughout the United States were analyzed for seasonal variations in urinary risk factors for nephrolithiasis. Determinations were performed for urine volume, pH, calcium, oxalate, phosphorus, sodium, magnesium, citrate, sulfate, uric acid, and the relative supersaturation (RS) of calcium oxalate, brushite, monosodium urate, and uric acid. Criteria for significant seasonal variation included a significant difference in monthly means of risk factors, seasonal grouping of the data by the Student-Newman-Keuls multiple range test, consistent year-to-year trends and a physiologically significant range. Minimum urine volume of 1.54 +/- 0.70 SD L/day occurred in October while a maximum urine volume of 1.76 +/- 0.78 SD L/day was observed during February. Minimum urine pH of 5.94 +/- 0.64 SD was observed during July and August while a maximum pH of 6.18 +/- 0.61 SD was observed during February. Daily urinary excretion of sodium was lowest during August, 158 +/- 74 SD mEq/day and highest during February 177 +/- 70 SD mEq/day. The RS of brushite and uric acid were found to display significant pH-dependent seasonal variation with a maximum RS of uric acid 2.26 +/- 1.98 SD in June and a low of 1.48 +/- 1.30 SD in February. Maximum RS of brushite 2.75 +/- 2.58 was observed during February. Minimum RS of brushite 1.93 +/- 1.70 SD was observed in June. Phosphorus excretion displayed seasonal variation about a spring-fall axis with a maximum value 1042 +/- 373 SD mg/day in April and a minimum value of 895 +/- 289 SD mg/day. Urine volume, sodium, and pH were significantly lower during the summer (June, July, August) than in the winter (December, January, February). The RS of uric acid was higher, but that of brushite and monosodium urate was lower in the summer than in the winter. The seasonal changes observed in urine volume, pH, sodium, and the RS of brushite and uric acid are consistent with summertime sweating and increased physical activity. Seasonal variations in phosphorus excretion are probably dietary in origin. The summertime was characterized by an increased propensity for the crystallization of uric acid but not of calcium oxalate or calcium phosphate.

Association Between Urinary Sodium and Potassium Excretion and Blood Pressure Among Adults in the United States: National Health and Nutrition Examination Survey, 2014.

PubMed

Jackson, Sandra L; Cogswell, Mary E; Zhao, Lixia; Terry, Ana L; Wang, Chia-Yih; Wright, Jacqueline; Coleman King, Sallyann M; Bowman, Barbara; Chen, Te-Ching; Merritt, Robert; Loria, Catherine M

2018-01-16

Higher levels of sodium and lower levels of potassium intake are associated with higher blood pressure. However, the shape and magnitude of these associations can vary by study participant characteristics or intake assessment method. Twenty-four-hour urinary excretion of sodium and potassium are unaffected by recall errors and represent all sources of intake, and were collected for the first time in a nationally representative US survey. Our objective was to assess the associations of blood pressure and hypertension with 24-hour urinary excretion of sodium and potassium among US adults. Cross-sectional data were obtained from 766 participants age 20 to 69 years with complete blood pressure and 24-hour urine collections in the 2014 National Health and Nutrition Examination Survey, a nationally representative survey of the US noninstitutionalized population. Usual 24-hour urinary electrolyte excretion (sodium, potassium, and their ratio) was estimated from ≤2 collections on nonconsecutive days, adjusting for day-to-day variability in excretion. Outcomes included systolic and diastolic blood pressure from the average of 3 measures and hypertension status, based on average blood pressure ≥140/90 and antihypertensive medication use. After multivariable adjustment, each 1000-mg difference in usual 24-hour sodium excretion was directly associated with systolic (4.58 mm Hg; 95% confidence interval [CI], 2.64-6.51) and diastolic (2.25 mm Hg; 95% CI, 0.83-3.67) blood pressures. Each 1000-mg difference in potassium excretion was inversely associated with systolic blood pressure (-3.72 mm Hg; 95% CI, -6.01 to -1.42). Each 0.5 U difference in sodium-to-potassium ratio was directly associated with systolic blood pressure (1.72 mm Hg; 95% CI, 0.76-2.68). Hypertension was linearly associated with progressively higher sodium and lower potassium excretion; in comparison with the lowest quartile of excretion, the adjusted odds of hypertension for the highest quartile was 4.22 (95% CI, 1.36-13.15) for sodium, and 0.38 (95% CI, 0.17-0.87) for potassium ( P <0.01 for trends). These cross-sectional results show a strong dose-response association between urinary sodium excretion and blood pressure, and an inverse association between urinary potassium excretion and blood pressure, in a nationally representative sample of US adults. © 2017 American Heart Association, Inc.

Optimum nutrition for kidney stone disease.

PubMed

Heilberg, Ita P; Goldfarb, David S

2013-03-01

We summarize the data regarding the associations of individual dietary components with kidney stones and the effects on 24-hour urinary profiles. The therapeutic recommendations for stone prevention that result from these studies are applied where possible to stones of specific composition. Idiopathic calcium oxalate stone-formers are advised to reduce ingestion of animal protein, oxalate, and sodium while maintaining intake of 800 to 1200 mg of calcium and increasing consumption of citrate and potassium. There are few data regarding dietary therapy of calcium phosphate stones. Whether the inhibitory effect of citrate sufficiently counteracts increasing urine pH to justify more intake of potassium and citrate is not clear. Reduction of sodium intake to decrease urinary calcium excretion would also be expected to decrease calcium phosphate stone recurrence. Conversely, the most important urine variable in the causation of uric acid stones is low urine pH, linked to insulin resistance as a component of obesity and the metabolic syndrome. The mainstay of therapy is weight loss and urinary alkalinization provided by a more vegetarian diet. Reduction in animal protein intake will reduce purine ingestion and uric acid excretion. For cystine stones, restriction of animal protein is associated with reduction in intake of the cystine precursor methionine as well as cystine. Reduction of urine sodium results in less urine cystine. Ingestion of vegetables high in organic anion content, such as citrate and malate, should be associated with higher urine pH and fewer stones because the amino acid cystine is soluble in more alkaline urine. Because of their infectious origin, diet has no definitive role for struvite stones except for avoiding urinary alkalinization, which may worsen their development. Published by Elsevier Inc.

Development of a Physiologically Based Computational Kidney Model to Describe the Renal Excretion of Hydrophilic Agents in Rats

PubMed Central

Niederalt, Christoph; Wendl, Thomas; Kuepfer, Lars; Claassen, Karina; Loosen, Roland; Willmann, Stefan; Lippert, Joerg; Schultze-Mosgau, Marcus; Winkler, Julia; Burghaus, Rolf; Bräutigam, Matthias; Pietsch, Hubertus; Lengsfeld, Philipp

2013-01-01

A physiologically based kidney model was developed to analyze the renal excretion and kidney exposure of hydrophilic agents, in particular contrast media, in rats. In order to study the influence of osmolality and viscosity changes, the model mechanistically represents urine concentration by water reabsorption in different segments of kidney tubules and viscosity dependent tubular fluid flow. The model was established using experimental data on the physiological steady state without administration of any contrast media or drugs. These data included the sodium and urea concentration gradient along the cortico-medullary axis, water reabsorption, urine flow, and sodium as well as urea urine concentrations for a normal hydration state. The model was evaluated by predicting the effects of mannitol and contrast media administration and comparing to experimental data on cortico-medullary concentration gradients, urine flow, urine viscosity, hydrostatic tubular pressures and single nephron glomerular filtration rate. Finally the model was used to analyze and compare typical examples of ionic and non-ionic monomeric as well as non-ionic dimeric contrast media with respect to their osmolality and viscosity. With the computational kidney model, urine flow depended mainly on osmolality, while osmolality and viscosity were important determinants for tubular hydrostatic pressure and kidney exposure. The low diuretic effect of dimeric contrast media in combination with their high intrinsic viscosity resulted in a high viscosity within the tubular fluid. In comparison to monomeric contrast media, this led to a higher increase in tubular pressure, to a reduction in glomerular filtration rate and tubular flow and to an increase in kidney exposure. The presented kidney model can be implemented into whole body physiologically based pharmacokinetic models and extended in order to simulate the renal excretion of lipophilic drugs which may also undergo active secretion and reabsorption. PMID:23355822

Measurement error corrected sodium and potassium intake estimation using 24-hour urinary excretion.

PubMed

Huang, Ying; Van Horn, Linda; Tinker, Lesley F; Neuhouser, Marian L; Carbone, Laura; Mossavar-Rahmani, Yasmin; Thomas, Fridtjof; Prentice, Ross L

2014-02-01

Epidemiological studies of the association of sodium and potassium intake with cardiovascular disease risk have almost exclusively relied on self-reported dietary data. Here, 24-hour urinary excretion assessments are used to correct the dietary self-report data for measurement error under the assumption that 24-hour urine recovery provides a biomarker that differs from usual intake according to a classical measurement model. Under this assumption, dietary self-reports underestimate sodium by 0% to 15%, overestimate potassium by 8% to 15%, and underestimate sodium/potassium ratio by ≈20% using food frequency questionnaires, 4-day food records, or three 24-hour dietary recalls in Women's Health Initiative studies. Calibration equations are developed by linear regression of log-transformed 24-hour urine assessments on corresponding log-transformed self-report assessments and several study subject characteristics. For each self-report method, the calibration equations turned out to depend on race and age and strongly on body mass index. After adjustment for temporal variation, calibration equations using food records or recalls explained 45% to 50% of the variation in (log-transformed) 24-hour urine assessments for sodium, 60% to 70% of the variation for potassium, and 55% to 60% of the variation for sodium/potassium ratio. These equations may be suitable for use in epidemiological disease association studies among postmenopausal women. The corresponding signals from food frequency questionnaire data were weak, but calibration equations for the ratios of sodium and potassium/total energy explained ≈35%, 50%, and 45% of log-biomarker variation for sodium, potassium, and their ratio, respectively, after the adjustment for temporal biomarker variation and may be suitable for cautious use in epidemiological studies. Clinical Trial Registration- URL: www.clinicaltrials.gov. Unique identifier: NCT00000611.

The potential role of salt abuse on the risk for kidney stone formation

NASA Technical Reports Server (NTRS)

Sakhaee, K.; Harvey, J. A.; Padalino, P. K.; Whitson, P.; Pak, C. Y.

1993-01-01

The kidney stone-forming risk of a high sodium diet was evaluated by assessing the effect of such a diet on the crystallization of stone-forming salts in urine. Fourteen normal subjects participated in 2 phases of study of 10 days duration each, comprising a low sodium phase (basal metabolic diet containing 50 mmol. sodium per day) and a high sodium phase (basal diet plus 250 mmol. sodium chloride per day). The high sodium intake significantly increased urinary sodium (34 +/- 12 to 267 +/- 56 mmol. per day), calcium (2.73 +/- 1.03 to 3.93 +/- 1.51 mmol. per day) and pH (5.79 +/- 0.44 to 6.15 +/- 0.25), and significantly decreased urinary citrate (3.14 +/- 1.19 to 2.52 +/- 0.83 mmol. per day). Arterialized venous blood bicarbonate and total serum carbon dioxide concentrations decreased significantly during the high sodium diet, whereas serum chloride concentration increased. However, no change in arterialized venous pH was detected. Thus, a high sodium intake not only increased calcium excretion, but also increased urinary pH and decreased citrate excretion. The latter effects are probably due to sodium-induced bicarbonaturia and a significant decrease in serum bicarbonate concentration, respectively. Commensurate with these changes, the urinary saturation of calcium phosphate (brushite) and monosodium urate increased, and the inhibitor activity against calcium oxalate crystallization (formation product) decreased. The net effect of a high sodium diet was an increased propensity for the crystallization of calcium salts in urine.

An increase in renal dopamine does not stimulate natriuresis after fava bean ingestion123

PubMed Central

Garland, Emily M; Cesar, Tericka S; Lonce, Suzanna; Ferguson, Marcus C; Robertson, David

2013-01-01

Background: Fava beans (Vicia faba) contain dihydroxyphenylalanine (dopa), and their ingestion may increase dopamine stores. Renal dopamine regulates blood pressure and blood volume via a natriuretic effect. Objective: The objective was to determine the relation between dietary fava beans, plasma and urinary catechols, and urinary sodium excretion in 13 healthy volunteers. Design: Catechol and sodium data were compared by using a longitudinal design in which all participants consumed a fixed-sodium study diet on day 1 and the fixed-sodium diet plus fava beans on day 2. Blood was sampled at 1, 2, 4, and 6 h after a meal, and 3 consecutive 4-h urine samples were collected. Results: Mean (±SD) plasma dopa was significantly greater 1 h after fava bean consumption (11,670 ± 5440 compared with 1705 ± 530 pg/mL; P = 0.001) and remained elevated at 6 h. Plasma dopamine increased nearly 15-fold during this period. Fava bean consumption also increased urinary dopamine excretion to 306 ± 116, 360 ± 235, and 159 ± 111 μg/4-h urine sample compared with 45 ± 21, 54 ± 29, and 44 ± 17 μg in the 3 consecutive 4-h samples after the control diet (P ≤ 0.005). These substantial increases in plasma and urinary dopa and dopamine were unexpectedly associated with decreased urinary sodium. Conclusion: The failure of fava bean consumption to provoke natriuresis may indicate that dopa concentrations in commercially available beans do not raise renal dopamine sufficiently to stimulate sodium excretion, at least when beans are added to a moderate-sodium diet in healthy volunteers. This trial was registered at clinicaltrials.gov as NCT01064739. PMID:23553159

Effects of Different Oral Doses of Sodium Chloride on the Basal Acid-Base and Mineral Status of Exercising Horses Fed Low Amounts of Hay.

PubMed

Zeyner, Annette; Romanowski, Kristin; Vernunft, Andreas; Harris, Patricia; Müller, Ann-Marie; Wolf, Carola; Kienzle, Ellen

2017-01-01

The provision of NaCl, according to current recommendations, to horses in moderate work has been shown to induce immediate postprandial acidosis. The present study aimed to clarify whether this NaCl induced acidosis i) persists beyond the immediate postprandial period, and ii) is still present after a 2 week adaptation period. Six adult warmblood mares in moderate work received daily 1.00 kg hay per 100 kg body weight (bwt) only together with 0.64 kg unprocessed cereal grains/100 kg bwt.d as fed basis. Using a 3x3 Latin Square, either 0 (NaCl-0), 50 (NaCl-50) or 100 (NaCl-100) g NaCl/d were fed together with the concentrates in two equal doses for 3 weeks. During the final week, a mineral digestibility trial was undertaken. The middle sodium and chloride intake (NaCl-50) at least met the most common recommendations for moderate work. Morning (7:00 AM) urine and venous blood samples were collected on days 0, 1-4, 8, and 15, and analysed for pH, acid-base status, creatinine and electrolyte concentrations. Fractional electrolyte clearances (FC) were determined. Mean apparent sodium digestibility ranged between 60-62% whereas chloride digestibility was consistently above 94%. Supplementing 100 g but not 50 g of NaCl resulted in significant reduction of blood pH and base excess as well as urinary pH and urine acid excretion. Both 50 g and 100 g NaCl supplementation caused a significant reduction in base and net acid-base excretion, urine density and potassium concentration, but increased urine sodium concentration and the FC of sodium and chloride (P < 0.05). This suggests that a high proportion of the recommended salt doses is excreted renally. The above effects of NaCl supplementation persisted over the 2 week measurement period. Results suggest that feeding 100 g NaCl to moderately exercising horses results in mild metabolic acidosis, whereas feeding 50 g according to current recommendations resulted in compensated acidosis.

Effects of Different Oral Doses of Sodium Chloride on the Basal Acid-Base and Mineral Status of Exercising Horses Fed Low Amounts of Hay

PubMed Central

Zeyner, Annette; Romanowski, Kristin; Vernunft, Andreas; Harris, Patricia; Müller, Ann-Marie; Wolf, Carola; Kienzle, Ellen

2017-01-01

The provision of NaCl, according to current recommendations, to horses in moderate work has been shown to induce immediate postprandial acidosis. The present study aimed to clarify whether this NaCl induced acidosis i) persists beyond the immediate postprandial period, and ii) is still present after a 2 week adaptation period. Six adult warmblood mares in moderate work received daily 1.00 kg hay per 100 kg body weight (bwt) only together with 0.64 kg unprocessed cereal grains/100 kg bwt.d as fed basis. Using a 3x3 Latin Square, either 0 (NaCl-0), 50 (NaCl-50) or 100 (NaCl-100) g NaCl/d were fed together with the concentrates in two equal doses for 3 weeks. During the final week, a mineral digestibility trial was undertaken. The middle sodium and chloride intake (NaCl-50) at least met the most common recommendations for moderate work. Morning (7:00 AM) urine and venous blood samples were collected on days 0, 1–4, 8, and 15, and analysed for pH, acid-base status, creatinine and electrolyte concentrations. Fractional electrolyte clearances (FC) were determined. Mean apparent sodium digestibility ranged between 60–62% whereas chloride digestibility was consistently above 94%. Supplementing 100 g but not 50 g of NaCl resulted in significant reduction of blood pH and base excess as well as urinary pH and urine acid excretion. Both 50 g and 100 g NaCl supplementation caused a significant reduction in base and net acid-base excretion, urine density and potassium concentration, but increased urine sodium concentration and the FC of sodium and chloride (P < 0.05). This suggests that a high proportion of the recommended salt doses is excreted renally. The above effects of NaCl supplementation persisted over the 2 week measurement period. Results suggest that feeding 100 g NaCl to moderately exercising horses results in mild metabolic acidosis, whereas feeding 50 g according to current recommendations resulted in compensated acidosis. PMID:28045916

Comparison of enteral and parenteral methods of urine alkalinization in patients receiving high-dose methotrexate.

PubMed

Rouch, Jamie A; Burton, Bradley; Dabb, Alix; Brown, Vicky; Seung, Amy H; Kinsman, Katharine; Holdhoff, Matthias

2017-01-01

Purpose Hyperhydration and urinary alkalinization is implemented with all high-dose (HD)-methotrexate infusions to promote excretion and prevent precipitation of methotrexate in the renal tubules. Our institution utilized enteral alkalinizing agents (sodium bicarbonate tablets and sodium citrate/citric acid solution) to alkalinize the urine of patients receiving HD-methotrexate during a parenteral sodium bicarbonate and sodium acetate shortage. The purpose of this study is to establish the safety and efficacy of the enteral route for urine alkalinization. Methods A single-center, retrospective, cohort study was conducted comparing cycles of HD-methotrexate using enteral alkalinizing agents to parenteral sodium bicarbonate. The primary objective was to compare the time, in hours, from administration of first inpatient administered dose of alkalinizing agent to time of achieving goal urine pH. Secondary objectives evaluated total dose of sodium bicarbonate required to achieve goal urine pH, time from start of urine alkalinizing agent until time of achieving methotrexate level safe for discharge, and toxicities associated with methotrexate and the alkalinizing agents. Results A total of 118 patients were included in this study, equally divided into two cohorts based on parenteral versus enteral routes of administration. No statistical difference was determined between the two cohorts regarding time to goal urine pH (6.5 h versus 7.9 h, P = 0.051) or regarding time to methotrexate level deemed safe for discharge (63.5 h versus 62.5 h, p = 0.835). There were no significant differences in methotrexate-induced toxicities. Conclusion Our study found enteral routes of urine alkalinization to be a viable alternative to the traditional parenteral sodium bicarbonate, especially during parenteral sodium bicarbonate and acetate shortages.

Relationship of nutrition knowledge and self-reported dietary behaviors with urinary excretion of sodium and potassium: comparison between dietitians and nondietitians.

PubMed

Sugimoto, Minami; Asakura, Keiko; Masayasu, Shizuko; Sasaki, Satoshi

2016-05-01

The effectiveness of better nutrition knowledge and dietary behavior on healthier dietary intake is still controversial. We hypothesized that nutritional knowledge and dietary behavior are associated with sodium and potassium intake in adult women. A cross-sectional study was conducted at welfare facilities located in 20 areas of Japan. Ninety-nine female dietitians and 117 nondietitians aged 20 to 69 years participated. Sodium and potassium intake were assessed with two 24-hour urine collections and 4-day semiweighed diet records. Nutritional knowledge and dietary behavior were accessed with 3 questionnaires. Analysis of covariance was performed to compare sodium and potassium excretion and selected nutrition and food intake between dietitians and nondietitians. After adjustment for age and smoking habit, sodium and potassium excretion did not significantly differ between the 2 groups (3857 vs 3959 mg/d, P = .57, and 2016 vs 1886 mg/d, P = .10, respectively). Sodium/potassium ratio was significantly lower in the dietitians (P = .044). The dietitians used food labels for sodium contents more often than the nondietitians and consumed more fruits and vegetables (P = .048 and P < .0001, respectively) and less sugar and confectionaries and fat and oils (P = .016 and P = .010, respectively). In conclusion, the higher level of nutritional knowledge and better dietary behavior were not associated with either sodium or potassium excretion but were moderately associated with sodium/potassium ratio. Copyright © 2016 Elsevier Inc. All rights reserved.

The role of angiotensin II in the renal responses to somatic nerve stimulation in the rat.

PubMed Central

Handa, R K; Johns, E J

1987-01-01

1. Electrical stimulation of the brachial nerves at 3 Hz (15 V, 0.2 ms), in sodium pentobarbitone-anaesthetized rats whose renal arterial pressure was held constant, elicited a 26% increase in systemic blood pressure, a 15% rise in heart rate, an 11% reduction in renal blood flow, did not alter glomerular filtration rate and significantly reduced absolute and fractional sodium excretions and urine flow by 44, 49 and 31%, respectively. 2. In a separate group of rats, brachial nerve stimulation at 3 Hz increased plasma renin activity approximately 2-fold, while in animals in which the brachial nerves were not stimulated plasma renin activity did not change. 3. Following inhibition of the renin-angiotensin system with captopril or sar-1-ile-8-angiotensin II, brachial nerve stimulation resulted in similar increases in systemic blood pressure and heart rate as in the animals with an intact renin-angiotensin system but, in captopril-infused rats, did not change renal haemodynamics or urine flow while absolute and fractional sodium excretions were reduced by 20 and 25%, respectively. In sar-1-ile-8-angiotensin II-infused animals, similar nerve stimulation decreased renal blood flow by 12%, glomerular filtration rate by 7% and absolute and fractional sodium excretions and urine flow by 25, 18 and 18%, respectively. These decreases in sodium and water output were significantly smaller than those observed in animals with an intact renin-angiotensin system. 4. Stimulation of the brachial nerves increased post-ganglionic efferent renal nerve activity by 20% and the magnitude of this response was unaffected following inhibition of the renin-angiotensin system. 5. The results show that low rates of brachial nerve stimulation in the rat can increase efferent renal nerve activity and result in an antinatriuresis and antidiuresis which is dependent on the presence of angiotensin II, and appears to be due to an action of angiotensin II at the level of the kidney. PMID:3328780

Renin-Angiotensin System Genes and Exercise Training-Induced Changes in Sodium Excretion in African American Hypertensives

PubMed Central

Jones, Jennifer M.; Park, Jung-Jun; Johnson, Jennifer; Vizcaino, Dave; Hand, Brian; Ferrell, Robert; Weir, Matthew; Dowling, Thomas; Obisesan, Thomas; Brown, Michael

2008-01-01

Objective To determine whether angiotensin-converting enzyme (ACE) and angiotensinogen (AGT) genotypes could predict changes in urinary sodium excretion in response to short-term aerobic exercise training (AEX). Design Longitudinal intervention. Setting The study was conducted at the University of Maryland at College Park and at Baltimore, and the University of Pittsburgh General Clinical Research Center. Participants 31 (age 53 ± 2 years) sedentary, hypertensive (146 ± 2/88 ± 2 mm Hg) African Americans. Intervention Aerobic exercise training (AEX) consisted of seven or eight consecutive days, 50 minutes per day, at 65% of heart rate reserve. Participants underwent a 24-hour period of ambulatory blood pressure (BP) monitoring and urine collection at baseline and 14–18 hours after the last exercise session. Main Outcome Measures Angiotensiongen (AGT) M235T and ACE I/D genotype and sodium excretion and ambulatory BP. Results Average sodium excretion for the entire group independent of genotype increased after AEX (108 ± 9 vs 143 ± 12 mEq/day, P=.003). Sodium excretion significantly increased after exercise training in the ACE II (114 ± 22 vs 169 ± 39 mEq/day, P=.04), but not in the ID (100 ± 8 vs 133 ± 17 mEq/day, P=.12) or DD (113 ± 18 vs 138 ± 11 mEq/day, P=.13) genotype groups. In the II genotype group, the increase in sodium excretion was significantly and inversely correlated with decreases in 24-hour diastolic (r=−.88, P=.02) and mean (r=−.95, P=.004) BP. The AGT TT and MT+MM genotype groups similarly increased their sodium excretion by 34 ± 16 (P=.05) and 37 ± 17 (P=.05) mEq/day respectively. Conclusions These results suggest that African American hypertensives with the ACE II genotype may be more susceptible to sodium balance and BP changes with exercise training compared with those with the ID and DD genotypes. PMID:16937603

Potassium urinary excretion and dietary intake: a cross-sectional analysis in 8-10 year-old children.

PubMed

Oliveira, Ana Catarina; Padrão, Patrícia; Moreira, André; Pinto, Mariana; Neto, Mafalda; Santos, Tânia; Madureira, Joana; Fernandes, Eduardo de Oliveira; Graça, Pedro; Breda, João; Moreira, Pedro

2015-05-17

Data from studies assessing the intake of potassium, and the concomitant sodium-to-potassium ratio are limited. The aim of this study was to evaluate potassium and sodium-to-potassium ratio intake in 8-10 year-old children. A cross-sectional survey was carried out from January to June 2014 and data from 163 children (81 boys) were included. Potassium intake was estimated by 24-h urine collection and coefficient of creatinine was used to validate completeness of urine collections. Urinary sodium and sodium-to-potassium ratio were also analysed. A 24-h dietary recall was used to provide information on dietary sources of potassium. Height and weight were measured according to international standards. The mean urinary potassium excretion was 1701 ± 594 mg/day in boys, and 1682 ± 541 mg/day in girls (p = 0.835); 8.0% of children met the WHO recommendations for potassium intake. The mean sodium excretion was 2935 ± 1075 mg/day in boys and 2381 ± 1045 mg/day in girls (p <0.001) and urinary sodium-to-potassium ratio was 3.2 ± 1.4 in boys, and 2.5 ± 1.1 in girls (p = 0.002). The mean fruit and vegetable intake was 353.1 ± 232.5 g/day in boys, and 290.8 ± 213.1 g/day in girls (p = 0.101). This study reported a low compliance of potassium intake recommendations in 8-10 year-old children. Health promotion interventions are needed in order to broaden public awareness of potassium inadequacy and to increase potassium intake.

The effect of a diet containing 70% protein from plants on mineral metabolism and musculoskeletal health in chronic kidney disease.

PubMed

Moorthi, Ranjani N; Armstrong, Cheryl L H; Janda, Kevin; Ponsler-Sipes, Kristen; Asplin, John R; Moe, Sharon M

2014-01-01

Chronic Kidney Disease (CKD) is associated with alterations in phosphorus excretion, and increases in fibroblast growth factor (FGF23) and parathyroid hormone (PTH). Plant protein-based phytate-bound phosphorus, is less bioavailable than that from animal sources. Our one-week study that was conducted previously showed that a nearly 100% plant protein-based diet benefits mineral metabolism in CKD; however, this diet may not be acceptable to patients. Here we hypothesize that a diet containing 70% protein from plants has similar efficacy and is tolerated by CKD patients. Thirteen subjects with CKD 3-4 received an omnivorous diet containing 70% protein from plants for 4 weeks. The primary outcome was change in 24 h urine phosphorus. Secondary outcomes were changes in serum phosphorus, FGF23, PTH, urine sodium excretion, grip strength and fat free mass. Repeated measures analysis of variance (ANOVA) was used to test differences in parameters over the 4 weeks. Mean age of subjects was 54.8 years. Median eGFR was 26 (IQR 14.7) ml/min/1.73 m(2). Over the 4-week period, urine phosphorus significantly decreased by 215 ± 232 mg/day (p < 0.001). No significant changes in serum FGF23, phosphorus or PTH were noted. Urine sodium and titratable acid decreased significantly on the diet. Hand grip strength and fat-free mass did not change. There were two hyperkalemia events both 5.8 mEq/l, corrected by food substitutions. No other adverse events were observed. A 70% plant protein diet is safe, tolerated, and efficacious in lowering urine phosphorus excretion and may be an alternative to phosphate binders. © 2015 S. Karger AG, Basel.

The Effect of a Diet containing 70% Protein from Plants on Mineral Metabolism and Musculoskeletal Health in Chronic Kidney Disease

PubMed Central

Moorthi, Ranjani N; Armstrong, Cheryl L. H.; Janda, Kevin; Ponsler-Sipes, Kristen; Asplin, John R.; Moe, Sharon M

2015-01-01

Background Chronic Kidney Disease (CKD) is associated with alterations in phosphorus excretion, and increases in fibroblast growth factor (FGF23) and parathyroid hormone (PTH). Plant protein based phytate bound phosphorus, is less bioavailable than that from animal sources. Our prior one week study showed that a nearly 100% plant protein based diet benefits mineral metabolism in CKD; however this diet may not be acceptable to patients. Here we hypothesize that a diet containing 70% protein from plants has similar efficacy and is tolerated by CKD patients. Methods Thirteen subjects with CKD 3-4 received an omnivore diet containing 70% protein from plants for 4 weeks. The primary outcome was change in 24 hour urine phosphorus. Secondary outcomes were changes in serum phosphorus, FGF23, PTH, urine sodium excretion, grip strength and fat free mass. Repeated measures analysis of variance (ANOVA) was used to test differences in parameters over the 4 weeks. Results Mean age of subjects was 54.8 years. Median eGFR was 26 (IQR 14.7) ml/min/1.73m2. Over the 4 week period, urine phosphorus significantly decreased by 215±232 mg/day (p<0.001). No significant changes in serum FGF23, phosphorus or PTH were noted. Urine sodium and titratable acid decreased significantly on the diet. Hand grip strength and fat-free mass did not change. There were two hyperkalemia events both 5.8 meq/l, corrected by food substitutions. No other adverse events were observed. Conclusions A 70% plant protein diet is safe, tolerated, and efficacious in lowering urine phosphorus excretion and may be an alternative to phosphate binders. PMID:25613675

Reproducibility of urinary biomarkers in multiple 24-h urine samples.

PubMed

Sun, Qi; Bertrand, Kimberly A; Franke, Adrian A; Rosner, Bernard; Curhan, Gary C; Willett, Walter C

2017-01-01

Limited knowledge regarding the reproducibility of biomarkers in 24-h urine samples has hindered the collection and use of the samples in epidemiologic studies. We aimed to evaluate the reproducibility of various markers in repeat 24-h urine samples. We calculated intraclass correlation coefficients (ICCs) of biomarkers measured in 24-h urine samples that were collected in 3168 participants in the NHS (Nurses' Health Study), NHSII (Nurses' Health Study II), and Health Professionals Follow-Up Study. In 742 women with 4 samples each collected over the course of 1 y, ICCs for sodium were 0.32 in the NHS and 0.34 in the NHSII. In 2439 men and women with 2 samples each collected over 1 wk to ≥1 mo, the ICCs ranged from 0.33 to 0.68 for sodium at various intervals between collections. The urinary excretion of potassium, calcium, magnesium, phosphate, sulfate, and other urinary markers showed generally higher reproducibility (ICCs >0.4). In 47 women with two 24-h urine samples, ICCs ranged from 0.15 (catechin) to 0.75 (enterolactone) for polyphenol metabolites. For phthalates, ICCs were generally ≤0.26 except for monobenzyl phthalate (ICC: 0.55), whereas the ICC was 0.39 for bisphenol A (BPA). We further estimated that, for the large majority of the biomarkers, the mean of three 24-h urine samples could provide a correlation of ≥0.8 with true long-term urinary excretion. These data suggest that the urinary excretion of various biomarkers, such as minerals, electrolytes, most polyphenols, and BPA, is reasonably reproducible in 24-h urine samples that are collected within a few days or ≤1 y. Our findings show that three 24-h samples are sufficient for the measurement of long-term exposure status in epidemiologic studies. © 2017 American Society for Nutrition.

Reproducibility of urinary biomarkers in multiple 24-h urine samples123

PubMed Central

Sun, Qi; Bertrand, Kimberly A; Franke, Adrian A; Rosner, Bernard; Curhan, Gary C; Willett, Walter C

2017-01-01

Background: Limited knowledge regarding the reproducibility of biomarkers in 24-h urine samples has hindered the collection and use of the samples in epidemiologic studies. Objective: We aimed to evaluate the reproducibility of various markers in repeat 24-h urine samples. Design: We calculated intraclass correlation coefficients (ICCs) of biomarkers measured in 24-h urine samples that were collected in 3168 participants in the NHS (Nurses’ Health Study), NHSII (Nurses’ Health Study II), and Health Professionals Follow-Up Study. Results: In 742 women with 4 samples each collected over the course of 1 y, ICCs for sodium were 0.32 in the NHS and 0.34 in the NHSII. In 2439 men and women with 2 samples each collected over 1 wk to ≥1 mo, the ICCs ranged from 0.33 to 0.68 for sodium at various intervals between collections. The urinary excretion of potassium, calcium, magnesium, phosphate, sulfate, and other urinary markers showed generally higher reproducibility (ICCs >0.4). In 47 women with two 24-h urine samples, ICCs ranged from 0.15 (catechin) to 0.75 (enterolactone) for polyphenol metabolites. For phthalates, ICCs were generally ≤0.26 except for monobenzyl phthalate (ICC: 0.55), whereas the ICC was 0.39 for bisphenol A (BPA). We further estimated that, for the large majority of the biomarkers, the mean of three 24-h urine samples could provide a correlation of ≥0.8 with true long-term urinary excretion. Conclusions: These data suggest that the urinary excretion of various biomarkers, such as minerals, electrolytes, most polyphenols, and BPA, is reasonably reproducible in 24-h urine samples that are collected within a few days or ≤1 y. Our findings show that three 24-h samples are sufficient for the measurement of long-term exposure status in epidemiologic studies. PMID:28049663

Concordance of dietary sodium intake and concomitant phosphate load: Implications for sodium interventions.

PubMed

Humalda, J K; Keyzer, C A; Binnenmars, S H; Kwakernaak, A J; Slagman, M C J; Laverman, G D; Bakker, S J L; de Borst, M H; Navis, G J

2016-08-01

Both a high dietary sodium and high phosphate load are associated with an increased cardiovascular risk in patients with chronic kidney disease (CKD), and possibly also in non-CKD populations. Sodium and phosphate are abundantly present in processed food. We hypothesized that (modulation of) dietary sodium is accompanied by changes in phosphate load across populations with normal and impaired renal function. We first investigated the association between sodium and phosphate load in 24-h urine samples from healthy controls (n = 252), patients with type 2 diabetes mellitus (DM, n = 255) and renal transplant recipients (RTR, n = 705). Secondly, we assessed the effect of sodium restriction on phosphate excretion in a nondiabetic CKD cohort (ND-CKD: n = 43) and a diabetic CKD cohort (D-CKD: n = 39). Sodium excretion correlated with phosphate excretion in healthy controls (R = 0.386, P < 0.001), DM (R = 0.490, P < 0.001), and RTR (R = 0.519, P < 0.001). This correlation was also present during regular sodium intake in the intervention studies (ND-CKD: R = 0.491, P < 0.001; D-CKD: R = 0.729, P < 0.001). In multivariable regression analysis, sodium excretion remained significantly correlated with phosphate excretion after adjustment for age, gender, BMI, and eGFR in all observational cohorts. In ND-CKD and D-CKD moderate sodium restriction reduced phosphate excretion (31 ± 10 to 28 ± 10 mmol/d; P = 0.04 and 26 ± 11 to 23 ± 9 mmol/d; P = 0.02 respectively). Dietary exposure to sodium and phosphate are correlated across the spectrum of renal function impairment. The concomitant reduction in phosphate intake accompanying sodium restriction underlines the off-target effects on other nutritional components, which may contribute to the beneficial cardiovascular effects of sodium restriction. (f) Registration numbers: Dutch Trial Register NTR675, NTR2366. Copyright © 2016. Published by Elsevier B.V.

Neurohumoral mechanism in the natriuretic action of intracerebroventricular administration of renin.

PubMed

Zavala, Lida; Barbella, Yarisma; Israel, Anita

2004-03-01

Intracerebroventricular (i.v.t.) administration of renin (R) decreases urinary volume and increases urinary sodium excretion. We investigated whether i.v.t.-R-induced natriuresis could be associated with the release of atrial natriuretic peptide (ANP), its interaction with renal ANP-A receptors (ANPR-A) and the subsequent increase of urinary cyclic 3-5 guanosine monophosphate (cGMP). In i.v.t. cannulated rats, the left carotid artery was catheterised with PE-50 tubing for blood collection, renin was injected i.v.t. and arterial blood samples were collected at 0, 2, 5, 10 and 15 minutes of injection, and urinary sodium and cGMP excretion at 1-, 3- and 6-hour periods of urine collection. Plasma ANP levels and urinary cGMP were determined by radioimmunoassay, and each urine sample was analysed for sodium concentration using a flame photometer. Our results demonstrate that i.v.t.-R administration increases plasma ANP levels after two minutes of injection and urinary cGMP concentration at 1-, 3- and 6 hour period of urine collection. The natriuretic action induced by i.v.t.-R was blunted by peripheral administration of anantin, an ANPR-A antagonist. We assessed the role of brain angiotensin II (Ang II) AT1-receptors on the i.v.t.-induced antidiuresis, natriuresis and cGMP urinary excretion, the last as an indirect index of ANP secretion. Blockade of brain Ang II AT1-receptors with losartan (LOS; 120 microg/3 microl, i.v.t.), inhibited the antidiuretic action and blocked the increased urinary sodium and cGMP excretion induced by i.v.t.-R (7.14 mGU/5 microl). The increase in urinary cGMP was independent of nitric oxide synthase stimulation, since L-NAME pre-treatment did not alter the renal actions induced by i.v.t.-R. Our results suggest that there is a link between the brain and the kidney. The activation of brain angiotensinergic neurons and stimulation of AT1- receptors may stimulate the release of ANP to the circulation. The released ANP circulates to the kidneys where it acts through renal ANPR-As and the consequent increase in cGMP to produce natriuresis.

Dietary Sources of High Sodium Intake in Turkey: SALTURK II.

PubMed

Erdem, Yunus; Akpolat, Tekin; Derici, Ülver; Şengül, Şule; Ertürk, Şehsuvar; Ulusoy, Şükrü; Altun, Bülent; Arıcı, Mustafa

2017-08-24

Previous research has shown daily salt intakes in Turkey to be far above the recommended limits. Knowing the sources of dietary salt could form a basis for preventive strategies aimed towards salt reduction. This study aimed to investigate dietary sources of salt in Turkey. A sub-group ( n = 657) was selected from the PatenT2 study population, which represented the urban and rural areas of 4 major cities (Ankara, Istanbul, Izmir, and Konya). A questionnaire inquiring about sociodemographic characteristics, medical histories, detailed histories of diet, and salt consumption was completed. Participants were asked to collect a 24-h urine sample and to record their food intake (dietary recall) on the same day. Of 925 participants selected, 657 (71%) provided accurate 24-h urine collections, based on creatinine excretion data. The mean daily 24-h urinary sodium excretion was 252.0 ± 92.2 mmol/day, equal to daily salt intake of 14.8 ± 5.4 g. Of the 657 participants with accurate 24-h urine collections, 464 (70%) provided fully completed dietary recalls. Among these 464 participants, there was a significant difference between the 24-h urinary sodium excretion-based salt intake estimation (14.5 ± 5.1 g/day) and the dietary recall-based salt intake estimation (12.0 ± 7.0 g/day) ( p < 0.001). On the other hand, a positive correlation was obtained between the dietary recall-based daily salt intake and 24-h urinary sodium excretion-based daily salt intake ( r = 0.277, p < 0.001). Bread was the main source of salt (34%) followed by salt added during cooking and preparing food before serving (30%), salt from various processed foods (21%), and salt added at the table during food consumption (11%). Conclusively, this study confirmed a very high salt intake of the adult population in four major cities in Turkey. The present findings support the emerging salt reduction strategy in Turkey by promoting lower salt content in baked bread, and less salt use in habitual food preparation and during food consumption in the home.

Diet and polycystic kidney disease: A pilot intervention study

PubMed Central

Taylor, Jacob M.; Hamilton-Reeves, Jill M.; Sullivan, Debra K.; Gibson, Cheryl A.; Creed, Catherine; Carlson, Susan E.; Wesson, Donald E.; Grantham, Jared J.

2016-01-01

SUMMARY Background & aims Dietary sodium, protein, acid precursors, and water have been linked to cyst growth in polycystic kidney disease; yet, no studies in patients have examined the feasibility of using a dietary intervention that controls all of these factors. The aim of this study was to determine if a diet, appropriate for persons of most ages, reduces the excretion of sodium, urea, acid, and decreases mean urine osmolality while gaining acceptance by patients with autosomal dominant polycystic kidney disease (ADPKD). Methods Twelve adults with ADPKD enrolled in a pre-post pilot feasibility study and served as their own controls. Individuals consumed their usual diet for one week then for four weeks followed an isocaloric diet lower in sodium and protein and higher in fruits, vegetables, and water. Three-day diet records and two 24-h urine samples were collected at baseline, week 2, and week 4 visits; blood pressure, weight, and serum were obtained at all three visits. A modified nutrition hassles questionnaire was completed on the last visit. Results During the dietary intervention, subjects (n = 11) consumed less sodium, protein, and dietary acid precursors 36%, 28%, and 99%, respectively, and increased fluid intake by 42%. Urinary sodium, urea, net acid excretion, osmoles, and osmolality decreased 20%, 28%, 20%, 37%, and 15%, respectively; volume increased 35%. Urine changes were in accord with the diet record. Ninety-one percent of participants reported that none of the hassles were worse than “somewhat severe”, and most participants felt “somewhat confident” or “very confident” that they could manage the new diet. Conclusions A majority of adult patients with ADPKD successfully prepared and followed a composite diet prescription with decreased sodium, protein, acid precursors, and increased fluid intake. This trail was registered at ClinicalTrials.gov (NCT01810614). PMID:26811129

Intrarenal Mas and AT1 receptors play a role in mediating the excretory actions of renal interstitial angiotensin-(1-7) infusion in anaesthetized rats.

PubMed

O'Neill, Julie; Healy, Vincent; Johns, Edward J

2017-12-01

What is the central question of this study? Dietary sodium manipulation alters the magnitude of angiotensin-(1-7) [Ang-(1-7)]-induced natriuresis. The present study sought to determine whether this was related to relative changes in the activity of intrarenal Mas and/or AT 1 receptors. What is the main finding and its importance? Angiotensin-(1-7)-induced diuresis and natriuresis is mediated by intrarenal Mas receptors. However, intrarenal AT 1 receptor blockade also had an inhibitory effect on Ang-(1-7)-induced natriuresis and diuresis. Thus, Ang-(1-7)-induced increases in sodium and water excretion are dependent upon functional Mas and AT 1 receptors. We investigated whether angiotensin-(1-7) [Ang-(1-7)]-induced renal haemodynamic and excretory actions were solely dependent upon intrarenal Mas receptor activation or required functional angiotensin II type 1 (AT 1 ) receptors. The renin-angiotensin system was enhanced in anaesthetized rats by prior manipulation of dietary sodium intake. Angiotensin-(1-7) and AT 1 and Mas receptor antagonists were infused into the kidney at the corticomedullary border. Mas receptor expression was measured in the kidney. Mean arterial pressure, urine flow and fractional sodium excretion were 93 ± 4 mmHg, 46.1 ± 15.7 μl min -1  kg -1 and 1.4 ± 0.3%, respectively, in the normal-sodium group and 91 ± 2 mmHg, 19.1 ± 3.3 μl min -1  kg -1 and 0.7 ± 0.2%, respectively, in the low-sodium group. Angiotensin-(1-7) infusion had no effect on mean arterial pressure in rats receiving a normal-sodium diet but decreased it by 4 ± 5% in rats receiving a low-sodium diet (P < 0.05). Interstitial Ang-(1-7) infusion increased urine flow twofold and fractional sodium excretion threefold (P < 0.05) in rats receiving a normal-sodium diet and to a greater extent, approximately three- and fourfold, respectively, in rats receiving the low-sodium diet (both P < 0.05). Angiotensin-(1-7)-induced increases in urine flow and fractional sodium excretion were absent in both dietary groups during intrarenal AT 1 or Mas receptor inhibition after either losartan or A-779, respectively. Thus, AT 1 receptor activation, as well as Mas receptor activation, plays an essential role in mediating Ang-(1-7)-induced natriuresis and diuresis. Whether this is because Ang-(1-7) partly antagonizes AT 1 receptors or whether Ang-(1-7)-induced natriuresis is mediated through AT 1 -Mas receptor dimerization remains unclear. © 2017 The Authors. Experimental Physiology © 2017 The Physiological Society.

More Efficient Sodium Removal by Ultrafiltration Compared to Diuretics in Acute Heart Failure; Underexplored and Overstated.

PubMed

Kazory, Amir

2016-01-01

Enhanced removal of sodium has often been cited as an advantage of ultrafiltration (UF) therapy over diuretic-based medical treatment in the management of acute decompensated heart failure. However, so far clinical studies have rarely evaluated the precise magnitude of sodium removal, and this assumption is largely based on the physiologic mechanisms and anecdotal observations that predate the contemporary management of heart failure. Recent data suggest that patients treated with UF experience substantial reduction in urinary sodium excretion possibly due to prolonged intravascular volume contraction. Consequently, the efficient sodium extraction through production of isotonic ultrafiltrate can be offset by urine hypotonicity. Based on the limited currently available data, it seems unlikely that the persistent benefits of UF could be solely explained by its greater efficiency in sodium removal. The design of the future studies should include frequent measurements of urine sodium to precisely compare the impact of UF and diuretics on sodium balance. © 2016 S. Karger AG, Basel.

Effect of Ramadan fasting on urinary risk factors for calculus formation.

PubMed

Miladipour, Amir Hossein; Shakhssalim, Nasser; Parvin, Mahmoud; Azadvari, Mohaddeseh

2012-01-01

Even though dehydration could aggravate formation of urinary calculi, the effects of fluid and food restriction on calculus formation is not thoroughly defined. The purpose of this study is to evaluate the effects of fluid and food restriction in Ramadan fasting on urinary factors in kidney and urinary calculus formation. Fifty-seven men aged 30 to 55 years old, including 37 recurrent calcium calculus formers and 20 with no history of kidney calculi were evaluated for blood tests, ultrasonography investigations, urinalysis, urine culture, and also 24-hour urine collection test. Metabolites including calcium, oxalate, citrate, uric acid, magnesium, phosphate, potassium, sodium, and creatinine were measured before and during Ramadan fasting. The values of calculus-precipitating solutes as well as inhibitory factors were documented thoroughly. Total excretion of calcium, phosphate, and magnesium in 24-hour urine and also urine volume during fasting were significantly lower than those in the nonfasting period. Urine concentration of calcium during fasting was significantly lower than nonfasting (P < .001). Urine concentrations of uric acid, citrate, phosphate, sodium, and potassium during fasting were significantly higher than nonfasting. Uric acid supersaturation was accentuated, and calcium phosphate supersaturation was decreased significantly during fasting. There was no significant increase in calcium oxalate supersaturation during the fasting period. Fasting during Ramadan has different effects on total excretion and concentrations of urinary precipitate and inhibitory factors contributing to calculus formation. We did not find enough evidence in favor of increased risks of calculus formation during Ramadan fasting.

Changes of hormones regulating electrolyte metabolism after space flight and hypokinesia

NASA Astrophysics Data System (ADS)

Macho, L.; Fickova, M.; Lichardus, B.; Kvetnansky, R.; Carrey, R. M.; Grigoriev, A.; Popova, I. A.; Tigranian, R. A.; Noskov, V. B.

The changes of hormones in plasma involved in the body fluid regulation were studied in human subjects during and after space flights in relation to redistribution of body fluids in the state of weightlessness. Since hypokinesia was used as a model for simulation of some effects of the stay in microgravity the plasma hormone levels in rats exposed to hypokinesia were also investigated. Plasma aldosterone values showed great individual variations during the first inflight days, the increased levels were observed with prolongation of space flights. The important elevation was found in the recovery period, however it was interesting to note, that in some cosmonauts with repeated exposure to space flight, the postflight plasma aldosterone levels were not elevated. The urine excretion of aldosterone was increased inflight, however in postflight period the decrease or increase were found in the first 1-5 days. The increase of plasma renin activity was observed in flight and postflight period. The rats were exposed to hypokinesia (forced restriction of motor activity) for 1, 7 and 60 days and urine was collected during last 24 hours. The animals were sacrificed and the concentration of electrolytes and of levels of corticosterone aldosteron (A), ANF and plasma-renin activity (PRA) were determined in plasma. In urine excretion of sodium and potassium were estimated. An important increase of plasma renin activity and aldosterone concentration was found after short-term hypokinesia (1 day). These hormonal values appear to decrease with time (7 days) and are not significantly different from controls after long-term hypokinesia (60 days). A decrease of values ANF in plasma was observed after 1 and 7 days hypokinesia. After prolonged hypokinesia a decrease of sodium plasma concentration was observed. The excretion of sodium in urine was higher in long-term hypokinetic animals. There were no significant changes of plasma potassium levels in rats exposed to hypokinesia, however the urinary excretion of potassium was elevated. In rats exposed to hypokinesia for 7 and 60 days an increase of urine osmolality was observed. The results of hormone and electrolyte determination in plasma of cosmonauts after space flight and in experimental animals after hypokinesia suggested that in evaluation of relations between the changes of hormone levels and electrolyte in plasma and urine other factors like emotional stress working load; altered diurnal cycles should be considered in interpretation of homeostatic response of fluid and electrolyte metabolism to space flight conditions.

Association of urinary sodium and potassium excretion with blood pressure.

PubMed

Mente, Andrew; O'Donnell, Martin J; Rangarajan, Sumathy; McQueen, Matthew J; Poirier, Paul; Wielgosz, Andreas; Morrison, Howard; Li, Wei; Wang, Xingyu; Di, Chen; Mony, Prem; Devanath, Anitha; Rosengren, Annika; Oguz, Aytekin; Zatonska, Katarzyna; Yusufali, Afzal Hussein; Lopez-Jaramillo, Patricio; Avezum, Alvaro; Ismail, Noorhassim; Lanas, Fernando; Puoane, Thandi; Diaz, Rafael; Kelishadi, Roya; Iqbal, Romaina; Yusuf, Rita; Chifamba, Jephat; Khatib, Rasha; Teo, Koon; Yusuf, Salim

2014-08-14

Higher levels of sodium intake are reported to be associated with higher blood pressure. Whether this relationship varies according to levels of sodium or potassium intake and in different populations is unknown. We studied 102,216 adults from 18 countries. Estimates of 24-hour sodium and potassium excretion were made from a single fasting morning urine specimen and were used as surrogates for intake. We assessed the relationship between electrolyte excretion and blood pressure, as measured with an automated device. Regression analyses showed increments of 2.11 mm Hg in systolic blood pressure and 0.78 mm Hg in diastolic blood pressure for each 1-g increment in estimated sodium excretion. The slope of this association was steeper with higher sodium intake (an increment of 2.58 mm Hg in systolic blood pressure per gram for sodium excretion >5 g per day, 1.74 mm Hg per gram for 3 to 5 g per day, and 0.74 mm Hg per gram for <3 g per day; P<0.001 for interaction). The slope of association was steeper for persons with hypertension (2.49 mm Hg per gram) than for those without hypertension (1.30 mm Hg per gram, P<0.001 for interaction) and was steeper with increased age (2.97 mm Hg per gram at >55 years of age, 2.43 mm Hg per gram at 45 to 55 years of age, and 1.96 mm Hg per gram at <45 years of age; P<0.001 for interaction). Potassium excretion was inversely associated with systolic blood pressure, with a steeper slope of association for persons with hypertension than for those without it (P<0.001) and a steeper slope with increased age (P<0.001). In this study, the association of estimated intake of sodium and potassium, as determined from measurements of excretion of these cations, with blood pressure was nonlinear and was most pronounced in persons consuming high-sodium diets, persons with hypertension, and older persons. (Funded by the Heart and Stroke Foundation of Ontario and others.).

Servo-control of water and sodium homeostasis during renal clearance measurements in conscious rats.

PubMed

Thomsen, Klaus; Shirley, David G

2007-01-01

Servo-controlled fluid and sodium replacement during clearance studies is used in order to prevent loss of body fluid and sodium following diuretic/natriuretic procedures. However, even under control conditions, the use of this technique is sometimes associated with increases in proximal tubular fluid output (assessed by lithium clearance) and excretion rates. The present study examined the reason for these increases. The first series of experiments showed that one cause is volume overloading. This can occur if the servo system is activated from the start, i.e., during the establishment of a suitably high urine flow rate by constant infusion of hypotonic glucose solution. The second series of experiments showed that replacement of blood samples with donor blood can also lead to increases in fractional lithium excretion and accompanying increases in water and sodium excretion, a problem not seen when blood samples are replaced with the animal's own red blood cells resuspended in isotonic saline. When these pitfalls are avoided, servo-controlled sodium and fluid replacement is a reliable technique that makes it possible to study the effects of natriuretic and/or diuretic stimuli without interference from unwanted changes in extracellular volume. 2007 S. Karger AG, Basel

Effect of urine urea nitrogen and protein intake adjusted by using the estimated urine creatinine excretion rate on the antiproteinuric effect of angiotensin II type I receptor blockers.

PubMed

Chin, Ho Jun; Kim, Dong Ki; Park, Jung Hwan; Shin, Sung Joon; Lee, Sang Ho; Choi, Bum Soon; Kim, Suhnggwon; Lim, Chun Soo

2015-01-01

The aim of this study was to determine the role of protein intake on proteinuria in chronic kidney disease (CKD), as it is presently not conclusive. This is a subanalysis of data from an open-label, case-controlled, randomized clinical trial on education about low-salt diets (NCT01552954). We estimated the urine excretion rate of parameters in a day, adjusted by using the equation for estimating urine creatinine excretion, and analyzed the effect of urine urea nitrogen (UUN), as well as estimating protein intake on the level of albuminuria in hypertensive patients with chronic kidney disease. Among 174 participants from whom complete 24-h urine specimens were collected, the estimates from the Tanaka equation resulted in the highest accuracy for the urinary excretion rate of creatinine, sodium, albumin, and UUN. Among 227 participants, the baseline value of estimated urine albumin excretion (eUalb) was positively correlated with the estimated UUN (eUUN) or protein intake according to eUUN (P = 0.012 and P = 0.038, respectively). We were able to calculate the ratios of eUalb and eUUN in 221 participants and grouped them according to the ratio of eUUN during 16-wk trial period. The proportion of patients that achieved a decrement of eUalb ≥25% during 16 wk with an angiotensin II type I receptor blocker (ARB) medication was 80% (24 of 30) in group 1, with eUUN ratio ≤-25%; 82.2% (111 of 135) in group 2, with eUUN ratio between -25% and 25%; and 66.1% (37 and 56) in group 3, with eUUN ratio ≥25% (P = 0.048). The probability of a decrease in albuminuria with ARB treatment was lower in patients with an increase of eUUN or protein intake during the 16 wk of ARB treatment, as observed in multiple logistic regression analysis as well. The estimated urine urea excretion rate showed a positive association with the level of albuminuria in hypertensive patients with chronic kidney disease. The increase of eUUN excretion ameliorated the antiproteinuric effect of ARB. Copyright © 2015 Elsevier Inc. All rights reserved.

Nocturnal polyuria and saluresis in renal allograft recipients.

PubMed Central

Chan, M K; Varghese, Z; Fernando, O N; Moorhead, J F

1980-01-01

The evolution of nocturnal polyuria and saluresis in renal allograft recipients was studied by comparing the day to night (D:N) ratios of urine volume and sodium excretion in 15 patients who had undergone transplantation less than one year previously (recent-transplant group) with those in 11 patients who had undergone transplantation at least one year previously. Eleven patients with chronic renal failure and 12 normal subjects served as controls. Patients in the recent-transplant group had significantly lower D:N ratios of urine volume and sodium excretion than the patients who had undergone transplantation at least a year before, while the ratios in this last group did not differ significantly from those in the normal subjects. Nocturnal polyuria and saluresis gradually subsided in five patients studied for three months. Chronic renal failure and uraemic autonomic neuropathy were unlikely causes of the nocturia. The patients in the recent-transplant group had significantly lower D:N ratios of urine volume than the controls with chronic renal failure, and the mean Valsalva ratio in eight of them was not significantly different from that in the normal subjects. An undue sensitivity of renal allografts to postural influences was proposed. PMID:6986946

Breathing Assistance by the Iron Lung Increases Sympathetic Tone and Modifies Fluid Excretion

NASA Astrophysics Data System (ADS)

Baisch, F. J.; Gerzer, R.

Adaptation to weightlessness is not accompanied by an increase in sodium- and urine- excretion in humans in contrast to the expectations and the bed rest model in use to simulate effects of weightlessness on earth. On earth the thorax remains compressed by gravity in the horizontal body position while its unloading in weightlessness reduces transmural pressure in the mediastinal walls and membranes. Thus, wall stretching. or the Henry-Gauer mechanism, is reduced and may even result in a reduced water and sodium excretion. We have therefore lowered the transmural mediastinal pressure by the principle of the "Iron Lung" in a terrestrial model, and have studied whether or not this principle might reduce body fluid loss seen during onset of head down tilt bed rest. Methods: Two experiment runs were performed in a cross over design: one run pure 6° head down tilt body position (HDT) and the other with iron lung assistance. Six male subjects (26.5 +/- 8.1 years old; 187+/- 5 cm tall; 84.0 +/- 6.6 kg body weight) participated. Lung pressure was modified by the iron lung where the whole body except the head is enclosed in a box. The air pressure inside the box was 5 cm H2O lower than ambient during activation of the iron lung. For inspiration negative pressure increased up to 15 cm H2O, roughly doubling resting breath tide. The counteracting lung pressure was 8.1 +/- 0.6 cm H2O for 4 hours in mean. Breathing rate was reduced under iron lung to avoid hyperventilation (10.2 +/- 0.6 bpm [iron lung] versus 14.0 +/- 1.2 Bpm [spontaneously]). The relationship between expiration and inspiration remained at 2:1 in both runs. End expiratory CO2 was measured breath by breath via a nose clip. Heart rate, peripheral oxygen saturation, and sphygmomanometric blood pressure were determined every half hour. Urine volume was measured hourly. sodium excretion and pH was determined. Ambient conditions were kept constant at thermoneutral conditions. Evaporative fluid loss was evaluated by a precise body weight determination (+/- 0.025 kg) before and after the four hour protocol. Results: End expiratory CO2 was lowered by iron lung (40.0 +/- 1.7 mmHg versus 30.4 +/- 1.7 mmHg; p < .01). pH increased 6.9 versus 7.3 +/- 0.13; p < .01). Oxygen saturation increased insignificantly (98.5 +/- .5 % versus 97.9 +/- .3 %). The urine volume production under iron lung was slightly reduced compared to pure 6° HDT (1,340 +/- 170 ml versus 1,210 +/- 190 ml; p < .01). Sodium excretion did not change significantly (45.0 +/- 4.9 mmol versus 58.6 +/- 15.8 mmol).Perspiration loss decreased by 50 % (390 +/- 65 g versus 176 +/- 30 g; p < .001). Blood pressure increased. Diastolic values rose significantly from 65.2 +/- 2.9 mmHg to 75.4 +/- 1.6 mmHg (p < .01). Heart rate remained unchanged at 60.5 +/- 2.8 BPM. Discussion: Treatment by iron lung in 6° HDT decreased body fluid loss. The 10% reduction in urine excretion during iron lung assistance was small, however, significant. The reduction of fluid loss by perspiration contributed most. The response in sodium excretion was not uniform. Five subjects showed a moderate increase and one a significant decrease in urine sodium excretion. The treatment by iron lung induced an increase in diastolic blood pressure and a decrease in pulse pressure thus total peripheral resistance increased by more than 20%. Since it was recently observed during the NEUROLAB mission that resting sympathetic nerve activities increase in parallel with a moderate increase in diastolic blood pressure, our new ground model might also be relevant for the simulation of cardiovascular changes in space. It confirms that a coupling exists between kidney and skin with respect to body fluid regulation. Treatment by the iron lung moderates the Henry - Gauer reflex clearly. Application of the iron lung together with 6° HDT might resemble conditions of weightlessness closer than any other terrestrial model of fluid homeostasis in space.

Long-term compliance with salt restriction assessed using the spot urine method in Japanese cardiology outpatients.

PubMed

Hirota, Shinichi; Sadanaga, Tsuneaki; Mitamura, Hideo; Fukuda, Keiichi

2013-12-01

The purpose of this study was to evaluate long-term compliance with salt restriction in Japanese cardiology outpatients assessed by spot urine measurements. A total of 466 patients (72 ± 10 years old, 216 females) who visited a cardiology outpatient clinic and were followed for at least 1 year were included in this study. Daily dietary salt intake was estimated based on the sodium and creatinine concentrations determined by spot urine at the time of enrollment, during an 8-26 week follow-up and at a long-term follow-up (>1 year). The average follow-up duration was 2.2 ± 0.6 (1.0-3.4) years after enrollment, and spot urines were collected 5.2 ± 2.8 times after 1 year. The baseline estimated salt excretion was 9.6 ± 2.7 g per day, which was reduced to 8.7 ± 2.3 g per day (P<0.01) at 8-26 weeks and remained unchanged at the long-term follow-up (8.9 ± 2.0 g per day, P = 0.36 vs. 8-26 weeks, P < 0.01 vs. baseline). The percent of patients who achieved an average salt excretion<6.0 g per day was unchanged from baseline (6.9% vs. 7.7%, P = 0.61). Among several variables (gender, age, body weight, salt excretion at enrollment) that might affect the incidence of salt excretion <6.0 g per day, salt excretion at baseline was the only determinant of successful salt restriction (P<0.01). In conclusion, compliance with salt restriction, assessed using a spot urine method, was maintained over the long term; however, achieving salt reduction to the level recommended by the guidelines remains a challenge.

THE METABOLISM OF SILICON IN THE RAT AND ITS RELATION TO THE FORMATION OF ARTIFICIAL SILICEOUS CALCULI

PubMed Central

Keeler, Richard F.; Lovelace, Stuart A.

1959-01-01

The urinary excretion of silicon in the rat was found to be enhanced beyond normal levels by the administration of various chemical forms of silicon. The excretion was enhanced to a much greater degree by the administration of ethyl silicate than by magnesium trisilicate, sodium metasilicate, or water glass. The tolerance level of rats to sustained daily doses of ethyl silicate fed via stomach tube was approximately 15 to 30 mg. of silicon per rat per day. Urinary silicon excretion was found to be a straight line function of the concentration of ethyl silicate administered, via stomach tube, with approximately 18 per cent of the administered silicon appearing in the urine at all levels tested. Using sustained dietary additions of ethyl silicate as a means of enhancing urine silicon levels, artificial siliceous urinary calculi were consistently produced on zinc pellets implanted in the bladders of rats. PMID:13654631

Within-country variation of salt intake assessed via urinary excretion in Japan: a multilevel analysis in all 47 prefectures.

PubMed

Uechi, Ken; Asakura, Keiko; Masayasu, Shizuko; Sasaki, Satoshi

2017-06-01

Salt intake in Japan remains high; therefore, exploring within-country variation in salt intake and its cause is an important step in the establishment of salt reduction strategies. However, no nationwide evaluation of this variation has been conducted by urinalysis. We aimed to clarify whether within-country variation in salt intake exists in Japan after adjusting for individual characteristics. Healthy men (n=1027) and women (n=1046) aged 20-69 years were recruited from all 47 prefectures of Japan. Twenty-four-hour sodium excretion was estimated using three spot urine samples collected on three nonconsecutive days. The study area was categorized into 12 regions defined by the National Health and Nutrition Survey Japan. Within-country variation in sodium excretion was estimated as a population (region)-level variance using a multilevel model with random intercepts, with adjustment for individual biological, socioeconomic and dietary characteristics. Estimated 24 h sodium excretion was 204.8 mmol per day in men and 155.7 mmol per day in women. Sodium excretion was high in the Northeastern region. However, population-level variance was extremely small after adjusting for individual characteristics (0.8 and 2% of overall variance in men and women, respectively) compared with individual-level variance (99.2 and 98% of overall variance in men and women, respectively). Among individual characteristics, greater body mass index, living with a spouse and high miso-soup intake were associated with high sodium excretion in both sexes. Within-country variation in salt intake in Japan was extremely small compared with individual-level variation. Salt reduction strategies for Japan should be comprehensive and should not address the small within-country differences in intake.

Comparison of two aquaretic drugs (niravoline and OPC-31260) in cirrhotic rats with ascites and water retention.

PubMed

Bosch-Marcé, M; Poo, J L; Jiménez, W; Bordas, N; Leivas, A; Morales-Ruiz, M; Muñoz, R M; Pérez, M; Arroyo, V; Rivera, F; Rodés, J

1999-04-01

kappa-Opioid receptor agonists (niravoline) or nonpeptide antidiuretic hormone (ADH) V2 receptor antagonists (OPC-31260) possess aquaretic activity in cirrhosis; however, there is no information concerning the effects induced by the chronic administration of these drugs under this condition. To compare the renal and hormonal effects induced by the long-term oral administration of niravoline, OPC-31260, or vehicle, urine volume, urinary osmolality, sodium excretion, and urinary excretion of aldosterone (ALD) and ADH were measured in basal conditions and for 10 days after the daily oral administration of niravoline, OPC-31260, or vehicle to cirrhotic rats with ascites and water retention. Creatinine clearance, serum osmolality, ADH mRNA expression, and systemic hemodynamics were also measured at the end of the study. Niravoline increased water excretion, peripheral resistance, serum osmolality, and sodium excretion and reduced creatinine clearance, ALD and ADH excretion, and mRNA expression of ADH. OPC-31260 also increased water metabolism and sodium excretion and reduced urinary ALD, although the aquaretic effect was only evident during the first 2 days, and no effects on serum osmolality, renal filtration, and systemic hemodynamics were observed. Therefore, both agents have aquaretic efficacy, but the beneficial therapeutic effects of the long-term oral administration of niravoline are more consistent than those of OPC-31260 in cirrhotic rats with ascites and water retention.

Sodium-blood pressure interrelationship in pregnancy.

PubMed

Franx, A; Steegers, E A; de Boo, T; Thien, T; Merkus, J M

1999-03-01

In non-pregnant individuals, a strong positive association of sodium intake with blood pressure has been established, but the relationship between sodium intake and blood pressure in human pregnancy remains obscure up to date. The aim of this prospective observational cohort study was to assess the relationship between urinary sodium excretion (as a measure for intake) and blood pressure from the early second trimester onwards throughout pregnancy. The study group consisted of 667 low-risk women with singleton pregnancies, of whom 350 were nulliparous and 317 parous. Blood pressure was measured in a standardised fashion at predetermined intervals from the first antenatal visit prior to 16 weeks gestation until delivery. Urinary sodium excretion was measured in 24-h urine collections on at least four occasions between 16 and 38 weeks gestation. Main outcome measures were the coefficients of correlation between changes in urinary sodium output and changes in blood pressure during six different gestational epochs. No significant correlations were found between changes in urinary sodium output and changes in blood pressure. Correlation coefficients were alike for nulliparous and parous women and for different gestational intervals. Prior to 32 weeks gestation, no differences were observed in sodium excretion between women who remained normotensive and those who developed gestational hypertension. These results suggest that changes in sodium intake are not associated with blood pressure changes in low-risk pregnant women. Blood pressure increases as observed in the second half of normotensive and hypertensive pregnancies are unlikely to be caused by changes in renal sodium handling.

Comparison of the effects of tolvaptan and furosemide on renal water and sodium excretion in patients with heart failure and advanced chronic kidney disease: a subanalysis of the K-STAR study.

PubMed

Tominaga, Naoto; Kida, Keisuke; Inomata, Takayuki; Sato, Naoki; Izumi, Tohru; Akashi, Yoshihiro J; Shibagaki, Yugo

2018-06-22

Tolvaptan (TLV) is known to increase electrolyte-free water clearance. However, TLV actions on renal electrolytes including urine sodium (uNa) excretion and its consequences are less well understood. This subanalysis investigated the effect of add-on TLV compared to increased furosemide (FUR) on both electrolyte-free water and electrolyte clearance in patients with congestive heart failure (CHF) complicated by advanced chronic kidney disease (CKD). The Kanagawa Aquaresis Investigators Trial of TLV on HF Patients with Renal Impairment (K-STAR) was a multicenter, open-labeled, randomized, and controlled prospective clinical study. Eighty-one Japanese patients with CHF and residual signs of congestion despite oral FUR treatment (≥ 40 mg/day) were recruited and randomly assigned to a 7-day add-on treatment with either ≤ 40 mg/day FUR or ≤ 15 mg/day TLV. Electrolyte-free water clearance, electrolyte osmolar clearance and electrolyte excretion were compared between the two groups before and after therapy. The change (Δ) in electrolyte-free water clearance was significantly higher in the add-on TLV group than in the add-on FUR group. However, Δelectrolyte osmolar clearance was also higher in the add-on TLV group than in the increased FUR group. This was primarily because ΔuNa excretion was significantly higher in the add-on TLV group than in the increased FUR group, since Δurine potassium excretion was significantly lower in the add-on TLV group than in the increased FUR group. Add-on TLV may increase both renal water and Na excretion in CHF patients with advanced CKD to a greater degree than increased FUR.

Evaluation of the process of recycling and renal parenchymal injury after eswl with metabolites excreted in the urine.

PubMed

Ceylan, Cavit; Dogan, Serkan; Saydam, Gulsevim; Kocak, Mehmet Zait; Doluoglu, Omer Gokhan

2013-01-01

To show renal parenchymal injury depending on extracorporeal shock wave lithotripsy (ESWL). The patients with one renal stone and in whom ESWL is planned among the patients in whom renal stone was determined. Their 24-h urine samples were collected just before and after the ESWL treatment. Cit (citrate), UrA (uric acid), RBP (retinol-binding protein), NAG (N-acetyl-β-Đ-glucosaminidase), Cr (creatinine), Na (sodium), K (potassium), P (phosphor), Ca (calcium), and Cl (chlorine) metabolites excreted in urine were evaluated after urine samples were taken on the study day. Changes in the metabolites excreted; the number, frequency, and duration of ESWL shock wave; the energy; and the body mass index were recorded. The results for p < 0.05 will be accepted as statistically significant. Two sessions of ESWL were applied to a total of 20 patients. When metabolites excreted in the urine before (B1E) and after (A1E) the first session of ESWL, and before (B2E) and after (A2E) the second session of ESWL, were evaluated, no statistically significant result for Ca and Cl excretion was noted. For NAG and Cr, a significant difference was observed in terms of metabolite excretion between B1E and B2E. For other metabolites, we saw that there is no difference between B1E and B2E. While a significant metabolite change was observed for RBP, NAG, Cr, and Na as long as A1E and A2E ESWL session number increases, other metabolites were not significant. Shock waves induce significant damage to the renal and adjacent tissues as indicated by a significant increase in cell-escaped enzymes and electrolytes and the extent of damage depends on the energy and the number of shock wave exposure.

Association between Parent and Child Dietary Sodium and Potassium Intakes as Assessed by 24-h Urinary Excretion.

PubMed

Service, Carrie; Grimes, Carley; Riddell, Lynn; He, Feng; Campbell, Karen; Nowson, Caryl

2016-04-01

The aim of this study was to assess the association between parent and child sodium (Na) and potassium (K) intake as assessed by 24-h urinary excretion (24hUE). Primary school children and their parent(s) provided one 24-h urine sample and information on cooking and children's discretionary salt use. Valid urine samples were provided by 108 mothers (mean age 41.8 (5.1) (SD) years, Na 120 (45) mmol/day) (7.0 g/day salt equivalent) and 40 fathers (44.4 (4.9) years, Na 152 (49) mmol/day (8.9 g/day salt), and 168 offspring (51.8% male, age 9.1 (2.0) years, Na 101 (47) mmol/day (5.9 g/day salt). When adjusted for parental age, child age and gender a 17 mmol/day Na (1 g/day salt) increase in mother's 24hUE was associated with a 3.4 mmol/day Na (0.2 g/day salt) increase in child's salt 24hUE (p = 0.04) with no association observed between father and child. Sixty-seven percent of parents added salt during cooking and 37% of children added salt at the table. Children who reported adding table salt had higher urinary excretion than those who did not (p = 0.01). The association between mother and child Na intake may relate to the consumption of similar foods and highlights the importance of the home environment in influencing total dietary sodium intake.

Cystinuria.

PubMed

Milliner, D S

1990-12-01

Cystinuria is an hereditary disorder of renal and intestinal transport characterized by the excessive urinary excretion of cystine, arginine, lysine, and ornithine. It is inherited as a common recessive gene with allelic mutations. Complementary studies of the plasma response to oral cystine loading, intestinal mucosal transport patterns, and urine cystine excretion allow separation of homozygous cystinuric subjects into three groups. In type I, the most common form, there is no active transport of cystine or dibasic amino acids across the mucosal gradient, and heterozygous subjects show normal urine cystine values. Type II is characterized by markedly reduced or absent intestinal transport of cystine. Heterozygotes for type II show significantly elevated urine cystine but less than is seen in homozygotes. In type III there is diminished, although demonstrable, intestinal absorption of cystine and dibasic amino acids. Urine cystine in heterozygotes is intermediate between types I and II. Urolithiasis with its attendant complications is the sole clinical manifestation of cystinuria and is due to the relative insolubility of cystine in the urine. The urolithiasis may become clinically manifest at any time from infancy through the ninth decade, although the mean age is the second to third decade. Clinical presentation is similar to that of other types of urolithiasis. Although cystinuria accounts for only 1% to 2% of all urolithiasis and 6% to 8% of urolithiasis in pediatric populations, repeated stone formation in affected patients often causes considerable morbidity. Cystine crystals in the urine are diagnostic but show up in only 19% to 26% of homozygous cystinuric patients. Sodium cyanide nitroprusside is a suitable screening test that should identify homozygous stone formers but will not detect all heterozygotes. A positive screening test should be followed by quantitation of urinary amino acids. A homozygous patient can be functionally defined as one who excretes 250 mg or more of cystine/g of creatinine in a 24-hour urine collection. Other causes of excess urinary cystine must be excluded. Medical therapy will be directed toward dissolution of existing calculi and prevention of new stone formation. Increasing urine volume by generous oral fluid intake is beneficial. Dietary sodium restriction has a favorable effect on urinary cystine excretion. Cystine solubility can be improved by urinary alkalinization and where necessary by the administration of thiol chelators, particularly D-penicillamine or mercaptopropionylglycine. Because these chelators have significant adverse effects, they should be reserved for patients who do not respond to a more conservative program. Patients with infected, symptomatic, or obstructing stones require surgical intervention.(ABSTRACT TRUNCATED AT 400 WORDS)

Dissociation between the effects of P1, P4-diadenosine tetraphosphate (Ap4A) on renal haemodynamics and tubular function in anaesthetized rats.

PubMed

Jankowski, M; Angielski, S; Szczepańska-Konkel, M

2008-03-01

Previous studies from our laboratory have reported a marked reduction in glomerular filtration rate (GFR) and sodium reabsorption in renal proximal tubule during intravenous infusion of P(1),P(4)-diadenosine tetraphosphate (Ap(4)A) at dose of 1.0 micromol/kg + 10 nmol/kg/min (i.v., injection followed by infusion) in anaesthetized Wistar rats. In the present study, the changes of GFR and urine sodium excretion were investigated in response to systemic infusion of Ap(4)A at different doses. Ap(4)A at dose of 0.1 micromol/kg + 1.0 nmol/kg/min did not change GFR and sodium urinary excretion whereas 2-fold higher dose produced significant (3.4-fold) increase in sodium excretion without changes in GFR. Significant but transient reduction in GFR by approximately 21% was observed during infusion of Ap(4)A at dose of 0.5 micromol/kg + 5.0 nmol/kg/min. Higher doses of Ap(4)A (1.0 micromol/kg + 10 nmol/kg/min and 2.0 micromol/kg + 20 nmol/kg/min) reduction in GFR and marked natriuresis. Our results suggest that tubular sodium transport systems are more sensitive to Ap(4)A than systems involved in GFR regulation.

Vasopressin regulates renal calcium excretion in humans

PubMed Central

Hanouna, Guillaume; Haymann, Jean-Philippe; Baud, Laurent; Letavernier, Emmanuel

2015-01-01

Antidiuretic hormone or arginine vasopressin (AVP) increases water reabsorption in the collecting ducts of the kidney. Three decades ago, experimental models have shown that AVP may increase calcium reabsorption in rat kidney. The objective of this study was to assess whether AVP modulates renal calcium excretion in humans. We analyzed calcium, potassium, and sodium fractional excretion in eight patients affected by insipidus diabetes (nephrogenic or central) under acute vasopressin receptor agonist action and in 10 patients undergoing oral water load test affected or not by inappropriate antidiuretic hormone secretion (SIADH). Synthetic V2 receptor agonist (dDAVP) reduced significantly calcium fractional excretion from 1.71% to 0.58% (P < 0.05) in patients with central diabetes insipidus. In patients with nephrogenic diabetes insipidus (resistant to AVP), calcium fractional excretion did not change significantly after injection (0.48–0.68%, P = NS). In normal subjects undergoing oral water load test, calcium fractional excretion increased significantly from 1.02% to 2.54% (P < 0.05). Patients affected by SIADH had a high calcium fractional excretion at baseline that remained stable during test from 3.30% to 3.33% (P = NS), possibly resulting from a reduced calcium absorption in renal proximal tubule. In both groups, there was a significant correlation between urine output and calcium renal excretion. In humans, dDAVP decreases calcium fractional excretion in the short term. Conversely, water intake, which lowers AVP concentration, increases calcium fractional excretion. The correlation between urine output and calcium excretion suggests that AVP-related antidiuresis increases calcium reabsorption in collecting ducts. PMID:26620256

Estimation model for habitual 24-hour urinary-sodium excretion using simple questionnaires from normotensive Koreans.

PubMed

Kong, Ji-Sook; Lee, Yeon-Kyung; Kim, Mi Kyung; Choi, Mi-Kyeong; Heo, Young-Ran; Hyun, Taisun; Kim, Sun Mee; Lyu, Eun-Soon; Oh, Se-Young; Park, Hae-Ryun; Rhee, Moo-Yong; Ro, Hee-Kyong; Song, Mi Kyung

2018-01-01

This study was conducted to develop an equation for estimation of 24-h urinary-sodium excretion that can serve as an alternative to 24-h dietary recall and 24-h urine collection for normotensive Korean adults. In total, data on 640 healthy Korean adults aged 19 to 69 years from 4 regions of the country were collected as a training set. In order to externally validate the equation developed from that training set, 200 subjects were recruited independently as a validation set. Due to heterogeneity by gender, we constructed a gender-specific equation for estimation of 24-h urinary-sodium excretion by using a multivariable linear regression model and assessed the performance of the developed equation in validation set. The best model consisted of age, body weight, dietary behavior ('eating salty food', 'Kimchi consumption', 'Korean soup or stew consumption', 'soy sauce or red pepper paste consumption'), and smoking status in men, and age, body weight, dietary behavior ('salt preference', 'eating salty food', 'checking sodium content for processed foods', 'nut consumption'), and smoking status in women, respectively. When this model was tested in the external validation set, the mean bias between the measured and estimated 24-h urinary-sodium excretion from Bland-Altman plots was -1.92 (95% CI: -113, 110) mmol/d for men and -1.51 (95% CI: -90.6, 87.6) mmol/d for women. The cut-points of sodium intake calculated based on the equations were ≥4,000 mg/d for men and ≥3,500 mg/d for women, with 89.8 and 76.6% sensitivity and 29.3 and 64.2% specificity, respectively. In this study, a habitual 24-hour urinary-sodium-excretion-estimation model of normotensive Korean adults based on anthropometric and lifestyle factors was developed and showed feasibility for an asymptomatic population.

Estimation model for habitual 24-hour urinary-sodium excretion using simple questionnaires from normotensive Koreans

PubMed Central

Choi, Mi-Kyeong; Heo, Young-Ran; Hyun, Taisun; Kim, Sun Mee; Lyu, Eun-Soon; Oh, Se-Young; Park, Hae-Ryun; Rhee, Moo-Yong; Ro, Hee-Kyong; Song, Mi Kyung

2018-01-01

This study was conducted to develop an equation for estimation of 24-h urinary-sodium excretion that can serve as an alternative to 24-h dietary recall and 24-h urine collection for normotensive Korean adults. In total, data on 640 healthy Korean adults aged 19 to 69 years from 4 regions of the country were collected as a training set. In order to externally validate the equation developed from that training set, 200 subjects were recruited independently as a validation set. Due to heterogeneity by gender, we constructed a gender-specific equation for estimation of 24-h urinary-sodium excretion by using a multivariable linear regression model and assessed the performance of the developed equation in validation set. The best model consisted of age, body weight, dietary behavior (‘eating salty food’, ‘Kimchi consumption’, ‘Korean soup or stew consumption’, ‘soy sauce or red pepper paste consumption’), and smoking status in men, and age, body weight, dietary behavior (‘salt preference’, ‘eating salty food’, ‘checking sodium content for processed foods’, ‘nut consumption’), and smoking status in women, respectively. When this model was tested in the external validation set, the mean bias between the measured and estimated 24-h urinary-sodium excretion from Bland-Altman plots was -1.92 (95% CI: -113, 110) mmol/d for men and -1.51 (95% CI: -90.6, 87.6) mmol/d for women. The cut-points of sodium intake calculated based on the equations were ≥4,000 mg/d for men and ≥3,500 mg/d for women, with 89.8 and 76.6% sensitivity and 29.3 and 64.2% specificity, respectively. In this study, a habitual 24-hour urinary-sodium-excretion-estimation model of normotensive Korean adults based on anthropometric and lifestyle factors was developed and showed feasibility for an asymptomatic population. PMID:29447201

Effects of high-tone external muscle stimulation on renal function in healthy volunteers.

PubMed

Peckova, Miroslava; Havlin, Jan; Charvat, Jiri; Horackova, Miroslava; Schück, Otto

2013-01-01

Hightone external muscle stimulation (HTEMS) ameliorates pain and discomfort of patients with polyneuropathy. Since some patients reported about an urge to urinate during these treatments, the potential effects of HTEMS application on renal function were investigated. For this purpose in healthy subjects, we analyzed in the current study the acute effects of electrotherapy on parameters of renal function. 24 healthy volunteers (14 women and 10 men), mean age 26 ± 4 years, were enrolled. The protocol was composed of a run-in period, a pre-treatment period, the active HTEMS treatment period of both lower extremities and the post-treatment period. The duration of each period was 60 min. Urine collection and blood samples were taken at the beginning and end of each period. To achieve a sufficient diuresis, the fluid intake was adapted to the amount of diuresis. Parameters of renal function included diuresis, glomerular filtration rate (endogenous creatinine clearance) and absolute and fractional sodium excretion. Moreover blood pressure and heart rate were monitored. HTEMS led to a significant increase of creatinine clearance and fractional sodium excretion which was limited to the active treatment period. These findings show for the first time that HTEMS can transiently increase glomerular filtration rate associated with a decreased tubular sodium reabsorption. The underlying mechanisms are to be elucidated.

Pharmacodynamic Effects of Single and Multiple Doses of Empagliflozin in Patients With Type 2 Diabetes.

PubMed

Heise, Tim; Jordan, Jens; Wanner, Christoph; Heer, Martina; Macha, Sreeraj; Mattheus, Michaela; Lund, Søren S; Woerle, Hans J; Broedl, Uli C

2016-10-01

Our aim was to investigate the effects of the sodium glucose cotransporter 2 inhibitor empagliflozin on urinary and serum glucose and electrolytes, urinary volume, osmolality, and the renin-angiotensin system in patients with type 2 diabetes. In an open-label study, 22 patients receiving metformin (median age 56 years; range 40-65 years) received empagliflozin 25 mg once daily for 5 days. Food, fluid, and sodium intake were standardized for 3 days before and during treatment. Twenty patients completed treatment. After single and multiple doses of empagliflozin, mean (SE) changes from baseline in 24-hour urinary glucose excretion were 463.3 (57.3) mmol/d and 599.5 (60.0) mmol/d, respectively (83.5 [10.3] g/d and 108.0 [10.8] g/d, respectively) (both P < 0.001), and in fasting serum glucose concentration were -1.8 (0.4) mmol/L and -1.1 (0.3) mmol/L, respectively (both P < 0.001). After a single dose, mean (SE) change from baseline in urine sodium excretion was 45.3 (9.6) mmol/d (P < 0.001), and in urine volume was 341.0 (140.5) g/d (P = 0.025), but there were no changes compared with baseline in either parameter after multiple doses. There were no changes in plasma renin or serum aldosterone with single or multiple doses of empagliflozin. There was a nonsignificant reduction in weight after a single dose of empagliflozin and a mean (SE) change of -1.4 (0.5) kg after multiple doses (P = 0.020). Empagliflozin 25 mg increased urinary glucose excretion and decreased serum glucose and weight with transient natriuresis and increases in urine volume, without significant changes in the renin-angiotensin system. Clinicaltrials.gov Identifier: NCT01276288. Copyright © 2016 Elsevier HS Journals, Inc. All rights reserved.

Gender-specific association between urinary sodium excretion and body composition: Analysis of the 2008-2010 Korean National Health and Nutrition Examination Surveys.

PubMed

Huh, Ji Hye; Lim, Jung Soo; Lee, Mi Young; Chung, Choon Hee; Shin, Jang Yel

2015-07-01

Few studies have reported the relationship between sarcopenia and the estimated amount of sodium excreted in 24 h, as measured by the spot urine test (E24UNA), in a community-dwelling cohort. We investigated the gender specific association between E24UNA values and body composition indices. Data from a total of 7162 participants (3545 men and 3617 postmenopausal women) aged 45 years or older were obtained from multiple Korea National Health and Nutrition Examination Surveys (2008-2010) and analyzed. The total amount of sodium excreted in the urine in a 24-h period was estimated with spot urine specimens. Sarcopenia was defined as an appendicular skeletal muscle mass divided by body weight (ASM/Wt) that was less than 1 standard deviation below the sex-specific mean for young adults. E24UNA values were positively correlated with body mass index, waist circumference, total fat mass, and blood pressure; in contrast, E24UNA values were negatively correlated with ASM/Wt in both sexes. Compared with those in the lowest E24UNA tertile, participants in the highest E24UNA tertile were at higher risk for sarcopenia (men: odds ratio (OR)=1.3 [95% confidence interval (CI)=1.07-1.59]; women: OR=1.41 [95% CI=1.16-1.73]). Further classification of subjects with sarcopenia into sarcopenic obese and sarcopenic nonobese groups revealed that the highest E24UNA values were found in the sarcopenic obese group; this difference was statistically significant. The next highest levels were found in the sarcopenic nonobese group, followed by the nonsarcopenic group. This trend was observed in both sexes. High E24UNA values were independently associated with both sarcopenia and obesity in Korean individuals older than 45 years. These results suggest that high salt intake may have a deleterious effect on body composition. Copyright © 2015. Published by Elsevier Inc.

Effects of dietary benzoic acid and sodium-benzoate on performance, nitrogen and mineral balance and hippuric acid excretion of piglets.

PubMed

Gräber, Tobias; Kluge, Holger; Hirche, Frank; Broz, Jirí; Stangl, Gabriele I

2012-06-01

The objective of this study was to compare the effects of sodium-benzoate (NaB) with those of benzoic acid (BAc) on growth performance of piglets as well as nutrient digestibility, nitrogen and mineral balance, urinary pH, and the urinary excretion of BAc and hippuric acid (HAc). The study was conducted with 120 weaning piglets (6.5 kg body weight), divided in four groups (15 replicates of two piglets each), which received (1) a basal diet (Control), or the basal diet supplemented with (2) 4 g NaB per kg (Group 4NaB), (3) 3.5 g BAc per kg (Group 3.5BAc) or (4) 5 g BAc per kg (Group 5BAc). Performance data were monitored over a 42-day period. Urine and faeces were collected from day 28-33 in metabolic cages with five piglets per treatment. Piglets of Groups 3.5BAc and 5BAc had similarly a considerably improved average daily gain and feed intake (p < 0.05). Performance of Group 4NaB was not significantly different from the other groups. Compared to the Control, the nitrogen retention was only improved in Group 5BAc (p < 0.05); the other groups showed intermediate values. In the supplemented groups, most of the BAc was excreted as HAc in urine, but only Groups 3.5BAc and 5BAc had reduced urinary pH (p < 0.05). Daily intake and faecal and urinary excretion of P and Ca were not affected by the treatment. The molar excess of Na in Group 4NaB was reflected by higher renal excretion of Na compared to the other groups (p < 0.05).

Estimating 24-h urinary sodium/potassium ratio from casual ('spot') urinary sodium/potassium ratio: the INTERSALT Study.

PubMed

Iwahori, Toshiyuki; Miura, Katsuyuki; Ueshima, Hirotsugu; Chan, Queenie; Dyer, Alan R; Elliott, Paul; Stamler, Jeremiah

2017-10-01

Association between casual and 24-h urinary sodium-to-potassium (Na/K) ratio is well recognized, although it has not been validated in diverse demographic groups. Our aim was to assess utility across and within populations of casual urine to estimate 24-h urinary Na/K ratio using data from the INTERSALT Study. The INTERSALT Study collected cross-sectional standardized data on casual urinary sodium and potassium and also on timed 24-h urinary sodium and potassium for 10 065 individuals from 52 population samples in 32 countries (1985-87). Pearson correlation coefficients and agreement were computed for Na/K ratio of casual urine against 24-h urinary Na/K ratio both at population and individual levels. Pearson correlation coefficients relating means of 24-h urine and casual urine Na/K ratio were r = 0.96 and r = 0.69 in analyses across populations and individuals, respectively. Correlations of casual urine Na/creatinine and K/creatinine ratios with 24-h urinary Na and K excretion, respectively, were lower than correlation of casual and 24-h urinary Na/K ratio in analyses across populations and individuals. The bias estimate with the Bland-Altman method, defined as the difference between Na/K ratio of 24-h urine and casual urine, was approximately 0.4 across both populations and individuals. Spread around, the mean bias was higher for individuals than populations. With appropriate bias correction, casual urine Na/K ratio may be a useful, low-burden alternative method to 24-h urine for estimation of population urinary Na/K ratio. It may also be applicable for assessment of the urinary Na/K ratio of individuals, with use of repeated measurements to reduce measurement error and increase precision. © The Author 2016. Published by Oxford University Press on behalf of the International Epidemiological Association

Sodium and water: an overview.

PubMed

Papper, S

1976-01-01

The renal regulation of sodium is intertwined with the extracellular fluid volume (ECFV). Most adjustments in sodium elimination in man are accomplished via alterations in tubular reabsorption. The latter is sensitive to change in ECFV. An expanded ECFV results in less reabsorption and more excretion of sodium, and a contracted ECFV has the converse effect. There are direct and indirect mechanisms whereby ECFV influences sodium reabsorption. Patients with nephrotic syndrome, heart failure, and cirrhosis "behave" physiologically as normal individuals with a contracted ECFV. Water balance is normally determined by intake and losses in sweat which is always hypoosmotic to plasma, by evaporation from skin and lungs, and through renal excretion. The major factors that determine the ability to concentrate the urine are (1) the establishment of a concentrated environment around the collecting ducts, and (2) the elaboration and effects on the kidney of antidiuretic hormone. The evaluation of a patient with abnormalities of sodium and water rests initially and largely on clinical information. The clinical setting provides clues to anticipating, preventing, and interpreting distortions of body sodium and water. The laboratory can detect an abnormality, confirm or refute clinical assessment, and assist in the quantitative aspects of treatment and its efficacy.

Biosynthesis of mercapturic acids from allyl alcohol, allyl esters and acrolein

PubMed Central

Kaye, Clive M.

1973-01-01

1. 3-Hydroxypropylmercapturic acid, i.e. N-acetyl-S-(3-hydroxypropyl)-l-cysteine, was isolated, as its dicyclohexylammonium salt, from the urine of rats after the subcutaneous injection of each of the following compounds: allyl alcohol, allyl formate, allyl propionate, allyl nitrate, acrolein and S-(3-hydroxypropyl)-l-cysteine. 2. Allylmercapturic acid, i.e. N-acetyl-S-allyl-l-cysteine, was isolated from the urine of rats after the subcutaneous injection of each of the following compounds: triallyl phosphate, sodium allyl sulphate and allyl nitrate. The sulphoxide of allylmercapturic acid was detected in the urine excreted by these rats. 3. 3-Hydroxypropylmercapturic acid was identified by g.l.c. as a metabolite of allyl acetate, allyl stearate, allyl benzoate, diallyl phthalate, allyl nitrite, triallyl phosphate and sodium allyl sulphate. 4. S-(3-Hydroxypropyl)-l-cysteine was detected in the bile of a rat dosed with allyl acetate. PMID:4762754

Water Intake and Hydration Indices in Healthy European Adults: The European Hydration Research Study (EHRS).

PubMed

Malisova, Olga; Athanasatou, Adelais; Pepa, Alex; Husemann, Marlien; Domnik, Kirsten; Braun, Hans; Mora-Rodriguez, Ricardo; Ortega, Juan F; Fernandez-Elias, Valentin E; Kapsokefalou, Maria

2016-04-06

Hydration status is linked with health, wellness, and performance. We evaluated hydration status, water intake, and urine output for seven consecutive days in healthy adults. Volunteers living in Spain, Germany, or Greece (n = 573, 39 ± 12 years (51.1% males), 25.0 ± 4.6 kg/m² BMI) participated in an eight-day study protocol. Total water intake was estimated from seven-day food and drink diaries. Hydration status was measured in urine samples collected over 24 h for seven days and in blood samples collected in fasting state on the mornings of days 1 and 8. Total daily water intake was 2.75 ± 1.01 L, water from beverages 2.10 ± 0.91 L, water from foods 0.66 ± 0.29 L. Urine parameters were: 24 h volume 1.65 ± 0.70 L, 24 h osmolality 631 ± 221 mOsmol/kg Η2Ο, 24 h specific gravity 1.017 ± 0.005, 24 h excretion of sodium 166.9 ± 54.7 mEq, 24 h excretion of potassium 72.4 ± 24.6 mEq, color chart 4.2 ± 1.4. Predictors for urine osmolality were age, country, gender, and BMI. Blood indices were: haemoglobin concentration 14.7 ± 1.7 g/dL, hematocrit 43% ± 4% and serum osmolality 294 ± 9 mOsmol/kg Η2Ο. Daily water intake was higher in summer (2.8 ± 1.02 L) than in winter (2.6 ± 0.98 L) (p = 0.019). Water intake was associated negatively with urine specific gravity, urine color, and urine sodium and potassium concentrations (p < 0.01). Applying urine osmolality cut-offs, approximately 60% of participants were euhydrated and 20% hyperhydrated or dehydrated. Most participants were euhydrated, but a substantial number of people (40%) deviated from a normal hydration level.

6β-HYDROXYTESTOSTERONE, A CYTOCHROME P450 1B1-TESTOSTERONE-METABOLITE, MEDIATES ANGIOTENSIN II-INDUCED RENAL DYSFUNCTION IN MALE MICE

PubMed Central

Pingili, Ajeeth K.; Thirunavukkarasu, Shyamala; Kara, Mehmet; Brand, David; Katsurada, Akemi; Majid, Dewan S. A.; Navar, L. Gabriel; Gonzalez, Frank J.; Malik, Kafait U.

2016-01-01

6β-hydroxytestosterone, a cytochrome P450 1B1-derived metabolite of testosterone, contributes to the development of angiotensin II-induced hypertension and associated cardiovascular pathophysiology. In view of the critical role of angiotensin II in the maintenance of renal homeostasis, development of hypertension and end organ damage, this study was conducted to determine the contribution of 6β-hydroxytestosterone to angiotensin II actions on water consumption and renal function in male Cyp1b1+/+ and Cyp1b1−/− mice. Castration of Cyp1b1+/+ mice or Cyp1b1−/− gene disruption minimized the angiotensin II-induced increase in water consumption, urine output, proteinuria, and sodium excretion and decreases in urine osmolality. 6β-hydroxytestosterone did not alter angiotensin II-induced increases in water intake, urine output, proteinuria, and sodium excretion or decreases in osmolality in Cyp1b1+/+ mice, but restored these effects of angiotensin II in Cyp1b1−/− or castrated mice Cyp1b1+/+ mice. Cyp1b1 gene disruption or castration prevented angiotensin II-induced renal fibrosis, oxidative stress, inflammation, urinary excretion of angiotensinogen, expression of angiotensin II type 1 receptor, and angiotensin converting enzyme. 6β-hydroxytestosterone did not alter angiotensin II-induced renal fibrosis, inflammation, oxidative stress, urinary excretion angiotensinogen, expression of angiotensin II type 1 receptor, or angiotensin converting enzyme in Cyp1b1+/+ mice; however, in Cyp1b1−/− or castrated mice Cyp1b1+/+ mice, it restored these effects of angiotensin II. These data indicate that 6β-hydroxytestosterone contributes to increased thirst, impairment of renal function, and end organ injury associated with angiotensin II-induced hypertension in male mice and that cytochrome P450 1B1 could serve as a novel target for treating renal disease and hypertension in males. PMID:26928804

Is tolvaptan indicated for refractory oedema in nephrotic syndrome?

PubMed

Park, Eun-Sik; Huh, Youn-sung; Kim, Gheun-Ho

2015-02-01

Tolvaptan is useful for correcting dilutional hyponatraemia because of its aquaretic effect. On the other hand, there is a distinct lack of data regarding tolvaptan-induced natriuresis, although previous studies have demonstrated improvement of congestive symptoms and signs in heart failure patients following tolvaptan treatment. Here, we report the case of a 47-year-old man diagnosed with minimal change nephrotic syndrome and whose refractory oedema was immediately controlled by tolvaptan before steroid response was induced. With tolvaptan treatment, patient urine output increased dramatically to approximately 5.5 L/day and body weight decreased by 9 kg over 5 days. Interestingly, urine sodium concentration, fractional excretion of sodium and urine osmolality all increased in response to tolvaptan administration. However, serum sodium concentration was maintained within the normal range, and mild azotaemia was corrected. Tolvaptan was discontinued after 11 days when heavy proteinuria and generalized oedema had been resolved. We discuss the potential mechanisms by which V2 receptor antagonists may stimulate natriuresis in the kidney. In conclusion, tolvaptan may be useful as an adjunctive treatment for oedematous disorders. © 2015 Asian Pacific Society of Nephrology.

Changes in the renal handling of urea in sheep on a low protein diet exposed to saline drinking water.

PubMed

Meintjes, R A; Engelbrecht, H

2004-09-01

Previous trials have demonstrated that sheep on a low protein diet and free access to water, and sheep dosed with boluses of NaCl intraruminally also with free access to water, showed decreases in urea loss via the urine compared to control animals. We monitored urea excretion in sheep on a relatively poor protein diet when they were exposed to saline drinking water, i.e. they were unable to vary their intake of NaCl:water. Sheep on isotonic saline drinking water (phase 3) excreted significantly more urea via the urine (284 mM/day) compared to phase 1 when they were on non-saline drinking water (urea excretion = 230 mM/day) and phase 2 when they were on half isotonic saline drinking water (urea excretion = 244 mM/day). This finding was explained by the high glomerular filtration rate (GFR) 91.9 l/day, compared to 82.4 l/day (phase 1) and 77.9 l/day (phase 2), together with a significantly raised fractional excretion of urea (FEurea) (51.1 %) during this phase, and was in spite of the significantly lower plasma concentrations of urea in phase 3 compared to phase 1. The FEurea probably results from the osmotic diuresis caused by the salt. There were indications of a raised plasma antidiuretic hormone (ADH) concentration and this would have opposed urea loss, as ADH promotes urea reabsorption. However, this ADH effect was probably counteracted to some extent by a low plasma angiotensin II concentration, for which again there were indications, inhibiting urea reabsorption during the phases of salt loading. As atrial natriuretic peptide both increases GFR and decrease sodium reabsorption from the tubule, it was probably instrumental in causing the increase in GFR and the increase in the fractional excretion of sodium (FE(Na)).

Pharmacology and safety of glycerol phenylbutyrate in healthy adults and adults with cirrhosis.

PubMed

McGuire, Brendan M; Zupanets, Igor A; Lowe, Mark E; Xiao, Xunjun; Syplyviy, Vasyliy A; Monteleone, Jon; Gargosky, Sharron; Dickinson, Klara; Martinez, Antonia; Mokhtarani, Masoud; Scharschmidt, Bruce F

2010-06-01

Phenylbutyric acid (PBA), which is approved for treatment of urea cycle disorders (UCDs) as sodium phenylbutyrate (NaPBA), mediates waste nitrogen excretion via combination of PBA-derived phenylacetic acid with glutamine to form phenylactylglutamine (PAGN) that is excreted in urine. Glycerol phenylbutyrate (GPB), a liquid triglyceride pro-drug of PBA, containing no sodium and having favorable palatability, is being studied for treatment of hepatic encephalopathy (HE). In vitro and clinical studies have been performed to assess GPB digestion, safety, and pharmacology in healthy adults and individuals with cirrhosis. GPB hydrolysis was measured in vitro by way of pH titration. Twenty-four healthy adults underwent single-dose administration of GPB and NaPBA and eight healthy adults and 24 cirrhotic subjects underwent single-day and multiple-day dosing of GPB, with metabolites measured in blood and urine. Simulations were performed to assess GPB dosing at higher levels. GPB was hydrolyzed by human pancreatic triglyceride lipase, pancreatic lipase-related protein 2, and carboxyl-ester lipase. Clinical safety was satisfactory. Compared with NaPBA, peak metabolite blood levels with GPB occurred later and were lower; urinary PAGN excretion was similar but took longer. Steady state was achieved within 4 days for both NaPBA and GPB; intact GPB was not detected in blood or urine. Cirrhotic subjects converted GPB to PAGN similarly to healthy adults. Simulations suggest that GPB can be administered safely to cirrhotic subjects at levels equivalent to the highest approved NaPBA dose for UCDs. GPB exhibits delayed release characteristics, presumably reflecting gradual PBA release by pancreatic lipases, and is well tolerated in adults with cirrhosis, suggesting that further clinical testing for HE is warranted.

Pharmacology and Safety of Glycerol Phenylbutyrate in Healthy Adults and Adults with Cirrhosis

PubMed Central

MCGuire, Brendan M.; Zupanets, Igor A.; Lowe, Mark E.; Xiao, Xunjun; Syplyviy, Vasyliy A.; Monteleone, Jon; Gargosky, Sharron; Dickinson, Klara; Martinez, Antonia; Mokhtarani, Masoud; Scharschmidt, Bruce F.

2013-01-01

Phenylbutyric acid (PBA), which is approved for treatment of urea cycle disorders (UCDs) as sodium phenylbutyrate (NaPBA), mediates waste nitrogen excretion via combination of PBA-derived phenylacetic acid with glutamine to form phenylactylglutamine (PAGN) that is excreted in urine. Glycerol phenylbutyrate (GPB), a liquid triglyceride pro-drug of PBA, containing no sodium and having favorable palatability, is being studied for treatment of hepatic encephalopathy (HE). In vitro and clinical studies have been performed to assess GPB digestion, safety, and pharmacology in healthy adults and individuals with cirrhosis. GPB hydrolysis was measured in vitro by way of pH titration. Twenty-four healthy adults underwent single-dose administration of GPB and NaPBA and eight healthy adults and 24 cirrhotic subjects underwent single-day and multiple-day dosing of GPB, with metabolites measured in blood and urine. Simulations were performed to assess GPB dosing at higher levels. GPB was hydrolyzed by human pancreatic triglyceride lipase, pancreatic lipase-related protein 2, and carboxyl-ester lipase. Clinical safety was satisfactory. Compared with NaPBA, peak metabolite blood levels with GPB occurred later and were lower; urinary PAGN excretion was similar but took longer. Steady state was achieved within 4 days for both NaPBA and GPB; intact GPB was not detected in blood or urine. Cirrhotic subjects converted GPB to PAGN similarly to healthy adults. Simulations suggest that GPB can be administered safely to cirrhotic subjects at levels equivalent to the highest approved NaPBA dose for UCDs. Conclusion GPB exhibits delayed release characteristics, presumably reflecting gradual PBA release by pancreatic lipases, and is well tolerated in adults with cirrhosis, suggesting that further clinical testing for HE is warranted. PMID:20512995

Diuretic activity of Maydis stigma extract in rats.

PubMed

Maksimović, Z; Dobrić, S; Kovacević, N; Milovanović, Z

2004-12-01

Maydis stigma (corn silk) is a herbal drug reputed for the treatment of urinary ailments in various traditional medicine systems. To determine its influence on urinary volume and the excretion of sodium, potassium and chloride, 5% and 10% decoctions were administered daily to adult male Wistar rats for eight days. The concentration of electrolytes and urea in plasma, the influence of treatment on urinary pH value as well as creatinine clearance were also investigated. Daily oral administration of 5% decoction at the dose of 10 ml/kg led to a significant and acute diuresis in rats, reaching the peak value in the first 24 h of treatment. Over a similar period, application of 10% decoction did not affect urinary excretion of water, but significantly increased the pH value of excreted urine. A significant decrease in sodium and chloride plasma levels was observed in both treated groups. The creatinine clearance was markedly increased after the treatment with both extracts. Our findings indicate that the diuretic effect of 5% aqueous Maydis stigma extract is in accordance with the increase in glomerular filtration rate and inhibition of sodium and chloride tubular reabsorption, caused a by still unidentified intrinsic factor, but not the salt-loading effect.

[Serum sodium imbalance in the bedridden elderly. Part One: Realities and problem of management].

PubMed

Sasaki, A; Kogure, D; Ogawa, K; Sakurai, H; Katsunuma, H; Maehata, Y; Takasaki, M

1996-06-01

Symptoms and other abnormalities associated with serum sodium imbalance were studied in bedridden elderly and healthy elderly subjects. 1. A significantly higher number of the bedridden elderly suffered from chronic wasting disease. 2. The average serum sodium concentration in bedridden elderly subjects was significantly lower than in healthy subjects, as was the sodium intake and the sodium content in urine, which indicate that the bedridden elderly subjects suffered from chronic sodium deficiency. 3. The bedridden elderly subjects had high levels of plasma PRA and antidiuretic hormone, and their aldosterone levels were low, which indicate that their condition was associated with a decrease in available circulating plasma, hypersecretion of antidiuretic hormone, and a decline in the ability to retain sodium. 4. Measurement of 24-hr creatinine clearance, albumin, and beta 2-microglobulin in urine revealed that bedridden elderly subjects had high levels of renal dysfunction, the result of which may a disturbance in water excretion. Abnormalities in serum sodium levels in the bedridden elderly subjects were related to a chronic deficiency in sodium intake, which reduced their ability to maintain sodium levels and impaired their renal function. Iatrogenic factors are likely to play an important role in the genesis of this condition, and should be taken into account in during management.

Urinary Excretion of Sodium, Nitrogen, and Sugar Amounts Are Valid Biomarkers of Dietary Sodium, Protein, and High Sugar Intake in Nonobese Adolescents.

PubMed

Moore, Lori B; Liu, Sarah V; Halliday, Tanya M; Neilson, Andrew P; Hedrick, Valisa E; Davy, Brenda M

2017-12-01

Background: Objective indicators of dietary intake (e.g., biomarkers) are needed to overcome the limitations of self-reported dietary intake assessment methods in adolescents. To our knowledge, no controlled feeding studies to date have evaluated the validity of urinary sodium, nitrogen, or sugar excretion as dietary biomarkers in adolescents. Objective: This investigation aimed to evaluate the validity of urinary sodium, nitrogen, and total sugars (TS) excretion as biomarkers for sodium, protein, and added sugars (AS) intake in nonobese adolescents. Methods: In a crossover controlled feeding study design, 33 adolescents [12-18 y of age, 47 ± 25th percentile (mean ± SD) of body mass index (BMI; in kg/m 2 ) for age] consumed 5% AS [low added sugars (LAS)] and 25% AS [high added sugars (HAS)] isocaloric, macronutrient-matched (55% carbohydrate, 30% fat, and 15% protein) diets for 7 d each, in a randomly assigned order, with a 4-wk washout period between diets. On the final 2 d of each diet period, 24-h urine samples were collected. Thirty-two adolescents completed all measurements (97% retention). Results: Urinary sodium was not different from the expected 90% recovery (mean ± SD: 88% ± 18%, P = 0.50). Urinary nitrogen was correlated with protein intake ( r = 0.69, P < 0.001), although it was below the 80% expected recovery (62% ± 7%, P < 0.001). Urinary TS values were correlated with AS intake during the HAS diet ( r = 0.77, P < 0.001) and had a higher R 2 value of 0.28 than did AS intake ( R 2 = 0.36). TS excretion differed between LAS (0.226 ± 0.09 mg/d) and HAS (0.365 ± 0.16 mg/d) feeding periods ( P < 0.001). Conclusions: Urinary sodium appears to be a valid biomarker for sodium intake in nonobese adolescents. Urinary nitrogen is associated with protein intake, but nitrogen excretion rates were less than previously reported for adults, possibly owing to adolescent growth rates. TS excretion reflects AS at 25% AS intake and was responsive to the change in AS intake. Thus, urinary biomarkers are promising objective indicators of dietary intake in adolescents, although larger-scale feeding trials are needed to confirm these findings. This trial was registered at clinicaltrials.gov as NCT02455388. © 2017 American Society for Nutrition.

Effectiveness of a Self-monitoring Device for Urinary Sodium-to-Potassium Ratio on Dietary Improvement in Free-Living Adults: a Randomized Controlled Trial.

PubMed

Iwahori, Toshiyuki; Ueshima, Hirotsugu; Ohgami, Naoto; Yamashita, Hideyuki; Miyagawa, Naoko; Kondo, Keiko; Torii, Sayuki; Yoshita, Katsushi; Shiga, Toshikazu; Ohkubo, Takayoshi; Arima, Hisatomi; Miura, Katsuyuki

2018-01-05

Reducing the urinary sodium-to-potassium ratio is important for reducing both blood pressure and risk of cardiovascular disease. Among free-living Japanese individuals, we carried out a randomized trial to clarify the effect of lifestyle modification for lowering urinary sodium-to-potassium ratio using a self-monitoring device. This was an open, prospective, parallel randomized, controlled trial. Ninety-two individuals were recruited from Japanese volunteers. Participants were randomly allocated into intervention and control groups. A month-long dietary intervention on self-monitoring urinary sodium-to-potassium ratio was carried out using monitors (HEU-001F, OMRON Healthcare Co., Ltd., Kyoto, Japan). All participants had brief dietary education and received a leaflet as usual care. Monitors were handed out to the intervention group, but not to the control group. The intervention group was asked to measure at least one spot urine sodium-to-potassium ratio daily, and advised to lower their sodium-to-potassium ratio toward the target of less than 1. Outcomes included changes in 24-hour urinary sodium-to-potassium ratio, sodium excretion, potassium excretion, blood pressure, and body weight in both groups. Mean measurement frequency of monitoring was 2.8 times/day during the intervention. Changes in urinary sodium-to-potassium ratio were -0.55 in the intervention group and -0.06 in the control group (P = 0.088); respective sodium excretion changes were -18.5 mmol/24 hours and -8.7 mmol/24 hours (P = 0.528); and corresponding potassium excretion was 2.6 mmol/24 hours and -1.5 mmol/24 hours (P = 0.300). No significant reductions were observed in either blood pressure or body weight after the intervention. Providing the device to self-monitor a sodium-to-potassium ratio did not achieve the targeted reduction of the ratio in "pure self-management" settings, indicating further needs to study an effective method to enhance the synergetic effect of dietary programs and self-monitoring practice to achieve the reduction. However, we cannot deny the possibility of reducing sodium-to-potassium ratio using a self-monitoring device.

[Influence of non-sodium restricted diet with diuretics on plasma rennin, renal blood flow and in patients with cirrhotic ascites].

PubMed

Zhu, Yin-fang; Gu, Xi-bing; Zhu, Hong-ying; Yang, Xiao-juan; Wang, Dong; Yu, Ping

2013-02-01

To explore influence of sodium restricted diet and non-sodium restricted diet on plasma rennin (PRA), angiotensin II (All), ALD, renal blood flow (RBF) and subside of ascites in patients with cirrhotic ascites. Eighty cases of hepatitis B with cirrhotic ascites were randomly divided into sodium restricted diet group and non-sodium restricted diet group. 39 cases were in non-sodium restricted diet group, taking sodium chloride 6500-8000 mg daily; 41 cases were in sodium restricted diet group, taking sodium chloride 5000 mg daily. Both groups received diuretics furosemide and spironolactone. Blood sodium, urine sodium, PRA, AII, ALD, RBF ascites subsiding were compared after treatment. In non-sodium restricted diet group, blood sodium and urine sodium increased 10 days after treatment compared with those before treatment, and compared with those of sodium restricted diet group 10 days after treatment, P <0. 01. RBF increased compared with that before treatment, and compared with that of sodium restricted diet group 10 days after treatment, P < 0. 01. Renal damage induced by low blood sodium after treatment was less in non-sodium restricted diet group than that in sodium restricted diet group, P <0. 05. Ascites disappearance upon discharge was more in sodium restricted diet group than that in non-sodium restricted diet group, P <0. 01. Time of ascites disappearance was shorter in non-sodium restricted diet group than that in sodium restricted diet group, P < 0. 01. Compared with sodium restricted diet, while using diuretics of both groups, non-sodium restricted diet can increase level of blood sodium, thus increasing excretion of urine sodium and diuretic effect. It can also decrease levels of PRA, AII and ALD, increase renal blood flow and prevent renal damage induced by low blood sodium and facilitate subsiding of ascites.

Self-reported taste preference can be a proxy for daily sodium intake in middle-aged Japanese adults.

PubMed

Takachi, Ribeka; Ishihara, Junko; Iwasaki, Motoki; Ishii, Yuri; Tsugane, Shoichiro

2014-05-01

Reducing dietary salt intake remains a challenging issue in the management of chronic disease. Taste preference is suspected to be an important proxy index of daily sodium consumption. This study examined the difference in daily sodium intake according to self-reported taste preference for miso soup as representative of homemade cooking in middle-aged urban Japanese adults. Among 896 candidates randomly selected from examinees of cancer screening provided by the National Cancer Center, Japan, 143 men and women participated in this cross-sectional study. During the period from May 2007 through April 2008, participants provided a food frequency questionnaire, which included information on taste preference and dietary behaviors, a weighed food record over 4 consecutive days, a simultaneous 24-hour urine collection, and a sample of miso soup as it is usually prepared in the home. Mean 24-hour urinary sodium excretion and daily sodium intake were compared according to the self-reported taste preference for miso soup. Taste preference was significantly associated with both 24-hour urinary sodium excretion (trend P<0.01) and daily sodium intake (trend P=0.01), with a corresponding regression coefficient per 1 rank preference increment of 403 mg and 315 mg/day, respectively. The observed association between preference and urinary excretion was attenuated by further adjustment for discretionary salt-related behaviors. These findings suggest that self-reported taste preference for homemade cooking is a defining feature of daily sodium intake through discretionary salt-related dietary behaviors. A reduction in daily sodium consumption per 1 rank light preference was estimated to equate to approximately 1 g salt/day. Copyright © 2014 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Control of sodium excretion in patients with cranial diabetes insipidus maintained on desamino-[8-D-arginine]vasopressin.

PubMed

Sutters, M; Brace, C; Hatfield, E; Whitehurst, A; Lightman, S L; Peart, W S

1993-11-01

1. We have studied the response of six patients with cranial diabetes insipidus and six age-matched control subjects to dietary sodium restriction during constant administration of the synthetic vasopressin analogue desamino-[8-D-arginine]vasopressin. 2. Urine flow increased on the first low salt day in the normal control subjects but not in the patients with cranial diabetes insipidus. Body weight fell 1.35 kg in the control subjects but was constant in the patients with cranial diabetes insipidus. 3. Urinary sodium excretion fell at the same rate in both groups. Diurnal variation of urinary sodium excretion and creatinine clearance was present in the control subjects but not in the patients with cranial diabetes insipidus. 4. Changes in plasma sodium concentration and osmolality were similar. Plasma protein concentration increased more in the control subjects (from 69.1 +/- 1.5 to 73 +/- 1.2 versus from 71.7 +/- 1 to 73.2 +/- 1.1 milligrams). The responses of plasma atrial natriuretic peptide, plasma renin activity and salivary aldosterone concentration were similar between the two groups. Salivary aldosterone concentration levels were consistently higher in the patients with cranial diabetes insipidus. 5. We confirm that the low salt diuresis is triggered by release from the antidiuretic activity of arginine vasopressin. In the patients with cranial diabetes insipidus extracellular fluid osmoregulation appeared to be achieved by the movement of water out of and sodium into the extracellular fluid. 6. Absent posterior pituitary function and hypothalamic disturbances did not alter renal sodium conservation.(ABSTRACT TRUNCATED AT 250 WORDS)

The Yanomami Indians in the INTERSALT Study.

PubMed

Mancilha-Carvalho, Jairo de Jesus; Souza e Silva, Nelson Albuquerque

2003-03-01

To study the distribution and interrelationship among constitutional and biochemical variables with blood pressure (BP) in an population of Yanomami indians. To compare these findings with those of other populations. The Yanomami indians were part of the INTERSALT, a study comprising 10,079 males and females, aged from 20 to 59 years, belonging to 52 populations in 32 countries in Africa, the Americas, Asia, and Europe. Each of the 52 centers was required to accrue 200 individuals, 25 participants in each age group. The variables analyzed were as follows: age, sex, arterial BP, urinary sodium and potassium excretion (24-hour urine), body mass index, and alcohol ingestion. The findings in the Yanomami population were as follows: a very low urinary sodium excretion (0.9 mmol/24 h); mean systolic and diastolic BP levels of 95.4 mmHg and 61.4 mmHg, respectively; no cases of hypertension or obesity; and they have no knowledge of alcoholic beverages. Their BP levels do not elevate with age. The urinary sodium excretion relates positively and the urinary potassium excretion relates negatively to systolic BP. This correlation was maintained even when controlled for age and body mass index. A positive relation between salt intake and blood pressure was detected in the analysis of a set of diverse populations participating in the INTERSALT Study, including populations such as the Yanomami Indians. The qualitative observation of their lifestyle provided additional information.

The comparison of the diuretic and natriuretic efficacy of continuous and bolus intravenous furosemide in patients with chronic kidney disease.

PubMed

Sanjay, Srinivas; Annigeri, Rajeev A; Seshadri, Rajagopalan; Rao, Budithi Subba; Prakash, Kowdle C; Mani, Muthu Krishna

2008-06-01

To compare natriuretic, kaliuretic, diuretic and free water clearance efficacy of continuous versus bolus intravenous furosemide administration in patients with chronic renal insufficiency. In a prospective randomized cross-over trial, 42 patients of chronic renal insufficiency were randomized to receive the same dose of intravenous furosemide as bolus and continuous infusion. The effects of bolus and intravenous administration of furosemide on the volume of urine, sodium and potassium excretion were assessed. Mean age was 53.6 +/- 14 years and 23 (55%) were male. The mean modification of diet in renal disease glomerular filtration rate was 20.5 +/- 17 mL/min per 1.73 m(2). The urinary excretion of sodium in intravenous bolus and infusion was 98.1 +/- 78 and 114.4 +/- 100 mmol, respectively (P = 0.001). Total urinary volume following bolus and infusion of furosemide was 1064 +/- 627 and 1170 +/- 764 mL, respectively (0.001). The excretion of potassium was similar in bolus (15.8 +/- 16.6) and infusion (14.3 +/- 9) administration (P = 0.11). The fractional excretion of sodium was higher following infusion (16.63 +/- 16.1) than bolus administration (12.87 +/- 9) of furosemide (P = 0.016). Continuous intravenous infusion of furosemide has significantly better natriuretic and diuretic effect than bolus administration of the same dose of the drug in patients with advanced chronic renal insufficiency.

RENAL TUBULAR TRANSPORT OF INORGANIC DIVALENT IONS BY THE AGLOMERULAR MARINE TELEOST, LOPHIUS AMERICANUS

PubMed Central

Berglund, Fredrik; Forster, Roy P.

1958-01-01

A characterization was attempted of the mechanisms involved in the tubular transport of inorganic divalent ions by the aglomerular kidney of Lophius, attention being paid particularly to the possible existence of transport maxima (Tm) and to competition for transport among related substances undergoing tubular excretion. Excretory rates of divalent ions in non-treated fish during standard laboratory conditions paralleled spontaneous changes in urine flow. Tm rates of excretion were reached for magnesium, sulfate, and thiosulfate with corresponding plasma levels of 2 to 5, 5 to 17, and 4 to 12 µM/ml. respectively. Elevation of magnesium chloride levels in plasma markedly depressed calcium excretion; sodium thiosulfate similarly depressed sulfate excretion. Experimental observations suggest the existence of a transport system for divalent cations separate from another for divalent anions. Within each transport system the ion with the higher excretion rate depressed competitively transfer of the other ion. Neither system was influenced by probenecid (benemid) in doses which markedly depressed the simultaneous excretion rate of p-aminohippuric acid. PMID:13491814

Kidney function and urine protein composition in healthy volunteers during space station fitness tests.

PubMed

Fomina, Elena V; Lisova, Natalia Iu; Kireev, Kirill S; Tiys, Evgeny S; Kononikhin, Alexey S; Larina, Irina M

2015-05-01

There is a close physiological connection between muscular activity and kidney function. During physical exercise (PE) the qualitative and quantitative composition of urine changes. This paper explores the influence of moderate PE on urine protein composition. The study of urine protein composition will help to make corrections to the existing methods of countermeasures. There were 10 healthy men who exercised on a treadmill similar to the one onboard the International Space Station. We analyzed their urinary proteome composition, potassium level, sodium level, and their level of osmotically active substances before and after PE. After moderate PE, a small increase in urine flow speed and a constant glomerular filtration rate were noted. The average-group index of total protein excretion within the urine was reliably increased. From the 148 proteins identified in the urine, 64 were associated with known tissue origin. We found that protein penetration into the urine had a positive correlation with their tissue expression. Selectivity of the glomerular barrier during PE decreased and high-molecular weight proteins penetrated through the glomerular barrier more easily after PE. Performance of moderate intensity physical exercise of short duration did not lead to an increase in the glomerular filtration rate nor did diuresis increase above the limits of baseline variability. However, the protein excretion rate increased after PE. We also observed that protein composition drift indicated a change in the set of biological processes in which a given protein participated, in some cases activating, in some cases inactivating them.

Simultaneous LC-MS/MS determination of phenylbutyrate, phenylacetate benzoate and their corresponding metabolites phenylacetylglutamine and hippurate in blood and urine.

PubMed

Laryea, Maurice D; Herebian, Diran; Meissner, Thomas; Mayatepek, Ertan

2010-12-01

Inborn errors of urea metabolism result in hyperammonemia. Treatment of urea cycle disorders can effectively lower plasma ammonium levels and results in survival in the majority of patients. Available medications for treating urea cycle disorders include sodium benzoate (BA), sodium phenylacetate (PAA), and sodium phenylbutyrate (PBA) and are given to provide alternate routes for disposition of waste nitrogen excretion. In this study, we develop and validate a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of benzoic acid, phenylacetic acid, phenylbutyric acid, phenylacetylglutamine, and hippuric acid in plasma and urine from children with inborn errors of urea synthesis. Plasma extracts and diluted urine samples were injected on a reverse-phase column and identified and quantified by selected reaction monitoring (SRM) in negative ion mode. Deuterated analogues served as internal standards. Analysis time was 7 min. Assay precision, accuracy, and linearity and sample stability were determined using enriched samples. Quantification limits of the method were 100 ng/ml (0.3-0.8 μmol/L) for all analytes, and recoveries were >90%. Inter- and intraday relative standard deviations were <10%. Our newly developed LC-MS/MS represents a robust, sensitive, and rapid method that allows simultaneous determination of the five compounds in plasma and urine.

Excess dietary sodium and inadequate potassium intake in Italy: results of the MINISAL study.

PubMed

Donfrancesco, C; Ippolito, R; Lo Noce, C; Palmieri, L; Iacone, R; Russo, O; Vanuzzo, D; Galletti, F; Galeone, D; Giampaoli, S; Strazzullo, P

2013-09-01

As excess sodium and inadequate potassium intake are causally related to hypertension and cardiovascular disease, the MINISAL-GIRCSI Program aimed to provide reliable estimates of dietary sodium and potassium intake in representative samples of the Italian population. Random samples of adult population were collected from 12 Italian regions, including 1168 men and 1112 women aged 35-79 yrs. Electrolyte intake was estimated from 24 hour urine collections and creatinine was measured to estimate the accuracy of the collection. Anthropometric indices were measured with standardised procedures. The average sodium excretion was 189 mmol (or 10.9 g of salt/day) among men and 147 mmol (or 8.5 g) among women (range 27-472 and 36-471 mmol, respectively). Ninety-seven % of men and 87% of women had a consumption higher than the WHO recommended target of 5g/day. The 24 h average potassium excretion was 63 and 55 mmol, respectively (range 17-171 and 20-126 mmol), 96% of men and 99% of women having an intake lower than 100 mmol/day (European and American guideline recommendation). The mean sodium/potassium ratio was 3.1 and 2.8 respectively, i.e. over threefold greater than the desirable level of 0.85. The highest sodium intake was observed in Southern regions. Sodium and potassium excretion were both progressively higher the higher the BMI (p < 0.0001). These MINISAL preliminary results indicate that in all the Italian regions thus far surveyed dietary sodium intake was largely higher and potassium intake lower than the recommended intakes. They also highlight the critical association between overweight and excess salt intake. Copyright © 2012 Elsevier B.V. All rights reserved.

Magnesium retention from metabolic-balance studies in female adolescents: impact of race, dietary salt, and calcium123

PubMed Central

Palacios, Cristina; Wigertz, Karin; Braun, Michelle; Martin, Berdine R; McCabe, George P; McCabe, Linda; Pratt, J Howard; Peacock, Munro; Weaver, Connie M

2013-01-01

Background: Previously, we showed that black girls retained more calcium than white girls did and that salt loading negatively affected calcium retention. Racial differences likely exist in other bone minerals also, such as magnesium, in response to salt loading during growth. Objective: We studied racial differences in magnesium metabolism in response to dietary sodium and calcium during rapid bone growth. Design: Twenty-seven white and 40 black girls (11–15 y old) were studied for 3 wk while they consumed low-sodium (1.3 g/d) and high-sodium (3.8 g/d) diets by using a randomized-order, crossover metabolic study with 3 dietary calcium intakes; the magnesium dietary intake was fixed at 230 mg/d. Urine and feces were collected during each 3-wk period in 24-h pools and analyzed for magnesium. A mixed-model ANOVA was used to determine the effect of race and dietary sodium with calcium intake as a covariate. Results: Salt loading or calcium intake had no significant effect on urinary magnesium excretion. Blacks excreted significantly less urinary magnesium (mean ± SD: 83.8 ± 25.6 mg/d) than did whites (94.9 ± 27.3 mg/d; P < 0.05). No effects were observed in fecal magnesium excretion. Magnesium retention was higher with the low-sodium diet (50.1 ± 44.0 mg/d) than with the high-sodium diet (39.3 ± 49.8 mg/d) (P < 0.05), with no effects of race or calcium intake. Salt loading had no effect on biomarkers. Whites had higher 25-hydroxyvitamin D and insulin-like growth factor binding protein 3 but lower 1,25-dihydroxyvitamin D and parathyroid hormone concentrations. Conclusions: Blacks excreted less urinary magnesium than did whites. Magnesium retention was similar between races but higher with the low-sodium diet. Kinetic studies are needed to fully explain magnesium homeostasis. This trial was registered at clinicaltrials.gov as NCT01564238. PMID:23553157

Mechanisms contributing to adverse cardiovascular events in patients with type 2 diabetes mellitus and stage 4 chronic kidney disease treated with bardoxolone methyl.

PubMed

Chin, Melanie P; Reisman, Scott A; Bakris, George L; O'Grady, Megan; Linde, Peter G; McCullough, Peter A; Packham, David; Vaziri, Nosratola D; Ward, Keith W; Warnock, David G; Meyer, Colin J

2014-01-01

Bardoxolone methyl, an Nrf2-activating and nuclear factor-κB-inhibiting semisynthetic oleanane triterpenoid compound, was evaluated in a phase 3 trial (BEACON) in patients with type 2 diabetes mellitus (T2DM) and stage 4 chronic kidney disease (CKD). The trial was terminated because of an increase in heart failure events in the bardoxolone methyl group, many of which appeared related to fluid retention. Thus, additional analyses were conducted to explain these serious adverse events. Patients (n = 2,185) were randomized to receive once-daily bardoxolone methyl (20 mg) or placebo. Twenty-four-hour urine collections were analyzed in a subset of the BEACON population and from a separate, open-label pharmacology study in patients with stage 3b/4 CKD and T2DM administered 20 mg bardoxolone methyl once daily for 56 consecutive days. Bardoxolone-methyl-treated patients in the BEACON substudy had a clinically meaningful reduction in urine volume and sodium excretion at week 4 relative to baseline (p < 0.05), and a separate study revealed that decreased sodium excretion and urine output occurred in some patients with stage 4 CKD but not those with stage 3b CKD. The clinical phenotype of fluid overload and heart failure in BEACON was similar to that observed with endothelin receptor antagonists in advanced CKD patients, and preclinical data demonstrate that bardoxolone methyl modifies endothelin signaling. The totality of the evidence suggests that through modulation of the endothelin pathway, bardoxolone methyl may pharmacologically promote acute sodium and volume retention and increase blood pressure in patients with more advanced CKD.

Plasma volume and renal function during and after ultramarathon running.

PubMed

Irving, R A; Noakes, T D; Burger, S C; Myburgh, K H; Querido, D; van Zyl Smit, R

1990-10-01

Plasma volume (PV) and renal function were studied in eight subjects for 3 d prior to and 6 d after a 56 km footrace. Immediately following the race, PV, creatinine clearance, and urine flow were unchanged from pre-race values. Over the subsequent 3 d, PV increased due initially to a 17 g influx of serum albumin and an associated increase in plasma sodium content, which persisted throughout the study period. A reduction in urine sodium secretion occurred during the race day. Creatinine clearance increased after the race and remained elevated for 48 h. Increases serum enzyme activities, C-reactive protein concentration, serum uric acid content, and plasma creatinine concentration and production suggest muscle damage. We suggested the following. First, the persistent post-exercise plasma volume expansion is initiated by an influx of albumin into the intravascular space with an associated increase in plasma sodium content. A decrease in urine sodium excretion during the race day would contribute to the latter. Second, the interpretation of post-race changes in serum constituents must take account of changes in plasma volume. Third, there is an increase in creatinine clearance, indicating an increase in glomerular filtration rate, after both standard and ultramarathon running. This may be caused by the products of muscle cell damage although the physiologic mechanism for this is unclear.

The Role of Epithelial Sodium Channel ENaC and the Apical Cl-/HCO3- Exchanger Pendrin in Compensatory Salt Reabsorption in the Setting of Na-Cl Cotransporter (NCC) Inactivation.

PubMed

Patel-Chamberlin, Mina; Varasteh Kia, Mujan; Xu, Jie; Barone, Sharon; Zahedi, Kamyar; Soleimani, Manoocher

2016-01-01

The absence of NCC does not cause significant salt wasting in NCC deficient mice under basal conditions. We hypothesized that ENaC and pendrin play important roles in compensatory salt absorption in the setting of NCC inactivation, and their inhibition and/or downregulation can cause significant salt wasting in NCC KO mice. WT and NCC KO mice were treated with a daily injection of either amiloride, an inhibitor of ENaC, or acetazolamide (ACTZ), a blocker of salt and bicarbonate reabsorption in the proximal tubule and an inhibitor of carbonic anhydrases in proximal tubule and intercalated cells, or a combination of acetazolamide plus amiloride for defined durations. Animals were subjected to daily balance studies. At the end of treatment, kidneys were harvested and examined. Blood samples were collected for electrolytes and acid base analysis. Amiloride injection significantly increased the urine output (UO) in NCC KO mice (from 1.3 ml/day before to 2.5 ml/day after amiloride, p<0.03, n = 4) but caused only a slight change in UO in WT mice (p>0.05). The increase in UO in NCC KO mice was associated with a significant increase in sodium excretion (from 0.25 mmol/24 hrs at baseline to 0.35 mmol/24 hrs after amiloride injection, p<0.05, n = 4). Daily treatment with ACTZ for 6 days resulted in >80% reduction of kidney pendrin expression in both WT and NCC KO mice. However, ACTZ treatment noticeably increased urine output and salt excretion only in NCC KO mice (with urine output increasing from a baseline of 1.1 ml/day to 2.3 ml/day and sodium excretion increasing from 0.22 mmole/day before to 0.31 mmole/day after ACTZ) in NCC KO mice; both parameters were significantly higher than in WT mice. Western blot analysis demonstrated significant enhancement in ENaC expression in medulla and cortex of NCC KO and WT mice in response to ACTZ injection for 6 days, and treatment with amiloride in ACTZ-pretreated mice caused a robust increase in salt excretion in both NCC KO and WT mice. Pendrin KO mice did not display a significant increase in urine output or salt excretion after treatment with amiloride or ACTZ. 1. ENaC plays an important role in salt reabsorption in NCC KO mice. 2. NCC contributes to compensatory salt reabsorption in the setting of carbonic anhydrase inhibition, which is associated with increased delivery of salt from the proximal tubule and the down regulation of pendrin. 3. ENaC is upregulated by ACTZ treatment and its inhibition by amiloride causes significant diuresis in NCC KO and WT mice. Despite being considered mild agents individually, we propose that the combination of acetazolamide and amiloride in the setting of NCC inhibition (i.e., hydrochlorothiazide) will be a powerful diuretic regimen.

Dietary potassium intake and renal handling, and their impact on the cardiovascular health of normotensive afro-caribbeans.

PubMed

Cohall, D H; Scantlebury-Manning, T; Rafie, C; James, S; Hall, K

2014-01-01

Recent nutritional profiles of dietary intake have indicated a shift from the ancient diet to the Western diet. The ancient diet provided a high potassium and low sodium intake, which in turn leads to sodium conservation and potassium excretion. This change in the dietary intake is expected to affect potassium and sodium handling in the kidneys. Numerous studies have been done to emphasize the importance of sodium handling by the kidneys and its impact on cardiovascular health. This study will investigate potassium intake and handling, and its impact on the cardiovascular health of a sample of normotensive Afro-Caribbeans by the possible modulation of the renin angiotensin aldosterone system (RAAS). A sample of 51 normotensive Afro-Caribbean participants was recruited for the study. Participants were observed over a two-day period in which they were given a 24-hour ambulatory blood pressure monitor and a container to collect blood pressure data and a 24-hour urine sample. Anthropometric measurements were noted. Urinary electrolytes and supine plasma renin activity (PRA) were determined from the 24-hour urine collection and a blood sample. Dietary potassium intake was estimated based on dietary intake observations and calculated based on the urinary potassium excretion. SPSS version 19 was used to analyse the data to make inferences. The daily potassium intake was observed to be 2.95 g/day and measured intake from the urinary potassium was between 4.95 and 7.32 g/day. Urinary potassium excretion was 3.66 (± 1.40) g/day. The urinary potassium excretion in the Afro-Caribbean sample in Barbados was higher than the other population samples. The averaged PRA of the participants (supine) was 0.778 (± 1.072) ng/mL/hour. The averaged nocturnal systolic blood pressure dip of the participants was 5.97 (± 4.324) %. There was no significant correlation between urinary potassium excretion, blood pressure, nocturnal systolic blood pressure dip and PRA. The Afro-Caribbean sample has an inadequate daily potassium intake based on the observed intake and recommended values, with a high urinary excretion of the electrolyte compared to other values in the literature. This high potassium excretion could have been partly due to low plasma renin activity levels in the study participants. As a possible consequence, an increase in the nocturnal peripheral resistance is a likely cause for the diminished systolic dip. The lack of correlations between dietary potassium excretion and the blood pressure parameters does not allow any firm inference of the electrolyte's handling and its impact on cardiovascular health in the normotensive Afro-Caribbean participants. However, further research is needed to get a more accurate daily potassium intake value, and a more statistically robust sample to assess whether potassium handling and blood pressure would be affected by a change in potassium intake.

Blood, urine, and hair kinetic analysis following an acute lead intoxication.

PubMed

Ho, G; Keutgens, A; Schoofs, R; Kotolenko, S; Denooz, R; Charlier, C

2011-01-01

A case of lead exposure resulting from the accidental ingestion of a lead-containing solution is reported. Because of clinical management rapidly performed through chelation therapy by 2,3-dimercaptopropane sulfonate sodium and meso-2,3-dimercaptosuccinic acid, blood lead levels of this 51-year-old patient were moderate (412.9 μg/L) and no clinical symptoms were observed. Numerous blood and urine samples were collected for kinetic analysis of lead elimination. However, we report the first case in which hair samples were analyzed to determine the excretion level of lead after acute intoxication.

Voluntary sodium intake during effort in hot environments

NASA Technical Reports Server (NTRS)

Sohar, E.; Adar, R.; Hershco, A.

1982-01-01

The factors that influence the amount of salt that a person adds to his food at mealtime, and the part played by the general requirement for salt in the daily diet stemming from the coluntary input of salt are studied. Careful measurements of salt intake and outflow were performed on ten marchers in a high temperature environment who were given individual salt shakers that were weighed before and after each meal. Some marchers were told to add salt to their meals on specific days. No parallelity was found between the voluntary sodium intake and the general sodium intake, the excretion of sodium in the urine or the environmental heat stress. Individual food habit was found to be the most important factor.

Urinary Phenylacetylglutamine as Dosing Biomarker for Patients with Urea Cycle Disorders

PubMed Central

Mokhtarani, M; Diaz, GA; Rhead, W; Lichter-Konecki, U; Bartley, J; Feigenbaum, A; Longo, N; Berquist, W; Berry, SA; Gallagher, R; Bartholomew, D; Harding, CO; Korson, MS; McCandless, SE; Smith, W; Vockley, J; Bart, S; Kronn, D; Zori, R; Cederbaum, S; Dorrani, N; Merritt, JL; Sreenath-Nagamani, Sandesh; Summar, M; LeMons, C; Dickinson, K; Coakley, DF; Moors, TL; Lee, B; Scharschmidt, BF

2013-01-01

We have analyzed pharmacokinetic data for glycerol phenylbutyrate (also GT4P or HPN-100) and sodium phenylbutyrate with respect to possible dosing biomarkers in patients with urea cycle disorders (UCD). Study Design These analyses are based on over 3000 urine and plasma data points from 54 adult and 11 pediatric UCD patients (ages 6–17) who participated in three clinical studies comparing ammonia control and pharmacokinetics during steady state treatment with glycerol phenylbutyrate or sodium phenylbutyrate. All patients received phenylbutyric acid equivalent doses of glycerol phenylbutyrate or sodium phenylbutyrate in a cross over fashion and underwent 24-hour blood samples and urine sampling for phenylbutyric acid, phenylacetic acid and phenylacetylglutamine. Results Patients received phenylbutyric acid equivalent doses of glycerol phenylbutyrate ranging from 1.5–31.8 g/day and of sodium phenylbutyrate ranging from 1.3–31.7 g/day. Plasma metabolite levels varied widely, with average fluctuation indices ranging from 1979% –5690% for phenylbutyric acid, 843% to 3931% for phenylacetic acid, and 881% -to 1434% for phenylacetylglutamine. Mean percent recovery of phenylbutyric acid as urinary phenylacetylglutamine was 66.4 and 69.0 for pediatric patients and 68.7 and 71.4 for adult patients on glycerol phenylbutyrate and sodium phenylbutyrate, respectively. The correlation with dose was strongest for urinary phenylacetylglutamine excretion, either as morning spot urine (r=0.730, p<0.001) or as total 24-hour excretion (r=0.791 p<0.001), followed by plasma phenylacetylglutamine AUC24-hour, plasma phenylacetic acid AUC24-hour and phenylbutyric acid AUC24-hour. Plasma phenylacetic acid levels in adult and pediatric patients did not show a consistent relationship with either urinary phenylacetylglutamine or ammonia control. Conclusion The findings are collectively consistent with substantial yet variable pre-systemic (1st pass) conversion of phenylbutyric acid to phenylacetic acid and/or phenylacetylglutamine. The variability of blood metabolite levels during the day, their weaker correlation with dose, the need for multiple blood samples to capture trough and peak, and the inconsistency between phenylacetic acid and urinary phenylacetylglutamine as a marker of waste nitrogen scavenging limit the utility of plasma levels for therapeutic monitoring. By contrast, 24-hour urinary phenylacetylglutamine and morning spot urine phenylacetylglutamine correlate strongly with dose and appear to be clinically useful non-invasive biomarkers for compliance and therapeutic monitoring. PMID:22958974

Urinary phenylacetylglutamine as dosing biomarker for patients with urea cycle disorders.

PubMed

Mokhtarani, M; Diaz, G A; Rhead, W; Lichter-Konecki, U; Bartley, J; Feigenbaum, A; Longo, N; Berquist, W; Berry, S A; Gallagher, R; Bartholomew, D; Harding, C O; Korson, M S; McCandless, S E; Smith, W; Vockley, J; Bart, S; Kronn, D; Zori, R; Cederbaum, S; Dorrani, N; Merritt, J L; Sreenath-Nagamani, Sandesh; Summar, M; Lemons, C; Dickinson, K; Coakley, D F; Moors, T L; Lee, B; Scharschmidt, B F

2012-11-01

We have analyzed pharmacokinetic data for glycerol phenylbutyrate (also GT4P or HPN-100) and sodium phenylbutyrate with respect to possible dosing biomarkers in patients with urea cycle disorders (UCD). These analyses are based on over 3000 urine and plasma data points from 54 adult and 11 pediatric UCD patients (ages 6-17) who participated in three clinical studies comparing ammonia control and pharmacokinetics during steady state treatment with glycerol phenylbutyrate or sodium phenylbutyrate. All patients received phenylbutyric acid equivalent doses of glycerol phenylbutyrate or sodium phenylbutyrate in a cross over fashion and underwent 24-hour blood samples and urine sampling for phenylbutyric acid, phenylacetic acid and phenylacetylglutamine. Patients received phenylbutyric acid equivalent doses of glycerol phenylbutyrate ranging from 1.5 to 31.8 g/day and of sodium phenylbutyrate ranging from 1.3 to 31.7 g/day. Plasma metabolite levels varied widely, with average fluctuation indices ranging from 1979% to 5690% for phenylbutyric acid, 843% to 3931% for phenylacetic acid, and 881% to 1434% for phenylacetylglutamine. Mean percent recovery of phenylbutyric acid as urinary phenylacetylglutamine was 66.4 and 69.0 for pediatric patients and 68.7 and 71.4 for adult patients on glycerol phenylbutyrate and sodium phenylbutyrate, respectively. The correlation with dose was strongest for urinary phenylacetylglutamine excretion, either as morning spot urine (r = 0.730, p < 0.001) or as total 24-hour excretion (r = 0.791 p<0.001), followed by plasma phenylacetylglutamine AUC(24-hour), plasma phenylacetic acid AUC(24-hour) and phenylbutyric acid AUC(24-hour). Plasma phenylacetic acid levels in adult and pediatric patients did not show a consistent relationship with either urinary phenylacetylglutamine or ammonia control. The findings are collectively consistent with substantial yet variable pre-systemic (1st pass) conversion of phenylbutyric acid to phenylacetic acid and/or phenylacetylglutamine. The variability of blood metabolite levels during the day, their weaker correlation with dose, the need for multiple blood samples to capture trough and peak, and the inconsistency between phenylacetic acid and urinary phenylacetylglutamine as a marker of waste nitrogen scavenging limit the utility of plasma levels for therapeutic monitoring. By contrast, 24-hour urinary phenylacetylglutamine and morning spot urine phenylacetylglutamine correlate strongly with dose and appear to be clinically useful non-invasive biomarkers for compliance and therapeutic monitoring. Copyright © 2012 Elsevier Inc. All rights reserved.

Water Prescription in Autosomal Dominant Polycystic Kidney Disease: A Pilot Study

PubMed Central

Creed, Catherine; Winklhofer, Franz T.; Grantham, Jared J.

2011-01-01

Summary Background and objectives In animal models of polycystic kidney disease, the ingestion of large amounts of water promotes diuresis by suppressing plasma levels of arginine vasopressin (AVP) and renal levels of cAMP, slowing cyst progression. Whether simple water ingestion is a potential therapeutic strategy for individuals with autosomal dominant polycystic kidney disease (ADPKD) is unknown. In this study, a simple method to quantify the amount of water to achieve a specific mean urine osmolality target in patients with ADPKD was developed and tested. Design, setting, participants, & measurements In eight ADPKD patients eating typical diets, osmolality and volume were measured in 24-hour urine collections. The amount of additional ingested water required daily to achieve a mean urine osmolality of 285 ± 45 mosm/kg was determined. Participants were instructed to distribute the prescribed water over waking hours for each of 5 days. Blood chemistries, 24-hour urine collections, BP, and weight were measured before and after the period of supplemental water intake. Results Five patients achieved the 285 mosm/kg urine target without difficulty. Mean urine osmolality decreased and mean urine volume increased; serum sodium, weight, and BP were unchanged. Daily osmolar excretion remained constant, indicating a stable ad lib dietary intake of solutes and protein over the 2-week study period. Conclusions The amount of additional water needed to achieve a urine osmolality target can be approximated from the urine osmolar excretion in ADPKD patients eating typical diets, providing a quantitative method to prescribe supplemental water for such individuals. PMID:20876670

The correlation of sodium and potassium metabolism with the level of energy consumption in man during adaptation to heat

NASA Technical Reports Server (NTRS)

Afanasyev, B. G.; Zhestovskiy, V. A.

1978-01-01

The sodium and potassium metabolism was studied in a thermal chamber at 35 deg and 80 percent relative humidity in 8 men for a period of 6 days. The control group (3 subjects) were outside of the chamber at a comfortable ambient temperature. The intracellular sodium and potassium metabolism were assessed based on their content in the erythrocytes. The finding was that during adaptation to heat, a considerable amount of sodium was excreted by the body in the sweat and urine (about 1/3 of the sodium content of the human body) as compared with its intake and the amount of potassium retained in the body. Changes in the concentration of sodium and potassium may serve as indexes of the state of adaptation processes during constant exposure to heat.

Prenatal programming of renal salt wasting resets postnatal salt appetite, which drives food intake in the rat.

PubMed

Alwasel, Saleh H; Barker, David J P; Ashton, Nick

2012-03-01

Sodium retention has been proposed as the cause of hypertension in the LP rat (offspring exposed to a maternal low-protein diet in utero) model of developmental programming because of increased renal NKCC2 (Na+/K+/2Cl- co-transporter 2) expression. However, we have shown that LP rats excrete more rather than less sodium than controls, leading us to hypothesize that LP rats ingest more salt in order to maintain sodium balance. Rats were fed on either a 9% (low) or 18% (control) protein diet during pregnancy; male and female offspring were studied at 4 weeks of age. LP rats of both sexes held in metabolism cages excreted more sodium and urine than controls. When given water to drink, LP rats drank more and ate more food than controls, hence sodium intake matched excretion. However, when given a choice between saline and water to drink, the total volume of fluid ingested by LP rats fell to control levels, but the volume of saline taken was significantly larger [3.8±0.1 compared with 8.8±1.3 ml/24 h per 100 g of body weight in control and LP rats respectively; P<0.001]. Interestingly food intake also fell to control levels. Total body sodium content and ECF (extracellular fluid) volumes were greater in LP rats. These results show that prenatal programming of renal sodium wasting leads to a compensatory increase in salt appetite in LP rats. We speculate that the need to maintain salt homoeostasis following malnutrition in utero stimulates greater food intake, leading to accelerated growth and raised BP (blood pressure).

Enantioselectivity of debrisoquine 4-hydroxylation in Brazilian Caucasian hypertensive patients phenotyped as extensive metabolizers.

PubMed

Cerqueira, P M; Mateus, F H; Cesarino, E J; Bonato, P S; Lanchote, V L

2000-12-01

Debrisoquine (D), an antihypertensive drug metabolized to 4-hydroxydebrisoquine (4-OHD) by CYP2D6, is commonly used as an in vivo probe of CYP2D6 activity and can be used to phenotype individuals as either extensive (EMs) or poor metabolizers (PMs) of such drugs as beta-adrenergic blockers, tricyclic antidepressants, and class 1C antiarrhythmics. This report describes reversed-phase HPLC systems by which D and 4-OHD or S-(+) and R-(-)-4-OHD in urine are more selectively quantified without the need for derivatization techniques. We also studied the urinary excretion of R-(-)- and S-(+)-4-hydroxydebrisoquine in EM hypertensive patients in order to determine weather 4-OHD formation exhibits enantioselectivity. Twelve patients with mild to severe essential hypertension were admitted to the study. They received a single tablet of Declinax containing 10 mg debrisoquine sulfate. All the urine excreted during the following 8 h was collected. The debrisoquine metabolic ratio (DMR) was calculated as % of dose excreted as D/% of dose excreted as 4-OHD and the debrisoquine recovery ratio (DRR) was calculated as % of dose excreted as 4-OHD/% of dose excreted as D+4-OHD. Debrisoquine and its metabolite were determined in urine by HPLC using a reversed-phase Select B LiChrospher column, a mobile phase of 0.25 N acetate buffer, pH 5-acetonitrile (9:1, v/v) and a fluorescence detector. The limit of quantitation was determined to be 25.0 ng/ml for D and 18.75 ng/ml for 4-OHD. Intra- and inter-day relative standard deviations (RSDs) were less than 10%. All hypertensive patients studied showed a DMR of less than 12.6 or a DRR higher than 0.12 and were classified as EMs. Direct enantioselective separation on chiral stationary phase involved resolution of S-(+)-4-OHD and R-(-)-4-OHD on a Chiralcel OD-R column with a mobile phase of 0.125 N sodium perchlorate, pH 5-acetonitrile-methanol (85:12:3, v/v/v). The quantitation limit of each enantiomer was 3.75 ng/ml of urine. Intra- and inter-day RSDs were less than 10% for each enantiomer. A high degree of enantioselectivity in the 4-hydroxylation of D favouring the S-(+) enantiomer was observed, resulting in R-(-)-4-OHD not detected in the urine of the EM hypertensive patients studied.

Urinary potassium excretion and risk of developing hypertension: the prevention of renal and vascular end-stage disease study.

PubMed

Kieneker, Lyanne M; Gansevoort, Ron T; Mukamal, Kenneth J; de Boer, Rudolf A; Navis, Gerjan; Bakker, Stephan J L; Joosten, Michel M

2014-10-01

Previous prospective cohort studies on the association between potassium intake and risk of hypertension have almost exclusively relied on self-reported dietary data, whereas repeated 24-hour urine excretions, as estimate of dietary uptake, may provide a more objective and quantitative estimate of this association. Risk of hypertension (defined as blood pressure ≥140/90 mm Hg or initiation of blood pressure-lowering drugs) was prospectively studied in 5511 normotensive subjects aged 28 to 75 years not using blood pressure-lowering drugs at baseline of the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study. Potassium excretion was measured in two 24-hour urine specimens at baseline (1997-1998) and midway during follow-up (2001-2003). Baseline median potassium excretion was 70 mmol/24 h (interquartile range, 57-85 mmol/24 h), which corresponds to a dietary potassium intake of ≈91 mmol/24 h. During a median follow-up of 7.6 years (interquartile range, 5.0-9.3 years), 1172 subjects developed hypertension. The lowest sex-specific tertile of potassium excretion (men: <68 mmol/24 h; women: <58 mmol/24 h) had an increased risk of hypertension after multivariable adjustment (hazard ratio, 1.20; 95% confidence interval, 1.05-1.37), compared with the upper 2 tertiles (Pnonlinearity=0.008). The proportion of hypertension attributable to low potassium excretion was 6.2% (95% confidence interval, 1.7%-10.9%). No association was found between the sodium to potassium excretion ratio and risk of hypertension after multivariable adjustment. Low urinary potassium excretion was associated with an increased risk of developing hypertension. Dietary strategies to increase potassium intake to the recommended level of 90 mmol/d may have the potential to reduce the incidence of hypertension. © 2014 American Heart Association, Inc.

Diurnal pattern of sodium excretion in dogs with and without chronically reduced renal perfusion pressure.

PubMed

Corea, M; Seeliger, E; Boemke, W; Reinhardt, H W

1996-01-01

In 5 conscious dogs the diurnal patterns of urinary sodium excretion (UNaV) were investigated, initially during 1 control day and, thereafter, during 4 days of servo-controlled reduction of renal perfusion pressure (rRPP). The individual dog's mean arterial blood pressure was reduced to 80% of the blood pressure on the control day. This value was always found to be below the threshold for the pressure-dependent renin release. During the entire study period urine was collected in 4-hour intervals and blood samples were taken every 4 h. The dogs were kept on a standardized high sodium and high water intake and were fed once daily at 8.30 h. On the control day, UNaV, urinary flow rate (UV), fractional lithium excretion (FELi) and fractional sodium excretion (FENa) had similar diurnal patterns. They peaked 4-8 h after food intake and decreased to low values during the night. On day 1 of rRPP, UNaV and FENa were maintained at very low levels in all collection periods, whereas the patterns of UV and FELi were unaltered compared with the patterns on the control day. On days 2-4 of rRPP, a clear-cut maximum in the patterns of UNaV and FENa recurred, comparable with the patterns on the control day. However, compared with the control day this maximum was shifted by 4 h towards the night. In contrast, the patterns of UV and FELi remained unchanged compared with the control day. The results indicate that UNaV has a typical time course in conscious, sodium- and water-replete dogs fed once daily. Endogenous stimulation of sodium reabsorption by means of rRPP results in a characteristic 4-hour shift of UNaV and FENa towards the night during rRPP days 2-4. This delay in UNaV seems to be evoked by processes in the distal tubule.

Natriuretic factor, a lasting enigma.

PubMed

Licht, A; Fine, L G; Bourgoignie, J J

1978-01-01

A gel filtration fraction of urine from patients with chronic uremia (natriuretic factor) decreases potential difference, net sodium flux and lumen to peritubular flux of sodium across the isolated rabbit cortical collecting tubule. These effects are consistent with the possibility that natriuretic factor represents a modulator of sodium excretion in the mammalian nephron. Natriuretic factor induces a dose-dependent inhibition of short-circuit current in the isolated toad bladder. By comparing the effects of natriuretic factor to those of a standard unit of reference, it may be possible to develop a quantitative assay for natriuretic factor. The acidic nature of natriuretic factor was confirmed by cation exchange column in a high pressure liquid chromatography system.

Effectiveness of a Self-monitoring Device for Urinary Sodium-to-Potassium Ratio on Dietary Improvement in Free-Living Adults: a Randomized Controlled Trial

PubMed Central

Ueshima, Hirotsugu; Ohgami, Naoto; Yamashita, Hideyuki; Miyagawa, Naoko; Kondo, Keiko; Torii, Sayuki; Yoshita, Katsushi; Shiga, Toshikazu; Ohkubo, Takayoshi; Arima, Hisatomi; Miura, Katsuyuki

2018-01-01

Background Reducing the urinary sodium-to-potassium ratio is important for reducing both blood pressure and risk of cardiovascular disease. Among free-living Japanese individuals, we carried out a randomized trial to clarify the effect of lifestyle modification for lowering urinary sodium-to-potassium ratio using a self-monitoring device. Methods This was an open, prospective, parallel randomized, controlled trial. Ninety-two individuals were recruited from Japanese volunteers. Participants were randomly allocated into intervention and control groups. A month-long dietary intervention on self-monitoring urinary sodium-to-potassium ratio was carried out using monitors (HEU-001F, OMRON Healthcare Co., Ltd., Kyoto, Japan). All participants had brief dietary education and received a leaflet as usual care. Monitors were handed out to the intervention group, but not to the control group. The intervention group was asked to measure at least one spot urine sodium-to-potassium ratio daily, and advised to lower their sodium-to-potassium ratio toward the target of less than 1. Outcomes included changes in 24-hour urinary sodium-to-potassium ratio, sodium excretion, potassium excretion, blood pressure, and body weight in both groups. Results Mean measurement frequency of monitoring was 2.8 times/day during the intervention. Changes in urinary sodium-to-potassium ratio were −0.55 in the intervention group and −0.06 in the control group (P = 0.088); respective sodium excretion changes were −18.5 mmol/24 hours and −8.7 mmol/24 hours (P = 0.528); and corresponding potassium excretion was 2.6 mmol/24 hours and −1.5 mmol/24 hours (P = 0.300). No significant reductions were observed in either blood pressure or body weight after the intervention. Conclusions Providing the device to self-monitor a sodium-to-potassium ratio did not achieve the targeted reduction of the ratio in “pure self-management” settings, indicating further needs to study an effective method to enhance the synergetic effect of dietary programs and self-monitoring practice to achieve the reduction. However, we cannot deny the possibility of reducing sodium-to-potassium ratio using a self-monitoring device. PMID:29093302

Misclassification of iodine intake level from morning spot urine samples with high iodine excretion among Inuit and non-Inuit in Greenland.

PubMed

Andersen, Stig; Waagepetersen, Rasmus; Laurberg, Peter

2015-05-14

Iodine nutrition is commonly assessed from iodine excretion in urine. A 24 h urine sample is ideal, but it is cumbersome and inconvenient. Hence, spot urine samples with creatinine to adjust for differences in void volume are widely used. Still, the importance of ethnicity and the timing of spot urine samples need to be settled. We, thus, collected 104 early morning spot urine samples and 24 h urine samples from Inuit and non-Inuit living in Greenland. Diet was assessed by a FFQ. Demographic data were collected from the national registry and by questionnaires. Iodine was measured using the Sandell-Kolthoff reaction, creatinine using the Jaffe method and para-amino benzoic acid by the HPLC method for the estimation of completeness of urine sampling and compensation of incomplete urine samples to 24 h excretion. A population-based recruitment was done from the capital city, a major town and a settlement (n 36/48/20). Participants were seventy-eight Inuit and twenty-six non-Inuit. The median 24 h iodine excretion was 138 (25th-75th percentile 89-225) μg/97 (25th-75th percentile 72-124) μg in Inuit/non-Inuit (P= 0.030), and 153 (25th-75th percentile 97-251) μg/102 (25th-75th percentile 73-138) μg (P= 0.026) when including compensated iodine excretion. Iodine excretion in 24 h urine samples increased with a rising intake of traditional Inuit foods (P= 0.005). Iodine excretion was lower in morning spot urine samples than in 24 h urine samples (P< 0.001). This difference was associated with iodine intake levels (P< 0.001), and was statistically significant when the iodine excretion level was above 150 μg/24 h. In conclusion, the iodine intake level was underestimated from morning spot urine samples if iodine excretion was above the recommended level.

The role of the cardiac nerves in regulation of sodium excretion in conscious dogs.

PubMed

Kaczmarczyk, G; Drake, A; Eisele, R; Mohnhaupt, R; Noble, M I; Simgen, B; Stubbs, J; Reinhardt, H W

1981-05-01

Conscious, chronically instrumented dogs, maintained on a high sodium intake, were used to investigate whether surgical cardiac denervation impairs the natriuresis associated with left atrial pressure increase produced in three ways: during an increase in left atrial pressure by means of a reversible mitral stenosis (protocol 1); after an i.v. saline load (1.0 ml 0.9% saline min-1 . kg-1 over 60 min) (protocol 2); after an oral saline load (14.5 mmol Na . kg-1 given with the food as isotonic solution) (protocol 3). During a reversible mitral stenosis, in intact dogs, urine volume and sodium excretion increased markedly (from 34--145 microliters . min-1 . kg-1 and from 3--12 mumol . min-1 . kg-1); mean arterial pressure increased by an average of 2 kPa (15 mm Hg) and heart rate by 53 b/min; plasma renin activity fell from 0.37--0.21 ng AI . ml-1 . h-1 . Cardiac denervation eliminated these effects of left atrial distension except for a small increase in heart rate (12 b/min). This indicates that the natriuresis and diuresis during left atrial distension resulted from stimulation of receptors located in the left atrium. In contrast, during protocol 2 and 3, the same amounts of sodium and water were excreted in the cardiac denervated dogs as compared to the intact dogs. A comparable decrease in plasma renin activity also was observed. -- Apparently the presence of the cardiac nerves is not a prerequisite for maintenance of sodium and water homeostasis.

Impaired natriuretic response to high-NaCl diet plus aldosterone infusion in mice overexpressing human CD39, an ectonucleotidase (NTPDase1).

PubMed

Zhang, Yue; Robson, Simon C; Morris, Kaiya L; Heiney, Kristina M; Dwyer, Karen M; Kishore, Bellamkonda K; Ecelbarger, Carolyn M

2015-06-15

Extracellular nucleotides acting through P2 receptors facilitate natriuresis. To define how purinergic mechanisms are involved in sodium homeostasis, we used transgenic (TG) mice that globally overexpress human CD39 (hCD39, NTPDase1), an ectonucleotidase that hydrolyzes extracellular ATP/ADP to AMP, resulting in an altered extracellular purine profile. On a high-sodium diet (HSD, 3.5% Na(+)), urine volume and serum sodium were significantly higher in TG mice but sodium excretion was unaltered. Furthermore, TG mice showed an attenuated fall in urine aldosterone with HSD. Western blot analysis revealed significantly lower densities (∼40%) of the β-subunit of the epithelial sodium channel (ENaC) in medulla, and the major band (85-kDa) of γ-ENaC in TG mice cortex. To evaluate aldosterone-independent differences, in a second experiment, aldosterone was clamped by osmotic minipump at 20 μg/day, and mice were fed either an HSD or a low-sodium diet (LSD, 0.03% Na(+)). Here, no differences in urine volume or osmolality, or serum aldosterone were found, but TG mice showed a modest, yet significant impairment in late natriuresis (days 3 and 4). Several major sodium transporters or channel subunits were differentially expressed between the genotypes. HSD caused a downregulation of Na-Cl cotransporter (NCC) in both genotypes; and had higher cortical levels of NCC, Na-K-ATPase (α-1 subunit), and α- and γ-ENaC. The Na-K-2Cl cotransporter (NKCC2) was downregulated by HSD in wild-type mice, but it increased in TG mice. In summary, our data support the concept that extracellular nucleotides facilitate natriuresis; they also reveal an aldosterone-independent downregulation of major renal sodium transporters and channel subunits by purinergic signaling.

Comparison of hypotensive, diuretic and renal effects between cladodes of Opuntia ficus-indica and furosemide.

PubMed

Bakour, Meryem; Al-Waili, Noori; El-Haskoury, Redouan; El-Menyiy, Nawal; Al-Waili, Thia; Al-Waili, Ali; Lyoussi, Badiaa

2017-09-01

To investigate the diuretic, hypotensive and renal effect of Opuntia ficus-indica in two different species in oral and intravenous administration. Diuretic activity was evaluated in rats with the plant cladode gel and aqueous extract administrated orally, and was evaluated in rabbits with plant extract administered intravenously. Single and repeated doses of cladode gel or aqueous extract of cladode were tested. Urine volume and blood and urine creatinine, sodium and potassium were measured, and creatinine clearance was calculated. The hypotensive effect of lyophilized extract of cladode was evaluated in rabbits. Two polyethylene PE50 catheters were used: one in the jugular vein for the infusion of the plant extract and the other in the carotid for the evaluation of the arterial pressure. The cladode gel or aqueous extract increased urine volume, creatinine clearance and urinary excretion of sodium and potassium without significant effect on serum creatinine or blood urea. Furosemide, gel and aqueous extract of cladode insignificantly lowered plasma potassium in rats. Intravenous administration of the lyophilized extract caused a significant decrease in mean arterial pressure in rabbits with a significant increase in urine volume and urine sodium and potassium; the effect was dose dependent. Intravenous administration of lyophilized extract did not affect plasma sodium or potassium. Gel and aqueous extract of Opuntia ficus-indica cladode have a significant diuretic effect on rats, and the lyophilized extract has a diuretic and hypotensive effect on normotensive rabbits without deterioration in renal function test. Additional studies on active ingredients are essential to pave the way for clinical studies on diuretic and hypotensive effect of the plant. Copyright © 2017 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

Estimation of daily protein intake based on spot urine urea nitrogen concentration in chronic kidney disease patients.

PubMed

Kanno, Hiroko; Kanda, Eiichiro; Sato, Asako; Sakamoto, Kaori; Kanno, Yoshihiko

2016-04-01

Determination of daily protein intake in the management of chronic kidney disease (CKD) requires precision. Inaccuracies in recording dietary intake occur, and estimation from total urea excretion presents hurdles owing to the difficulty of collecting whole urine for 24 h. Spot urine has been used for measuring daily sodium intake and urinary protein excretion. In this cross-sectional study, we investigated whether urea nitrogen (UN) concentration in spot urine can be used to predict daily protein intake instead of the 24-h urine collection in 193 Japanese CKD patients (Stages G1-G5). After patient randomization into 2 datasets for the development and validation of models, bootstrapping was used to develop protein intake estimation models. The parameters for the candidate multivariate regression models were male gender, age, body mass index (BMI), diabetes mellitus, dyslipidemia, proteinuria, estimated glomerular filtration rate, serum albumin level, spot urinary UN and creatinine level, and spot urinary UN/creatinine levels. The final model contained BMI and spot urinary UN level. The final model was selected because of the higher correlation between the predicted and measured protein intakes r = 0.558 (95 % confidence interval 0.400, 0.683), and the smaller distribution of the difference between the measured and predicted protein intakes than those of the other models. The results suggest that UN concentration in spot urine may be used to estimate daily protein intake and that a prediction formula would be useful for nutritional control in CKD patients.

Long-term aquaretic efficacy of a selective nonpeptide V(2)-vasopressin receptor antagonist, SR121463, in cirrhotic rats.

PubMed

Jiménez, W; Gal, C S; Ros, J; Cano, C; Cejudo, P; Morales-Ruiz, M; Arroyo, V; Pascal, M; Rivera, F; Maffrand, J P; Rodés, J

2000-10-01

Water retention in experimental cirrhosis can be reversed by blocking V(2)-vasopressin (AVP) receptors with the nonpeptide antagonist OPC-31260 or by using the kappa-opioid receptor agonist niravoline, a compound inhibiting central AVP release. However, reluctance to use these drugs in human beings has emerged because the former loses aquaretic efficacy in rats after 2 days of treatment and the latter may have adverse effects in humans. Recently, a new potent and selective nonpeptide V(2)-AVP receptor antagonist, SR121463, has been developed that could be useful for the treatment of dilutional hyponatremia in human cirrhosis. The current study assessed the aquaretic efficacy of 10-day chronic oral administration of SR121463 (0.5 mg/kg/day) in cirrhotic rats with ascites and impaired water excretion after a water load (minimum urinary osmolality >160 mOsm/kg and percentage of water load excreted <60%). Urine volume (UV), osmolality (U(Osm)V), and sodium excretion (U(Na)V) were measured daily. At the end of the 10-day treatment, mean arterial pressure also was measured. In basal conditions cirrhotic rats showed ascites, sodium retention, and impaired water excretion. UV, U(Osm)V, and U(Na)V did not change throughout the study in cirrhotic rats receiving the vehicle. In contrast, SR121463 increased UV and reduced U(Osm)V during the 10-day treatment. This resulted in a greater renal ability to excrete a water load and normalization in serum sodium and osmolality. During the first 6 days of treatment, SR121463 also increased U(Na)V without affecting mean arterial pressure. These data suggest that SR121463 could be of therapeutical value for chronic management of human cirrhosis.

Associations between the intake of miso soup and Japanese pickles and the estimated 24-hour urinary sodium excretion: a population-based cross-sectional study.

PubMed

Wakasugi, Minako; James Kazama, Junichiro; Narita, Ichiei

2015-01-01

In Japan, reducing the consumption of miso soup and Japanese pickles, both traditional Japanese dishes, is recommended in order to decrease dietary salt intake. With the Westernization of dietary habits, however, these dishes are now consumed less frequently, and thus a reduction in their effect on sodium intake is suspected. This study examined cross-sectional associations between the frequency of intake of miso soup and Japanese pickles and the estimated 24-hour urine sodium excretion using data obtained from health examination surveys conducted in 2013 in Sado City, Japan. The level of daily salt intake was estimated based on spot urine sodium and creatinine measurements. The frequency of intake of miso soup and Japanese pickles was determined using a self-reported questionnaire. Multiple linear regression models were used to assess associations. Among a total of 8,821 participants (3,956 men; age range, 19-97 years), the mean daily salt intake was 9.4 g/day. The frequency of intake of miso soup and Japanese pickles increased with age and was associated with the level of daily salt intake (p for trend <0.0001). A linear regression model analysis adjusted for age, sex, body mass index, hypertension, diabetes, hypercholesterolemia and chronic kidney disease revealed that daily salt intake was associated with the frequency of intake of miso soup (p<0.0001) and Japanese pickles (p<0.0001) in all age groups, except those ≥ 80 years of age. These findings suggest that reducing the consumption of miso soup and Japanese pickles may be an effective approach for decreasing the level of dietary salt intake in the general Japanese population, although not in octogenarians or nonagenarians.

The Role of Epithelial Sodium Channel ENaC and the Apical Cl-/HCO3- Exchanger Pendrin in Compensatory Salt Reabsorption in the Setting of Na-Cl Cotransporter (NCC) Inactivation

PubMed Central

Patel-Chamberlin, Mina; Varasteh Kia, Mujan; Xu, Jie; Barone, Sharon; Zahedi, Kamyar; Soleimani, Manoocher

2016-01-01

Background The absence of NCC does not cause significant salt wasting in NCC deficient mice under basal conditions. We hypothesized that ENaC and pendrin play important roles in compensatory salt absorption in the setting of NCC inactivation, and their inhibition and/or downregulation can cause significant salt wasting in NCC KO mice. Methods WT and NCC KO mice were treated with a daily injection of either amiloride, an inhibitor of ENaC, or acetazolamide (ACTZ), a blocker of salt and bicarbonate reabsorption in the proximal tubule and an inhibitor of carbonic anhydrases in proximal tubule and intercalated cells, or a combination of acetazolamide plus amiloride for defined durations. Animals were subjected to daily balance studies. At the end of treatment, kidneys were harvested and examined. Blood samples were collected for electrolytes and acid base analysis. Results Amiloride injection significantly increased the urine output (UO) in NCC KO mice (from 1.3 ml/day before to 2.5 ml/day after amiloride, p<0.03, n = 4) but caused only a slight change in UO in WT mice (p>0.05). The increase in UO in NCC KO mice was associated with a significant increase in sodium excretion (from 0.25 mmol/24 hrs at baseline to 0.35 mmol/24 hrs after amiloride injection, p<0.05, n = 4). Daily treatment with ACTZ for 6 days resulted in >80% reduction of kidney pendrin expression in both WT and NCC KO mice. However, ACTZ treatment noticeably increased urine output and salt excretion only in NCC KO mice (with urine output increasing from a baseline of 1.1 ml/day to 2.3 ml/day and sodium excretion increasing from 0.22 mmole/day before to 0.31 mmole/day after ACTZ) in NCC KO mice; both parameters were significantly higher than in WT mice. Western blot analysis demonstrated significant enhancement in ENaC expression in medulla and cortex of NCC KO and WT mice in response to ACTZ injection for 6 days, and treatment with amiloride in ACTZ-pretreated mice caused a robust increase in salt excretion in both NCC KO and WT mice. Pendrin KO mice did not display a significant increase in urine output or salt excretion after treatment with amiloride or ACTZ. Conclusion 1. ENaC plays an important role in salt reabsorption in NCC KO mice. 2. NCC contributes to compensatory salt reabsorption in the setting of carbonic anhydrase inhibition, which is associated with increased delivery of salt from the proximal tubule and the down regulation of pendrin. 3. ENaC is upregulated by ACTZ treatment and its inhibition by amiloride causes significant diuresis in NCC KO and WT mice. Despite being considered mild agents individually, we propose that the combination of acetazolamide and amiloride in the setting of NCC inhibition (i.e., hydrochlorothiazide) will be a powerful diuretic regimen. PMID:26963391

Urinary concentration does not exclusively rely on plasma vasopressin. A study between genders. Gender and diurnal urine regulation.

PubMed

Graugaard-Jensen, C; Hvistendahl, G M; Frøkiaer, J; Bie, P; Djurhuus, J C

2014-09-01

We investigated the influence of gender on the diurnal regulation of urine production with special focus on vasopressin, oxytocin and prostaglandin E2. Fifteen young women in mid-follicular phase and 22 young men (20-33 years) were included. All participants underwent a 24-h circadian inpatient study under standardized conditions for measurements of plasma vasopressin, oxytocin, sodium and osmolality. Urine was fractionally collected for measurements of electrolytes, aquaporin-2 and prostaglandin E2. Plasma vasopressin expressed a diurnal rhythm with a night-time increase in both genders (P < 0.001). The ratio between mean daytime and mean night-time was 1.57 [95% CI: 1.33-1.84] P < 0.001 in men and 1.35 [95% CI: 1.11-1.64] P = 0.002 in women. P-vasopressin was higher in males during the night (P < 0.05). There was no difference in diuresis (P = 0.43), urine osmolality (P = 0.12) or aquaporin-2 excretion (P = 0.80) between genders. We found a trend towards a higher reabsorption of free water in males (P = 0.07). The excretion of prostaglandin E2 was higher in males (P < 0.001). There was no diurnal rhythm in p-oxytocin (P = 0.37) and no correlation to diuresis, urine osmolality or aquaporin-2 excretions. Similar urinary flows and osmolalities are associated with levels of plasma vasopressin and renal PGE2, which are higher in males than in females. Oxytocin does not seem to play a role in the diurnal urine formation, whereas prostaglandin E2 could represent a mediator of the gender difference, not only as a mediator of the vasopressin response, but also as an independent factor. These findings need further elucidation. © 2014 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Human metabolism and renal excretion of selenium compounds after oral ingestion of sodium selenite and selenized yeast dependent on the trimethylselenium ion (TMSe) status.

PubMed

Jäger, Thomas; Drexler, Hans; Göen, Thomas

2016-05-01

A human in vivo metabolism study was carried out to investigate the impact of the trimethylselenium ion (TMSe) status on metabolism and toxicokinetics of sodium selenite and selenized yeast. Nine healthy human volunteers were orally exposed to 200 µg selenium as sodium selenite and seven with selenized yeast (100 µg selenium). In each intervention group, three subjects belong to TMSe eliminators. Blood samples were withdrawn before and up to 6 h after administration. Urine samples were collected before and within 24 h after administration. Total selenium (Se) was quantified in blood plasma and urine and low molecular Se species in urine. Selenium concentration in plasma increased from 84.5 ± 13.2 µg Se/L before to 97.4 ± 13.2 µg Se/L 2-3 h after selenite supplementation and 89.5 ± 12.9 µg Se/L to 92.1 ± 13.9 µg Se/L after selenized yeast intake. The oral ingestion caused an additional Se elimination via urine of 16.9 ± 10.6 µg/24 h (TMSe elim.: 10.8 ± 6.9 µg/24 h; non-TMSe elim.: 20.0 ± 11.3 µg Se/24 h) after selenite exposure and 11.8 ± 4.1 µg/24 h (TMSe elim.: 10.8 ± 4.6 µg/24 h; non-TMSe elim.: 12.6 ± 4.2 µg Se/24 h) after selenized yeast exposure. Methyl-2-acetamido-2-deoxy-1-seleno-β-D-galactopyranoside (SeSug1) was the main metabolite in all urine samples, whereas TMSe was another main metabolite in TMSe eliminators' urine. After selenite exposure, a small amount of the dose (0.5 ± 0.2 %) was oxidized to selenate and rapidly excreted via urine. With the exception of selenite exposure in TMSe eliminators, the comparison of total Se and the sum of quantified Se species revealed a high renal portion of unidentified species. The study indicated a different metabolism of inorganic and organic Se compounds in human, but also crucial differences of Se metabolism in TMSe eliminators and non-TMSe eliminators.

Iodine Excretion in 24-hour Urine Collection and Its Dietary Determinants in Healthy Japanese Adults

PubMed Central

Katagiri, Ryoko; Asakura, Keiko; Uechi, Ken; Masayasu, Shizuko; Sasaki, Satoshi

2016-01-01

Background Since seaweed is a common component of the Japanese diet, iodine intake in Japanese is expected to be high. However, urinary iodine excretion, measured using 24-hour urine samples, and its dietary determinants are not known. Methods Apparently healthy adults aged 20 to 69 years living in 20 areas throughout Japan were recruited in February and March, 2013. Urinary iodine excretion was evaluated using 24-hour urine collected from 713 subjects (362 men and 351 women), and the difference among age groups was assessed. The association between dietary intake of food groups and urinary iodine excretion was assessed among 358 subjects who completed a semi-weighed 4-day diet record (DR) and urine collection. The correlations between iodine intake and iodine excretion were also evaluated, and correlation coefficients were calculated for iodine intake in the DR of the overlapping day or the DR 1 day before and after urine collection. Results Median iodine excretion in 24-hour urine was 365 µg, and excretion was significantly higher in older subjects. Iodine intake estimated by the DRs was significantly correlated with urinary iodine excretion when DRs and urine collection were obtained on the same day (r = 0.37). After adjustment for confounding factors, iodine excretion was significantly associated with intakes of kelp and soup stock from kelp and fish. Conclusions Although multiple measurements for urinary iodine are required to confirm our results, this study showed the current iodine status of healthy Japanese adults. The results suggest that kelp and fish are the main contributors to Japanese iodine status measured by 24-hour urine. PMID:27374137

New secondary metabolites of phenylbutyrate in humans and rats.

PubMed

Kasumov, Takhar; Brunengraber, Laura L; Comte, Blandine; Puchowicz, Michelle A; Jobbins, Kathryn; Thomas, Katherine; David, France; Kinman, Renee; Wehrli, Suzanne; Dahms, William; Kerr, Douglas; Nissim, Itzhak; Brunengraber, Henri

2004-01-01

Phenylbutyrate is used to treat inborn errors of ureagenesis, malignancies, cystic fibrosis, and thalassemia. High-dose phenylbutyrate therapy results in toxicity, the mechanism of which is unexplained. The known metabolites of phenylbutyrate are phenylacetate, phenylacetylglutamine, and phenylbutyrylglutamine. These are excreted in urine, accounting for a variable fraction of the dose. We identified new metabolites of phenylbutyrate in urine of normal humans and in perfused rat livers. These metabolites result from interference between the metabolism of phenylbutyrate and that of carbohydrates and lipids. The new metabolites fall into two categories, glucuronides and phenylbutyrate beta-oxidation side products. Two questions are raised by these data. First, is the nitrogen-excreting potential of phenylbutyrate diminished by ingestion of carbohydrates or lipids? Second, does competition between the metabolism of phenylbutyrate, carbohydrates, and lipids alter the profile of phenylbutyrate metabolites? Finally, we synthesized glycerol esters of phenylbutyrate. These are partially bioavailable in rats and could be used to administer large doses of phenylbutyrate in a sodium-free, noncaustic form.

Evaluation of the Pharmacodynamic Effects of the Potassium Binder RDX7675 in Mice.

PubMed

Davidson, James P; King, Andrew J; Kumaraswamy, Padmapriya; Caldwell, Jeremy S; Korner, Paul; Blanks, Robert C; Jacobs, Jeffrey W

2018-05-01

Hyperkalemia is a common complication in patients with heart failure or chronic kidney disease, particularly those who are taking inhibitors of the renin-angiotensin-aldosterone system. RDX7675, the calcium salt of a reengineered polystyrene sulfonate-based resin, is a potassium binder that is being investigated as a novel treatment for hyperkalemia. This study evaluated the pharmacodynamic effects of RDX7675 in mice, compared to 2 current treatments, sodium polystyrene sulfonate (SPS) and patiromer. Seven groups of 8 male CD-1 mice were given either standard chow (controls) or standard chow containing 4.0% or 6.6% active moiety of RDX7675, patiromer, or SPS for 72 hours. Stool and urine were collected over the final 24 hours of treatment for ion excretion analyses. RDX7675 increased stool potassium (mean 24-hour excretion: 4.0%, 9.19 mg; 6.6%, 18.11 mg; both P < .0001) compared with controls (4.47 mg) and decreased urinary potassium (mean 24-hour excretion: 4.0%, 12.05 mg, P < .001; 6.6%, 6.68 mg, P < .0001; vs controls, 20.38 mg). The potassium-binding capacity of RDX7675 (stool potassium/gram of resin: 4.0%, 1.14 mEq/g; 6.6%, 1.32 mEq/g) was greater (all P < .0001) than for patiromer (4.0%, 0.63 mEq/g; 6.6%, 0.48 mEq/g) or SPS (4.0%, 0.73 mEq/g; 6.6% 0.55 mEq/g). RDX7675 and patiromer decreased urinary sodium (mean 24-hour excretion: 0.07-1.38 mg; all P < .001) compared to controls (5.01 mg). In contrast, SPS increased urinary sodium excretion (4.0%, 13.31 mg; 6.6%, 17.60 mg; both P < .0001) compared to controls. RDX7675 reduced intestinal potassium absorption and had a greater potassium-binding capacity than patiromer or SPS in mice. The calcium-based resins RDX7675 and patiromer reduced intestinal sodium absorption, unlike sodium-based SPS. These results support further studies in humans to confirm the potential of RDX7675 for the treatment of patients with hyperkalemia.

Clinical findings and effect of sodium hydrogen carbonate in patients with glutathione synthetase deficiency.

PubMed

Gündüz, Mehmet; Ünal, Özlem; Kavurt, Sumru; Türk, Emrecan; Mungan, Neslihan Önenli

2016-04-01

Glutathione synthetase (GS) deficiency is a rare inborn error of glutathione (GSH) metabolism manifested by severe metabolic acidosis, hemolytic anemia, neurological problems and massive excretion of pyroglutamic acid (5-oxoproline) in the urine. The disorder has mild, moderate, and severe clinical variants. We aimed to report clinical and laboratory findings of four patients, effect of sodium hydrogen carbonate treatment and long-term follow up of three patients. Urine organic acid analysis was performed with gas chromatography-mass spectrometry. Molecular genetic analysis was performed in three patients, mutation was found in two of them. Enzyme analysis was performed in one patient. Clinical and laboratory findings of four patients were evaluated. One patient died at 4 months old, one patient's growth and development are normal, two patients have developed intellectual disability and seizures in the long term follow up period. Three patients benefited from sodium hydrogen carbonate treatment. The clinical picture varies from patient to patient, so it is difficult to predict the prognosis and the effectiveness of treatment protocols. We reported long term follow up of four patients and demonstrated that sodium hydrogen carbonate is effective for treatment of chronic metabolic acidosis in GS deficieny.

Space motion sickness medications: interference with biomedical parameters

NASA Technical Reports Server (NTRS)

Vernikos-Danellis, J.; Winget, C. M.; Leach, C. S.; Rosenblatt, L. S.; Lyman, J.; Beljan, J. R.

1977-01-01

The possibility that drugs administered to Skylab 3 (SL-3) and 4 (SL-4) crewmen for space motion sickness may have interfered with their biomedical evaluation in space was investigated. Healthy volunteers received combinations of Scopolamine/Dexedrine for four days in regimens similar to those used in these missions. Urine samples, heart rate, body temperature, mood and performance were analyzed for drug-related changes. Twenty-four hour urine samples were analyzed by the same procedures as those used to analyze the flight samples. Hormone concentrations determined included cortisol, epinephrine, norepinephrine, aldosterone and antidiuretic hormone (ADH). In addition, volume, specific gravity, osmolarity, sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), chloride (Cl), inorganic phosphate, uric acid and creatinine were measured. Performance was not affected by the Scopolamine/Dexedrine. The drug combination increased daily mean heart rate (HR) significantly in all the subjects and daily mean rectal temperature (RT) in some of the subjects. A 2-4 hr phase shift in the HR circadian rhythm was also observed which indicates that internal circadian synchrony was disturbed by the drugs. Psychological and subjective evaluation indicated that the subjects could usually identify which days they were given the drugs by an increase in tension and anxiety, decreased patience, restlessness, decreased appetite, difficulty in sleeping and feelings of increased heart rate and body temperature. Urinary electrolytes were not changed significantly by the drug, but marked and significant changes occurred in urine volume and hormone excretion patterns. Scopolamine/Dexedrine caused consistent elevations in urinary cortisol and epinephrine and a transient elevation in ADH. Norepinephrine excretion was decreased, but there was no significant change in aldosterone excretion or in 24 hr urine volume. A comparison of these findings with the first four days of inflight data from the SL-3 and SL-4 missions leads to the conclusion that the dramatic increases in aldosterone excretion during the first three days of spaceflight probably can be directly attributed to weightlessness, whereas the antimotion sickness medication could have substantially contributed to the early increased excretion of epinephrine and cortisol during these missions.

Urinary Potassium Excretion and Renal and Cardiovascular Complications in Patients with Type 2 Diabetes and Normal Renal Function

PubMed Central

Haneda, Masakazu; Koya, Daisuke; Kondo, Keiko; Tanaka, Sachiko; Arima, Hisatomi; Kume, Shinji; Nakazawa, Jun; Chin-Kanasaki, Masami; Ugi, Satoshi; Kawai, Hiromichi; Araki, Hisazumi; Uzu, Takashi; Maegawa, Hiroshi

2015-01-01

Background and objectives We investigated the association of urinary potassium and sodium excretion with the incidence of renal failure and cardiovascular disease in patients with type 2 diabetes. Design, setting, participants, & measurements A total of 623 Japanese type 2 diabetic patients with eGFR≥60 ml/min per 1.73 m2 were enrolled in this observational follow-up study between 1996 and 2003 and followed-up until 2013. At baseline, a 24-hour urine sample was collected to estimate urinary potassium and sodium excretion. The primary end point was renal and cardiovascular events (RRT, myocardial infarction, angina pectoris, stroke, and peripheral vascular disease). The secondary renal end points were the incidence of a 50% decline in eGFR, progression to CKD stage 4 (eGFR<30 ml/min per 1.73 m2), and the annual decline rate in eGFR. Results During the 11-year median follow-up period, 134 primary end points occurred. Higher urinary potassium excretion was associated with lower risk of the primary end point, whereas urinary sodium excretion was not. The adjusted hazard ratios for the primary end point in Cox proportional hazards analysis were 0.56 (95% confidence interval [95% CI], 0.33 to 0.95) in the third quartile of urinary potassium excretion (2.33–2.90 g/d) and 0.33 (95% CI, 0.18 to 0.62) in the fourth quartile (>2.90 g/d) compared with the lowest quartile (<1.72 g/d). Similar associations were observed for the secondary renal end points. The annual decline rate in eGFR in the fourth quartile of urinary potassium excretion (–1.3 ml/min per 1.73 m2/y; 95% CI, –1.5 to –1.0) was significantly slower than those in the first quartile (–2.2; 95% CI, –2.4 to –1.8). Conclusions Higher urinary potassium excretion was associated with the slower decline of renal function and the lower incidence of cardiovascular complications in type 2 diabetic patients with normal renal function. Interventional trials are necessary to determine whether increasing dietary potassium is beneficial. PMID:26563378

Behavioral responses and fluid regulation in male rats after combined dietary sodium deficiency and water deprivation.

PubMed

Lucia, Kimberly J; Curtis, Kathleen S

2018-02-01

Most investigators use a single treatment such as water deprivation or dietary sodium deficiency to evaluate thirst or sodium appetite, which underlie behavioral responses to body fluid challenges. The goal of the present experiments was to assess the effects of combined treatments in driving behaviors. Therefore, we evaluated the effect of combined overnight water deprivation and dietary sodium deficiency on water intake and salt intake by adult male rats in 2-bottle (0.5M NaCl and water) tests. Overnight water deprivation alone increased water intake, and 10days of dietary sodium deficiency increased 0.5M NaCl intake, with a secondary increase in water intake. During combined water deprivation and dietary sodium deficiency, water intake was enhanced and 0.5M NaCl was reduced, but not eliminated, suggesting that physiologically relevant behavioral responses persist. Nonetheless, the pattern of fluid intake was altered by the combined treatments. We also assessed the effect of these behaviors on induced deficits in body sodium and fluid volume during combined treatments and found that, regardless of treatment, fluid ingestion partially repleted the induced deficits. Finally, we examined urine volume and sodium excretion during dietary sodium deficiency with or without overnight water deprivation and found that, whether or not rats were water deprived, and regardless of water consumption, sodium excretion was minimal. Thus, the combination of water deprivation and dietary sodium deficiency appears to arouse drives that stimulate compensatory behavioral responses. These behaviors, in conjunction with physiological adaptations to the treatments, underlie body sodium and volume repletion in the face of combined water deprivation and dietary sodium deficiency. Copyright © 2017 Elsevier Inc. All rights reserved.

Seasonal variation in natural abundance of 2H and 18O in urine samples from rural Nigeria

PubMed Central

Dugas, Lara R.; Brieger, William; Tayo, Bamidele O.; Alabi, Tunrayo; Schoeller, Dale A.; Luke, Amy

2015-01-01

The doubly labeled water (DLW) method is used to measure free-living energy expenditure in humans. Inherent to this technique is the assumption that natural abundances of stable isotopes 2H and 18O in body water remain constant over the course of the measurement period and after elimination of the loading dose of DLW will return to the same predose level. To determine variability in the natural abundances of 2H and 18O in humans living in a region with seasonal shifts in rain patterns and sources of drinking water, over the course of 12 mo we collected weekly urine samples from four individuals living in southwest Nigeria as well as samples of their drinking water. From ongoing regional studies of hypertension, obesity, and energy expenditure, we estimated average water turnover rate, urine volumes, and sodium and potassium excretion. Results suggest that 2H and 18O in urine, mean concentrations of urinary sodium and potassium, urine volume, and total body turnover differed significantly from dry to rainy season. Additionally, seasonal weather variables (mean monthly maximum temperatures, total monthly rainfall, and minimum relative humidity) were all significantly associated with natural abundances in urine. No seasonal difference was observed in drinking water samples. Findings suggest that natural abundances in urine may not remain constant as assumed, and studies incorporating DLW measurements across the transition of seasons should interpret results with caution unless appropriate doses of the tracers are used. PMID:25977450

Nontraumatic Exertional Rhabdomyolysis Leading to Acute Kidney Injury in a Sickle Trait Positive Individual on Renal Biopsy.

PubMed

Janga, Kalyana C; Greenberg, Sheldon; Oo, Phone; Sharma, Kavita; Ahmed, Umair

2018-01-01

A 26-year-old African American male with a history of congenital cerebral palsy, sickle cell trait, and intellectual disability presented with abdominal pain that started four hours prior to the hospital visit. The patient denied fever, chills, diarrhea, or any localized trauma. The patient was at a party at his community center last evening and danced for 2 hours, physically exerting himself more than usual. Labs revealed blood urea nitrogen (BUN) level of 41 mg/dL and creatinine (Cr) of 2.8 mg/dL which later increased to 4.2 mg/dL while still in the emergency room. Urinalysis revealed hematuria with RBC > 50 on high power field. Imaging of the abdomen revealed no acute findings for abdominal pain. With fractional excretion of sodium (FeNa) > 3%, findings suggested nonoliguric acute tubular necrosis. Over the next couple of days, symptoms of dyspepsia resolved; however, BUN/Cr continued to rise to a maximum of 122/14 mg/dL. With these findings, along with stable electrolytes, urine output matching the intake, and prior use of proton pump inhibitors, medical decision was altered for the possibility of acute interstitial nephritis. Steroids were subsequently started and biopsy was taken. Biopsy revealed heavy deposits of myoglobin. Creatinine phosphokinase (CPK) levels drawn ten days later after the admission were found to be elevated at 334 U/dl, presuming the levels would have been much higher during admission. This favored a diagnosis of acute kidney injury (AKI) secondary to exertional rhabdomyolysis. We here describe a case of nontraumatic exertional rhabdomyolysis in a sickle cell trait (SCT) individual that was missed due to findings of microscopic hematuria masking underlying myoglobinuria and fractional excretion of sodium > 3%. As opposed to other causes of ATN, rhabdomyolysis often causes FeNa < 1%. The elevated fractional excretion of sodium in this patient was possibly due to the underlying inability of SCT positive individuals to reabsorb sodium/water and concentrate their urine. Additionally, because of their inability to concentrate urine, SCT positive individuals are prone to intravascular depletion leading to renal failure as seen in this patient. Disease was managed with continuing hydration and tapering steroids. Kidney function improved and the patient was discharged with a creatinine of 3 mg/dL. A month later, renal indices were completely normal with persistence of microscopic hematuria from SCT.

Effects of a behavioral intervention that emphasizes spices and herbs on adherence to recommended sodium intake: results of the SPICE randomized clinical trial.

PubMed

Anderson, Cheryl A M; Cobb, Laura K; Miller, Edgar R; Woodward, Mark; Hottenstein, Annette; Chang, Alex R; Mongraw-Chaffin, Morgana; White, Karen; Charleston, Jeanne; Tanaka, Toshiko; Thomas, Letitia; Appel, Lawrence J

2015-09-01

For decades, dietary sodium intake in the United States has remained high, and few studies have examined strategies for maintaining recommended intakes. We examined the effects of a behavioral intervention, which emphasized spices and herbs, on the maintenance of sodium intake at the recommended intake of 1500 mg/d in individuals to whom the US Dietary Guidelines for Americans apply. We conducted a 2-phase study that included adults ≥18 y of age for whom Dietary Guidelines for Americans recommends 1500 mg Na/d. The study was conducted in Baltimore, Maryland, from 2012 to 2014. In phase 1, 55 individuals consumed a low-sodium diet for 4 wk. Participants were provided all foods, snacks, and calorie-containing drinks. In phase 2, 40 participants from phase 1 were randomly assigned to either a behavioral intervention to reduce sodium intake (n = 20) or a self-directed control group (n = 20) for 20 wk. The primary study outcome was the change in mean 24-h urinary sodium excretion during phase 2. Linear regression analyses were used to determine intervention effects on urinary sodium excretion. Participant characteristics were as follows: women: 65%; African American: 88%; hypertension: 63%; diabetes: 18%; mean age: 61 y; and mean body mass index (in kg/m(2)): 30. At the end of phase 2, mean 24-h sodium excretion was lower in the behavioral intervention than in the self-directed group (mean difference: -956.8 mg/d; 95% CI: -1538.7, -374.9 mg/d) after sodium intake at screening was controlled for (P = 0.002). These findings persisted in sensitivity analyses that excluded potentially incomplete urine collections [Mage's equation mean difference: -1090 mg/d (P = 0.001); Joosens' equation mean difference: -796 mg/d (P = 0.04)]. A multifactorial behavioral intervention emphasizing spices and herbs significantly reduced sodium intake. Because of the ubiquity of sodium in the US food supply, multilevel strategies addressing individual behaviors and the food supply are needed to improve adherence to recommendations. This trial was registered at clinicaltrials.gov as NCT01615159. © 2015 American Society for Nutrition.

Calciuric effects of protein and potassium bicarbonate but not of sodium chloride or phosphate can be detected acutely in adult women and men.

PubMed

Whiting, S J; Anderson, D J; Weeks, S J

1997-05-01

An acute load test was used to test the influence of dietary factors on urinary calcium excretion. In study 1, 10 fasting premenopausal women consumed test meals providing a moderate amount of protein (MP; 23 g), MP plus 23 mmol KHCO3 (MP+K), MP plus 23 mmol NaCl (MP+Na), and a high amount of protein (HP; 53 g), HP plus 70 mmol KHCO3 (HP+K), and HP plus 70 mmol NaCl (HP+Na). Protein was casein:lactalbumin (80:20), except for the treatments with added sodium chloride, to which only casein was added. In study 2, the effects of HP and HP plus 50 mmol KHCO3 (HP+K) were compared with those of MP or MP plus 7.5 mmol phosphate (MP+Pi), equaling the additional phosphate of HP, in 10 adult men. Subjects completed all treatments in random order. In study 1, the peak of calcium excretion was at 3 h for all treatments, except for HP+K, which indicated an acute hypocalciuric effect of potassium. Unexpectedly, there was no hypercalciuric effect of adding sodium chloride, nor was urine sodium increased. In study 2, calcium excretion was significantly higher with HP than with MP+Pi but not with MP at 3 h, indicating an acute hypercalciuric effect of protein alone. A hypocalciuric effect of potassium (HP+K compared with HP) but not of phosphate (MP compared with MP+Pi) was seen. An acute load test measuring changes 3 h postload was appropriate for examining the calciuric effects of protein and potassium bicarbonate, but not those of sodium chloride or phosphate in adults.

High salt intake increases plasma trimethylamine N-oxide (TMAO) concentration and produces gut dysbiosis in rats.

PubMed

Bielinska, Klaudia; Radkowski, Marek; Grochowska, Marta; Perlejewski, Karol; Huc, Tomasz; Jaworska, Kinga; Motooka, Daisuke; Nakamura, Shota; Ufnal, Marcin

2018-03-22

A high-salt diet is considered a cardiovascular risk factor; however, the mechanisms are not clear. Research suggests that gut bacteria-derived metabolites such as trimethylamine N-oxide (TMAO) are markers of cardiovascular diseases. We evaluated the effect of high salt intake on gut bacteria and their metabolites plasma level. Sprague Dawley rats ages 12-14 wk were maintained on either water (controls) or 0.9% or 2% sodium chloride (NaCl) water solution (isotonic and hypertonic groups, respectively) for 2 wk. Blood plasma, urine, and stool samples were analyzed for concentrations of trimethylamine (TMA; a TMAO precursor), TMAO, and indoxyl sulfate (indole metabolite). The gut-blood barrier permeability to TMA and TMA liver clearance were assessed at baseline and after TMA intracolonic challenge test. Gut bacterial flora was analyzed with a 16S ribosomal ribonucleic acid (rRNA) gene sequence analysis. The isotonic and hypertonic groups showed a significantly higher plasma TMAO and significantly lower 24-hr TMAO urine excretion than the controls. However, the TMA stool level was similar between the groups. There was no significant difference between the groups in gut-blood barrier permeability and TMA liver clearance. Plasma indoxyl concentration and 24-hr urine indoxyl excretion were similar between the groups. There was a significant difference between the groups in gut bacteria composition. High salt intake increases plasma TMAO concentration, which is associated with decreased TMAO urine excretion. Furthermore, high salt intake alters gut bacteria composition. These findings suggest that salt intake affects an interplay between gut bacteria and their host homeostasis. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of sauna bathing and beer ingestion on plasma concentrations of purine bases.

PubMed

Yamamoto, Tetsuya; Moriwaki, Yuji; Ka, Tuneyoshi; Takahashi, Sumio; Tsutsumi, Zenta; Cheng, Jidong; Inokuchi, Taku; Yamamoto, Asako; Hada, Toshikazu

2004-06-01

To determine whether sauna bathing alone or in combination with beer ingestion increases the plasma concentration of uric acid, 5 healthy subjects were tested. Urine and plasma measurements were performed before and after each took a sauna bath, ingested beer, and ingested beer just after taking a sauna bath, with a 2-week interval between each activity. Sauna bathing alone increased the plasma concentrations of uric acid and oxypurines (hypoxanthine and xanthine), and decreased the urinary and fractional excretion of uric acid, while beer ingestion alone increased the plasma concentrations and urinary excretion of uric acid and oxypurines. A combination of both increased the plasma concentration of uric acid and oxypurines, and decreased the urinary and fractional excretion of uric acid, with an increase in the urinary excretion of oxypurines. The increase in plasma concentration of uric acid with the combination protocol was not synergistic as compared to the sum of the increases by each alone. Body weight, urine volume, and the urinary excretion of sodium and chloride via dehydration were decreased following sauna bathing alone. These results suggest that sauna bathing had a relationship with enhanced purine degradation and a decrease in the urinary excretion of uric acid, leading to an increase in the plasma concentration of uric acid. Further, we concluded that extracellular volume loss may affect the common renal transport pathway of uric acid and xanthine. Therefore, it is recommended that patients with gout refrain from drinking alcoholic beverages, including beer, after taking a sauna bath, since the increase in plasma concentration of uric acid following the combination of sauna bathing and beer ingestion was additive.

Breathing awareness meditation and LifeSkills Training programs influence upon ambulatory blood pressure and sodium excretion among African American adolescents.

PubMed

Gregoski, Mathew J; Barnes, Vernon A; Tingen, Martha S; Harshfield, Gregory A; Treiber, Frank A

2011-01-01

To evaluate the effect of breathing awareness meditation (BAM), Botvin LifeSkills Training (LST), and health education control (HEC) on ambulatory blood pressure and sodium excretion in African American adolescents. Following 3 consecutive days of systolic blood pressure (SBP) screenings, 166 eligible participants (i.e., SBP >50th-95th percentile) were randomized by school to either BAM (n = 53), LST (n = 69), or HEC (n = 44). In-school intervention sessions were administered for 3 months by health education teachers. Before and after the intervention, overnight urine samples and 24-hour ambulatory SBP, diastolic blood pressure, and heart rate were obtained. Significant group differences were found for changes in overnight SBP and SBP, diastolic blood pressure, and heart rate over the 24-hour period and during school hours. The BAM treatment exhibited the greatest overall decreases on these measures (Bonferroni adjusted, ps < .05). For example, for school-time SBP, BAM showed a change of -3.7 mmHg compared with no change for LST and a change of -.1 mmHg for HEC. There was a nonsignificant trend for overnight urinary sodium excretion (p = .07), with the BAM group displaying a reduction of -.92 ± 1.1 mEq/hr compared with increases of .89 ± 1.2 mEq/hr for LST and .58 ± .9 mEq/hr for HEC group. BAM appears to improve hemodynamic function and may affect sodium handling among African American adolescents who are at increased risk for development of cardiovascular disease. Published by Elsevier Inc.

Conservation of body calcium by increased dietary intake of potassium: A potential measure to reduce the osteoporosis process during prolonged exposure to microgravity

NASA Technical Reports Server (NTRS)

Nechay, Bohdan R.

1989-01-01

During the 1988 NASA Summer Faculty Fellowship Program, it was proposed that the loss of skeletal calcium upon prolonged exposure to microgravity could be explained, in part, by a renal maladjustment characterized by an increased urinary excretion of calcium. It was theorized that because the conservation of body fluids and electrolytes depends upon the energy of adenosine triphosphate and enzymes that control the use of its energy for renal ion transport, an induction of renal sodium and potassium-dependent adenosine triphosphatase (Na + K ATPase) by oral loading with potassium would increase the reabsorption of sodium directly and that of calcium indirectly, leading to improved hydration and to reduced calcium loss. Preliminary studies showed the following. Rats drinking water containing 0.2 M potassium chloride for six to 13 days excreted in urine 22 muEq of calcium and 135 muEq of sodium per 100 grams of body weight per day. The corresponding values for control rats drinking tap water were 43 muEq and 269 muEq respectively. Renal Na + K ATPase activity in potassium loaded rats was higher than in controls. Thus, oral potassium loading resulted in increased Na + K ATPase activity and diminished urinary excretion of calcium and of sodium as predicted by the hypothesis. An extension of these studies to humans has the potential of resulting in development of harmless, non-invasive, drug-free, convenient measures to reduce bone loss and other electrolyte and fluid problems in space travelers exposed to prolonged periods of microgravity.

Monosodium glutamate (MSG) consumption is associated with urolithiasis and urinary tract obstruction in rats.

PubMed

Sharma, Amod; Prasongwattana, Vitoon; Cha'on, Ubon; Selmi, Carlo; Hipkaeo, Wiphawi; Boonnate, Piyanard; Pethlert, Supattra; Titipungul, Tanin; Intarawichian, Piyapharom; Waraasawapati, Sakda; Puapiroj, Anucha; Sitprija, Visith; Reungjui, Sirirat

2013-01-01

The peritoneal injection of monosodium glutamate (MSG) can induce kidney injury in adult rats but the effects of long-term oral intake have not been determined. We investigated the kidney histology and function in adult male Wistar rats that were fed ad libitum with a standard rat chow pellet and water with or without the addition of 2 mg/g body weight MSG/day in drinking water (n=10 per group). Both MSG-treated and control animals were sacrificed after 9 months when renal function parameters, blood and urine electrolytes, and tissue histopathology were determined. MSG-treated rats were more prone to kidney stone formation, as represented by the alkaline urine and significantly higher activity product of calcium phosphate. Accordingly, 3/10 MSG-treated rats developed kidney stones over 9 months versus none of the control animals. Further, 2/10 MSG-treated rats but none (0/10) of the controls manifested hydronephrosis. MSG-treated rats had significantly higher levels of serum creatinine and potassium including urine output volume, urinary excretion sodium and citrate compared to controls. In contrast, MSG-treated rats had significantly lower ammonium and magnesium urinary excretion. Oral MSG consumption appears to cause alkaline urine and may increase the risks of kidney stones with hydronephrosis in rats. Similar effects in humans must be verified by dedicated studies.

Monosodium Glutamate (MSG) Consumption Is Associated with Urolithiasis and Urinary Tract Obstruction in Rats

PubMed Central

Sharma, Amod; Prasongwattana, Vitoon; Cha’on, Ubon; Selmi, Carlo; Hipkaeo, Wiphawi; Boonnate, Piyanard; Pethlert, Supattra; Titipungul, Tanin; Intarawichian, Piyapharom; Waraasawapati, Sakda; Puapiroj, Anucha; Sitprija, Visith; Reungjui, Sirirat

2013-01-01

Background The peritoneal injection of monosodium glutamate (MSG) can induce kidney injury in adult rats but the effects of long-term oral intake have not been determined. Methods We investigated the kidney histology and function in adult male Wistar rats that were fed ad libitum with a standard rat chow pellet and water with or without the addition of 2 mg/g body weight MSG/day in drinking water (n=10 per group). Both MSG-treated and control animals were sacrificed after 9 months when renal function parameters, blood and urine electrolytes, and tissue histopathology were determined. Results MSG-treated rats were more prone to kidney stone formation, as represented by the alkaline urine and significantly higher activity product of calcium phosphate. Accordingly, 3/10 MSG-treated rats developed kidney stones over 9 months versus none of the control animals. Further, 2/10 MSG-treated rats but none (0/10) of the controls manifested hydronephrosis. MSG-treated rats had significantly higher levels of serum creatinine and potassium including urine output volume, urinary excretion sodium and citrate compared to controls. In contrast, MSG-treated rats had significantly lower ammonium and magnesium urinary excretion. Conclusion Oral MSG consumption appears to cause alkaline urine and may increase the risks of kidney stones with hydronephrosis in rats. Similar effects in humans must be verified by dedicated studies. PMID:24086562

Activation of the Endogenous Renin-Angiotensin-Aldosterone System or Aldosterone Administration Increases Urinary Exosomal Sodium Channel Excretion.

PubMed

Qi, Ying; Wang, Xiaojing; Rose, Kristie L; MacDonald, W Hayes; Zhang, Bing; Schey, Kevin L; Luther, James M

2016-02-01

Urinary exosomes secreted by multiple cell types in the kidney may participate in intercellular signaling and provide an enriched source of kidney-specific proteins for biomarker discovery. Factors that alter the exosomal protein content remain unknown. To determine whether endogenous and exogenous hormones modify urinary exosomal protein content, we analyzed samples from 14 mildly hypertensive patients in a crossover study during a high-sodium (HS, 160 mmol/d) diet and low-sodium (LS, 20 mmol/d) diet to activate the endogenous renin-angiotensin-aldosterone system. We further analyzed selected exosomal protein content in a separate cohort of healthy persons receiving intravenous aldosterone (0.7 μg/kg per hour for 10 hours) versus vehicle infusion. The LS diet increased plasma renin activity and aldosterone concentration, whereas aldosterone infusion increased only aldosterone concentration. Protein analysis of paired urine exosome samples by liquid chromatography-tandem mass spectrometry-based multidimensional protein identification technology detected 2775 unique proteins, of which 316 exhibited significantly altered abundance during LS diet. Sodium chloride cotransporter (NCC) and α- and γ-epithelial sodium channel (ENaC) subunits from the discovery set were verified using targeted multiple reaction monitoring mass spectrometry quantified with isotope-labeled peptide standards. Dietary sodium restriction or acute aldosterone infusion similarly increased urine exosomal γENaC[112-122] peptide concentrations nearly 20-fold, which correlated with plasma aldosterone concentration and urinary Na/K ratio. Urine exosomal NCC and αENaC concentrations were relatively unchanged during these interventions. We conclude that urinary exosome content is altered by renin-angiotensin-aldosterone system activation. Urinary measurement of exosomal γENaC[112-122] concentration may provide a useful biomarker of ENaC activation in future clinical studies. Copyright © 2016 by the American Society of Nephrology.

Activation of the Endogenous Renin-Angiotensin-Aldosterone System or Aldosterone Administration Increases Urinary Exosomal Sodium Channel Excretion

PubMed Central

Qi, Ying; Wang, Xiaojing; Rose, Kristie L.; MacDonald, W. Hayes; Zhang, Bing; Schey, Kevin L.

2016-01-01

Urinary exosomes secreted by multiple cell types in the kidney may participate in intercellular signaling and provide an enriched source of kidney-specific proteins for biomarker discovery. Factors that alter the exosomal protein content remain unknown. To determine whether endogenous and exogenous hormones modify urinary exosomal protein content, we analyzed samples from 14 mildly hypertensive patients in a crossover study during a high-sodium (HS, 160 mmol/d) diet and low-sodium (LS, 20 mmol/d) diet to activate the endogenous renin-angiotensin-aldosterone system. We further analyzed selected exosomal protein content in a separate cohort of healthy persons receiving intravenous aldosterone (0.7 μg/kg per hour for 10 hours) versus vehicle infusion. The LS diet increased plasma renin activity and aldosterone concentration, whereas aldosterone infusion increased only aldosterone concentration. Protein analysis of paired urine exosome samples by liquid chromatography-tandem mass spectrometry–based multidimensional protein identification technology detected 2775 unique proteins, of which 316 exhibited significantly altered abundance during LS diet. Sodium chloride cotransporter (NCC) and α- and γ-epithelial sodium channel (ENaC) subunits from the discovery set were verified using targeted multiple reaction monitoring mass spectrometry quantified with isotope-labeled peptide standards. Dietary sodium restriction or acute aldosterone infusion similarly increased urine exosomal γENaC[112–122] peptide concentrations nearly 20-fold, which correlated with plasma aldosterone concentration and urinary Na/K ratio. Urine exosomal NCC and αENaC concentrations were relatively unchanged during these interventions. We conclude that urinary exosome content is altered by renin-angiotensin-aldosterone system activation. Urinary measurement of exosomal γENaC[112–122] concentration may provide a useful biomarker of ENaC activation in future clinical studies. PMID:26113616

New Method To Estimate Total Polyphenol Excretion: Comparison of Fast Blue BB versus Folin-Ciocalteu Performance in Urine.

PubMed

Hinojosa-Nogueira, Daniel; Muros, Joaquín; Rufián-Henares, José A; Pastoriza, Silvia

2017-05-24

Polyphenols are bioactive substances of vegetal origin with a significant impact on human health. The assessment of polyphenol intake and excretion is therefore important. The Folin-Ciocalteu (F-C) method is the reference assay to measure polyphenols in foods as well as their excretion in urine. However, many substances can influence the method, making it necessary to conduct a prior cleanup using solid-phase extraction (SPE) cartridges. In this paper, we demonstrate the use of the Fast Blue BB reagent (FBBB) as a new tool to measure the excretion of polyphenols in urine. Contrary to F-C, FBBB showed no interference in urine, negating the time-consuming and costly SPE cleanup. In addition, it showed excellent linearity (r 2 = 0.9997), with a recovery of 96.4% and a precision of 1.86-2.11%. The FBBB method was validated to measure the excretion of polyphenols in spot urine samples from Spanish children, showing a good correlation between polyphenol intake and excretion.

Urine Anion Gap to Predict Urine Ammonium and Related Outcomes in Kidney Disease.

PubMed

Raphael, Kalani L; Gilligan, Sarah; Ix, Joachim H

2018-02-07

Low urine ammonium excretion is associated with ESRD in CKD. Few laboratories measure urine ammonium, limiting clinical application. We determined correlations between urine ammonium, the standard urine anion gap, and a modified urine anion gap that includes sulfate and phosphate and compared risks of ESRD or death between these ammonium estimates and directly measured ammonium. We measured ammonium, sodium, potassium, chloride, phosphate, and sulfate from baseline 24-hour urine collections in 1044 African-American Study of Kidney Disease and Hypertension participants. We evaluated the cross-sectional correlations between urine ammonium, the standard urine anion gap (sodium + potassium - chloride), and a modified urine anion gap that includes urine phosphate and sulfate in the calculation. Multivariable-adjusted Cox models determined the associations of the standard urine anion gap and the modified urine anion gap with the composite end point of death or ESRD; these results were compared with results using urine ammonium as the predictor of interest. The standard urine anion gap had a weak and direct correlation with urine ammonium ( r =0.18), whereas the modified urine anion gap had a modest inverse relationship with urine ammonium ( r =-0.58). Compared with the highest tertile of urine ammonium, those in the lowest urine ammonium tertile had higher risk of ESRD or death (hazard ratio, 1.46; 95% confidence interval, 1.13 to 1.87) after adjusting for demographics, GFR, proteinuria, and other confounders. In comparison, participants in the corresponding standard urine anion gap tertile did not have higher risk of ESRD or death (hazard ratio, 0.82; 95% confidence interval, 0.64 to 1.07), whereas the risk for those in the corresponding modified urine anion gap tertile (hazard ratio, 1.32; 95% confidence interval, 1.03 to 1.68) approximated that of directly measured urine ammonium. Urine anion gap is a poor surrogate of urine ammonium in CKD unless phosphate and sulfate are included in the calculation. Because the modified urine anion gap merely estimates urine ammonium and requires five measurements, direct measurements of urine ammonium are preferable in CKD. Copyright © 2018 by the American Society of Nephrology.

[Renal physiology].

PubMed

Gueutin, Victor; Deray, Gilbert; Isnard-Bagnis, Corinne

2012-03-01

The kidneys are responsible for the urinary excretion of uremic toxins and the regulation of several body systems such as intra and extracellular volume status, acid-base status, calcium and phosphate metabolism or erythropoiesis. They adapt quantitative and qualitative composition of the urine to keep these systems in balance. The flow of plasma is filtered in the range of 120 mL/min, and depends on the systemic and renal hemodynamics which is subject to self-regulation. The original urine will then be modified in successive segments of the nephron. The proximal nephron is to lead the massive reabsorption of water and essential elements such as sodium, bicarbonates, amino-acids and glucose. The distal nephron includes the distal convoluted tubule, the connector tube and the collecting duct. Its role is to adapt the quality composition of urine to the needs of the body.

Raised urinary glucocorticoid and adrenal androgen precursors in the urine of young hypertensive patients: possible evidence for partial glucocorticoid resistance

PubMed Central

Shamim, W; Yousufuddin, M; Francis, D; Gualdiero, P; Honour, J; Anker, S; Coats, A

2001-01-01

OBJECTIVE—To evaluate urinary glucocorticoid excretion profiles in a cohort of recently diagnosed young hypertensive patients.
METHODS—After excluding patients with secondary causes, 60 individuals with premature hypertension were recruited (diagnosed by ambulatory blood pressure monitoring before the age of 36 years). In addition, 30 older hypertensive controls (age of onset > 36 years, "middle aged hypertensive controls"), and 30 normal controls (age matched to the young hypertensive group) were studied. All provided 24 hour urine collections for mass spectrometry for total cortisol metabolites and total androgen metabolites by gas chromatography.
RESULTS—Among male patients, those with premature hypertension had higher total urinary excretion of cortisol metabolites (mean (SD), 13 332 (6472) µg/day) than age matched normal controls (7270 (1788) µg/day; p = 0.00001) or middle aged hypertensive controls (8315 (3565) µg/day; p = 0.002). A similar increase was seen among the female patients, although the absolute concentrations were lower. There was no significant difference between middle aged hypertensive patients and normal controls. Urinary total androgen excretion profiles in female patients also showed an unusual increase in the premature hypertension group (2958 (1672) µg/day) compared with the other groups (middle aged hypertensive controls, 1373 (748) µg/day, p = 0.0003; normal controls, 1687 (636) µg/day, p = 0.002). In all subjects, serum sodium and creatinine concentrations were within the normal range; serum potassium concentrations were found to be low before the start of treatment.
CONCLUSIONS—Individuals presenting with premature hypertension have an abnormally high excretion of glucocorticoid metabolites in the urine. While the mechanism remains uncertain, these findings are compatible with partial resistance of the glucocorticoid receptors, with a compensatory increase in cortisol and androgen metabolites. The mineralocorticoid effects of the latter (sodium and water retention) may contribute to an abnormally high blood pressure and may have implications for targeted selection of first line treatment in young hypertensive patients.


Keywords: premature hypertension; glucocorticoid resistance; cortisol metabolites; glucocorticoid receptor resistance PMID:11454825

The renal response to electrical stimulation of renal efferent sympathetic nerves in the anaesthetized greyhound.

PubMed Central

Poucher, S M; Karim, F

1991-01-01

1. The effect of direct electrical stimulation of the renal efferent nerves upon renal haemodynamics and function was studied in greyhounds anaesthetized with chloralose and artificially ventilated. The left kidney was neurally and vascularly isolated, and perfused with blood from one of the femoral arteries at a constant pressure of 99 +/- 1 mmHg. Renal blood flow was measured with a cannulating electromagnetic flow probe placed in the perfusion circuit, glomerular filtration rate by creatinine clearance, urinary sodium excretion by flame photometry and solute excretion by osmometry. Beta-Adrenergic receptor activation was blocked by the infusion of dl-propranolol (17 micrograms kg-1 min-1). The peripheral ends of the ligated renal nerves were stimulated at 0.5, 1.0, 1.5 and 2.0 Hz. 2. At 0.5 Hz frequency only osmolar excretion was significantly reduced (10.3 +/- 3.2%, P less than 0.05, n = 6). Reductions in sodium excretion (53.6 +/- 8.5%, P less than 0.01, n = 6) and water excretion (26.9 +/- 8.0%, P less than 0.05, n = 6) and further reductions of osmolar excretion (20.7 +/- 3.7%, P less than 0.01, n = 6) were observed at 1.0 Hz; however, these were observed in the absence of significant changes in renal blood flow and glomerular filtration rate. Significant reductions were observed in glomerular filtration rate at 1.5 Hz (16.3 +/- 4.1%, P less than 0.02, n = 5) and in renal blood flow at 2.0 Hz (13.1 +/- 4.0%, P less than 0.05, n = 5). Further reductions in urine flow and sodium excretion were also observed at these higher frequencies. 3. These results clearly show that significant changes in renal tubular function can occur in the absence of changes in renal blood flow and glomerular filtration rate when the renal nerves are stimulated electrically from a zero baseline activity up to a frequency of 1.5 Hz. Higher frequencies caused significant changes in both renal haemodynamics and function. PMID:2023113

Safety, tolerability, pharmacokinetics and pharmacodynamics of single doses of empagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor, in healthy Japanese subjects.

PubMed

Sarashina, Akiko; Koiwai, Kazuki; Seman, Leo J; Yamamura, Norio; Taniguchi, Atsushi; Negishi, Takahiro; Sesoko, Shogo; Woerle, Hans J; Dugi, Klaus A

2013-01-01

This randomized, placebo-controlled within dose groups, double-blind, single rising dose study investigated the safety, tolerability, pharmacokinetics and pharmacodynamics of 1 mg to 100 mg doses of empagliflozin in 48 healthy Japanese male subjects. Empagliflozin was rapidly absorbed, reaching peak levels in 1.25 to 2.50 h; thereafter, plasma concentrations declined in a biphasic fashion, with mean terminal elimination half-life ranging from 7.76 to 11.7 h. Increase in empagliflozin exposure was proportional to dose. Oral clearance was dose independent and ranged from 140 to 172 mL/min. In the 24 h following 100 mg empagliflozin administration, the mean (%CV) amount of glucose excreted in urine was 74.3 (17.1) g. The amount and the maximum rate of glucose excreted via urine increased with dose of empagliflozin. Nine adverse events, all of mild intensity, were reported by 8 subjects (7 with empagliflozin and 1 with the placebo). No hypoglycemia was reported. In conclusion, 1 mg to 100 mg doses of empagliflozin had a good safety and tolerability profile in healthy Japanese male subjects. Exposure to empagliflozin was dose proportional. The amount and rate of urinary glucose excretion were higher with empagliflozin than with the placebo, and increased with empagliflozin dose.

[Diuretic activity of the infusion of flowers from Lavandula officinalis].

PubMed

Elhajili, M; Baddouri, K; Elkabbaj, S; Meiouat, F; Settaf, A

2001-01-01

The diuretic activity of an infusion of Lavandula officinalis was studied in the Wistar rat. Thus, the kinetics of hydroelectrolytic elimination in response to the oral administration of an infusion of pharmaceutical lavender flowers were measured in the rats. Experiments were completed under similar conditions using a synthetic pharmacological diuretic, Diamox. The aqueous extract of this aromatic plant accelerated the elimination of the water overload. At the peak of the diuretic response, urinary osmolarity was significantly less than that of controls (111+/-14 vs. 195+/-11 mosmol x kg(-1)). Sodium excretion was moderate following administration of the infusion when compared to the synthetic diuretic. The stability of the aldosterone concentrations in the plasma and the absence of correlation with plasma sodium concentrations, coupled with the observed clearance of the free water (0.055+/-0.007 vs. 0.045+/-0.012 mL x min(-1)) show that the increase in diuresis and the moderate increase in sodium excretion are of tubular origin. The result of the phytochemical analysis of hexane extracts in the infusion and in urine indicated that four or five chemical factors may be involved in the diuretic effect of lavender.

Effect of dietary glycine and benzoate level on benzoate metabolism in mink (Mustela vision), blue fox (Alopex lagopus), and raccoon dog (Nyctereutes procyonoides).

PubMed

Pölönen, I J; Partanen, K H; Jalava, T K; Toivonen, V F

2000-04-01

Three 2 x 4 factorial experiments were carried out from August to September with 30 juvenile male mink, 24 raccoon dogs, and 24 blue foxes to investigate the effect of dietary glycine supply (low or high) on the efficiency of these species to excrete hippuric acid with incremental benzoate intake (0, 1, 2, or 4 mmol/kg BW). For mink, two additional treatments with 1 or 2 mmol/kg BW of ethyl benzoate were included. A basal low-glycine diet was formulated to meet the minimum protein requirements of fur animals (30% of ME). This diet was supplemented with 0 or 3 g/kg of glycine, or with 0, 1.0, 2.07, or 4.15 g/kg of sodium benzoate for mink and blue foxes, and with 0 or 4.5 g/kg of glycine and 0, 1.58, 3.17, or 6.34 g/kg of sodium benzoate for raccoon dogs, respectively. Two additional diets with .76 or 1.53 g/kg of ethyl benzoate were made for mink. Fecal and urinary benzoic and hippuric acid excretion were measured for 3 d. The 24-h recovery of [14C]benzoic acid injected intraperitoneally was measured from urine, the liver, and the kidneys. All animals appeared healthy and no clinical signs of benzoate overdose were observed. Dietary benzoate level did not affect ADFI or ADG in any species. Glycine supplementation lowered ADFI in mink. The majority of ingested benzoates were absorbed from the gut (over 95%), except in blue foxes, which excreted 6 to 15% of ingested benzoates in feces with incremental increases in benzoate intake. Urinary free benzoic acid excretion accounted for 10% of the ingested benzoates in blue foxes but less than 5% in mink and raccoon dogs. When benzoate intake was 1 mmol/kg BW, mink, blue foxes, and raccoon dogs excreted 71, 77, and 34% of ingested benzoates as hippuric acid in urine, respectively. With higher benzoate intakes, urinary hippuric acid excretion decreased quadratically with mink to 20%, and linearly with blue foxes and raccoon dogs to 45 and 16%, respectively. The hippuric acid pathway appears to be the principal route of benzoate elimination in the mink and blue fox, whereas, in the raccoon dog, other pathways appear to be more important. In mink, the elimination of ethyl benzoate did not differ from that of sodium benzoate. Because glycine conjugation is the primary route of benzoate elimination, it is recommended that benzoate content in fur animal feeds should not exceed 1 g/kg feed on an as-fed basis.

Seasonal variation in natural abundance of 2H and 18O in urine samples from rural Nigeria.

PubMed

Harbison, Justin E; Dugas, Lara R; Brieger, William; Tayo, Bamidele O; Alabi, Tunrayo; Schoeller, Dale A; Luke, Amy

2015-07-01

The doubly labeled water (DLW) method is used to measure free-living energy expenditure in humans. Inherent to this technique is the assumption that natural abundances of stable isotopes (2)H and (18)O in body water remain constant over the course of the measurement period and after elimination of the loading dose of DLW will return to the same predose level. To determine variability in the natural abundances of (2)H and (18)O in humans living in a region with seasonal shifts in rain patterns and sources of drinking water, over the course of 12 mo we collected weekly urine samples from four individuals living in southwest Nigeria as well as samples of their drinking water. From ongoing regional studies of hypertension, obesity, and energy expenditure, we estimated average water turnover rate, urine volumes, and sodium and potassium excretion. Results suggest that (2)H and (18)O in urine, mean concentrations of urinary sodium and potassium, urine volume, and total body turnover differed significantly from dry to rainy season. Additionally, seasonal weather variables (mean monthly maximum temperatures, total monthly rainfall, and minimum relative humidity) were all significantly associated with natural abundances in urine. No seasonal difference was observed in drinking water samples. Findings suggest that natural abundances in urine may not remain constant as assumed, and studies incorporating DLW measurements across the transition of seasons should interpret results with caution unless appropriate doses of the tracers are used. Copyright © 2015 the American Physiological Society.

Association between urinary sodium excretion and uric acid, and its interaction on the risk of prehypertension among Chinese young adults.

PubMed

Wang, Yang; Hu, Jia-Wen; Qu, Peng-Fei; Wang, Ke-Ke; Yan, Yu; Chu, Chao; Zheng, Wen-Ling; Xu, Xian-Jing; Lv, Yong-Bo; Ma, Qiong; Gao, Ke; Yuan, Yue; Li, Hao; Yuan, Zu-Yi; Mu, Jian-Jun

2018-05-17

High uric acid (UA) level and high salt intake are reportedly associated with cardiovascular disease. This study investigated the association between UA and urinary sodium excretion, as well as its interaction on the risk of prehypertension. A total of 1869 participants without hypertension were recruited from a previously established cohort in Shaanxi Province, China. The participants were classified as normotensive or prehypertensive on the basis of their blood pressure. Increasing quartiles of sodium excretion were associated with high urinary UA/creatinine levels in prehypertensive participants. Estimated sodium excretion positively correlated with urinary UA/creatinine excretions in the prehypertensive group. In addition, the multivariate-adjusted odds ratios for prehypertension compared with normotension were 1.68 (1.27-2.22) for sodium excretion and 1.71 (1.21-2.42) for serum UA. Increasing sodium excretion and serum UA were associated with higher risk of prehypertension. Compared with the lowest quartiles, the highest sodium excretion and serum UA quartiles entailed 3.48 times greater risk of prehypertension. Sodium excretion is associated with urinary UA excretion in prehypertensive participants. The present study shows that high levels of salt intake and serum UA simultaneously are associated with a higher risk of prehypertension.

Consumption of a high-salt diet by ewes during pregnancy alters nephrogenesis in 5-month-old offspring.

PubMed

Tay, S H; Blache, D; Gregg, K; Revell, D K

2012-11-01

Maternal nutrition during pregnancy can affect kidney development in the foetus, which may lead to adverse consequences in the mature kidney. It was expected that high-salt intake by pregnant ewes would lead to a reduction in foetal glomerular number but that the ovine kidney would adapt to maintain homoeostasis, in part by increasing the size of each glomerulus. Merino ewes that were fed either a control (1.5% NaCl) or high-salt (10.5% NaCl) diet during pregnancy, as well as their 5-month-old offspring, were subjected to a dietary salt challenge, and glomerular number and size and sodium excretion were measured. The high-salt offspring had 20% fewer glomeruli compared with the control offspring (P < 0.001), but they also had larger glomerular radii compared with the control offspring (P < 0.001). Consequently, the cross-sectional area of glomeruli was 18% larger in the high-salt offspring than in the control offspring (P < 0.05). There was no difference in the daily urinary sodium excretion between the two offspring groups (P > 0.05), although the high-salt offspring produced urine with a higher concentration of sodium. Our results demonstrated that maternal high-salt intake during pregnancy affected foetal nephrogenesis, altering glomerular number at birth. However, the ability to concentrate and excrete salt was not compromised, which indicates that the kidney was able to adapt to the reduction in the number of glomeruli.

Gravitational force and the cardiovascular system

NASA Technical Reports Server (NTRS)

Pendergast, D. R.; Olszowka, A. J.; Rokitka, M. A.; Farhi, L. E.

1991-01-01

Ground-based simulation studies have been conducted to clarify the problems of the cardiovascular adaptation to alterations in gravitational force. Simulated microgravity experiments resulted in increases in cardiac stretch, urine flow, and sodium excretion, which were accompanied by lower plasma renin, aldosterone, and ADH. There appears to be a decrease in plasma volume as well as in sympathetic tone after 2-3 days of 0 Gz. Complete adjustment to 0 Gz is found within 8 h without a decrease in plasma volume, when subjects are allowed to dehydrate mildly.

Protective effects of hydroxytyrosol on gentamicin induced nephrotoxicity in mice.

PubMed

Chashmi, Nooshin Ahmadian; Emadi, Sarvenaz; Khastar, Hossein

2017-01-22

Gentamicin (GM) is an effective and common antibiotic against severe gram-negative infections. However, its nephrotoxic action has limited the extent of its use. The aim of this study was to investigate the protective effects of hydroxytyrosol (HT) on gentamicin induced nephrotoxicity in mice. Male mice (n = 27) were randomly assigned to three groups: (1) Sham, (2) GM (100 mg/kg for 7 days) (3) GM + HT (2 mg/kg BW; gastric gavages, for 7 days). 24-h urine samples were collected on day 8 and then animal were anesthetized. The blood and kidney tissue samples were collected. Gentamicin led to increase in plasma BUN and creatinine, fractional excretion of sodium and potassium and decrease in creatinine clearance and urine flow rate. SOD and GSH levels were reduced and MDA was increased in the GM group compared with the sham group. In GM + HT group, plasma BUN and creatinine, fractional excretion of Na, creatinine clearance and urine flow rate were decreased in contrast to GM group. Increase in SOD and GSH activity and decrease in MDA compared to GM group were seen. Findings suggest that HT partly protected the kidneys from gentamicin induced nephrotoxicity and it is partly due to antioxidant effect of HT. Copyright © 2016 Elsevier Inc. All rights reserved.

Assessment of Sodium and Potassium Intake by 24 h Urinary Excretion in a Healthy Mexican Cohort.

PubMed

Vallejo, Maite; Colín-Ramírez, Eloisa; Rivera Mancía, Susana; Cartas Rosado, Raúl; Madero, Magdalena; Infante Vázquez, Oscar; Vargas-Barrón, Jesús

2017-02-01

A high dietary sodium intake and a low potassium intake are associated with adverse cardiovascular health. Data on these nutrients consumption in Mexico is limited. The aim of this study was to assess sodium and potassium intake by 24 h urinary excretion in a clinically healthy Mexican population. We additionally explored their association with blood pressure. 711 clinically healthy participants aged 20-50 years old recruited in the Tlalpan 2020 cohort from September 2014-December 2015, were included in this cross-sectional analysis. All participants provided a 24 h urine sample and underwent anthropometric, biochemical, and blood pressure evaluations. Univariate and multivariate linear regression analyses were used to assess the association of urinary sodium, potassium, and Na/K ratio with blood pressure. Mean (95% confidence interval [CI]) urinary sodium and potassium in the overall population was 3150.1 (3054.2-3246.0) mg/d and 1909.5 (1859.3-1959.6) mg/d, respectively. Overall, only 121 (17%) met the WHO recommendation for sodium intake (<2000 mg/d) and 16 (2.3%) met the goal for potassium intake (≥3510 mg/d). Urinary sodium (β coefficient 1.3, 95% CI: 0.7, 1.8, p <0.001) and potassium (β coefficient 2.1, 95% CI: 1.0, 3.2, p <0.001) were found to be associated with systolic blood pressure in the univariate analysis but not in the multivariate analysis. Sodium intake was higher and potassium intake was lower than the WHO recommendations in this healthy Mexican population. Sodium and potassium intakes were not associated with blood pressure at the mean levels of intake observed in this population, after adjusting for key variables. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

Socioeconomic Status Associated With Urinary Sodium and Potassium Excretion in Japan: NIPPON DATA2010.

PubMed

Miyagawa, Naoko; Okuda, Nagako; Nakagawa, Hideaki; Takezaki, Toshiro; Nishi, Nobuo; Takashima, Naoyuki; Fujiyoshi, Akira; Ohkubo, Takayoshi; Kadota, Aya; Okamura, Tomonori; Ueshima, Hirotsugu; Okayama, Akira; Miura, Katsuyuki

2018-01-01

Although socioeconomic status (SES) may affect food and nutrient intakes, few studies have reported on sodium (Na) and potassium (K) intakes among individuals with various SESs in Japan. We investigated associations of SES with Na and K intake levels using urinary specimens in a representative Japanese population. This was a cross-sectional study of 2,560 men and women (the NIPPON DATA2010 cohort) who participated in the National Health and Nutrition Survey Japan in 2010. Casual urine was used to calculate estimated excretion in 24-hour urinary Na (E24hr-Na) and K (E24hr-K). The urinary sodium-to-potassium (Na/K) ratio was calculated from casual urinary electrolyte values. An analysis of covariance was performed to investigate associations of aspects of SES, including equivalent household expenditure (EHE), educational attainment, and job category, with E24hr-Na, E24hr-K, and the Na/K ratio for men and women separately. A stratified analysis was performed on educational attainment and the job category for younger (<65 years) and older (≥65 years) participants. In men and women, average E24hr-Na was 176.2 mmol/day and 172.3, average E24hr-K was 42.5 and 41.3, and the average Na/K ratio was 3.61 and 3.68, respectively. Lower EHE was associated with a higher Na/K ratio in women and lower E24hr-K in men and women. A shorter education was associated with a higher Na/K ratio in women and younger men, and lower E24hr-K in older men and women. Lower EHE and a shorter education were associated with a lower K intake and higher Na/K ratio estimated from casual urine specimens in Japanese men and women.

Co-administration of furosemide with albumin for overcoming diuretic resistance in patients with hypoalbuminemia: a meta-analysis.

PubMed

Kitsios, Georgios D; Mascari, Paolo; Ettunsi, Riad; Gray, Anthony W

2014-04-01

To systematically review clinical studies of co-administration of albumin and loop diuretics in hypoalbuminemic patients as a strategy to overcome diuretic resistance. Systematic search of electronic databases up to October 2012. We included randomized clinical trials of adults with hypoalbuminemia, comparing co-administration of loop diuretics and albumin versus loop diuretics alone. Quantitative data were synthesized with meta-analytic techniques for clinical, surrogate (urinary volume and urinary sodium excretion) and intermediate (pharmacokinetic and hemodynamic parameters) outcomes. Ten studies were included, of which 8 trials with crossover design were synthesized with meta-analysis. A statistically significant increase in the amount of urine volume (increment of 231 mL [95% confidence interval 135.5-326.5]) and sodium excreted (15.9 mEq [4.9-26.8]) at 8 hours were found in favor of co-administration of albumin and furosemide. These differences were no longer statistically significant at 24 hours. Meta-analyses for intermediate outcomes (ie, furosemide excretion, distribution volume etc.) did not reveal statistically significant differences. Synthesis of a heterogeneous body of evidence shows transient effects of modest clinical significance for co-administration of albumin with furosemide in hypoalbuminemic patients. Pragmatic, large-scale randomized studies are needed to delineate the role of this strategy. Copyright © 2014 Elsevier Inc. All rights reserved.

Urine Potassium Excretion, Kidney Failure, and Mortality in CKD.

PubMed

Leonberg-Yoo, Amanda K; Tighiouart, Hocine; Levey, Andrew S; Beck, Gerald J; Sarnak, Mark J

2017-03-01

Low urine potassium excretion, as a surrogate for dietary potassium intake, is associated with higher risk for hypertension and cardiovascular disease in a general population. Few studies have investigated the relationship of urine potassium with clinical outcomes in chronic kidney disease (CKD). Longitudinal cohort study. The MDRD (Modification of Diet in Renal Disease) Study was a randomized controlled trial (N = 840) conducted in 1989 to 1993 to examine the effects of blood pressure control and dietary protein restriction on kidney disease progression in adults aged 18 to 70 years with CKD stages 2 to 4. This post hoc analysis included 812 participants. The primary predictor variable was 24-hour urine potassium excretion, measured at baseline and at multiple time points (presented as time-updated average urine potassium excretion). Kidney failure, defined as initiation of dialysis therapy or transplantation, was determined from US Renal Data System data. All-cause mortality was assessed using the National Death Index. Median follow-up for kidney failure was 6.1 (IQR, 3.5-11.7) years, with 9 events/100 patient-years. Median all-cause mortality follow-up was 19.2 (IQR, 10.8-20.6) years, with 3 deaths/100 patient-years. Baseline mean urine potassium excretion was 2.39±0.89 (SD) g/d. Each 1-SD higher baseline urine potassium level was associated with an adjusted HR of 0.95 (95% CI, 0.87-1.04) for kidney failure and 0.83 (95% CI, 0.74-0.94) for all-cause mortality. Results were consistent using time-updated average urine potassium measurements. Analyses were performed using urine potassium excretion as a surrogate for dietary potassium intake. Results are obtained from a primarily young, nondiabetic, and advanced CKD population and may not be generalizable to the general CKD population. Higher urine potassium excretion was associated with lower risk for all-cause mortality, but not kidney failure. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Association Between Estimated 24-h Urinary Sodium Excretion and Metabolic Syndrome in Korean Adults

PubMed Central

Won, Jong Chul; Hong, Jae Won; Noh, Jung Hyun; Kim, Dong-Jun

2016-01-01

Abstract High sodium intake is 1 of the modifiable risk factors for cardiovascular disease, but in Korea, daily sodium intake is estimated to be double the level recommended by World Health Organization. We investigated the association between the estimated 24-h urinary sodium excretion (24hUNaE) and metabolic syndrome using nationwide population data. In total, 17,541 individuals (weighted n = 33,200,054; weighted men, 52.5% [95% confidence interval, CI = 51.8–53.3]; weighted age, 45.2 years [44.7–45.7]) who participated in the Korean Health and Nutrition Examination Survey 2009 to 2011 were investigated. NCEP-ATP III criteria for metabolic syndrome were used, and sodium intake was estimated by 24hUNaE using Tanaka equation with a spot urine sample. The weighted mean 24hUNaE values were 3964 mg/d (95% CI = 3885–4044) in men and 4736 mg/d (4654–4817) in women. The weighted age-adjusted prevalence of metabolic syndrome was 22.2% (21.4–23.0), and it increased with 24hUNaE quartile in both men and women (mean ± standard error of the mean; men: 22.5 ± 1.0%, 23.0 ± 1.0%, 26.0 ± 1.2%, and 26.0 ± 1.2%; P = 0.026; women: 19.4 ± 0.8%, 17.7 ± 0.8%, 19.8 ± 1.0%, and 23.0 ± 1.1%; P = 0.002, for quartiles 1–4, respectively). Even after adjustment for age, daily calorie intake, heavy alcohol drinking, regular exercise, college graduation, and antihypertensive medication, the weighted prevalence of metabolic syndrome increased with the increase in 24hUNaE in men and women. The weighted 24hUNaE was positively associated with the number of metabolic syndrome components after adjustment for confounding factors in men and women. In subjects without antihypertensive medication, the odds ratio for metabolic syndrome in quartile 4 of 24hUNaE compared with quartile 1 was 1.56 (1.33–1.84, P < 0.001) in the total population, 1.66 (1.34–2.06, P < 0.001) in men, and 1.94 (1.49–2.53, P < 0.001) in women. In this nationwide population study, we observed a significant independent association between high sodium intake, estimated by spot urine sodium excretion, and the presence of metabolic syndrome in men and women. PMID:27082553

Lack of detectable DNA alkylation for bromhexine in man.

PubMed

Farmer, P B; Parry, A; Franke, H; Schmid, J

1988-09-01

It is known that in vitro incubation of the expectorant drug bromhexine (N-methyl-N-cyclohexyl-(2-amino-3,5-dibromobenzyl)-ammonium hydrochloride) with nitrite yields methylcyclohexyl nitrosamine (NMCA). NMCA is capable of methylating DNA when administered to rats. In vivo tests with bromhexine have also demonstrated that the drug methylates DNA when it is orally administered in the presence of sodium nitrite, presumably due to the intragastric formation of NMCA. In this study the potential of bromhexine to methylate nucleic acids in man, under physiological conditions, has been investigated. 20 volunteers were orally administered on each of three successive days 48 mg of bromhexine hydrochloride, labelled with three deuterium atoms in the N-methyl group. Urine was collected before treatment and subsequent to the last dose, and analysed by GC-MS for d0- and d3-7-methylguanine. 7-Methylguanine is naturally occurring in urine owing to the turnover of t-RNA of which it is a minor constituent. It is also a repair product from nucleic acids methylated by carcinogens, which is known to be excreted unmetabolised largely within 24 h of the methylation process. Unlabelled 7-methylguanine was present at levels of 7.36 +/- 2.43 mg/d in control urine and 6.12 +/- 2.36 mg/d in treated urine, in accord with previously published values. The excretion of isotopically labelled 7-methylguanine averaged 0.43 +/- 0.077% of the unlabelled concentration for control urines and 0.44 +/- 0.066% for treated urines, i.e. no d3-7-methylguanine could be detected following the drug treatment. The observed signals were largely accounted for by the naturally occurring isotopes 13C and 15N.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis and Management of Combined Central Diabetes Insipidus and Cerebral Salt Wasting Syndrome After Traumatic Brain Injury.

PubMed

Wu, Xuehai; Zhou, Xiaolan; Gao, Liang; Wu, Xing; Fei, Li; Mao, Ying; Hu, Jin; Zhou, Liangfu

2016-04-01

Combined central diabetes insipidus and cerebral salt wasting syndrome after traumatic brain injury (TBI) is rare, is characterized by massive polyuria leading to severe water and electrolyte disturbances, and usually is associated with very high mortality mainly as a result of delayed diagnosis and improper management. We retrospectively reviewed the clinical presentation, management, and outcomes of 11 patients who developed combined central diabetes insipidus and cerebral salt wasting syndrome after traumatic brain injury to define distinctive features for timely diagnosis and proper management. The most typical clinical presentation was massive polyuria (10,000 mL/24 hours or >1000 mL/hour) refractory to vasopressin alone but responsive to vasopressin plus cortisone acetate. Other characteristic presentations included low central venous pressure, high brain natriuretic peptide precursor level without cardiac dysfunction, high 24-hour urine sodium excretion and hypovolemia, and much higher urine than serum osmolarity; normal serum sodium level and urine specific gravity can also be present. Timely and adequate infusion of sodium chloride was key in treatment. Of 11 patients, 5 had a good prognosis 3 months later (Extended Glasgow Outcome Scale score ≥6), 1 had an Extended Glasgow Outcome Scale score of 4, 2 died in the hospital of brain hernia, and 3 developed a vegetative state. For combined diabetes insipidus and cerebral salt wasting syndrome after traumatic brain injury, massive polyuria is a major typical presentation, and intensive monitoring of fluid and sodium status is key for timely diagnosis. To achieve a favorable outcome, proper sodium chloride supplementation and cortisone acetate and vasopressin coadministration are key. Copyright © 2016 Elsevier Inc. All rights reserved.

Use of mean spot urine sodium concentrations to estimate daily sodium intake in patients with chronic kidney disease.

PubMed

Kang, Shin Sook; Kang, Eun Hee; Kim, Seon Ok; Lee, Moo Song; Hong, Changgi D; Kim, Soon Bae

2012-03-01

Sodium intake is an important issue for patients with chronic kidney disease (CKD). The two most widely used methods to measure sodium are 24-h urinary sodium excretion (24HUNa), which can be difficult to perform routinely, and sodium intake by dietary recall, which can be inaccurate. This study evaluated use of the mean value of three spot urinary sodium (UNa) concentrations to estimate daily sodium intake in patients with CKD. This cross-sectional study enrolled 305 patients with CKD, none of whom were on dialysis, who visited the nephrology clinic at the Asan Medical Center (Seoul, Korea). We performed three spot UNa tests, three calculations of the UNa/creatinine (UCr) ratio, one measurement of 24HUNa, and one measurement of sodium intake by dietary recall. The 24HUNa and mean spot UNa values were significantly lower in patients with more advanced CKD (P = 0.006 and P < 0.001, respectively). One-time spot UNa was significantly higher in the evening than in the morning for patients with stage III, IV, or V CKD. Total sodium intake, but not sodium nutrient density (milligrams of sodium per 1000 kcal), was significantly different for patients with different stages of CKD (P = 0.001). The correlation coefficient between 24HUNa and mean spot UNa was 0.477 (95% confidence interval [CI] 0.384-0.562, P < 0.001), slightly higher than that between 24HUNa excretion and mean spot UNa/UCr (r = 0.313, 95% CI 0.207-0.465, P < 0.001). There was a linear relation between spot UNa and 24HUNa: mean spot UNa = 0.27 × 24HUNa + 60. Therefore, a 24HUNa excretion of 87 mEq (sodium intake 2 g/d) corresponded to a mean spot UNa level of 83 mEq/L. The correlation coefficient between sodium intake and mean spot UNa was 0.435 (95% CI 0.336-0.524, P < 0.001), significantly higher than that between sodium intake and mean spot UNa/UCr (r = 0.197, 95% CI 0.091-0.301, P = 0.001). Mean spot UNa tended to be better correlated with 24HUNa than with sodium intake. Mean spot UNa is a simple and effective method that can be used to monitor sodium intake in patients with CKD. A daily intake of 2 g of sodium corresponds to a mean spot UNa level of approximately 83 mEq/L in patients with CKD. Copyright © 2012 Elsevier Inc. All rights reserved.

Residual veterinary antibiotics in pig excreta after oral administration of sulfonamides.

PubMed

Qiu, Jinrong; Zhao, Tao; Liu, Qingyun; He, Jinhua; He, Dechun; Wu, Genyi; Li, Yongtao; Jiang, Chengai; Xu, Zhencheng

2016-04-01

Sulfonamides (SAs) are applied widely as feed additives in the farming of livestock and poultry. It can lead to the excretion of large amounts of SAs in manure and result in persistent environmental pollution. We evaluated the fate of four SAs, sulfamerazine (SM1), sulfachloropyridazine (SCP), sulfadimoxine (SDM') and sulfaquinoxaline (SQ), from oral administration to excretion in urine and feces in pigs. The four SAs were added to homemade feed to make them reach the required concentration gradient, which were 0, 50 and 100 mg/kg (low, normal and high concentrations, respectively). In different treatments, excretions of the four SAs were 35.68-86.88 %. With regard to total excretion, the order was SQ > SCP > SM1 > SDM' for all treatments. The concentration of SAs in the feed had significant effects on the amount of the four SAs excreted every day. The concentration of SAs in feces and in the urine for different treatments was 15.03-26.55 and 14.54-69.22 %, respectively. In each treatment, excretions of SCP, SDM' and SQ in feces were lower than that in urine. The four SAs remained longer in urine than in feces. Excretions in urine and feces were lower if SAs were administered orally rather than by injection.

Effects of a behavioral intervention that emphasizes spices and herbs on adherence to recommended sodium intake: results of the SPICE randomized clinical trial12

PubMed Central

Anderson, Cheryl AM; Cobb, Laura K; Miller, Edgar R; Woodward, Mark; Hottenstein, Annette; Chang, Alex R; Mongraw-Chaffin, Morgana; White, Karen; Charleston, Jeanne; Tanaka, Toshiko; Thomas, Letitia; Appel, Lawrence J

2015-01-01

Background: For decades, dietary sodium intake in the United States has remained high, and few studies have examined strategies for maintaining recommended intakes. Objective: We examined the effects of a behavioral intervention, which emphasized spices and herbs, on the maintenance of sodium intake at the recommended intake of 1500 mg/d in individuals to whom the US Dietary Guidelines for Americans apply. Design: We conducted a 2-phase study that included adults ≥18 y of age for whom Dietary Guidelines for Americans recommends 1500 mg Na/d. The study was conducted in Baltimore, Maryland, from 2012 to 2014. In phase 1, 55 individuals consumed a low-sodium diet for 4 wk. Participants were provided all foods, snacks, and calorie-containing drinks. In phase 2, 40 participants from phase 1 were randomly assigned to either a behavioral intervention to reduce sodium intake (n = 20) or a self-directed control group (n = 20) for 20 wk. The primary study outcome was the change in mean 24-h urinary sodium excretion during phase 2. Linear regression analyses were used to determine intervention effects on urinary sodium excretion. Results: Participant characteristics were as follows: women: 65%; African American: 88%; hypertension: 63%; diabetes: 18%; mean age: 61 y; and mean body mass index (in kg/m2): 30. At the end of phase 2, mean 24-h sodium excretion was lower in the behavioral intervention than in the self-directed group (mean difference: −956.8 mg/d; 95% CI: −1538.7, −374.9 mg/d) after sodium intake at screening was controlled for (P = 0.002). These findings persisted in sensitivity analyses that excluded potentially incomplete urine collections [Mage’s equation mean difference: −1090 mg/d (P = 0.001); Joosens’ equation mean difference: −796 mg/d (P = 0.04)]. Conclusions: A multifactorial behavioral intervention emphasizing spices and herbs significantly reduced sodium intake. Because of the ubiquity of sodium in the US food supply, multilevel strategies addressing individual behaviors and the food supply are needed to improve adherence to recommendations. This trial was registered at clinicaltrials.gov as NCT01615159. PMID:26269371

Estimated 24-hour urine sodium excretion is correlated with blood pressure in Korean population: 2009-2011 Korean National Health and Nutritional Examination Survey.

PubMed

Oh, Jieun; Lee, Jeonghwan; Koo, Ho Seok; Kim, Suhnggwon; Chin, Ho Jun

2014-09-01

No large-scale studies have investigated the association between salt intake and hypertension in Korean population. To investigate the relationship of blood pressure to salt consumption, we analyzed data from 19,476 participants in the 2009-2011 Korean National Health and Nutritional Examination Survey (KNHANES). Urinary sodium excretion over 24-hr (24HUNa) was estimated from spot urine tests using Tanaka's equation. The study subjects were stratified into hypertensive and normotensive groups. Hypertensive participants (n=6,552, 33.6%) had higher estimated 24HUNa, 150.4±38.8 mEq/day, than normotensive participants, 140.5±34.6 mEq/day (P<0.001). The association between 24HUNa and blood pressure outcomes was not affected by adjustment for other risk factors for hypertension (odds ratio 0.001; 95% confidence interval 0.001-0.003; P<0.001). Increases in 24HUNa of 100 mEq/day were associated with a 6.1±0.3/2.9±0.2 mmHg increase in systolic/diastolic blood pressure in all participants. This effect was stronger in hypertensive participants (increase of 8.1±0.5/3.4±0.3 mmHg per 100 mEq/day) and smaller in normotensive participants (2.9±0.3/1.3±0.2 mmHg). These results support recommendations for low salt intake in Korean population to prevent and control adverse blood pressure levels.

The comparability of oxalate excretion and oxalate:creatinine ratio in the investigation of primary hyperoxaluria: review of data from a referral centre.

PubMed

Clifford-Mobley, Oliver; Tims, Christopher; Rumsby, Gill

2015-01-01

Urine oxalate measurement is an important investigation in the evaluation of renal stone disease. Primary hyperoxaluria (PH) is a rare inherited metabolic disease characterised by persistently elevated urine oxalate, but the diagnosis may be missed in adults until renal failure has developed. Urine oxalate results were reviewed to compare oxalate:creatinine ratio and oxalate excretion, and to estimate the potential numbers of undiagnosed PH. Urine oxalate results from August 2011 to April 2013 were reviewed. Oxalate excretion and oxalate:creatinine ratio were evaluated for 24 h collections and ratio alone for spot urine samples. Oxalate:creatinine ratio and oxalate excretion were moderately correlated (R=0.63) in 24-h urine collections from patients aged 18 years and above. Sex-related differences were found requiring implementation of male and female reference ranges for oxalate:creatinine ratio. Of samples with both ratio and excretion above the reference range, 7% came from patients with confirmed PH. There were 24 patients with grossly elevated urine oxalate who had not been evaluated for PH. Oxalate:creatinine ratio and oxalate excretion were discordant in many patients, which is likely to be a result of intra-individual variation in creatinine output and imprecision in the collection itself. Some PH patients had urine oxalate within the reference range on occasion, and therefore it is not possible to exclude PH on the finding of a single normal result. A significant number of individuals had urine oxalate results well above the reference range who potentially have undiagnosed PH and are consequently at risk of renal failure. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Low sodium intake does not impair renal compensation of hypoxia-induced respiratory alkalosis.

PubMed

Höhne, Claudia; Boemke, Willehad; Schleyer, Nora; Francis, Roland C; Krebs, Martin O; Kaczmarczyk, Gabriele

2002-05-01

Acute hypoxia causes hyperventilation and respiratory alkalosis, often combined with increased diuresis and sodium, potassium, and bicarbonate excretion. With a low sodium intake, the excretion of the anion bicarbonate may be limited by the lower excretion rate of the cation sodium through activated sodium-retaining mechanisms. This study investigates whether the short-term renal compensation of hypoxia-induced respiratory alkalosis is impaired by a low sodium intake. Nine conscious, tracheotomized dogs were studied twice either on a low-sodium (LS = 0.5 mmol sodium x kg body wt-1 x day-1) or high-sodium (HS = 7.5 mmol sodium x kg body wt-1 x day-1) diet. The dogs breathed spontaneously via a ventilator circuit during the experiments: first hour, normoxia (inspiratory oxygen fraction = 0.21); second to fourth hour, hypoxia (inspiratory oxygen fraction = 0.1). During hypoxia (arterial PO2 34.4 +/- 2.1 Torr), plasma pH increased from 7.37 +/- 0.01 to 7.48 +/- 0.01 (P < 0.05) because of hyperventilation (arterial PCO2 25.6 +/- 2.4 Torr). Urinary pH and urinary bicarbonate excretion increased irrespective of the sodium intake. Sodium excretion increased more during HS than during LS, whereas the increase in potassium excretion was comparable in both groups. Thus the quick onset of bicarbonate excretion within the first hour of hypoxia-induced respiratory alkalosis was not impaired by a low sodium intake. The increased sodium excretion during hypoxia seems to be combined with a decrease in plasma aldosterone and angiotensin II in LS as well as in HS dogs. Other factors, e.g., increased mean arterial blood pressure, minute ventilation, and renal blood flow, may have contributed.

Increased urinary excretion of platelet activating factor in mice with lupus nephritis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Macconi, D.; Noris, M.; Benfenati, E.

1991-01-01

Platelet activating factor (PAF) is present in urine from humans and experimental animals in normal conditions. Very little is known about changes in PAF urinary excretion under pathologic conditions and no data are available about the origin of PAF in the urine. In the present study we explored the possibility that immunologic renal disease is associated with an increase in PAF urinary excretion using gas chromatography-mass spectrometry technique. To clarify the renal or extrarenal origin of urinary PAF we evaluated whether exogenously administered PAF (1-(1{prime},2{prime}-{sup 3}H)alkyl) is filtered through the glomerulus and excreted in the urine. The results show that:more » (1) urine from mice with lupus nephritis in the early phase of the disease contained amounts of PAF comparable to those excreted in normal mouse urine, (2) PAF levels increased when animals started to develop high grade proteinuria, (3) after intravenous injection of ({sup 3}H) PAF In nephritic mice, a negligible amount of ({sup 3}H) ether lipid, corresponding to ({sup 3}H)1-alkyl -2-acyl-3-phosphocholine (alkyl-2-acyl-GPC), was recovered from the 24 h urine extract.« less

Effect of salt intake and potassium supplementation on urinary renalase and serum dopamine levels in Chinese adults.

PubMed

Wang, Yang; Wang, Dan; Chu, Chao; Mu, Jian-Jun; Wang, Man; Liu, Fu-Qiang; Xie, Bing-Qing; Yang, Fan; Dong, Zhen-Zhen; Yuan, Zu-Yi

2015-01-01

The aim of our study was to assess the effects of altered salt and potassium intake on urinary renalase and serum dopamine levels in humans. Forty-two subjects (28–65 years of age) were selected from a rural community of northern China. All subjects were sequentially maintained on a low-salt diet for 7 days (3.0 g/day of NaCl), a high-salt diet for an additional 7 days (18.0 g/day of NaCl), and a high-salt diet with potassium supplementation for a final 7 days (18.0 g/day of NaCl + 4.5 g/day of KCl). Urinary renalase excretions were significantly higher during the high-salt diet intervention than during the low-salt diet. During high-potassium intake, urinary renalase excretions were not significantly different from the high-salt diet, whereas they were significantly higher than the low-salt levels. Serum dopamine levels exhibited similar trends across the interventions. Additionally, a significant positive relationship was observed between the urine renalase and serum dopamine among the different dietary interventions. Also, 24-hour urinary sodium excretion positively correlated with urine renalase and serum dopamine in the whole population. The present study indicates that dietary salt intake and potassium supplementation increase urinary renalase and serum dopamine levels in Chinese subjects. © 2015 S. Karger AG, Basel

The Key to Life Nutrition Program: results from a community-based dietary sodium reduction trial

PubMed Central

Robare, Joseph F; Milas, N Carole; Bayles, Constance M; Williams, Kathy; Newman, Anne B; Lovalekar, Mita T; Boudreau, Robert; McTigue, Kathleen; Albert, Steven M; Kuller, Lewis H

2016-01-01

Objective Evaluation of a dietary Na reduction trial in a community setting. Design Community-based randomized trial. Ten-week nutrition intervention activities focused on lifestyle modification to decrease dietary Na intake, under the supervision of a registered dietitian. Twenty-four hour urine specimens were collected at baseline and follow-up visits to determine 24 h urinary Na excretion. Setting The University of Pittsburgh Center for Healthy Aging, Key to Life Nutrition Program. Subjects Hypertensive adults at least 65 years of age. Results Mean age of participants was 75 years. Twenty-four hour mean urinary Na excretion at baseline was 3174 mg/d. This reduced to 2944 mg/d (P = 0·30) and 2875 mg/d (P ≤ 0·03) at 6-and 12-month follow-ups, respectively. In a sub-sample (urine volume of ≥ 1000 ml, baseline to 12 months), mean urinary Na excretion decreased from 3220 mg/d to 2875 mg/d (P ≤ 0·02). Conclusions Significant reductions in mean 24 h urinary Na were reported, but results fell short of the recommended guidelines of 1500 mg/d for at-risk individuals. Our results reiterate the difficulty in implementing these guidelines in community-based programmes. More aggressive public health efforts, food industry support and health policy changes are needed to decrease Na levels in older adults to the recommended guidelines. PMID:19781124

Calcium and vitamin D intake and biochemical tests in short-stature children and adolescents.

PubMed

Bueno, A L; Czepielewski, M A; Raimundo, F V

2010-11-01

Growth is highly dependent on the absorption of nutrients. Inadequate calcium and vitamin D intake may compromise bone mineralization and growth. There is a great deal of concern regarding calcium and vitamin D intake, as well as biochemical changes in children and adolescents, which led us to investigate calcium and vitamin D levels during growth. Fifty-eight children and adolescents with short stature (z-score <3 s.d.) were evaluated from September 2005 to February 2007. Blood biochemical analyses and 24-h urine tests were performed and were used to evaluate calcium, phosphorus, creatinine, sodium, alkaline phosphatase, parathyroid hormone (PTH) and 25(OH)D levels. Dietary inquiries, repeated three times, were used to estimate the actual intake of these substances. A reduced calcium (608.6 mg/day) and vitamin D (72.5 IU/day) intake was observed. Calcium excretion in 24-h urine (56 mg/24 h) and calcium excretion by weight (2.0 mg/24 h/kg) showed scores that were below normal. A negative correlation between PTH and both dietary vitamin D (r=-0.46; P<0.01) and calcium intake (r =-0.41; P<0.001) was observed. The low calcium and vitamin D intake observed in short-stature children and adolescents was associated with biochemical results, and suggested that PTH and calcium excretion may be useful screening tests for evaluating dietary calcium and vitamin D.

Dental hyponatraemia.

PubMed

Simpson, R M

2011-08-01

A 14-year-old girl developed dental pain and was treated for acute infected pulpitis of her right upper lateral incisor with drilling and filling. The pain continued and was helped by analgesia, sucking ice cubes and drinking cold water. Forty-eight hours later, she became confused and disoriented. She started to vomit and complained of headache. Investigations revealed hyponatraemia with normal serum potassium levels and initially normal urinary sodium excretion. Over the next 24 hours, she passed 5.45 L of urine and her serum sodium rose from 125 to 143 mmol/L. Self-induced water intoxication has been described during drinking games and initiation ceremonies, but this would appear to an unusual cause. Conservative management proved successful in allowing this girl to recover without sequelae.

Non-accidental salt poisoning.

PubMed Central

Meadow, R

1993-01-01

The clinical features of 12 children who incurred non-accidental salt poisoning are reported. The children usually presented to hospital in the first six months of life with unexplained hypernatraemia and associated illness. Most of the children suffered repetitive poisoning before detection. The perpetrator was believed to the mother for 10 children, the father for one, and either parent for one. Four children had serum sodium concentrations above 200 mmol/l. Seven children had incurred other fabricated illness, drug ingestion, physical abuse, or failure to thrive/neglect. Two children died; the other 10 remained healthy in alternative care. Features are described that should lead to earlier detection of salt poisoning; the importance of checking urine sodium excretion, whenever hypernatraemia occurs, is stressed. PMID:8503665

Dietary sodium and nocturnal blood pressure dipping in normotensive men and women.

PubMed

Brian, M S; Dalpiaz, A; Matthews, E L; Lennon-Edwards, S; Edwards, D G; Farquhar, W B

2017-02-01

Impaired nocturnal blood pressure (BP) dipping (i.e., <10% decline in nocturnal BP) is associated with an increased risk of cerebrovascular and cardiovascular diseases. Excess sodium has been shown to impair BP regulation and increase cardiovascular disease risk, yet few studies have assessed the influence of dietary sodium on nocturnal dipping in normotensive adults. The purpose of this study was to determine the effects of dietary sodium on BP dipping in normotensive men and women. Eighty healthy normotensive adults participated in a controlled feeding study (men: n=39, 34±2 years; women: n=41, 41±2 years). Participants consumed a standardized run-in 100 mmol sodium per day diet for 7 days, followed by 7 days of low-sodium (LS; 20 mmol per day) and high-sodium (HS; 300 mmol per day) diets in random order. On the final day of each diet, subjects wore a 24 h ambulatory BP monitor, collected a 24 h urine sample and provided a blood sample. During the run-in diet, 24 h urinary sodium excretion was 79.4±5.1 mmol per 24 h in men and 85.3±5.5 mmol per 24 h in women (P>0.05). Systolic BP dipping was not different between men (11.4±1.0%) and women (11.2±0.9%); (P>0.05). During the HS diet, 24 h urinary sodium excretion increased compared with the LS diet in men (LS=31.7±4.6 mmol per 24 h vs HS=235.0±13.9 mmol per 24 h, P<0.01) and women (LS=25.8±2.2 mmol per 24 h vs HS=234.7±13.8 mmol per 24 h, P<0.01). Despite this large increase in sodium intake and excretion, systolic BP dipping was not blunted in men (LS=8.9±1.0% vs HS=9.4±1.2%, P>0.05) or women (LS=10.3±0.8% vs HS=10.5±0.8%, P>0.05). Among normotensive men and women, HS does not blunt nocturnal BP dipping.

Urinary potassium excretion and risk of cardiovascular events.

PubMed

Kieneker, Lyanne M; Gansevoort, Ron T; de Boer, Rudolf A; Brouwers, Frank P; Feskens, Edith Jm; Geleijnse, Johanna M; Navis, Gerjan; Bakker, Stephan Jl; Joosten, Michel M

2016-05-01

Observational studies on dietary potassium and risk of cardiovascular disease (CVD) have reported weak-to-modest inverse associations. Long-term prospective studies with multiple 24-h urinary samples for accurate estimation of habitual potassium intake, however, are scarce. We examined the association between urinary potassium excretion and risk of blood pressure-related cardiovascular outcomes. We studied 7795 subjects free of cardiovascular events at baseline in the Prevention of Renal and Vascular End-stage Disease study, a prospective, observational cohort with oversampling of subjects with albuminuria at baseline. Main cardiovascular outcomes were CVD [including ischemic heart disease (IHD), stroke, and vascular interventions], IHD, stroke, and new-onset heart failure (HF). Potassium excretion was measured in two 24-h urine specimens at the start of the study (1997-1998) and midway through follow-up (2001-2003). Baseline median urinary potassium excretion was 70 mmol/24 h (IQR: 56-84 mmol/24 h). During a median follow-up of 10.5 y (IQR: 9.9-10.8 y), a total of 641 CVD, 465 IHD, 172 stroke, and 265 HF events occurred. After adjustment for age and sex, inverse associations were observed between potassium excretion and risk [HR per each 26-mmol/24-h (1-g/d) increase; 95% CI] of CVD (0.87; 0.78, 0.97) and IHD (0.86; 0.75, 0.97), as well as nonsignificant inverse associations for risk of stroke (0.85; 0.68, 1.06) and HF (0.94; 0.80, 1.10). After further adjustment for body mass index, smoking, alcohol consumption, education, and urinary sodium and magnesium excretion, urinary potassium excretion was not statistically significantly associated with risk (multivariable-adjusted HR per 1-g/d increment; 95% CI) of CVD (0.96; 0.85, 1.09), IHD (0.90; 0.81, 1.04), stroke (1.09; 0.86, 1.39), or HF (0.99; 0.83, 1.18). No associations were observed between the sodium-to-potassium excretion ratio and risk of CVD, IHD, stroke, or HF. In this cohort with oversampling of subjects with albuminuria at baseline, urinary potassium excretion was not independently associated with a lower risk of cardiovascular events. © 2016 American Society for Nutrition.

Inhibition of hyaluronan synthesis in rats reduces renal ability to excrete fluid and electrolytes during acute hydration

PubMed Central

Stridh, Sara; Palm, Fredrik

2013-01-01

Background. Hyaluronan (HA) is the dominant glycosaminoglycan in the renomedullary interstitium. Renomedullary HA has been implicated in tubular fluid handling due to its water-attracting properties and the changes occurring in parallel to acute variations in the body hydration status. Methods. HA production was inhibited by 4-methylumbelliferone (4-MU in drinking water for 5 days, 1.45 ± 0.07 g/day/kg body weight) in rats prior to hydration. Results. Following hypotonic hydration for 135 min in control animals, diuresis and osmotic excretion increased while sodium excretion and glomerular filtration rate (GFR) remained unchanged. The medullary and cortical HA contents were 7.85 ± 1.29 ng/mg protein and 0.08 ± 0.01 ng/mg protein, respectively. Medullary HA content after 4-MU was 38% of that in controls (2.98 ± 0.95 ng/g protein, p < 0.05), while the low cortical levels were unaffected. Baseline urine flow was not different from that in controls. The diuretic response to hydration was, however, only 51% of that in controls (157 ± 36 versus 306 ± 54 µl/g kidney weight/135 min, p < 0.05) and the osmolar excretion only 47% of that in controls (174 ± 47 versus 374 ± 41 µOsm/g kidney weight/135 min, p < 0.05). Sodium excretion, GFR, and arterial blood pressure were similar to that in control rats and unaltered during hydration. Conclusions. Reduction of renomedullary interstitial HA using 4-MU reduces the ability of the kidney to respond appropriately upon acute hydration. The results strengthen the concept of renomedullary HA as a modulator of tubular fluid handling by changing the physicochemical properties of the interstitial space. PMID:24102146

Smartphone technology facilitates dietary change in healthy adults.

PubMed

Ipjian, Michelle L; Johnston, Carol S

2017-01-01

Many individuals are advised to adhere to specific diet plans for their personal health; hence, it is important that tools are available to support these behaviors. Smartphone applications (apps) may assist health care professionals in educating their clients on specific dietary modifications. This pilot study focused on a single dietary modification, reducing sodium intake, to determine whether a commercial health app is useful for promoting dietary change. Thirty healthy adults (age 34.4 ± 15.7 y; body mass index 25.6 ± 4.3 kg/m 2 ) were recruited from a university community and completed this 4-wk randomized parallel trial. Participants were instructed to reduce their sodium intake to ≤2300 mg/d by using the MyFitnessPal app to receive feedback on sodium content of foods or by paper tallying of estimated sodium intake. The predicted 24-h sodium excretion, estimated using the ratio of sodium to creatinine from the first morning urine void, and participant satisfaction were the main outcomes measured. The change in the predicted 24-h sodium excretion differed between groups: -838 ± 1093 and +236 ± 1333 mg/24 h predicted for the app and journal groups, respectively (P = 0.010). Moreover, participants in the app group reported significantly greater satisfaction with their method of diet tracking than the journal group (P = 0.001). These data suggest that smartphone apps have the potential to facilitate the implementation of dietary advice. This was a small pilot study with limited scope, and more research is necessary to determine the value of smartphone apps for facilitating dietary change. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparison of clinical and biochemical markers of dehydration with the clinical dehydration scale in children: a case comparison trial

PubMed Central

2014-01-01

Background The clinical dehydration scale (CDS) is a quick, easy-to-use tool with 4 clinical items and a score of 1–8 that serves to classify dehydration in children with gastroenteritis as no, some or moderate/severe dehydration. Studies validating the CDS (Friedman JN) with a comparison group remain elusive. We hypothesized that the CDS correlates with a wide spectrum of established markers of dehydration, making it an appropriate and easy-to-use clinical tool. Methods This study was designed as a prospective double-cohort trial in a single tertiary care center. Children with diarrhea and vomiting, who clinically required intravenous fluids for rehydration, were compared with minor trauma patients who required intravenous needling for conscious sedation. We compared the CDS with clinical and urinary markers (urinary electrolytes, proteins, ratios and fractional excretions) for dehydration in both groups using receiver operating characteristic (ROC) curves to determine the area under the curve (AUC). Results We enrolled 73 children (male = 36) in the dehydration group and 143 (male = 105) in the comparison group. Median age was 32 months (range 3–214) in the dehydration and 96 months (range 2.6-214 months, p < 0.0001) in the trauma group. Median CDS was 3 (range 0–8) within the dehydration group and 0 in the comparison group (p < 0.0001). The following parameters were statistically significant (p < 0.05) between the comparison group and the dehydrated group: difference in heart rate, diastolic blood pressure, urine sodium/potassium ratio, urine sodium, fractional sodium excretion, serum bicarbonate, and creatinine measurements. The best markers for dehydration were urine Na and serum bicarbonate (ROC AUC = 0.798 and 0.821, respectively). CDS was most closely correlated with serum bicarbonate (Pearson r = -0.3696, p = 0.002). Conclusion Although serum bicarbonate is not the gold standard for dehydration, this study provides further evidence for the usefulness of the CDS as a dehydration marker in children. Trial registration Registered at ClinicalTrials.gov (NCT00462527) on April 18, 2007. PMID:24935348

Comparison of clinical and biochemical markers of dehydration with the clinical dehydration scale in children: a case comparison trial.

PubMed

Tam, Ron K; Wong, Hubert; Plint, Amy; Lepage, Nathalie; Filler, Guido

2014-06-16

The clinical dehydration scale (CDS) is a quick, easy-to-use tool with 4 clinical items and a score of 1-8 that serves to classify dehydration in children with gastroenteritis as no, some or moderate/severe dehydration. Studies validating the CDS (Friedman JN) with a comparison group remain elusive. We hypothesized that the CDS correlates with a wide spectrum of established markers of dehydration, making it an appropriate and easy-to-use clinical tool. This study was designed as a prospective double-cohort trial in a single tertiary care center. Children with diarrhea and vomiting, who clinically required intravenous fluids for rehydration, were compared with minor trauma patients who required intravenous needling for conscious sedation. We compared the CDS with clinical and urinary markers (urinary electrolytes, proteins, ratios and fractional excretions) for dehydration in both groups using receiver operating characteristic (ROC) curves to determine the area under the curve (AUC). We enrolled 73 children (male = 36) in the dehydration group and 143 (male = 105) in the comparison group. Median age was 32 months (range 3-214) in the dehydration and 96 months (range 2.6-214 months, p < 0.0001) in the trauma group. Median CDS was 3 (range 0-8) within the dehydration group and 0 in the comparison group (p < 0.0001). The following parameters were statistically significant (p < 0.05) between the comparison group and the dehydrated group: difference in heart rate, diastolic blood pressure, urine sodium/potassium ratio, urine sodium, fractional sodium excretion, serum bicarbonate, and creatinine measurements. The best markers for dehydration were urine Na and serum bicarbonate (ROC AUC = 0.798 and 0.821, respectively). CDS was most closely correlated with serum bicarbonate (Pearson r = -0.3696, p = 0.002). Although serum bicarbonate is not the gold standard for dehydration, this study provides further evidence for the usefulness of the CDS as a dehydration marker in children. Registered at ClinicalTrials.gov (NCT00462527) on April 18, 2007.

Dietary salt restriction is beneficial to the management of autosomal dominant polycystic kidney disease.

PubMed

Torres, Vicente E; Abebe, Kaleab Z; Schrier, Robert W; Perrone, Ronald D; Chapman, Arlene B; Yu, Alan S; Braun, William E; Steinman, Theodore I; Brosnahan, Godela; Hogan, Marie C; Rahbari, Frederic F; Grantham, Jared J; Bae, Kyongtae T; Moore, Charity G; Flessner, Michael F

2017-02-01

The CRISP study of polycystic kidney disease (PKD) found that urinary sodium excretion associated with the rate of total kidney volume increase. Whether sodium restriction slows the progression of Autosomal Dominant PKD (ADPKD) is not known. To evaluate this we conducted a post hoc analysis of the HALT-PKD clinical trials of renin-angiotensin blockade in patients with ADPKD. Linear mixed models examined whether dietary sodium affected rates of total kidney volume or change in estimated glomerular filtration rate (eGFR) in patients with an eGFR over 60 ml/min/1.73 m 2 (Study A) or the risk for a composite endpoint of 50% reduction in eGFR, end-stage renal disease or death, or the rate of eGFR decline in patients with an eGFR 25-60 ml/min/1.73 m 2 (Study B) all in patients initiated on an under100 mEq sodium diet. During the trial urinary sodium excretion significantly declined by an average of 0.25 and 0.41 mEq/24 hour per month in studies A and B, respectively. In Study A, averaged and time varying urinary sodium excretions were significantly associated with kidney growth (0.43%/year and 0.09%/year, respectively, for each 18 mEq urinary sodium excretion). Averaged urinary sodium excretion was not significantly associated with faster eGFR decline (-0.07 ml/min/1.73m 2 /year for each 18 mEq urinary sodium excretion). In Study B, the averaged but not time-varying urinary sodium excretion significantly associated with increased risk for the composite endpoint (hazard ratio 1.08 for each 18 mEq urinary sodium excretion) and a significantly faster eGFR decline (-0.09 ml/min/1.73m 2 /year for each mEq 18 mEq urinary sodium excretion). Thus, sodium restriction is beneficial in the management of ADPKD. Copyright © 2016 International Society of Nephrology. All rights reserved.

[Validity of the assessment of urinary protein excretion by spot urine in patients with chronic kidney disease].

PubMed

Hayashi, Ami; Okada, Tomonari; Matsumoto, Hiroshi; Nagaoka, Yume; Wada, Toshikazu; Gondo, Asako; Nango, Tomoka; Miyaoka, Yoshitaka; Watanabe, Kanna; Iwata, Azusa; Nakao, Toshiyuki

2013-01-01

We investigate the validity of the assessment of urinary protein excretion by spot urine samples collected by different methods in outpatients with chronic kidney disease (CKD). SUBJECTS AND METHODS We obtained 24-hour urine and two spot urine samples, including the first morning urine and daytime urine in 159 CKD patients. Urinary protein excretion was assessed by the protein/creatinine ratio from spot urine samples (morning: m-UP (g/gCr), daytime: d-UP (g/gCr) ]. We examined the correlations and the differences among m-UP, d-UP and the actual urinary protein excretion obtained by 24-hour urine (a-UP(g/day) . Significant correlations were found between m-UP and a-UP, and between d-UP and a-UP (r = 0.88, 0.85; p < 0.001). Correlations between m-UP and a-UP were greater relative to those between d-UP and a-UP in patients with less than 3.5 g/day of a-UP and in patients with CKD stages 1 to approximately 3. The percent difference between m-UP and a-UP was--16.0 +/- 40.5%, and that between d-UP and a-UP was 27.1 +/- 72.9%. The absolute value of the percent difference between d-UP and a-UP tended to be greater than that between m-UP and a-UP (34.9 +/- 25.9% vs. 49.9 +/- 59.9%, p = 0.06). Urinary protein/creatinie ratio of the first morning urine is better approximate the urinary protein excretion obtained by 24-hour urine compared with that of spot urine in the daytime.

Variability of urinary salt excretion estimated by spot urine in treated hypertensive patients.

PubMed

Arakawa, Kimika; Sakaki, Minako; Sakata, Satoko; Oniki, Hideyuki; Tominaga, Mitsuhiro; Tsuchihashi, Takuya

2015-01-01

Among the several methods used to assess salt intake, estimating 24 h urinary salt excretion by spot urine seems appropriate for clinical practice. In this study, we investigated variability in urinary salt excretion using spot urine in hypertensive outpatients. Participants included 200 hypertensive patients who underwent spot urinary salt excretion at least three times during the observation period. Mean urinary salt excretion and the coefficient of the variation were 8.62 ± 1.96 g/day and 19.0 ± 10.2%, respectively. In the analysis of participants who underwent assessment of urinary salt excretion at least eight times (n = 54), a significant reduction in mean urinary salt excretion was found at the 5th measurement. On the contrary, the coefficient of the variation of urinary salt excretion continued to increase until the 5th measurement, and became stable thereafter. Mean urinary salt excretion was positively correlated with mean clinic diastolic blood pressure (r = 0.27, p < 0.05). Clinic diastolic blood pressure in the high urinary salt excretion group (≥ 10 g/day) was significantly higher than that of the low group (76.2 ± 7.5 vs 73.4 ± 8.3 mmHg, p < 0.05). Mean urinary salt excretion in summer was significantly lower than that of the other seasons (7.75 ± 1.94 vs 9.09 ± 2.68 (spring), 8.72 ± 2.12 (autumn), 8.92 ± 2.17 (winter) g/day, p < 0.01). In conclusion, repeated measurements of urinary salt excretion using spot urine are required to assess daily salt intake of hypertensive patients.

Urinary free cortisol and cortisone excretion in healthy individuals: influence of water loading.

PubMed

Fenske, Martin

2006-11-01

The influence of water loading on urinary excretion of free cortisol and cortisone was investigated in healthy men. The results were as follows: water loading tests (intake of 0.25-1.5 L) in a single individual showed that a water load of 1.5 L reliably increased the excretion of urine, free cortisol and cortisone (p < 0.01). Regression analyses gave significant correlations of urine volume with free cortisol and free cortisone, and of free cortisol and free cortisone. Corresponding results were obtained when water loading tests were performed in males who ingested 1.5 L of water (n = 8): the excretion of urine, free cortisol and free cortisone were significantly augmented; correlated was urine volume with free cortisol and free cortisone, and free cortisol with free cortisone. In a third set of tests, volunteers collected one 5 h urine (10:00-15:00 h) after the intake of 3 x 0.1 or 0.5 L at 11:00, 12:00 and 14:00 h. Excretion of urine, free cortisol and free cortisone in males of the low water loading group (3 x 0.1 L) was 0.59 mL/min, and 8.2 or 15.0 microg/5 h; corresponding values in individuals ingesting 3 x 0.5 L of water were 1.5 mL/min (p < 0.01), 12.3 microg/5 h (p > 0.05) and 26.3 microg/5 h (p < 0.02). In summary, urinary free cortisol and cortisone excretion in healthy men depends on urine volume, especially during water diuresis. Thus, interpretation of free cortisol and especially of free cortisone excretion is only possible if subjects strictly control their fluid intake and if urine volume is considered an important pre-analytical parameter-otherwise, interpretation of urinary free cortisol results is difficult and of urinary free cortisone data remains tenuous at best.

BILIARY EXCRETION AND TISSUE DISTRIBUTION OF CADMIUM-109 ADMINISTERED TO RATS

EPA Science Inventory

The difference in the excretion of cadmium in urine and feces was measured in rats with either ligated or intact bile ducts. Three days following a single oral-administration of cadmium-109 plus stabe cadmium chloride, 0.004 percent of the dose was excreted in the urine of rats w...

Urinary Fluoride Concentration in Children with Disabilities Following Long-Term Fluoride Tablet Ingestion

ERIC Educational Resources Information Center

Liu, Hsiu-Yueh; Chen, Jung-Ren; Hung, Hsin-Chia; Hsiao, Szu-Yu; Huang, Shun-Te; Chen, Hong-Sen

2011-01-01

Urine is the most commonly utilized biomarker for fluoride excretion in public health and epidemiological studies. Approximately 30-50% of fluoride is excreted from urine in children. Urinary fluoride excretion reflects the total fluoride intake from multiple sources. After administering fluoride tablets to children with disabilities, urinary…

Sodium-bicarbonated mineral water decreases aldosterone levels without affecting urinary excretion of bone minerals.

PubMed

Schoppen, Stefanie; Pérez-Granados, Ana M; Carbajal, Angeles; Sarriá, Beatriz; Navas-Carretero, Santiago; Pilar Vaquero, M

2008-06-01

AIM To assess in healthy postmenopausal women the influence of consuming sodium-bicarbonated mineral water on postprandial evolution of serum aldosterone and urinary electrolyte excretion. Eighteen postmenopausal women consumed 500 ml of two sodium-bicarbonated mineral waters (sodium-bicarbonated mineral water 1 and sodium-bicarbonated mineral water 2) and a low-mineral water with a standard meal. Postprandial blood samples were taken at 60, 120, 240, 360 and 420 min and aldosterone concentrations were measured. Postprandial urinary minerals were determined. Urinary and total mineral excretion and urinary mineral concentrations did not differ except for sodium concentration, which was significantly higher with sodium-bicarbonated mineral water 1 than with low-mineral water (P = 0.005). There was a time effect (P = 0.003) on the aldosterone concentration. At 120 min, aldosterone concentrations were lower with sodium-bicarbonated mineral water 1 (P = 0.021) and sodium-bicarbonated mineral water 2 (P = 0.030) compared with low-mineral water. Drinking a sodium-rich bicarbonated mineral water with a meal increases urinary sodium concentration excretion without changes in the excretion of potassium and bone minerals.

Osmoregulatory traits of broad-toothed field mouse (Apodemus mystacinus) populations from different habitats.

PubMed

Scantlebury, Michael; Shanas, Uri; Or-Chen, Keren; Haim, Abraham

2009-12-01

One mechanism for physiological adjustment of small mammals to different habitats and different seasons is by seasonal acclimatization of their osmoregulatory system. We examined the abilities of broad-toothed field mice (Apodemus mystacinus) from different ecosystems ('sub-alpine' and 'Mediterranean') to cope with salinity stress under short day (SD) and long day (LD) photoperiod regimes. We compared urine volume, osmolarity, urea and electrolyte (sodium, potassium and chloride) concentrations. Significant differences were noted in the abilities of mice from the two ecosystems to deal with salinity load; in particular sub-alpine mice produced less concentrated urine than Mediterranean mice with SD- sub-alpine mice seeming to produce particularly dilute urine. Urea concentration generally decreased with increasing salinity, whereas sodium and potassium levels increased, however SD- sub-alpine mice behaved differently and appeared not to be able to excrete electrolytes as effectively as the other groups of mice. Differences observed provide an insight into the kinds of variability that are present within populations inhabiting different ecosystems, thus how populations may be able to respond to potential changes in their environment. Physiological data pertaining to adaptation to increased xeric conditions, as modelled by A. mystacinus, provides valuable information as to how other species may cope with potential climatic challenges.

Maturation of the renal response to hypertonic sodium chloride loading in rats: micropuncture and clearance studies.

PubMed Central

Baker, J T; Solomon, S

1976-01-01

1. The ability of maturing rats to excrete a sodium load was studied by micropuncture and clearance procedures. 2. During control conditions, no change of glomerular filtration rate or sodium excretion was observed for the time period of the entire procedure (P greater than 0-20). During the infusion of hypertonic (4%) sodium chloride, fractional sodium excretion was 0-08 +/- 0-01 in rats 21-30 days old and 0-14 +/- 0-01 (P less than 0-01) in adults. However, the depression of proximal tubular water re-absorption was equal in both groups (P greater than 0-20). 3. Proximal glomerulotubular balance for water re-absorption was similar in all groups (P less than 0-20). Since end proximal tubular water excretion and depression of fractional water excretion were the same in all animals, differences of urinary sodium excretion during development are probably due to differences of function of segments beyond the proximal tubule during development. 4. Fractional potassium excretion was reduced in young rats (0-17 +/- 0-04) during hypertonic sodium chloride infusion, compared to adults (0-24 +/- 0-01, P less than 0-05). 5. Passage time of fast green through cortical segments in seconds is prolonged in young rats during control conditions. Similar decreases of passage time were seen in all groups during hypertonic sodium chloride infusion. No segmental differences of passage time were seen during developmental. 6. No difference in the relationship between fractional sodium and water excretion was seen during development of the renal response to hypertonic sodium chloride infusion. Thus, altered sensitivity to sodium chloride osmotic diuresis does not exist during maturation in rats. PMID:945839

Intake and urinary excretion of sodium chloride under varying conditions of effort and environment heat

NASA Technical Reports Server (NTRS)

Zohar, E.; Adar, R.; Tennenbaum, J.; Kesten, M.

1982-01-01

Intake and urinary excretion of sodium were investigated in a group of young, healthy and acclimated men. The sodium excretions of workers and of machinists in the engine rooms of a ship were also investigated.

Effect of Cuscuta chinensis on renal function in ischemia/reperfusion-induced acute renal failure rats.

PubMed

Shin, Sun; Lee, Yun Jung; Kim, Eun Ju; Lee, An Sook; Kang, Dae Gill; Lee, Ho Sub

2011-01-01

The kidneys play a central role in regulating water, ion composition and excretion of metabolic waste products in the urine. Cuscuta chinensis has been known as an important traditional Oriental medicine for the treatment of liver and kidney disorders. Thus, we studied whether an aqueous extract of Cuscuta chinensis (ACC) seeds has an effect on renal function parameters in ischemia/reperfusion-induced acute renal failure (ARF) rats. Administration of 250 mg/kg/day ACC showed that renal functional parameters including urinary excretion rate, osmolality, Na(+), K(+), Cl(-), creatinine clearance, solute-free water reabsorption were significantly recovered in ischemia/reperfusion-induced ARF. Periodic acid Schiff staining showed that administration of ACC improved tubular damage in ischemia/reperfusion-induced ARF. In immunoblot and immunohistological examinations, ischemia/reperfusion-induced ARF decreased the expressions of water channel AQP 2, 3 and sodium potassium pump Na,K-ATPase in the renal medulla. However, administration of ACC markedly incremented AQP 2, 3 and Na,K-ATPase expressions. Therefore, these data indicate that administration of ACC ameliorates regulation of the urine concentration and renal functions in rats with ischemia/reperfusion-induced ARF.

Endocrine and fluid metabolism in males and females of different ages after bedrest, acceleration and lower body negative pressure

NASA Technical Reports Server (NTRS)

Leach, C. S.; Vernikos-Danellis, J.; Krauhs, J. M.; Sandler, H.

1985-01-01

Space shuttle flight simulations were conducted to determine the effects of weightlessness, lower body negative pressure (LBNP), and acceleration of fluid and electrolyte excretion and the hormones that control it. Measurements were made on male and female subjects of different ages before and after bedrest. After admission to a controlled environment, groups of 6 to 14 subjects in the age ranges 25 to 35, 35 to 45, 45 to 55 to 65 years were exposed to +3 G sub z for 15 minutes (G1) and to LBNP (LBNP1) on different days. On 3 days during this prebedrest period, no tests were conducted. Six days of bedrest followed, and the G sub z (G2) and LBNP (LBNP2) tests were run again. Hormones, electrolytes, and other parameters were measured in 24-hour urine pools throughout the experiment. During bedrest, cortisol and aldosterone excretion increased. Urine volume decreased, and specific gravity and osmolality increased. Urinary electrolytes were statistically unchanged from levels during the non-stress control period. During G2, cortisol increased significantly over its control and bedrest levels. Urine volume, sodium, and chloride were significantly lower; specific gravity and osmolality were higher during the control period or bedrest. The retention of fluids and electrolytes after +G sub z may at least partially explain decreased urine volume and increased osmolality observed during bedrest in this study. There were some who indicated that space flight would not affect the fluid and electrolyte metabolism of females or older males any more severely than it has affected that of male astronauts.

Sildenafil for the Treatment of Congenital Nephrogenic Diabetes Insipidus.

PubMed

Assadi, Farahnak; Sharbaf, Fatemeh Ghane

2015-01-01

Congenital nephrogenic diabetes insipidus (NDI) is characterized by massive polyuria and polydipsia due to defects in the vasopressin-sensitive signaling system expression of the acuaporin-2 (AQP2) water channel of the kidney collecting duct principal cells. Current conventional treatment regimen including hydration, diuretics and nonsteroidal anti-inflammatory drugs can only partially reduce polyuria. Recent experimental studies have suggested that treatment with sildenafil, a selective phosphodiesterase inhibitor, may enhance cyclic guanosine monophosphate (cGMP)-mediated apical trafficking of AQP2 and may be effective in increasing water reabsorption in patients with congenital NDI. A 4-year old boy with X-linked NDI resistant to conventional therapy was treated with sildenafil for 10 days after a 2-day washout period between the 2 treatment regimens. Aliquots of the 24-hour urine collections before and after treatment were analyzed for urine volume, osmolality, cGMP and AQP2 determinations. Blood samples were also obtained for sodium and osmolality measurements. The primary endpoint was 24-hour urine volume after 10 days of sildenafil and conventional treatments. Compared to conventional therapy, treatment with sildenafil resulted in substantial reduction in 24-hour urine volume (1,764 vs. 950 ml) and serum sodium (148 vs. 139) mEq/l, and increased urine osmolality (104 vs. 215 mOsm/l), and AQP2 excretion (5 vs. 26 fmol/mg creatinine). The patient tolerated sildenafil well and experienced no adverse effects. Sildenafil citrate should be considered an alternative agent in the treatment of X-linked NDI resistant to conventional therapy. © 2015 S. Karger AG, Basel

Production and actions of superoxide in the renal medulla.

PubMed

Zou, A P; Li, N; Cowley, A W

2001-02-01

The present study characterized the biochemical pathways responsible for superoxide (O(2)(-.)) production in different regions of the rat kidney and determined the role of O(2)(-.)in the control of renal medullary blood flow (MBF) and renal function. By use of dihydroethidium/DNA fluorescence spectrometry with microtiter plates, the production of O(2)(-. )was monitored when tissue homogenate from different kidney regions was incubated with substrates for the major O(2)(-.)-producing enzymes, such as NADH/NADPH oxidase, xanthine oxidase, and mitochondrial respiratory chain enzymes. The production of O(2)(-. )via NADH oxidase was greater (P<0.05) in the renal cortex and outer medulla (OM) than in the papilla. The mitochondrial enzyme activity for O(2)(-.)production was higher (P<0.05) in the OM than in the cortex and papilla. Compared with NADH oxidase and mitochondrial enzymes, xanthine oxidase and NADPH oxidase produced much less O(2)(-. )in the kidney under this condition. Overall, the renal OM exhibited the greatest enzyme activities for O(2)(-.)production. In anesthetized rats, renal medullary interstitial infusion of a superoxide dismutase inhibitor, diethyldithiocarbamate, markedly decreased renal MBF and sodium excretion. Diethyldithiocarbamate (5 mg/kg per minute by renal medullary interstitial infusion [RI]) reduced the renal medullary laser-Doppler flow signal from 0.6+/-0.04 to 0.4+/-0.03 V, a reduction of 33%, and both urine flow and sodium excretion decreased by 49%. In contrast, a membrane-permeable superoxide dismutase mimetic, 4-hydroxytetramethyl-piperidine-1-oxyl (TEMPOL, 30 micromol/kg per minute RI) increased MBF and sodium excretion by 34% and 69%, respectively. These effects of TEMPOL on renal MBF and sodium excretion were not altered by pretreatment with N(G)-nitro-L-arginine methyl ester (10 microgram/kg per minute RI). We conclude that (1) renal medullary O(2)(-. )is primarily produced in the renal OM; (2) both NADH oxidase and mitochondrial enzymes are responsible for the O(2)(-.)production in this kidney region; and (3) O(2)(-. )exerts a tonic regulatory action on renal MBF.

Winter fasting and refeeding effects on urine characteristics in white-tailed deer

USGS Publications Warehouse

DelGiudice, G.D.; Mech, L.D.; Seal, U.S.; Karns, P.D.

1987-01-01

The effects of dietary protein, fasting, and refeeding on urinary characteristics of 9 captive, female white-tailed deer (Odocoileus virginianus) were studied from 23 February to 3 May 1984. Urinary sodium (na) and potassium (K) were diminished in fasted deer after 2 and 4 weeks. Renal excretion of Na and K were lower, whereas urinary phosphorus (P) was higher in fasted deer compared to deer fed high protein-high energy (HPHE) diets. Urinary P excretion of the fasted deer was also greater than in a low protein-high energy (LPHE)-fed group. Urinary area excretion of fasted deer was similar to that of deer fed low and high protein diets. One fasted deer died during the study and exhibited notably high excretion of urea, Na, K, and calcium (Ca). No effects of the 2 levels of dietary protein on urinary characteristics were detected. Urinary Na:C and K:C ratios wer significantly correlated with Na and K intake. Urinalysis has potential as a sensitive means of monitoring the nutritional status of white-tailed deer. Data are presented as reference values for interpretation of data from deer under less controlled circumstances.

Urine oxalate biological variation in patients with primary hyperoxaluria.

PubMed

Clifford-Mobley, Oliver; Sjögren, Anna; Lindner, Elisabeth; Rumsby, Gill

2016-08-01

Hyperoxaluria is a well-recognised risk factor for urolithiasis and patients with primary hyperoxaluria (PH) gradually build up calcium oxalate deposits leading to chronic kidney disease. Efforts to improve treatment for PH have focused on reducing urine oxalate excretion and thus decreasing lithogenesis. To determine the efficacy of treatments designed to alter a biochemical parameter it is necessary to know the biological and analytical variation of that parameter. In this study, we estimated the intra-individual biological variation of urine oxalate excretion in patients with PH, and from this determined what would constitute a significant change in the form of a reference change value (RCV). Each patient collected four 24-h urines on consecutive weeks. The intra-individual biological variation of oxalate excretion calculated from these samples ranged from 0 to 36 % with a mean of 14 %. The corresponding RCVs were 4-84 % with a mean of 32 %. This result implies that, on average, a reduction of almost one-third in urine oxalate excretion is required to prove an effect from treatment. The wide range of biological variation between individuals may reflect other, as yet unknown, determinants of oxaluria in PH, as well as inaccuracies in urine collection. The data suggest that it is more appropriate to use individual RCVs established prior to treatment to determine its efficacy: a relatively small fall in urine oxalate excretion may be outside the biological variation of some patients but not of others.

Relation of Urinary Calcium and Magnesium Excretion to Blood Pressure

PubMed Central

Kesteloot†, Hugo; Tzoulaki, Ioanna; Brown, Ian J.; Chan, Queenie; Wijeyesekera, Anisha; Ueshima, Hirotsugu; Zhao, Liancheng; Dyer, Alan R.; Unwin, Robert J.; Stamler, Jeremiah; Elliott, Paul

2011-01-01

Data indicate an inverse association between dietary calcium and magnesium intakes and blood pressure (BP); however, much less is known about associations between urinary calcium and magnesium excretion and BP in general populations. The authors assessed the relation of BP to 24-hour excretion of calcium and magnesium in 2 cross-sectional studies. The International Study of Macro- and Micro-Nutrients and Blood Pressure (INTERMAP) comprised 4,679 persons aged 40–59 years from 17 population samples in China, Japan, the United Kingdom, and the United States, and the International Cooperative Study on Salt, Other Factors, and Blood Pressure (INTERSALT) comprised 10,067 persons aged 20–59 years from 52 samples around the world. Timed 24-hour urine collections, BP measurements, and nutrient data from four 24-hour dietary recalls (INTERMAP) were collected. In multiple linear regression analyses, urinary calcium excretion was directly associated with BP. After adjustment for multiple confounders (including weight, height, alcohol intake, calcium intake, urinary sodium level, and urinary potassium intake), systolic BP was 1.9 mm Hg higher per each 4.1 mmol per 24 hours (2 standard deviations) of higher urinary calcium excretion (associations were smaller for diastolic BP) in INTERMAP. Qualitatively similar associations were observed in INTERSALT analyses. Associations between magnesium excretion and BP were small and nonsignificant for most of the models examined. The present data suggest that altered calcium homoeostasis, as exhibited by increased calcium excretion, is associated with higher BP levels. PMID:21624957

Germanium in ginseng is low and causes no sodium and water retention or renal toxicity in the diuretic-resistant rats

PubMed Central

Tan, Chunjiang; Xiao, Lu; Chen, Wenlie

2015-01-01

Ginseng preparations contain high concentrations of germanium (Ge), which was reported to contribute to diuretic resistance or renal failure. However, Ge content in ginseng and the influence on renal functions remain unclear. Forty rats were randomly divided into control group, low, moderate, and high Ge ginseng-treated group and observed for 25 days. Daily urine, renal functions, and serum and urine electrolytics were measured. Ge retention in the organs and renal histological changes were also evaluated. Ge content ranged from 0.007 to 0.450 µg/g in various ginseng samples. Four groups showed no difference in the daily urine output, glomerular filtration rate, urinary electrolytes excretions, 24 h-urine protein, as well as plasma and urine urea nitrogen, creatinine, osmotic pressure, and pH values. Ge did not cause any renal pathological effects in this study. No Na and water retention was detected in the ginseng-treated groups. Ge retention in various organs was found highest in spleen, followed by the kidney, liver, lung, stomach, heart, and pancreas. The total Ge contents in various ginsengs were low, and ginseng treatment did not affect renal functions or cause renal histological changes. PMID:25711879

Hypothesis: discrepancy between intra- and interpopulation studies of the relationship between dietary salt and blood pressure: fact or fiction?

PubMed

Omvik, P

1984-01-01

It is a paradox that intra-population studies fail to show significant correlation between sodium excretion and blood pressure while a clear relationship exists in cross-cultural studies. Since daily variation of sodium excretion is high, the discrepancy between the two observations could be due to non-comparable data on sodium excretion. This is a discussion of the hypothesis that the finding of a significant correlation or not between sodium excretion and blood pressure depends on the statistical analysis of the data.

Examining the proportion of dietary phosphorus from plants, animals and food additives excreted in urine

PubMed Central

St-Jules, David E; Jagannathan, Ram; Gutekunst, Lisa; Kalantar-Zadeh, Kamyar; Sevick, Mary Ann

2016-01-01

Phosphorus bioavailability is an emerging topic of interest in the field of renal nutrition that has important research and clinical implications. Estimates of phosphorus bioavailability, based on digestibility, indicate that bioavailability of phosphorus increases from plants to animals to food additives. In this commentary, we examined the proportion of dietary phosphorus from plants, animals and food additives excreted in urine from four controlled feeding studies conducted in healthy adults and patients with chronic kidney disease. As expected, a smaller proportion of phosphorus from plant foods was excreted in urine compared to animal foods. However, contrary to expectations, phosphorus from food additives appeared to be incompletely absorbed. The apparent discrepancy between digestibility of phosphorus additives and the proportion excreted in urine suggests a need for human balance studies to determine the bioavailability of different sources of phosphorus. PMID:27810171

Examining the Proportion of Dietary Phosphorus From Plants, Animals, and Food Additives Excreted in Urine.

PubMed

St-Jules, David E; Jagannathan, Ram; Gutekunst, Lisa; Kalantar-Zadeh, Kamyar; Sevick, Mary Ann

2017-03-01

Phosphorus bioavailability is an emerging topic of interest in the field of renal nutrition that has important research and clinical implications. Estimates of phosphorus bioavailability, based on digestibility, indicate that bioavailability of phosphorus increases from plants to animals to food additives. In this commentary, we examined the proportion of dietary phosphorus from plants, animals, and food additives excreted in urine from four controlled-feeding studies conducted in healthy adults and patients with chronic kidney disease. As expected, a smaller proportion of phosphorus from plant foods was excreted in urine compared to animal foods. However, contrary to expectations, phosphorus from food additives appeared to be incompletely absorbed. The apparent discrepancy between digestibility of phosphorus additives and the proportion excreted in urine suggests a need for human balance studies to determine the bioavailability of different sources of phosphorus. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Circadian rhythmicity of the urinary excretion of mercury, potassium and catecholamines in unconventional shift-work systems.

PubMed

Vokac, Z; Gundersen, N; Magnus, P; Jebens, E; Bakka, T

1980-09-01

The round the clock urinary excretion rates of mercury were assessed for two series of unconventional patterns of activity and sleep in subjects who were not exposed to occupational, medical, or other obvious sources of mercury. In the first series the urine was collected in 3-h periods from six subjects during the first and last 2 d of a four-week, continuous 6-h shift (car ferry, watches either 0800--1400 and 2000--0200 or 1400--2000 and 0200--0800). In the second series the urine was collected in 4-h periods from five subjects working an 8-h experimental rotation shift compressed into 5 d (work two mornings--8-h interval--work two nights--8-h interval--work two afternoons). The mean daily excretion rate of the 11 subjects (48 investigation days, 334 urine samples) was 14.5 pmol of mercury/min (range 5.5--24.4 pmol of mercury/min). The mercury excretion oscillated regularly during 24 h by +/- 20--25% of the individual's daily mean excretion rates. The peak excretion rates were found at 0652 in the first and 0642 in the second series (cosinor treatment). Due to the circadian rhythm the mean 24-h excretion rates were best represented (correlation coefficient 0.92) by analyses of urine produced around noon (spot samples, collection periods 1100--1400 and 1000-1400, respectively). The circadian oscillations of mercury excretion were not influenced by the widely different and varying activity-sleep patterns of the two series. The rhythmicity of potassium excretion (peaks at around 1400) was more irregular. The stable oscillations of mercury excretion contrasted most with the excretion of adrenaline and noradrenaline, which, without losing the basic 24-h rhythmicity, closely followed the unconventional patterns of activity and sleep.

Absorption, Distribution, Metabolism, and Excretion of [14C]-Volixibat in Healthy Men: Phase 1 Open-Label Study.

PubMed

Siebers, Nicholas; Palmer, Melissa; Silberg, Debra G; Jennings, Lee; Bliss, Caleb; Martin, Patrick T

2018-02-01

Volixibat is a potent inhibitor of the apical sodium-dependent bile acid transporter in development for the treatment of nonalcoholic steatohepatitis. This phase 1, open-label study investigated the absorption, distribution, metabolism, and excretion of [ 14 C]-volixibat in heathy men. Eligible men (n = 8) aged 18-50 years (body mass index 18.0-30.0 kg/m 2 ; weight >50 kg) received a single oral dose of [ 14 C]-volixibat 50 mg containing ~5.95 µCi radioactivity. The primary objectives were to assess the pharmacokinetics of [ 14 C]-volixibat and to determine the total radioactivity in whole blood, plasma, urine, and feces at pre-selected time points over 6 days. The secondary objectives were to characterize metabolites and to assess the safety and tolerability. Low concentrations of volixibat (range 0-0.179 ng/mL) were detected in plasma up to 8 h following administration; the pharmacokinetic parameters could not be calculated. No radioactivity was observed in plasma or whole blood. The percentage (mean ± standard deviation) of total radioactivity in urine was 0.01 ± 0.007%. The vast majority (92.3 ± 5.25%) of volixibat was recovered in feces (69.2 ± 33.1% within 24 h). Unchanged volixibat was the only radioactive component detected in feces. Adverse events were mild in severity and mostly gastrointestinal. Changes in laboratory values were not clinically meaningful. Following oral administration, [ 14 C]-volixibat was excreted unchanged from the parent compound almost exclusively via fecal excretion, indicating that the drug is minimally absorbed. Consistent with other studies, adverse events were primarily gastrointestinal in nature. ClinicalTrials.gov identifier NCT02571192.

Neural mechanisms in body fluid homeostasis.

PubMed

DiBona, G F

1986-12-01

Under steady-state conditions, urinary sodium excretion matches dietary sodium intake. Because extracellular fluid osmolality is tightly regulated, the quantity of sodium in the extracellular fluid determines the volume of this compartment. The left atrial volume receptor mechanism is an example of a neural mechanism of volume regulation. The left atrial mechanoreceptor, which functions as a sensor in the low-pressure vascular system, is located in the left atrial wall, which has a well-defined compliance relating intravascular volume to filling pressure. The left atrial mechanoreceptor responds to changes in wall left atrial tension by discharging into afferent vagal fibers. These fibers have suitable central nervous system representation whose related efferent neurohumoral mechanisms regulate thirst, renal excretion of water and sodium, and redistribution of the extracellular fluid volume. Efferent renal sympathetic nerve activity undergoes appropriate changes to facilitate renal sodium excretion during sodium surfeit and to facilitate renal sodium conservation during sodium deficit. By interacting with other important determinants of renal sodium excretion (e.g., renal arterial pressure), changes in efferent renal sympathetic nerve activity can significantly modulate the final renal sodium excretion response with important consequences in pathophysiological states (e.g., hypertension, edema-forming states).

Effects of SiC nanoparticles orally administered in a rat model: Biodistribution, toxicity and elemental composition changes in feces and organs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lozano, Omar, E-mail: omar.lozanogarcia@fundp.ac.be; Research Centre for the Physics of Matter and Radiation; Laloy, Julie

2012-10-15

Background: Silicon carbide (SiC) presents noteworthy properties as a material such as high hardness, thermal stability, and photoluminescent properties as a nanocrystal. However, there are very few studies in regard to the toxicological potential of SiC NPs. Objectives: To study the toxicity and biodistribution of silicon carbide (SiC) nanoparticles in an in vivo rat model after acute (24 h) and subacute (28 days) oral administrations. The acute doses were 0.5, 5, 50, 300 and 600 mg·kg{sup −1}, while the subacute doses were 0.5 and 50 mg·kg{sup −1}. Results: SiC biodistribution and elemental composition of feces and organs (liver, kidneys, andmore » spleen) have been studied by Particle-Induced X-ray Emission (PIXE). SiC and other elements in feces excretion increased by the end of the subacute assessment. SiC did not accumulate in organs but some elemental composition modifications were observed after the acute assessment. Histopathological sections from organs (stomach, intestines, liver, and kidneys) indicate the absence of damage at all applied doses, in both assessments. A decrease in the concentration of urea in blood was found in the 50 mg·kg{sup −1} group from the subacute assessment. No alterations in the urine parameters (sodium, potassium, osmolarity) were found. Conclusion: This is the first study that assesses the toxicity, biodistribution, and composition changes in feces and organs of SiC nanoparticles in an in vivo rat model. SiC was excreted mostly in feces and low traces were retrieved in urine, indicating that SiC can cross the intestinal barrier. No sign of toxicity was however found after oral administration. -- Highlights: ► SiC nanoparticles were orally administered to rats in acute and subacute doses. ► SiC was found in low traces in urine. It is mostly excreted in feces within 5 days. ► SiC excretion rate, feces and organ elemental composition change with time. ► No morphological alteration were found on GI tract, liver, kidneys, or spleen. ► Urea increased in blood in the subacute assessment. No change in urine properties.« less

Study design and baseline characteristics of a combined educational and environmental intervention trial to lower sodium intake in Swiss employees.

PubMed

Beer-Borst, Sigrid; Luta, Xhyljeta; Hayoz, Stefanie; Sommerhalder, Kathrin; Krause, Corinna Gréa; Eisenblätter, Julia; Jent, Sandra; Siegenthaler, Stefan; Aubert, Rafael; Haldimann, Max; Strazzullo, Pasquale

2018-04-02

Blood pressure is a primary cardiovascular disease risk factor. Population-wide governmental strategies aim to reduce lifestyle and dietary risk factors for hypertension, one of which is an unbalanced diet with high sodium and low potassium intakes. Nutrition interventions in the workplace are considered a promising approach in encouraging health-promoting behaviors. We developed and conducted the health promoting sodium reduction trial "Healthful & Tasty: Sure!" in worksites in the German-speaking part of Switzerland from May 2015 to Nov 2016, for which we present the study protocol and baseline characteristics. Healthful & Tasty, a cluster nonrandomized single-arm trial with calibration arm, aimed to demonstrate the effectiveness of a combined educational and environmental intervention in the workplace in reducing employees' average daily sodium/salt intake by 15%. To this end, health and food literacy of employees and guideline compliance among the catering facility team needed to be improved. The primary outcome measure was sodium/salt intake estimated from sodium excretion in a 24-h urine sample. Secondary outcome measures included changes in the overall qualitative diet composition, blood pressure, anthropometric indices, and health and food literacy. Of eight organizations with catering facilities, seven organizations took part in the nutrition education and catering salt reduction interventions, and one organization participated as a control. Overall, 145 consenting employees were included in the staggered, one-year four-phase trial, of which 132 participated in the intervention group. In addition to catering surveys and food sampling, the trial included five follow-up health assessments including questionnaires, blood pressure measurements, anthropometrics, and sodium, potassium, and iodine intake measurements obtained from 24-h and spot urine samples, and a food record checklist. Exploratory and hypothesis generating baseline statistical analysis included 141 participants with adequate 24-h urine samples. Despite practice-driven limitations to the study design and small cluster and participant numbers, this trial has methodological strength and will provide important insights into the effectiveness of a combined educational and environmental intervention to reduce salt intake among female and male Swiss employees. German Clinical Trials Register, DRKS00006790 . Registered 23 September 2014.

Sodium intake may promote weight gain; results of the FANPE study in a representative sample of the adult Spanish population.

PubMed

Navia, Beatriz; Aparicio, Aránzazu; Perea, José Miguel; Pérez-Farinós, Napoleon; Villar-Villalba, Carmen; Labrado, Estefania; Ortega, Rosa María

2014-06-01

Recent studies have indicated that diets rich in sodium may predispose to the development of obesity, either directly, or be associated with the consumption of foods that promote weight gain. The aims of this study were to analyze the association between urinary sodium and the presence of excess of weight. Additionally, the study investigated the relationships between salt intake and dietary habits, as a high salt intake may be associated with inadequate eating habits and a high incidence of obesity. This study involved 418 adults (196 men and 222 women) aged 18 to 60 years old. Weight, height and waist circumference were measured, and we calculated, BMI and waist/height ratio. Dietary intake was estimated using a "24 h recalls", for two consecutive days, and sodium content was determined from 24 h urine sample. The 34.4% of the population had overweight and 13.6% had obesity. A positive association was seen between BMI and urinary sodium concentration. Urine sodium values were also positively associated with others adiposity indicators such as waist circumference and waist/height ratio. Body weight, BMI, waist circumference, and waist/height ratio were higher in the group of individuals with a urinary sodium excretion ≥154 mmol/l (Percentile 50) (P50). Additionally, individuals placed in this group presented a higher caloric intake and total food intake, in particular, more meat, processed food and snacks. Adjusting by energy intake, a higher sodium intake was a risk factor of being overweight or obese (OR = 1.0041, IC 95% 1.0015-1.0067, p < 0.01). Salt intake was associated with obesity; since people with higher sodium intake consumed more energy and presented worse eating habits. Additionally, sodium intake itself appears to be related to obesity. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Low blood pressure in vegetarians: the possible role of potassium.

PubMed

Ophir, O; Peer, G; Gilad, J; Blum, M; Aviram, A

1983-05-01

Ninety-eight confirmed adult vegetarians were examined against a matched group of nonvegetarians living in the same urban environment in order to evaluate the prevalence of arterial hypertension. The average blood pressure was 126/77 for the vegetarians and 147/88 for the control group (p less than 0.05). Significantly lower blood pressure was found in every decade of age. Only 2% of the vegetarians had hypertension (higher than 160/95) as compared to 26% hypertensives in the nonvegetarians. These differences in blood pressure were maintained also when individuals with the same "relative weight" were compared. Family history of hypertension was similar in both groups. Analysis of factors such as coffee drinking and smoking did not favor reduced blood pressure among the vegetarian group. Sodium and potassium intake were evaluated from their ratios to creatinine in a single urine sample. It was evident that both groups excreted the same amounts of sodium, while potassium excretion was significantly higher in the vegetarians. In view of the increasing evidence that potassium plays an important role in the regulation of blood pressure it is concluded that the protective antihypertensive factor in the vegetarian diet is the presence of high amounts of potassium.

Salt adaptation in Bufo bufo

PubMed Central

Ferreira, H. G.; Jesus, C. H.

1973-01-01

1. The capacity of adaptation of toads (Bufo bufo) to environments of high salinity was studied and the relative importance of skin, kidney and urinary bladder in controlling the balance of water and salt was assessed. 2. Toads were kept in NaCl solutions of 20, 50, 110, 150 and 220 mM and studied in their fourth week of adaptation. A group of animals considered as `control' was kept in wet soil with free access to water. Plasma, ureter urine, and bladder and colon contents were analysed for sodium, potassium, chloride and osmolality, and total body sodium and water were determined. Absorption of water and 22Na through the skin, and water flow and sodium excretion through the ureter, of intact animals was studied. Hydrosmotic water transport through the isolated urinary bladder of `control' and adapted animals was determined. The effects of pitressin and aldosterone on the water and sodium balance are described. 3. The survival rates of toads kept in saline concentrations up to 150 mM were identical to that of `control' animals, but half of the animals kept in 220 mM died within 4 weeks. 4. There is a linear correlation between the sodium concentrations and osmolality of plasma and of the external media. 5. The sodium concentration in colon contents rose with rising external concentrations, up to values higher than the values in plasma. 6. Sodium concentrations and osmolalities of ureter and bladder urine increased in adapted animals, the values for bladder urine becoming much higher than those for ureter urine in animals adapted to 110, 150 and 220 mM. 7. Total body water, as a percentage of total weight was kept within very narrow limits, although the total body sodium increased with adaptation. 8. Absorption of water through the skin for the same osmotic gradients was smaller in adapted than in `control' animals. 9. The ureteral output of water of toads adapted to 110 and 150 mM-NaCl was larger than the water absorption through the skin. 10. Skin absorption of sodium was lower in animals adapted to concentrated saline solutions than in `control' animals. 11. Sodium output by the ureter was identical to skin absorption in `control' animals adapted to 20, 50 and 110 mM-NaCl but was higher in animals adapted to 150 mM-NaCl. 12. Aldosterone increased the absorption of sodium in `control' and adapted toads, but at all dose levels absorption by control was greater than by adapted animals. 13. The stimulation of water absorption by vasopressin in vivo or in isolated bladders was not modified in animals adapted to high salinities. PMID:4633911

The excretion and metabolism of oral 14C-pyridostigmine in the rat

PubMed Central

Husain, M. A.; Roberts, J. B.; Thomas, B. H.; Wilson, A.

1968-01-01

1. Pyridostigmine labelled with carbon-14 in the methyl group of the quaternary nitrogen has been used to investigate the excretion and metabolism of the drug after administration of single doses (500 μg) to the rat by stomach tube. 2. Pyridostigmine is slowly excreted in the urine; the maximum excretion occurs between 1-3 hr after administration. In 24 hr 42% of the dose is excreted in urine and 38.4% is present in faeces and intestinal contents. 3. The peak concentration of radioactivity in liver and blood occurs about 2 hr after administration. 4. About 75% of the radioactivity in urine is present as unchanged pyridostigmine, the remainder as metabolite. 5. The results are compared with those previously obtained after oral administration of neostigmine. 6. It is concluded that after oral administration the absorption of pyridostigmine is greater and the metabolism substantially less than that of neostigmine. PMID:5687596

Renal effects of anti-gravity suit inflation in man in relation to cardiovascular and hormonal changes

NASA Technical Reports Server (NTRS)

Geelen, G.; Kravik, S. E.; Hadj-Aissa, A.; Vincent, M.; Sem-Jacobsen, C. W.; Greenleaf, J.; Gharib, C.

1987-01-01

It is shown that inflation for 3 hr of an antigravity suit that covered the legs and abdomen of normal standing subjects results in significant increases in urine flow, osmolar and free water clearances, total and fractional sodium excretion, and potassium excretion, while glomerular filtration rate and renal plasma flow are transiently increased. Such changes in kidney function are the consequence of the increase in thoracic blood volume induced by inflation which also results in an immediate increase in blood pressure and reflex bradycardia, together with a progressive lowering of plasma renin activity and aldosterone. The changes in kidney excretory patterns brought about by suit inflation appear to be similar in nature and magnitude to those observed during water immersion or in the early phase of bed rest, situations known to result in a headward redistribution of blood.

Determination of neostigmine and pyridostigmine in the urine of patients with myasthenia gravis

PubMed Central

Nowell, P. T.; Scott, Carol A.; Wilson, A.

1962-01-01

A method has been described for the estimation of neostigmine and pyridostigmine in urine by ion exchange treatment and colorimetric estimation of the blue complex produced when either of the drugs is made to react with bromophenol blue. Urine containing 2 μg/ml. or more of neostigmine or 3 μg/ml. or more of pyridostigmine can be quantitatively estimated. After intramuscular injection of neostigmine to patients with myasthenia gravis, up to 67% of the drug is excreted, whilst after oral administration less than 5% is excreted. When pyridostigmine is given by mouth, the amount of drug excreted in the urine varies between approximately 2 and 16%. It has been established by chromatographic analysis that the blue complexes formed under these conditions are due only to neostigmine and pyridostigmine respectively and that the quantitative estimation described is a true measure of the amount of these drugs excreted in the urine. The significance of these results is discussed in relation to the absorption and metabolism of the two drugs. PMID:14480648

High Prolactin Excretion in Patients with Diabetes Mellitus and Impaired Renal Function.

PubMed

Triebel, Jakob; Moreno-Vega, Aura Ileana; Vázquez-Membrillo, Miguel; Nava, Gabriel; García-Franco, Renata; López-Star, Ellery; Baldivieso-Hurtado, Olivia; Ochoa, Daniel; Macotela, Yazmín; Bertsch, Thomas; Martinez de la Escalera, Gonzalo; Clapp, Carmen

2015-01-01

The metabolic clearance of prolactin (PRL) is partially executed by the kidney. Here, we investigate the urine excretion of PRL in patients with Diabetes Mellitus and renal impairment. Serum and urine samples were collected from male, mestizo patients in central Mexico employing a cross-sectional study design. Ninety-eight individuals had either no diabetes and normal renal function (control), diabetes and normal renal function, or diabetes with impaired renal function. PRL was determined by a chemiluminescent immunometric assay; protein, albumin, and creatinine were evaluated using quantitative colorimetric assays. The results were analyzed using ANOVA-testing. Patients with Diabetes Mellitus and renal impairment had significantly higher urine PRL levels than patients with Diabetes Mellitus and normal renal function and control patients. Higher urine PRL levels were associated with lower glomerular filtration rates, higher serum creatinine, and higher urinary albumin-to-creatinine ratios (UACR). Urine PRL levels correlated positively with UACR. Serum PRL levels were similar among groups. Patients with Diabetes Mellitus and impaired renal function demonstrate a high urinary PRL excretion. Urinary PRL excretion in the context of proteinuria could contribute to PRL dysregulation in renal impairment.

The role of the kidney in compensating the alkaline tide, electrolyte load, and fluid balance disturbance associated with feeding in the freshwater rainbow trout, Oncorhynchus mykiss.

PubMed

Bucking, Carol; Landman, Michael J; Wood, Chris M

2010-05-01

The effect in freshwater rainbow trout of digesting a commercial pellet meal on the renal handling of water, ions and acid-base equivalents was investigated through urine collection over a 48 h period following meal ingestion. The glomerular filtration rate (GFR) and urine flow rate (UFR) were reduced in fed fish between 12 and 24h following the meal, likely reflecting a loss of endogenous water across the gastric epithelium as a result of ingesting dry, ion-rich food pellets. The kidney was also responsible for the excretion of some excess dietary Ca(2+), and, to a much lesser extent, Na(+) and Cl(-), while the urinary excretion of K(+) was unaffected. The most dramatic effect of feeding was the elevation of renal Mg(2+) excretion, with the kidney transitioning from net Mg(2+) reabsorption to net Mg(2+) secretion during digestion. The renal handling of dietary ions accounted for 3-27% of the total ions absorbed from the diet, indicating that a majority of the ions are excreted extra-renally or incorporated into growth. However this does highlight the underestimation of renal ion handling when using unfed fish models. The metabolic alkalosis created by digestion (the alkaline tide) resulted in an increase in urine pH as well as a transition from net acidic equivalent excretion in the urine to net basic equivalent excretion. This was due to a decrease in the titratable acidity minus bicarbonate component of urine as well as a decrease in ammonia secretion. Additionally, the experimental separation of the urinary component of acid-base excretion from that of the gills highlighted the substantially larger contribution of the latter. During the alkaline tide, renal excretion accounted for approximately 5% of the total basic equivalent excretion to the external water. Copyright 2009 Elsevier Inc. All rights reserved.

Lower potassium intake is associated with increased wave reflection in young healthy adults

PubMed Central

2014-01-01

Background Increased potassium intake has been shown to lower blood pressure (BP) even in the presence of high sodium consumption however the role of dietary potassium on vascular function has received less attention. The aim of this study was to evaluate the relationship between habitual intake of sodium (Na) and potassium (K) and measures of arterial stiffness and wave reflection. Methods Thirty-six young healthy adults (21 M, 15 F; 24 ± 0.6 yrs; systolic BP 117 ± 2; diastolic BP 63 ± 1 mmHg) recorded their dietary intake for 3 days and collected their urine for 24 hours on the 3rd day. Carotid-femoral pulse wave velocity (PWV) and the synthesis of a central aortic pressure waveform (by radial artery applanation tonometry and generalized transfer function) were performed. Aortic augmentation index (AI), an index of wave reflection, was calculated from the aortic pressure waveform. Results Subjects consumed an average of 2244 kcals, 3763 mg Na, and 2876 mg of K. Average urinary K excretion was 67 ± 5.3 mmol/24 hr, Na excretion was 157 ± 11 mmol/24 hr and the average Na/K excretion ratio was 2.7 ± 0.2. An inverse relationship between AI and K excretion was found (r = -0.323; p < 0.05). A positive relationship between AI and the Na/K excretion ratio was seen (r = 0.318; p < 0.05) while no relationship was noted with Na excretion alone (r = 0.071; p > 0.05). Reflection magnitude, the ratio of reflected and forward waves, was significantly associated with the Na/K excretion ratio (r = 0.365; p <0.05) but not Na or K alone. PWV did not correlate with Na or the Na/K excretion ratio (p > 0.05) but showed an inverse relationship with K excretion (r = -0.308; p < 0.05). Conclusions These data suggest that lower potassium intakes are associated with greater wave reflection and stiffer arteries in young healthy adults. PMID:24775098

Relative excretion of nitrogen from alfalfa silage, corn silage, corn grain, and soybean meal in urine and feces by lactating dairy cows

USDA-ARS?s Scientific Manuscript database

The main objective of this trial is to determine the partitioning of nitrogen (N) from different feed ingredients in milk, feces, and urine. This abstract focuses on relative excretion of N in feces and urine. Twelve multiparous late-lactation Holstein cows (means±SD; 264±18 days in milk) were fed a...

Kinetics of Rituximab Excretion into Urine and Peritoneal Fluid in Two Patients with Nephrotic Syndrome.

PubMed

Stahl, Klaus; Duong, Michelle; Schwarz, Anke; Wagner, A D; Haller, Hermann; Schiffer, Mario; Jacobs, Roland

2017-01-01

Clinical observations suggest that treatment of Rituximab might be less effective in patients with nephrotic range proteinuria when compared to nonnephrotic patients. It is conceivable that the reason for this is that significant amounts of Rituximab might be lost in the urine in a nephrotic patient and that these patients require a repeated or higher dosage. However, this has not been systematically studied. In this case report we describe two different patients with nephrotic range proteinuria receiving Rituximab. The first patient received Rituximab for therapy resistant cryoglobulinemic membranoproliferative glomerulonephritis and the other for second line treatment of Felty's syndrome. We employed flow cytometry to determine the amount of Rituximab excretion in both urine and peritoneal fluid specimens in these patients following administration of Rituximab. We found that a significant amount of Rituximab is lost from the circulation by excretion into the urine. Furthermore we saw a close correlation of the excretion of Rituximab to the excretion of IgG molecules suggesting selectivity of proteinuria as the determining factor of Rituximab excretion. Further larger scale clinical studies could have the potential to evaluate an optimal cut-off value of IgG urinary loss before a possible administration of Rituximab therefore contributing to a more individualized treatment approach in patients with nonselective and nephrotic range proteinuria.

The Use and Interpretation of Sodium Concentrations in Casual (Spot) Urine Collections for Population Surveillance and Partitioning of Dietary Iodine Intake Sources

PubMed Central

Conkle, Joel; van der Haar, Frits

2016-01-01

In 2013, the World Health Organization (WHO) called for joint surveillance of population salt and iodine intakes using urinary analysis. 24-h urine collection is considered the gold standard for salt intake assessment, but there is an emerging consensus that casual urine sampling can provide comparable information for population-level surveillance. Our review covers the use of the urinary sodium concentration (UNaC) and the urinary iodine concentration (UIC) from casual urine samples to estimate salt intakes and to partition the sources of iodine intakes. We reviewed literature on 24-h urinary sodium excretion (UNaE) and UNaC and documented the use of UNaC for national salt intake monitoring. We combined information from our review of urinary sodium with evidence on urinary iodine to assess the appropriateness of partitioning methods currently being adapted for cross-sectional survey analyses. At least nine countries are using casual urine collection for surveillance of population salt intakes; all these countries used single samples. Time trend analyses indicate that single UNaC can be used for monitoring changes in mean salt intakes. However; single UNaC suffers the same limitation as single UNaE; i.e., an estimate of the proportion excess salt intake can be biased due to high individual variability. There is evidence, albeit limited, that repeat UNaC sampling has good agreement at the population level with repeat UNaE collections; thus permitting an unbiased estimate of the proportion of excess salt intake. High variability of UIC and UNaC in single urine samples may also bias the estimates of dietary iodine intake sources. Our review concludes that repeated collection, in a sub-sample of individuals, of casual UNaC data would provide an immediate practical approach for routine monitoring of salt intake, because it overcomes the bias in estimates of excess salt intake. Thus we recommend more survey research to expand the evidence-base on predicted-UNaE from repeat casual UNaC sampling. We also conclude that the methodology for partitioning the sources of iodine intake based on the combination of UIC and UNaC measurements in casual urine samples can be improved by repeat collections of casual data; which helps to reduce regression dilution bias. We recommend more survey research to determine the effect of regression dilution bias and circadian rhythms on the partitioning of dietary iodine intake sources. PMID:28025546

Dietary salt intake assessed by 24 h urinary sodium excretion in Australian schoolchildren aged 5-13 years.

PubMed

Grimes, Carley A; Riddell, Lynn J; Campbell, Karen J; Nowson, Caryl A

2013-10-01

To measure total daily salt intake using 24 h urinary Na excretion within a sample of Victorian schoolchildren aged 5-13 years and to assess discretionary salt use habits of children and parents. Cross-sectional study. Completed within a convenience sample of independent primary schools (n 9) located in Victoria, Australia. Two hundred and sixty children completed a 24 h urine collection over a school (34%) or non-school day (66%). Samples deemed incomplete (n 18), an over-collection (n 1) or that were incorrectly processed at the laboratory (n 3) were excluded. The sample comprised 120 boys and 118 girls with a mean age of 9.8 (SD 1.7) years. The average 24 h urinary Na excretion (n 238) was 103 (SD 43) mmol/24 h (salt equivalent 6.0 (SD 2.5) g/d). Daily Na excretion did not differ by sex; boys 105 (SD 46) mmol/24 h (salt equivalent 6.1 (SD 2.7) g/d) and girls 100 (SD 41) mmol/24 h (salt equivalent 5.9 (SD 2.4) g/d; P=0.38). Sixty-nine per cent of children (n 164) exceeded the recommended daily Upper Limit for Na. Reported discretionary salt use was common: two-thirds of parents reported adding salt during cooking and almost half of children reported adding salt at the table. The majority of children had salt intakes exceeding the recommended daily Upper Limit. Strategies to lower salt intake in children are urgently required, and should include product reformulation of lower-sodium food products combined with interventions targeting discretionary salt use within the home.

Urinary and proximal tubule acidification during reduction of renal blood flow in the rat.

PubMed Central

Jaramillo-Juárez, F; Aires, M M; Malnic, G

1990-01-01

1. The effects of reduction in renal blood flow (RBF) on urinary acidification and proximal tubule H+ ion secretion were studied after partial aortic clamping in rats. 2. Acute reduction of the renal perfusion pressure (from 109 +/- 3.88 to 77.4 +/- 1.05 mmHg) decreased both inulin and PAH (p-aminohippurate) clearances to about one-third of their control values. Absolute levels of urinary sodium excretion also decreased markedly, but fractional sodium excretion did not change significantly. 3. Urine pH and bicarbonate levels were not affected, but titratable acidity increased significantly from 0.12 +/- 0.011 to 0.25 +/- 0.042 muequiv min-1 ml-1 glomerular filtration rate (GFR). During aortic clamping, cortical PCO2 as determined by means of Severinghaus microelectrodes was reduced by a mean value of 7.0 +/- 1.5 mmHg. 4. Proximal tubule acidification kinetics were studied by stationary microperfusion techniques in which the time course of pH changes was monitored by pH microelectrodes. Steady-state pH fell from a mean control value of 6.77 +/- 0.03 to 6.65 +/- 0.02, and stationary bicarbonate concentrations from 4.70 +/- 0.27 to 2.84 +/- 0.18 mM. Acidification half-time decreased from 5.07 +/- 0.30 to 4.39 +/- 0.19 s, and net bicarbonate reabsorption increased from 1.63 +/- 0.14 to 1.99 +/- 0.12 nmol cm-2 s-1, these changes being statistically significant. 5. The experiments demonstrate that both overall acid excretion and proximal acid secretion are not compromised by a large decrease of RBF to about one-third of the control value; titratable acid excretion and proximal net bicarbonate reabsorption were even moderately increased under these conditions. PMID:2348400

The effect of empagliflozin on muscle sympathetic nerve activity in patients with type II diabetes mellitus.

PubMed

Jordan, Jens; Tank, Jens; Heusser, Karsten; Heise, Tim; Wanner, Christoph; Heer, Martina; Macha, Sreeraj; Mattheus, Michaela; Lund, Søren S; Woerle, Hans J; Broedl, Uli C

2017-09-01

Inhibition of sodium glucose cotransporter 2 with empagliflozin results in caloric loss by increasing urinary glucose excretion and has a mild diuretic effect. Diuretic effects are usually associated with reflex-mediated increases in sympathetic tone, whereas caloric loss is associated with decreased sympathetic tone. In an open-label trial, muscle sympathetic nerve activity (MSNA) (burst frequency, burst incidence, and total MSNA) was assessed using microneurography performed off-treatment and on day 4 of treatment with empagliflozin 25 mg once daily in 22 metformin-treated patients with type II diabetes (mean [range] age 54 [40-65] years). Systolic and diastolic blood pressure (BP), heart rate, urine volume, and body weight were assessed before and on day 4 (BP, heart rate), day 5 (urine volume), or day 6 (body weight) of treatment with empagliflozin. After 4 days of treatment with empagliflozin, no significant changes in MSNA were apparent despite a numerical increase in urine volume, numerical reductions in BP, and significant weight loss. There were no clinically relevant changes in heart rate. Empagliflozin is not associated with clinically relevant reflex-mediated sympathetic activation in contrast to increases observed with diuretics in other studies. Our study suggests a novel mechanism through which sodium glucose cotransporter 2 inhibition affects human autonomic cardiovascular regulation. Copyright © 2017 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Studies on the excretion of ascorbic acid 2-sulfate and total vitamin C into human urine after oral administration of ascorbic acid 2-sulfate.

PubMed

Tsujimura, M; Fukuda, T; Kasai, T

1982-10-01

The excretion of AsS and total vitamin C into urine after oral administration of AsS to humans was investigated. When 10 mmol of AsS was administered to the subjects, the excretion of AsS into urine continued for 60 hr in males and 48 hr in females. The average amount excreted per hour was less than 5 mg. These results differed from those for AsA and DAsA orally administered to humans. The determination of vitamin C after oral administration of AsS to the subjects consisting of ten males and six females showed no vitamin C effect in humans, similarly to the case with the guinea pig and the rhesus monkey.

Dietary Sodium Restriction and Association with Urinary Marinobufagenin, Blood Pressure, and Aortic Stiffness

PubMed Central

Fedorova, Olga V.; Racine, Matthew L.; Geolfos, Candace J.; Gates, Phillip E.; Chonchol, Michel; Fleenor, Bradley S.; Lakatta, Edward G.; Bagrov, Alexei Y.; Seals, Douglas R.

2013-01-01

Summary Background and objectives Systolic BP and large elastic artery stiffness both increase with age and are reduced by dietary sodium restriction. Production of the natriuretic hormone marinobufagenin, an endogenous α1 Na+,K+-ATPase inhibitor, is increased in salt-sensitive hypertension and contributes to the rise in systolic BP during sodium loading. Design, setting, participants, & measurements The hypothesis was that dietary sodium restriction performed in middle-aged/older adults (eight men and three women; 60±2 years) with moderately elevated systolic BP (139±2/83±2 mmHg) would reduce urinary marinobufagenin excretion as well as systolic BP and aortic pulse-wave velocity (randomized, placebo-controlled, and crossover design). This study also explored the associations among marinobufagenin excretion with systolic BP and aortic pulse-wave velocity across conditions of 5 weeks of a low-sodium (77±9 mmol/d) and 5 weeks of a normal-sodium (144±7 mmol/d) diet. Results Urinary marinobufagenin excretion (weekly measurements; 25.4±1.8 versus 30.7±2.1 pmol/kg per day), systolic BP (127±3 versus 138±5 mmHg), and aortic pulse-wave velocity (700±40 versus 843±36 cm/s) were lower during the low- versus normal-sodium condition (all P<0.05). Across all weeks, marinobufagenin excretion was related with systolic BP (slope=0.61, P<0.001) and sodium excretion (slope=0.46, P<0.001). These associations persisted during the normal- but not the low-sodium condition (both P<0.005). Marinobufagenin excretion also was associated with aortic pulse-wave velocity (slope=0.70, P=0.02) and endothelial cell expression of NAD(P)H oxidase-p47phox (slope=0.64, P=0.006). Conclusions These results show, for the first time in humans, that dietary sodium restriction reduces urinary marinobufagenin excretion and that urinary marinobufagenin excretion is positively associated with systolic BP, aortic stiffness (aortic pulse-wave velocity), and endothelial cell expression of the oxidant enzyme NAD(P)H oxidase. Importantly, marinobufagenin excretion is positively related to systolic BP over ranges of sodium intake typical of an American diet, extending previous observations in rodents and humans fed experimentally high-sodium diets. PMID:23929930

Self-reports of salt intake by 10- to 18-year-olds: relationship to urinary sodium excretion.

PubMed

Murphy, J K; Alpert, B S; Stapleton, F B; Miller, L A; Willey, E S; Walker, S S; Nanney, G C

1990-03-01

Our data indicated that self-reports of consumption of salty foods by children and adolescents were associated with 24-hour urinary sodium excretion. Specifically, youths 10 to 18 years of age who selected a poster depicting high-sodium foods excreted significantly more sodium than youths who selected a poster depicting low-sodium foods. Future research is needed to refine simplified self-report measures, to corroborate the validity of the measures, and to extend the studies to other samples, e.g., younger children.

Relationships between urinary electrolytes excretion and central hemodynamics, and arterial stiffness in hypertensive patients.

PubMed

Han, Weizhong; Han, Xiao; Sun, Ningling; Chen, Yunchao; Jiang, Shiliang; Li, Min

2017-08-01

High sodium intake plays an important role in the onset and exacerbation of hypertension. However, the relationships between urinary electrolytes excretion and central hemodynamics and between urinary electrolyte excretion and arterial stiffness are still the subject of debate. This study sought to clarify the associations of salt intake with central aortic pressure and arterial stiffness indicators. A total of 431 untreated hypertensive individuals were recruited into the study. Twenty-four-hour urinary samples were collected to measure the excretion of urinary electrolytes. Central hemodynamics parameters and brachial-ankle pulse wave velocity (baPWV) were measured. We evaluated the independent relationship between urinary sodium or potassium excretion and the abovementioned indices. The mean 24-h urinary sodium of all subjects was 166.6±70.0 mmol/24 h. With increases in urinary sodium excretion, central blood pressure and baPWV values markedly increased. Multiple regression analysis showed that urinary sodium was independently associated with increases in central systolic blood pressure, central diastolic blood pressure, the augmentation index, and baPWV. Significant correlations were identified between high dietary sodium and central hemodynamics and between high dietary sodium and arterial elasticity. Prospective interventional studies in hypertensive patients may be required to determine the effect of salt intake on central hemodynamics.

Mathematical Model of Ammonia Handling in the Rat Renal Medulla

PubMed Central

Noiret, Lorette; Baigent, Stephen; Jalan, Rajiv; Thomas, S. Randall

2015-01-01

The kidney is one of the main organs that produces ammonia and release it into the circulation. Under normal conditions, between 30 and 50% of the ammonia produced in the kidney is excreted in the urine, the rest being absorbed into the systemic circulation via the renal vein. In acidosis and in some pathological conditions, the proportion of urinary excretion can increase to 70% of the ammonia produced in the kidney. Mechanisms regulating the balance between urinary excretion and renal vein release are not fully understood. We developed a mathematical model that reflects current thinking about renal ammonia handling in order to investigate the role of each tubular segment and identify some of the components which might control this balance. The model treats the movements of water, sodium chloride, urea, NH3 and NH4+, and non-reabsorbable solute in an idealized renal medulla of the rat at steady state. A parameter study was performed to identify the transport parameters and microenvironmental conditions that most affect the rate of urinary ammonia excretion. Our results suggest that urinary ammonia excretion is mainly determined by those parameters that affect ammonia recycling in the loops of Henle. In particular, our results suggest a critical role for interstitial pH in the outer medulla and for luminal pH along the inner medullary collecting ducts. PMID:26280830

Turnover and urinary excretion of free and acetylated MS-222 rainbow trout, Salmo gairdneri

USGS Publications Warehouse

Hunn, J.B.; Schoettger, R.A.; Willford, W.A.

1968-01-01

Rainbow trout (Salmo gairdneri) anesthetized in 100 mg/liter of M.S. 222 at 12 C excreted the drug in free and acetylated forms via the urine during a 24-hr recovery period in freshwater. Of the M.S. 222 excreted, 77-96% was acetylated. Blood levels of free drug in anesthetized trout approximated 75% of the anesthetic concentration, but the amount of acetylated M.S. 222 was relatively insignificant. The blood and urine were cleared of the two fractions of M.S. 222 in 8 and 24 hr respectively. Low levels of aromatic amines of natural origin occurred in blood and urine and were subtracted from measurements of M.S. 222. Intraperitoneal injections of 10-100 mg/kg of M.S. 222 did not induce anesthesia; however, the 24-hr pattern of drug excretion was similar to that observed after anesthesia by immersion. Only 15-21 % of the injected dose was found in the urine, suggesting a second route of drug elimination.

Spectrophotometric determination of pyrrole-like substances in urine of rat and man: an assay for the evaluation of 2,5-hexanedione formed from n-hexane.

PubMed

Kessler, W; Heilmaier, H; Kreuzer, P; Shen, J H; Filser, M; Filser, J G

1990-01-01

Male Wistar rats exposed to atmospheric n-hexane excreted in their urine substances which gave rise to absorption spectra like those of pyrroles after the reaction with Ehrlich's reagent. A simple spectrophotometric assay was developed to determine these "pyrrole-like substances" in urine. Their excretion kinetics were evaluated by exposing rats for 8 h to atmospheric n-hexane concentrations between 50 and 3000 ppm. The dose-response curve revealed saturation kinetics according to Michaelis-Menten, Vmax being 1.12 [delta E526.ml urine/8 h n-hexane exposure] and "Km", the atmospheric n-hexane concentration at Vmax/2, being 250 ppm. The excretion of pyrrole-like substances closely correlated with that of 2,5-hexanedione measured by Fedtke and Bolt (1987). Pyrrole-like substances were also found in the urine of a male volunteer. When exposing the person for 3 h to atmospheric n-hexane at a concentration of 146 ppm (equivalent to 55 ppm/8 h) the excreted amount was twice the background value. Due to the sensitivity of this assay it is possible to determine pyrrole-like substances in urine according to the present German MAK or US TLV conditions for n-hexane (50 ppm/8 h).

Prediction of manure nitrogen and organic matter excretion for young Holstein cattle fed on grass silage-based diets.

PubMed

Jiao, H P; Yan, T; McDowell, D A

2014-07-01

The objectives of the present study were to evaluate the effects of sex (steers vs. heifers) of young Holstein cattle on N and OM excretion in feces and urine and to use these data to develop prediction models for N and OM excretion. Data used were derived from a study with 20 autumn-born Holstein cattle (10 steers and 10 heifers) with N and OM intake and output measured at age of 6, 12, 18, and 22 mo, respectively. The cattle were offered a typical diet used on U.K. commercial farms containing a single grass silage mixed with concentrates. In each period, the cattle were housed as a single group in cubicle accommodation for the first 20 d, individually in metabolism units for the next 3 d, and then in calorimeter chambers for the final 5 d with feed intake, feces, and urine excretion measured during the final 4 d. Within each period, sex had no effect (P > 0.05) on N or OM intake or excretion or N utilization efficiency, with exceptions of steers having a greater intake of N (P = 0.036) and OM (P = 0.018) at age of 18 mo and a lower ratio of fecal N:N intake (P = 0.023) at age of 6 mo. A range of regression relationships (P < 0.05) were developed for prediction of N (g/d) and OM (kg/d) excretion in feces and urine. The present data were also used to calculate accumulated N and OM intake (kg) and excretion for the 2 sexes. Sex had no effects (P > 0.05) on accumulated N or OM intake or N or OM excretion in feces and urine or retained N and OM during the first or second year of life. On average for the 2 sexes at first and second year of age, the accumulated N excretions in feces were 11.4 and 21.1 kg and in urine 11.6 and 30.6 kg, respectively, and the corresponding values for accumulated OM excretions were respectively 241.5, 565.7, 30.3 and 81.5 kg. A number of equations were developed to predict accumulated N and OM excretion in feces and urine (kg) using BW (kg; P < 0.001, r(2) = 0.95 to 0.97). The accurate prediction of N and OM excretion in feces and urine is essential for reducing N pollution to ground and surface water and calculating methane and nitrous oxide emissions from manure management of dairy and beef production systems. These data can add novel information to the scientific literature and can be used to improve national inventories of manure N output and greenhouse gas emissions and to develop appropriate mitigation strategies for young Holstein cattle.

Geographic and socioeconomic variation of sodium and potassium intake in Italy: results from the MINISAL-GIRCSI programme

PubMed Central

Cappuccio, Francesco P; Ji, Chen; Donfrancesco, Chiara; Palmieri, Luigi; Ippolito, Renato; Vanuzzo, Diego; Giampaoli, Simona; Strazzullo, Pasquale

2015-01-01

Objectives To assess geographic and socioeconomic gradients in sodium and potassium intake in Italy. Setting Cross-sectional survey in Italy. Participants 3857 men and women, aged 39–79 years, randomly sampled in 20 regions (as part of a National cardiovascular survey of 8714 men and women). Primary outcome measures Participants’ dietary sodium and potassium intakes were measured by 24 h urinary sodium and potassium excretions. 2 indicators measured socioeconomic status: education and occupation. Bayesian geoadditive models were used to assess spatial and socioeconomic patterns of sodium and potassium intakes accounting for sociodemographic, anthropometric and behavioural confounders. Results There was a significant north-south pattern of sodium excretion in Italy. Participants living in southern Italy (eg, Calabria, Basilicata and Puglia >180 mmol/24 h) had a significantly higher sodium excretion than elsewhere (eg, Val d'Aosta and Trentino-Alto Adige <140 mmol/24 h; p<0.001). There was a linear association between occupation and sodium excretion (p<0.001). When compared with occupation I (top managerial), occupations III and IV had a 6.5% higher sodium excretion (coefficients: 0.054 (90% credible levels 0.014, 0.093) and 0.064 (0.024, 0.104), respectively). A similar relationship was found between educational attainment and sodium excretion (p<0.0001). When compared with those with a university degree, participants with primary and junior school education had a 5.9% higher urinary sodium (coefficients: 0.074 (0.031, 0.116) and 0.038 (0.001, 0.075), respectively). The socioeconomic gradient explained the spatial variation. Potassium excretion was higher in central regions and in some southern regions. Those in occupation V (low-skill workers) showed a 3% lower potassium excretion compared with those in occupation I. However, the socioeconomic gradient only partially explained the spatial variation. Conclusions Salt intake in Italy is significantly higher in less advantaged social groups. This gradient is independent of confounders and explains the geographical variation. PMID:26359282

Geographic and socioeconomic variation of sodium and potassium intake in Italy: results from the MINISAL-GIRCSI programme.

PubMed

Cappuccio, Francesco P; Ji, Chen; Donfrancesco, Chiara; Palmieri, Luigi; Ippolito, Renato; Vanuzzo, Diego; Giampaoli, Simona; Strazzullo, Pasquale

2015-09-10

To assess geographic and socioeconomic gradients in sodium and potassium intake in Italy. Cross-sectional survey in Italy. 3857 men and women, aged 39-79 years, randomly sampled in 20 regions (as part of a National cardiovascular survey of 8714 men and women). Participants' dietary sodium and potassium intakes were measured by 24 h urinary sodium and potassium excretions. 2 indicators measured socioeconomic status: education and occupation. Bayesian geoadditive models were used to assess spatial and socioeconomic patterns of sodium and potassium intakes accounting for sociodemographic, anthropometric and behavioural confounders. There was a significant north-south pattern of sodium excretion in Italy. Participants living in southern Italy (eg, Calabria, Basilicata and Puglia >180 mmol/24 h) had a significantly higher sodium excretion than elsewhere (eg, Val d'Aosta and Trentino-Alto Adige <140 mmol/24 h; p<0.001). There was a linear association between occupation and sodium excretion (p<0.001). When compared with occupation I (top managerial), occupations III and IV had a 6.5% higher sodium excretion (coefficients: 0.054 (90% credible levels 0.014, 0.093) and 0.064 (0.024, 0.104), respectively). A similar relationship was found between educational attainment and sodium excretion (p<0.0001). When compared with those with a university degree, participants with primary and junior school education had a 5.9% higher urinary sodium (coefficients: 0.074 (0.031, 0.116) and 0.038 (0.001, 0.075), respectively). The socioeconomic gradient explained the spatial variation. Potassium excretion was higher in central regions and in some southern regions. Those in occupation V (low-skill workers) showed a 3% lower potassium excretion compared with those in occupation I. However, the socioeconomic gradient only partially explained the spatial variation. Salt intake in Italy is significantly higher in less advantaged social groups. This gradient is independent of confounders and explains the geographical variation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Inductively coupled plasma mass-spectrometric determination of platinum in excretion products of client-owned pet dogs.

PubMed

Janssens, T; Brouwers, E E M; de Vos, J P; de Vries, N; Schellens, J H M; Beijnen, J H

2015-06-01

Residues of antineoplastic drugs in canine excretion products may represent exposure risks to veterinary personnel, owners of pet dogs and other animal care-takers. The aim of this study was to measure the extent and duration of platinum (Pt) excretion in pet dogs treated with carboplatin. Samples were collected before and up to 21 days after administration of carboplatin. We used validated, ultra-sensitive, inductively coupled plasma-mass spectrometry assays to measure Pt in canine urine, faeces, saliva, sebum and cerumen. Results showed that urine is the major route of elimination of Pt in dogs. In addition, excretion occurs via faeces and saliva, with the highest amounts eliminated during the first 5 days. The amount of excreted Pt decreased over time but was still quantifiable at 21 days after administration of carboplatin. In conclusion, increased Pt levels were found in all measured excretion products up to 21 days after administration of carboplatin to pet dogs, with urine as the main route of excretion. These findings may be used to further adapt current veterinary guidelines on safe handling of antineoplastic drugs and treated animals. © 2013 Blackwell Publishing Ltd.

Collecting duct prorenin receptor knockout reduces renal function, increases sodium excretion, and mitigates renal responses in ANG II-induced hypertensive mice.

PubMed

Prieto, Minolfa C; Reverte, Virginia; Mamenko, Mykola; Kuczeriszka, Marta; Veiras, Luciana C; Rosales, Carla B; McLellan, Matthew; Gentile, Oliver; Jensen, V Behrana; Ichihara, Atsuhiro; McDonough, Alicia A; Pochynyuk, Oleh M; Gonzalez, Alexis A

2017-12-01

Augmented intratubular angiotensin (ANG) II is a key determinant of enhanced distal Na + reabsorption via activation of epithelial Na + channels (ENaC) and other transporters, which leads to the development of high blood pressure (BP). In ANG II-induced hypertension, there is increased expression of the prorenin receptor (PRR) in the collecting duct (CD), which has been implicated in the stimulation of the sodium transporters and resultant hypertension. The impact of PRR deletion along the nephron on BP regulation and Na + handling remains controversial. In the present study, we investigate the role of PRR in the regulation of renal function and BP by using a mouse model with specific deletion of PRR in the CD ( CD PRR-KO). At basal conditions, CD PRR-KO mice had decreased renal function and lower systolic BP associated with higher fractional Na + excretion and lower ANG II levels in urine. After 14 days of ANG II infusion (400 ng·kg -1 ·min -1 ), the increases in systolic BP and diastolic BP were mitigated in CD PRR-KO mice. CD PRR-KO mice had lower abundance of cleaved αENaC and γENaC, as well as lower ANG II and renin content in urine compared with wild-type mice. In isolated CD from CD PRR-KO mice, patch-clamp studies demonstrated that ANG II-dependent stimulation of ENaC activity was reduced because of fewer active channels and lower open probability. These data indicate that CD PRR contributes to renal function and BP responses during chronic ANG II infusion by enhancing renin activity, increasing ANG II, and activating ENaC in the distal nephron segments. Copyright © 2017 the American Physiological Society.

[The efficacy of desmopressin in the treatment of central diabetes insipidus after resection of chiasmo-sellar region tumors].

PubMed

Astaf'eva, L I

Central diabetes insipidus (CDI) is a neuroendocrine disease, the pathogenesis of which is associated with abnormal secretion of the antidiuretic hormone. One of the specific causes of CDI is neurosurgical resection of chiasmatic-sellar region tumors. to study the efficacy and safety of desmopressin in CDI patients after resection of chiasmatic-sellar region (CSR) tumors. Examination and treatment of patients were performed at a hospital for 7-14 days after surgery and then were continued after discharge. During treatment, the following tests were performed: a daily fluid intake and excretion volume, serum levels of sodium, potassium, and glucose twice a day, morning urine specific gravity, and Zimnitsky's test. Twenty-three patients with CSR tumors (11 craniopharyngiomas, 10 pituitary adenomas, 1 skull base chordoma, and 1 CSR meningioma) and CDI after neurosurgical treatment received desmopressin. On treatment, a thirst decrease, a reduced rate of diuresis, a reduced amount of excreted urine, and normalization of the sodium level were observed in all patients. In 12 patients (with pituitary adenoma, skull base chordoma, and meningioma) with transient CDI, desmopressin therapy was discontinued upon regression of symptoms 7-30 days after surgery. Eleven patients with permanent CDI continued to receive the drug at a dose of 1 to 4 doses per day. All patients well tolerated the drug without significant adverse effects. Therapy with desmopressin in the form of a nasal spray (vazomirin) in patients with transient and permanent CDI after resection CSR tumors of various histological nature (craniopharyngiomas, pituitary adenomas, meningiomas, and chordomas) was effective and safe in the early postoperative and long-term postoperative periods.

Changes in the Expression and Distribution of Claudins, Increased Epithelial Apoptosis, and a Mannan-Binding Lectin-Associated Immune Response Lead to Barrier Dysfunction in Dextran Sodium Sulfate-Induced Rat Colitis

PubMed Central

Yuan, Bosi; Zhou, Shuping; Lu, Youke; Liu, Jiong; Jin, Xinxin; Wan, Haijun; Wang, Fangyu

2015-01-01

Background/Aims This animal study aimed to define the underlying cellular mechanisms of intestinal barrier dysfunction. Methods Rats were fed 4% with dextran sodium sulfate (DSS) to induce experimental colitis. We analyzed the sugars in 24-hour urine output by high pressure liquid chromatography. The expression of claudins, mannan-binding lectin (MBL), and MBL-associated serine proteases 2 (MASP-2) were detected in the colonic mucosa by immunohistochemistry; and apoptotic cells in the colonic epithelium were detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method assay. Results The lactulose and sucralose excretion levels in the urine of rats with DSS-induced colitis were significantly higher than those in the control rats. Mannitol excretion was lower and lactulose/mannitol ratios and sucralose/mannitol ratios were significantly increased compared with those in the control group (p<0.05). Compared with the controls, the expression of sealing claudins (claudin 3, claudin 5, and claudin 8) was significantly decreased, but that of claudin 1 was increased. The expression of pore-forming claudin 2 was upregulated and claudin 7 was downregulated in DSS-induced colitis. The epithelial apoptotic ratio was 2.8%±1.2% in controls and was significantly increased to 7.2%±1.2% in DSS-induced colitis. The expression of MBL and MASP-2 in the intestinal mucosa showed intense staining in controls, whereas there was weak staining in the rats with colitis. Conclusions There was increased intestinal permeability in DSS-induced colitis. Changes in the expression and distribution of claudins, increased epithelial apoptosis, and the MASP-2-induced immune response impaired the intestinal epithelium and contributed to high intestinal permeability. PMID:25717051

Changes in the Expression and Distribution of Claudins, Increased Epithelial Apoptosis, and a Mannan-Binding Lectin-Associated Immune Response Lead to Barrier Dysfunction in Dextran Sodium Sulfate-Induced Rat Colitis.

PubMed

Yuan, Bosi; Zhou, Shuping; Lu, Youke; Liu, Jiong; Jin, Xinxin; Wan, Haijun; Wang, Fangyu

2015-11-23

This animal study aimed to define the underlying cellular mechanisms of intestinal barrier dysfunction. Rats were fed 4% with dextran sodium sulfate (DSS) to induce experimental colitis. We analyzed the sugars in 24-hour urine output by high pressure liquid chromatography. The expression of claudins, mannan-binding lectin (MBL), and MBL-associated serine proteases 2 (MASP-2) were detected in the colonic mucosa by immunohistochemistry; and apoptotic cells in the colonic epithelium were detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method assay. The lactulose and sucralose excretion levels in the urine of rats with DSS-induced colitis were significantly higher than those in the control rats. Mannitol excretion was lower and lactulose/mannitol ratios and sucralose/mannitol ratios were significantly increased compared with those in the control group (p<0.05). Compared with the controls, the expression of sealing claudins (claudin 3, claudin 5, and claudin 8) was significantly decreased, but that of claudin 1 was increased. The expression of pore-forming claudin 2 was upregulated and claudin 7 was downregulated in DSS-induced colitis. The epithelial apoptotic ratio was 2.8%±1.2% in controls and was significantly increased to 7.2%±1.2% in DSS-induced colitis. The expression of MBL and MASP-2 in the intestinal mucosa showed intense staining in controls, whereas there was weak staining in the rats with colitis. There was increased intestinal permeability in DSS-induced colitis. Changes in the expression and distribution of claudins, increased epithelial apoptosis, and the MASP-2-induced immune response impaired the intestinal epithelium and contributed to high intestinal permeability.

Evidence for net renal tubule oxalate secretion in patients with calcium kidney stones

PubMed Central

Zisman, Anna L.; Asplin, John R.; Worcester, Elaine M.; Coe, Fredric L.

2011-01-01

Little is known about the renal handling of oxalate in patients with idiopathic hypercalciuria (IH). To explore the role of tubular oxalate handling in IH and to evaluate whether differences exist between IH and normal controls, we studied 19 IH subjects, 8 normal subjects, and 2 bariatric stone formers (BSF) during a 1-day General Clinical Research Center protocol utilizing a low-oxalate diet. Urine and blood samples were collected at 30- to 60-min intervals while subjects were fasting and after they ate three meals providing known amounts of calcium, phosphorus, sodium, protein, oxalate, and calories. Plasma oxalate concentrations and oxalate-filtered loads were similar between patients (includes IH and BSF) and controls in both the fasting and fed states. Urinary oxalate excretion was significantly higher in patients vs. controls regardless of feeding state. Fractional excretion of oxalate (FEOx) was >1, suggesting tubular secretion of oxalate, in 6 of 19 IH and both BSF, compared with none of the controls (P < 0.00001). Adjusted for water extraction along the nephron, urine oxalate rose more rapidly among patients than normal subjects with increases in plasma oxalate. Our findings identify tubular secretion of oxalate as a key mediator of hyperoxaluria in calcium stone formers, potentially as a means of maintaining plasma oxalate in a tight range. PMID:21123489

Anthropometry-based 24-h urinary creatinine excretion reference for Chinese children

PubMed Central

Wang, Wei; Du, Cong; Lin, Laixiang; Chen, Wen; Tan, Long; Shen, Jun; Pearce, Elizabeth N.; Zhang, Yixin; Gao, Min; Bian, Jianchao; Wang, Xiaoming; Zhang, Wanqi

2018-01-01

To establish 24-h urinary creatinine excretion reference ranges based on anthropometry in healthy Chinese children, a cross-sectional survey was conducted using twice-sampled 24-h urine and anthropometric variables. Age- and sex-specific 24-h creatinine excretion reference ranges (crude and related to individual anthropometric variables) were derived. During October 2013 and May 2014, urine samples were collected. Anthropometric variables were measured in the first survey. Data of 710 children (377 boys and 333 girls) aged 8–13 years who completed the study were analyzed. No significant difference was observed in 24-h urine volumes between the two samples (median [interquartile range): 855.0 [600.0–1272.0) mL vs. 900.0 [660.0–1220.0) mL, P = 0.277). The mean 24-h urine creatinine excretion was regarded as representative of absolute daily creatinine excretion in children. Sex-specific, body-weight-adjusted creatinine excretion reference values were 15.3 mg/kg/day (0.1353 mmol/kg/day) for boys and 14.3 mg/kg/day (0.1264 mmol/kg/day) for girls. Differences were significant between boys and girls within the same age group but not across different age groups within the same sex. Ideal 24-h creatinine excretion values for height were derived for potential determination of the creatinine height index. These data can serve as reference ranges to calculate ratios of analyte to creatinine. The creatinine height index can be used to assess somatic protein status. PMID:29791502

Urine alkalization facilitates uric acid excretion

PubMed Central

2010-01-01

Background Increase in the incidence of hyperuricemia associated with gout as well as hypertension, renal diseases and cardiovascular diseases has been a public health concern. We examined the possibility of facilitated excretion of uric acid by change in urine pH by managing food materials. Methods Within the framework of the Japanese government's health promotion program, we made recipes which consist of protein-rich and less vegetable-fruit food materials for H+-load (acid diet) and others composed of less protein but vegetable-fruit rich food materials (alkali diet). Healthy female students were enrolled in this consecutive 5-day study for each test. From whole-day collected urine, total volume, pH, organic acid, creatinine, uric acid and all cations (Na+,K+,Ca2+,Mg2+,NH4+) and anions (Cl-,SO42-,PO4-) necessary for the estimation of acid-base balance were measured. Results Urine pH reached a steady state 3 days after switching from ordinary daily diets to specified regimens. The amount of acid generated ([SO42-] +organic acid-gut alkai) were linearly related with those of the excretion of acid (titratable acidity+ [NH4+] - [HCO3-]), indicating that H+ in urine is generated by the metabolic degradation of food materials. Uric acid and excreted urine pH retained a linear relationship, where uric acid excretion increased from 302 mg/day at pH 5.9 to 413 mg/day at pH 6.5, despite the fact that the alkali diet contained a smaller purine load than the acid diet. Conclusion We conclude that alkalization of urine by eating nutritionally well-designed food is effective for removing uric acid from the body. PMID:20955624

Diuretic effects of medetomidine compared with xylazine in healthy dogs.

PubMed

Talukder, Md Hasanuzzaman; Hikasa, Yoshiaki

2009-07-01

This study aimed to investigate and compare the effects of medetomidine and xylazine on diuretic and hormonal variables in healthy dogs. Five dogs, used in each of 11 groups, were injected intramuscularly with physiological saline solution (control), 5, 10, 20, 40, and 80 microg/kg of medetomidine, and 0.25, 0.5, 1, 2, and 4 mg/kg of xylazine. Urine and blood samples were taken 11 times over 24 h. Both medetomidine and xylazine increased urine production in a dose-dependent manner up to 4 h after injection, but the increase was much less with medetomidine than with xylazine at the tested doses. Urine specific gravity, pH, osmolality, and concentrations of creatinine, sodium, potassium, chloride, and arginine vasopressin (AVP) were decreased in a dose-dependent manner with both medetomidine and xylazine. Plasma osmolality and concentrations of sodium, potassium, and chloride were increased significantly with both drugs. Total amounts of urine AVP excreted and plasma AVP concentrations were significantly decreased by higher doses of medetomidine but were not significantly decreased by xylazine. Higher doses of both drugs significantly increased the plasma concentration of atrial natriuretic peptide (ANP), but the effect was greater with medetomidine than with xylazine. The results revealed that both drugs induce a profound diuresis, but medetomidine's effect is less dose-dependent than xylazine's effect. Although changes in plasma concentrations of AVP and ANP may partially influence the diuresis induced by medetomidine, other factors may be involved in the mechanism of the diuretic response to both drugs. Thus, both agents can be used clinically for transient but effective diuresis accompanied by sedation.

Development and Validation of a UPLC-MS/MS Method to Monitor Cephapirin Excretion in Dairy Cows following Intramammary Infusion

PubMed Central

Ray, Partha; Knowlton, Katharine F.; Shang, Chao; Xia, Kang

2014-01-01

Cephapirin, a cephalosporin antibiotic, is used by the majority of dairy farms in the US. Fecal and urinary excretion of cephapirin could introduce this compound into the environment when manure is land applied as fertilizer, and may cause development of bacterial resistance to antibiotics critical for human health. The environmental loading of cephapirin by the livestock industry remains un-assessed, largely due to a lack of appropriate analytical methods. Therefore, this study aimed to develop and validate a cephapirin quantification method to capture the temporal pattern of cephapirin excretion in dairy cows following intramammary infusion. The method includes an extraction with phosphate buffer and methanol, solid-phase extraction (SPE) clean-up, and quantification using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The LOQ values of the developed method were 4.02 µg kg−1 and 0.96 µg L−1 for feces and urine, respectively. This robust method recovered >60% and >80% cephapirin from spiked blank fecal and urine samples, respectively, with acceptable intra- and inter-day variation (<10%). Using this method, we detected trace amounts (µg kg−1) of cephapirin in dairy cow feces, and cephapirin in urine was detected at very high concentrations (133 to 480 µg L−1). Cephapirin was primarily excreted via urine and its urinary excretion was influenced by day (P = 0.03). Peak excretion (2.69 mg) was on day 1 following intramammary infusion and decreased sharply thereafter (0.19, 0.19, 0.08, and 0.17 mg on day 2, 3, 4, and 5, respectively) reflecting a quadratic pattern of excretion (Quadratic: P = 0.03). The described method for quantification of cephapirin in bovine feces and urine is sensitive, accurate, and robust and allowed to monitor the pattern of cephapirin excretion in dairy cows. This data will help develop manure segregation and treatment methods to minimize the risk of antibiotic loading to the environment from dairy farms. PMID:25375097

The effect of tolvaptan on renal excretion of electrolytes and urea nitrogen in patients undergoing coronary artery bypass surgery.

PubMed

Kato, Tomoko S; Nakamura, Hiroshi; Murata, Mai; Kuroda, Kishio; Suzuki, Hitoshi; Yokoyama, Yasutaka; Shimada, Akie; Matsushita, Satoshi; Yamamoto, Taira; Amano, Atsushi

2016-09-13

Adequate fluid management is an important component of patient care following cardiac surgery. Our aim in this study was to determine the benefits of tolvaptan, an oral selective vasopressin-2 receptor antagonist that causes electrolyte-free water diuresis, in postoperative fluid management. We prospectively examined the effect of tolvaptan on renal excretion of electrolytes and urea nitrogen in cardiac surgery patients. Patients undergoing coronary artery bypass surgery were randomized to receive conventional loop diuretics (Group C, n = 30) or conventional loop diuretic therapy plus tolvaptan (Group T, n = 27). Fractional excretions of sodium (FENA), potassium (FEK) and urea nitrogen (FEUN) were measured in both groups during post-surgical hospitalization. Urine output was greater with tolvaptan (Group T) than without it (Group C), and some patients in Group C required intravenous as well as oral loop diuretics. Serum sodium concentrations decreased after surgery in Group C, but were unchanged in Group T (postoperative day [POD] 3, 139.8 ± 3.5 vs. 142.3 ± 2.6 mEq/L, p = 0.006). However, postoperative FENA values in Group C did not decrease, and the values were similar in both groups. Serum potassium levels remained lower and FEK values remained higher than the preoperative values, but only in Group C (all p < 0.05). BUN increased postoperatively in both groups, but it remained higher than its preoperative value only in Group C (all p < 0.01). Group T showed an initial increase in BUN, which peaked and then returned to its preoperative value within a week. The FEUN increased postoperatively in both groups, but the change was more pronounced in Group T (POD7, 52.7 ± 9.3 vs. 58.2 ± 6.5 %, p = 0.025). Renal excretion of sodium and potassium reflects the changes in serum concentration in patients treated with tolvaptan. Patients treated only with loop diuretics showed a continuous excretion of sodium and potassium that led to electrolyte imbalance, whereas the combination of loop diuretics and tolvaptan increased renal urea nitrogen elimination. Tolvaptan therefore appears to be an effective diuretic that minimally affects serum electrolytes while adequately promoting the elimination of urea nitrogen from the kidneys in patients undergoing coronary artery bypass surgery. The present study is registered with the UMIN Clinical Trials Registry (ID: UMIN000011039 ).

Idiopathic hypercalciuria and formation of calcium renal stones

PubMed Central

Coe, Fredric L.; Worcester, Elaine M.; Evan, Andrew P.

2018-01-01

The most common presentation of nephrolithiasis is idiopathic calcium stones in patients without systemic disease. Most stones are primarily composed of calcium oxalate and form on a base of interstitial apatite deposits, known as Randall’s plaque. By contrast some stones are composed largely of calcium phosphate, as either hydroxyapatite or brushite (calcium monohydrogen phosphate), and are usually accompanied by deposits of calcium phosphate in the Bellini ducts. These deposits result in local tissue damage and might serve as a site of mineral overgrowth. Stone formation is driven by supersaturation of urine with calcium oxalate and brushite. The level of supersaturation is related to fluid intake as well as to the levels of urinary citrate and calcium. Risk of stone formation is increased when urine citrate excretion is <400 mg per day, and treatment with potassium citrate has been used to prevent stones. Urine calcium levels >200 mg per day also increase stone risk and often result in negative calcium balance. Reduced renal calcium reabsorption has a role in idiopathic hypercalciuria. Low sodium diets and thiazide-type diuretics lower urine calcium levels and potentially reduce the risk of stone recurrence and bone diseas PMID:27452364

Effects of positive acceleration /+Gz/ on renal function and plasma renin in normal man

NASA Technical Reports Server (NTRS)

Epstein, M.; Shubrooks, S. J., Jr.; Fishman, L. M.; Duncan, D. C.

1974-01-01

The effects of positive radial centrifugation (+Gz) on plasma resin activity (PRA) and renal function were assessed in 15 normal male subjects under carefully controlled conditions of Na, K, and water intake. Twenty minutes of +2.0 Gz resulted in significant decreases in the mean rate of sodium excretion and creatine clearance and in a doubling of PRA in seven sodium-depleted subjects (10 meq Na intake). In eight sodium-replete subjects (200 mq Na intake), 30 min of +2.0 Gz was also associated with a decrease in the mean rate of sodium excretion. As a consequence of a concurrent decrease in creatine clearance, the fractional excretion of sodium during centrifugation did not differ from control, suggesting that the changes in Na excretion were mediated primarily by renal hemodynamic factors, although enhanced renal tubular sodium reabsorption may also have played a role.

Diet effects on urine composition of cattle and N2O emissions.

PubMed

Dijkstra, J; Oenema, O; van Groenigen, J W; Spek, J W; van Vuuren, A M; Bannink, A

2013-06-01

Ruminant production contributes to emissions of nitrogen (N) to the environment, principally ammonia (NH3), nitrous oxide (N2O) and di-nitrogen (N2) to air, nitrate (NO3 -) to groundwater and particulate N to surface waters. Variation in dietary N intake will particularly affect excretion of urinary N, which is much more vulnerable to losses than is faecal N. Our objective is to review dietary effects on the level and form of N excreted in cattle urine, as well as its consequences for emissions of N2O. The quantity of N excreted in urine varies widely. Urinary N excretion, in particular that of urea N, is decreased upon reduction of dietary N intake or an increase in the supply of energy to the rumen microorganisms and to the host animal itself. Most of the N in urine (from 50% to well over 90%) is present in the form of urea. Other nitrogenous components include purine derivatives (PD), hippuric acid, creatine and creatinine. Excretion of PD is related to rumen microbial protein synthesis, and that of hippuric acid to dietary concentration of degradable phenolic acids. The N concentration of cattle urine ranges from 3 to 20 g/l. High-dietary mineral levels increase urine volume and lead to reduced urinary N concentration as well as reduced urea concentration in plasma and milk. In lactating dairy cattle, variation in urine volume affects the relationship between milk urea and urinary N excretion, which hampers the use of milk urea as an accurate indicator of urinary N excretion. Following its deposition in pastures or in animal houses, ubiquitous microorganisms in soil and waters transform urinary N components into ammonium (NH4 +), and thereafter into NO3 - and ultimately in N2 accompanied with the release of N2O. Urinary hippuric acid, creatine and creatinine decompose more slowly than urea. Hippuric acid may act as a natural inhibitor of N2O emissions, but inhibition conditions have not been defined properly yet. Environmental and soil conditions at the site of urine deposition or manure application strongly influence N2O release. Major dietary strategies to mitigating N2O emission from cattle operations include reducing dietary N content or increasing energy content, and increasing dietary mineral content to increase urine volume. For further reduction of N2O emission, an integrated animal nutrition and excreta management approach is required.

Ability of self-reported estimates of dietary sodium, potassium and protein to detect an association with general and abdominal obesity: comparison with the estimates derived from 24 h urinary excretion.

PubMed

Murakami, Kentaro; Livingstone, M Barbara E; Sasaki, Satoshi; Uenishi, Kazuhiro

2015-04-28

As under-reporting of dietary intake, particularly by overweight and obese subjects, is common in dietary surveys, biases inherent in the use of self-reported dietary information may distort true diet-obesity relationships or even create spurious ones. However, empirical evidence of this possibility is limited. The present cross-sectional study compared the relationships of 24 h urine-derived and self-reported intakes of Na, K and protein with obesity. A total of 1043 Japanese women aged 18-22 years completed a 24 h urine collection and a self-administered diet history questionnaire. After adjustment for potential confounders, 24 h urine-derived Na intake was associated with a higher risk of general obesity (BMI≥25 kg/m2) and abdominal obesity (waist circumference≥80 cm; both P for trend=0·04). For 24 h urine-derived protein intake, positive associations with general and abdominal obesity were observed (P for trend=0·02 and 0·053, respectively). For 24 h urine-derived K intake, there was an inverse association with abdominal obesity (P for trend=0·01). Conversely, when self-reported dietary information was used, only inverse associations between K intake and general and abdominal obesity were observed (P for trend=0·04 and 0·02, respectively), with no associations of Na or protein intake. In conclusion, we found positive associations of Na and protein intakes and inverse associations of K intake with obesity when using 24 h urinary excretion for estimating dietary intakes. However, no association was observed based on using self-reported dietary intakes, except for inverse association of K intake, suggesting that the ability of self-reported dietary information using the diet history questionnaire for investigating diet-obesity relationships is limited.

Urinary Neutrophil Gelatinase-associated Lipocalin in the evaluation of Patent Ductus Arteriosus and AKI in Very Preterm Neonates: a cohort study.

PubMed

Sellmer, Anna; Bech, Bodil H; Bjerre, Jesper V; Schmidt, Michael R; Hjortdal, Vibeke E; Esberg, Gitte; Rittig, Søren; Henriksen, Tine B

2017-01-10

A patent ductus arteriosus (PDA) is frequently found in very preterm neonates and is associated with increased risk of morbidity and mortality. A shunt across a PDA can result in an unfavorable distribution of the cardiac output and may in turn result in poor renal perfusion. Urinary Neutrophil Gelatinase-associated Lipocalin (U-NGAL) is a marker of renal ischemia and may add to the evaluation of PDA. Our primary aim was to investigate if U-NGAL is associated with PDA in very preterm neonates. Secondary, to investigate whether U-NGAL and PDA are associated with AKI and renal dysfunction evaluated by fractional excretion of sodium (FENa) and urine albumin in a cohort of very preterm neonates. A cohort of 146 neonates born at a gestational age less than 32 weeks were consecutively examined with echocardiography for PDA and serum sodium, and urine albumin and sodium were measured on postnatal day 3 and U-NGAL and serum creatinine day 3 and 6. AKI was defined according to modified neonatal Acute Kidney Injury Network (AKIN) criteria. The association between U-NGAL and PDA was investigated. And secondly we investigated if PDA and U-NGAL was associated with AKI and renal dysfunction. U-NGAL was not associated with a PDA day 3 when adjusted for gestational age and gender. A PDA day 3 was not associated with AKI when adjusted for gestational age and gender; however, it was associated with urine albumin. U-NGAL was not associated with AKI, but was found to be associated with urine albumin and FENa. Based on our study U-NGAL is not considered useful as a diagnostic marker to identify very preterm neonates with a PDA causing hemodynamic changes resulting in early renal morbidity. The interpretation of NGAL in preterm neonates remains to be fully elucidated.

24-hour urinary aldosterone excretion test

MedlinePlus

Aldosterone - urine; Addison disease - urine aldosterone; Cirrhosis - serum aldosterone ... A 24-hour urine sample is needed. You will need to collect your urine over 24 hours . Your health care provider will tell ...

Dietary sodium intake and the risk of airway hyperreactivity in a random adult population.

PubMed Central

Britton, J.; Pavord, I.; Richards, K.; Knox, A.; Wisniewski, A.; Weiss, S.; Tattersfield, A.

1994-01-01

BACKGROUND--High dietary sodium intake has been identified as a potential cause of asthma and airway hyperreactivity. This study was designed to test the hypothesis that dietary sodium intake is an independent determinant of the risk of hyperreactivity in the general population, and to assess the role of atopy in the association between these factors. METHODS--Airway reactivity to methacholine, atopy, 24 hour urinary sodium excretion, and self-reported smoking and symptom history were measured in a random sample of 1702 adults aged 18-70 from an administrative district of Nottingham. Hyperreactivity was defined as a PD20FEV1 of 12.25 mumol or less, and atopy was defined quantitatively as the mean allergen skin weal response to Dermatophagoides pteronyssinus, cat fur, and grass pollen, and categorically as the occurrence of any allergen response 1 mm or greater than the saline control. Multiple logistic regression analysis was used to estimate the independent relative odds of hyperreactivity, atopy, or symptoms in relation to sodium excretion in all 1702 subjects, and multiple linear regression to assess the independent relation between sodium excretion and mean allergen skin weal diameter, and the PD20 value amongst hyperreactive subjects. RESULTS--There was no relation between the relative odds of hyperreactivity to methacholine and 24 hour urinary sodium excretion, either before or after adjustment for age, smoking, allergen skin weal diameter, and sex, and similarly no relation if the analysis was restricted to men or women only. The relative odds of having at least one allergen skin test response 1 mm greater than the saline control were increased in relation to sodium excretion after adjustment for age, sex, and smoking by a ratio of 2.08 (95% CI 1.04 to 4.15) per log10 unit increase in sodium excretion, but there was no evidence of an association between sodium excretion and the occurrence of self-reported wheeze, hay fever, eczema, or asthma. There was no relation between 24 hour sodium excretion and the magnitude of the mean allergen skin weal response or the PD20 value. CONCLUSIONS--These findings do not support the hypothesis that a high dietary sodium intake is a risk factor for airway hyperreactivity or atopic disease in the general adult population. PMID:7940426

AT₁ receptor and NAD(P)H oxidase mediate angiotensin II-stimulated antioxidant enzymes and mitogen-activated protein kinase activity in the rat hypothalamus.

PubMed

Silva, José; Pastorello, Mariella; Arzola, Jorge; Zavala, Lida E; De Jesús, Sara; Varela, Maider; Matos, María Gabriela; del Rosario Garrido, María; Israel, Anita

2010-12-01

Angiotensin II (AngII) regulates blood pressure and water and electrolyte metabolism through the stimulation of NAD(P)H oxidase and production of reactive oxygen species (ROS) such as O₂⁻, which is metabolised by superoxide dismutase, catalase and glutathione peroxidase. We assessed the role of AT₁ and AT₂ receptors, NAD(P)H oxidase and protein kinase C (PKC) in Ang II-induced sodium and water excretion and their capacity to stimulate antioxidant enzymes in the rat hypothalamus, a brain structure known to express a high density of AngII receptors. Male Sprague-Dawley rats were intracerebroventricularly (ICV) injected with AngII and urinary sodium and water excretion was assessed. Urine sodium concentration was determined using flame photometry. After decapitation the hypothalamus was microdissected under stereomicroscopic control. Superoxide dismutase, catalase and glutathione peroxidase activity were determined spectrophotometrically and extracellular signal-regulated kinase (ERK1/2) activation was analysed by Western blot. AngII-ICV resulted in antidiuresis and natriuresis. ICV administration of losartan, PD123319, apocynin and chelerythrine blunted natriuresis. In hypothalamus, AngII increased catalase, superoxide dismutase and glutation peroxidase activity and ERK1/2 phosphorylation. These actions were prevented by losartan, apocynin and chelerythrine, and increased by PD123319. AT₁ and AT₂ receptors, NAD(P)H oxidase and PKC pathway are involved in the regulation of hydromineral metabolism and antioxidant enzyme activity induced by AngII.

Magnesium, zinc, arsenic, selenium and platinum urinary excretion from cancer patients of Antofagasta region, Chile: multi-metal approach

PubMed Central

Pizarro, I; Rivera, L; Ávila, J; Cortés, P

2016-01-01

Objectives To evaluate the short-term 24 h urinary excretion of platinum, arsenic, selenium, magnesium and zinc in patients with lung cancer and with cancer other than lungs treated with cisplatin or/and carboplatin from Antofagasta, Chile. Design Urine measurements of Pt and Se were made by inductively coupled plasma optical emission spectrometry, As by hydride-generation atomic absorption spectrometry and Mg and Zn by means of flame furnace atomic absorption spectrometry. Setting All samples were provided by the Oncological Centre of Antofagasta Regional Hospital (Region of Antofagasta, Chile). Participants Ninety 24-h urine samples from cancer patients after the infusion of Pt-base drugs and 10 24-h urine samples from cancer patients not treated with metal-base drugs. Main outcome measures Concentrations of Pt, Se, As, Zn and Mg coming from 24-h urine samples. Results Pt excreted was not significantly different between patients with lung and other cancers treated with cisplatin. The excretion of Mg, Zn and Se was greater than As. Then, Pt favours the excretion of essential elements. For lung and other types of cancers treated with drugs without Pt, excretion of Mg, Zn and Se was also greater than that of As, suggesting antagonism Mg-Zn-Se–anti-cancer drug relationship. Conclusions The amounts of Mg, Zn and Se excreted were greater than for As either with or without Pt-containing drugs, suggesting antagonist Mg-Zn-Se–anti-cancer drug relationships. The excretion of As, Mg, Zn and Se is induced by Pt. Knowledge obtained can contribute to understanding the arsenic cancer mechanism and the As-Mg-Zn-Se-Pt inter-element association for lung cancer and other types of cancer. PMID:27757244

Modifiable factors associated with copeptin concentration: a general population cohort.

PubMed

van Gastel, Maatje D A; Meijer, Esther; Scheven, Lieneke E; Struck, Joachim; Bakker, Stephan J L; Gansevoort, Ron T

2015-05-01

Vasopressin plays an important role in maintaining volume homeostasis. However, recent studies suggest that vasopressin also may play a detrimental role in the progression of chronic kidney disease. It therefore is of interest to identify factors that influence vasopressin concentration, particularly modifiable ones. Cross-sectional analyses. Data used are from participants in a large general-population cohort study (Prevention of Renal and Vascular Endstage Disease [PREVEND]). Patients with a missing copeptin value (n=888), nonfasting blood sample (n=495), missing or assumed incorrect 24-hour urine collection (n=388), or heart failure (n=20) were excluded, leaving 6,801 participants for analysis. Identification of lifestyle- and diet-related factors that are associated with copeptin concentration. Copeptin concentration as surrogate for vasopressin. Copeptin was measured by an immunoluminometric assay as a surrogate for vasopressin. Associations were assessed in uni- and multivariable linear regression analyses. Median copeptin concentration was 4.7 (IQR, 2.9-7.6) pmol/L. When copeptin was studied as a dependent variable, the final stepwise backward model revealed associations with higher copeptin concentrations for lower 24-hour urine volume (P < 0.001), higher sodium excretion (P < 0.001), higher systolic blood pressure (P < 0.001), current smoking (P < 0.001), higher alcohol use (P < 0.001), higher urea excretion (P = 0.003), lower potassium excretion (P = 0.002), use of glucose-lowering drugs (P = 0.02), higher body mass index (P < 0.001), and higher plasma glucose level (P < 0.001). No associations with copeptin concentration were found for C-reactive protein or use of diuretics or nondiuretic antihypertensives. The cross-sectional study design does not allow firm conclusions on cause-effect relationships. Important lifestyle- and diet-related factors associated with copeptin concentration are current smoking, alcohol use, protein and potassium intake, and particularly fluid and sodium intake. These data form a rationale to investigate whether intervening on these factors results in a lower vasopressin concentration with concomitant beneficial renal effects. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Global, regional and national sodium intakes in 1990 and 2010: a systematic analysis of 24 h urinary sodium excretion and dietary surveys worldwide

PubMed Central

Powles, John; Fahimi, Saman; Micha, Renata; Khatibzadeh, Shahab; Shi, Peilin; Ezzati, Majid; Engell, Rebecca E; Lim, Stephen S; Danaei, Goodarz; Mozaffarian, Dariush

2013-01-01

Objectives To estimate global, regional (21 regions) and national (187 countries) sodium intakes in adults in 1990 and 2010. Design Bayesian hierarchical modelling using all identifiable primary sources. Data sources and eligibility We searched and obtained published and unpublished data from 142 surveys of 24 h urinary sodium and 103 of dietary sodium conducted between 1980 and 2010 across 66 countries. Dietary estimates were converted to urine equivalents based on 79 pairs of dual measurements. Modelling methods Bayesian hierarchical modelling used survey data and their characteristics to estimate mean sodium intake, by sex, 5 years age group and associated uncertainty for persons aged 20+ in 187 countries in 1990 and 2010. Country-level covariates were national income/person and composition of food supplies. Main outcome measures Mean sodium intake (g/day) as estimable by 24 h urine collections, without adjustment for non-urinary losses. Results In 2010, global mean sodium intake was 3.95 g/day (95% uncertainty interval: 3.89 to 4.01). This was nearly twice the WHO recommended limit of 2 g/day and equivalent to 10.06 (9.88–10.21) g/day of salt. Intake in men was ∼10% higher than in women; differences by age were small. Intakes were highest in East Asia, Central Asia and Eastern Europe (mean >4.2 g/day) and in Central Europe and Middle East/North Africa (3.9–4.2 g/day). Regional mean intakes in North America, Western Europe and Australia/New Zealand ranged from 3.4 to 3.8 g/day. Intakes were lower (<3.3 g/day), but more uncertain, in sub-Saharan Africa and Latin America. Between 1990 and 2010, modest, but uncertain, increases in sodium intakes were identified. Conclusions Sodium intakes exceed the recommended levels in almost all countries with small differences by age and sex. Virtually all populations would benefit from sodium reduction, supported by enhanced surveillance. PMID:24366578

Pharmacokinetics of colistin and colistimethate sodium after a single 80-mg intravenous dose of CMS in young healthy volunteers.

PubMed

Couet, W; Grégoire, N; Gobin, P; Saulnier, P J; Frasca, D; Marchand, S; Mimoz, O

2011-06-01

Colistin pharmacokinetics (PK) was investigated in young healthy volunteers after a 1-h infusion of 80 mg (1 million international units (MIU)) of the prodrug colistin methanesulfonate (CMS). Concentration levels of CMS and colistin were determined in plasma and urine using a new chromatographic assay and analyzed simultaneously with a population approach after correcting the urine-related data for postexcretion hydrolysis of CMS into colistin. CMS and colistin have low volumes of distribution (14.0 and 12.4 liters, respectively), consistent with distribution being restricted to extracellular fluid. CMS is mainly excreted unchanged in urine (70% on average), with a typical renal clearance estimated at 103 ml/min-close to the glomerular filtration rate. Colistin elimination is essentially extrarenal, given that its renal clearance is 1.9 ml/min, consistent with extensive reabsorption. Colistin elimination is not limited by the formation rate because its half-life (3 h) is longer than that of CMS. The values of these pharmacokinetic parameters will serve as reference points for future comparisons with patients' data.

Metabolism study of boldenone in human urine by gas chromatography-tandem mass spectrometry.

PubMed

Wu, Xinchen; Gao, Feng; Zhang, Wenxin; Ni, Jian

2015-11-10

Boldenone (BOLD), an anabolic steroid, is likely to be abused in livestock breeding and in sports. Although some of BOLD metabolites in human urine, such as 5β-adrost-1-en-17β-ol-3-one (BM1), have been detected, investigations on their excretion patterns for both genders are insufficient. Moreover, little research on 17α-BOLD glucuronide as a metabolite in human urine has been reported. The aim of this study is to make a contribution to the knowledge of 17β-BOLD metabolism in humans. Three male and three female volunteers were orally administrated with 30mg 17β-BOLD. Urine samples were collected and analyzed with gas chromatography-tandem mass spectrometry. The data proved that 17β-BOLD, BM1, and 17α-BOLD were excreted in urine in both free and glucuronic conjugated forms after administration of 17β-BOLD. For most subjects, the urinary concentrations of BM1 were higher than that of 17β-BOLD. 17α-BOLD was excreted in small amounts. 17α-BOLD, 17β-BOLD, and BM1 were present naturally in urine with low concentrations. Administration of 30mg 17β-BOLD could not influence the excretion profiles of urinary androsterone, etiocholanolone, and testosterone/epitestosterone ratio. There were no differences in BOLD metabolic patterns between man and woman. Copyright © 2015 Elsevier B.V. All rights reserved.

Histopathological changes of renal tissue following sodium fluoride administration in two consecutive generations of mice. Correlation with the urinary elimination of fluoride.

PubMed

Dimcevici Poesina, Nicoleta; Bălălău, Cristian; Nimigean, Vanda Roxana; Nimigean, Victor; Ion, Ion; Baconi, Daniela; Bârcă, Maria; Băran Poesina, Violeta

2014-01-01

The present study was designed to investigate the toxic effects (evaluated as histopathological changes) of sodium fluoride on the kidney in two consecutive generations of NMRI mice. An attempt to correlate the toxicity with the urinary elimination of fluoride has been made, as urinary fluoride excretion has been widely used as an indicator of fluoride intake and exposure. Six mixed (males and females) animal groups have been constituted by dividing the populations of mice derived from pregnant females (named "mothers" 0.5 mg sodium fluoride) treated with 0.5 mg sodium fluoride by daily gavage and pregnant females (named "mothers" 0.25 mg sodium fluoride) treated with 0.25 mg sodium fluoride by daily gavage; three types of sodium fluoride treatments were administrated: homeopathic, allopathic-homeopathic and allopathic. When the animals reached the adulthood, by randomization, they were selected in pairs for giving birth to the second generation of mice. No treatments were administrated to the second generation of mice; thus, the urinary elimination of fluoride in the second generation is attributed to exposure at sodium fluoride before birth. The administration of sodium fluoride to the first generation (F1) is realized until the mice reached the adulthood. For the first generation, the urine was collected at three times, every three weeks: at the age of four weeks, seven weeks and 11 weeks; single sampling urine, at the age of four weeks, has been conducted for the second generation. The urine samples have been analyzed using the ion selective electrode method for fluoride. For the histopathological examination, the animals were killed by cervical dislocation; the kidneys were collected in a 10% formalin solution. The preparation of samples for optical microscopy was realized with Hematoxylin-Eosin staining. The results indicate that the elimination of fluoride was similar (at the second evaluation, at 7-week-old of the first generation) for the both generations of mice. Histopathological observation of the kidney has revealed granular dystrophy of the renal tubules, necrosis of the endothelial cells and of the mesangial cells of renal glomerulus. The study indicates that different sodium fluoride treatments produce some pathological aspects of the kidneys and influence the urinary elimination of fluoride in two consecutive generations of mice. For the higher doses, the pathological changes of the kidney are more important, and the urinary elimination of fluoride is higher, especially for the allopathic doses.

Association of urinary citrate with acid-base status, bone resorption, and calcium excretion in older men and women

USDA-ARS?s Scientific Manuscript database

Context: Elevated urine net acid excretion (NAE), indicative of subclinical metabolic acidosis, has been associated with higher bone turnover. While NAE is the gold-standard clinical measure of acid-base status, it is impractical to measure in most clinical/research settings. Urine citrate, which is...

Animal models of Central Diabetes Insipidus: Human relevance of acquired beyond hereditary syndromes and the role of oxytocin.

PubMed

Bernal, Antonio; Mahía, Javier; Puerto, Amadeo

2016-07-01

The aim of this study was to review different animal models of Central Diabetes Insipidus, a neurobiological syndrome characterized by the excretion of copious amounts of diluted urine (polyuria), a consequent water intake (polydipsia), and a rise in the serum sodium concentration (hypernatremia). In rodents, Central Diabetes Insipidus can be caused by genetic disorders (Brattleboro rats) but also by various traumatic/surgical interventions, including neurohypophysectomy, pituitary stalk compression, hypophysectomy, and median eminence lesions. Regardless of its etiology, Central Diabetes Insipidus affects the neuroendocrine system that secretes arginine vasopressin, a neurohormone responsible for antidiuretic functions that acts trough the renal system. However, most Central Diabetes Insipidus models also show disorders in other neurobiological systems, specifically in the secretion of oxytocin, a neurohormone involved in body sodium excretion. Although the hydromineral behaviors shown by the different Central Diabetes Insipidus models have usually been considered as very similar, the present review highlights relevant differences with respect to these behaviors as a function of the individual neurobiological systems affected. Increased understanding of the relationship between the neuroendocrine systems involved and the associated hydromineral behaviors may allow appropriate action to be taken to correct these behavioral neuroendocrine deficits. Copyright © 2016 Elsevier Ltd. All rights reserved.

Acute Pharmacodynamic Effects of Empagliflozin With and Without Diuretic Agents in Patients With Type 2 Diabetes Mellitus.

PubMed

Heise, Tim; Jordan, Jens; Wanner, Christoph; Heer, Martina; Macha, Sreeraj; Mattheus, Michaela; Lund, Søren S; Woerle, Hans J; Broedl, Uli C

2016-10-01

The goal of this study was to investigate the pharmacodynamic effects of co-administration of empagliflozin, a sodium glucose cotransporter 2 inhibitor, with diuretic agents. In a randomized, open-label cross-over study, 22 patients with type 2 diabetes mellitus received empagliflozin 25 mg for 5 days and either hydrochlorothiazide 25 mg for 4 days followed by hydrochlorothiazide 25 mg plus empagliflozin 25 mg for 5 days, or torasemide 5 mg for 4 days followed by torasemide 5 mg plus empagliflozin 25 mg for 5 days; 20 completed treatment. Food, fluid, and sodium intake were standardized for 3 days before and during treatment. At baseline, the median age of the treated patients was 56 years (range, 40-65 years), body mass index was 26.8 kg/m 2 (range, 20.1-34.4 kg/m 2 ), fasting plasma glucose was 8.6 mmol/L (range, 6.0-12.9 mmol/L), and glycosylated hemoglobin level was 7.6% (range, 7%-10%). Empagliflozin significantly increased 24-hour urinary glucose excretion and reduced fasting serum glucose levels. These effects were maintained after co-administration with either diuretic. Urinary sodium excretion did not significantly change with empagliflozin or diuretic administration alone, but seemed to increase compared with either diuretic alone when empagliflozin was co-administered with either diuretic. Plasma renin and serum aldosterone levels were unaltered with empagliflozin or torasemide alone, but tended to increase with hydrochlorothiazide alone, and tended to increase when empagliflozin was co-administered with a diuretic compared with either diuretic alone. Urinary volume did not increase with empagliflozin or diuretics alone, but increased when empagliflozin was co-administered with either diuretic. Empagliflozin alone for 5 days increased urinary glucose excretion but did not seem to have a relevant impact on urine volume or electrolytes. When empagliflozin was co-administered with a diuretic agent, urinary glucose excretion remained increased, and the renin-angiotensin system was activated. Clinicaltrials.gov identifier: NCT01276288. Copyright © 2016 Elsevier HS Journals, Inc. All rights reserved.

Metabolic syndrome and renal sodium handling in three ethnic groups living in England.

PubMed

Barbato, A; Cappuccio, F P; Folkerd, E J; Strazzullo, P; Sampson, B; Cook, D G; Alberti, K G M M

2004-01-01

Increased proximal renal sodium re-absorption is associated with central adiposity and insulin resistance in white men. Our study examined whether this association also exists in other ethnic groups with different prevalences of insulin resistance and associated metabolic abnormalities. We studied the association between fractional renal excretion of endogenous lithium (FELi) and metabolic syndrome in a population study of 1190 randomly selected men and women who where 40 to 59 years of age (426 white, 397 of African and 367 of South Asian origin). Anthropometric values, blood pressure, biochemical values, questionnaire data and timed urine collections were obtained with standardised techniques. Endogenous lithium in serum and urine was measured by absorption spectrophotometry. Metabolic markers were the homeostasis model assessment (HOMA) index, waist circumference, serum triglycerides, serum HDL cholesterol and metabolic syndrome as defined by Adult Treatment Panel III criteria. In white men and women a higher rate of proximal sodium re-absorption was inversely associated with higher waist circumference, serum triglycerides and HOMA index, and with lower serum HDL cholesterol (all p< or =0.001). No associations were found in people of African or South Asian origin. The former had lower FELi than the other groups. White people with the metabolic syndrome had a lower FELi than those without (15.9% vs 19.0%; p=0.003). No difference was found in people of African or South Asian origin. Increased proximal sodium re-absorption is associated with the metabolic syndrome in white men and women. This relationship is not seen in people of African or South Asian origin, despite a greater degree of insulin resistance.

Sodium and potassium content of 24 h urinary collections: a comparison between field- and laboratory-based analysers.

PubMed

Yin, Xuejun; Neal, Bruce; Tian, Maoyi; Li, Zhifang; Petersen, Kristina; Komatsu, Yuichiro; Feng, Xiangxian; Wu, Yangfeng

2018-04-01

Measurement of mean population Na and K intakes typically uses laboratory-based assays, which can add significant logistical burden and costs. A valid field-based measurement method would be a significant advance. In the current study, we used 24 h urine samples to compare estimates of Na, K and Na:K ratio based upon assays done using the field-based Horiba twin meter v. laboratory-based methods. The performance of the Horiba twin meter was determined by comparing field-based estimates of mean Na and K against those obtained using laboratory-based methods. The reported 95 % limits of agreement of Bland-Altman plots were calculated based on a regression approach for non-uniform differences. The 24 h urine samples were collected as part of an ongoing study being done in rural China. One hundred and sixty-six complete 24 h urine samples were qualified for estimating 24 h urinary Na and K excretion. Mean Na and K excretion were estimated as 170·4 and 37·4 mmol/d, respectively, using the meter-based assays; and 193·4 and 43·8 mmol/d, respectively, using the laboratory-based assays. There was excellent relative reliability (intraclass correlation coefficient) for both Na (0·986) and K (0·986). Bland-Altman plots showed moderate-to-good agreement between the two methods. Na and K intake estimations were moderately underestimated using assays based upon the Horiba twin meter. Compared with standard laboratory-based methods, the portable device was more practical and convenient.

Ethnicity is important for creatinine excretion among Inuit and Caucasians in Greenland.

PubMed

Andersen, Stig; Dehnfeld, Marie; Laurberg, Peter

2015-01-01

Human nutrition, contamination and renal function are commonly assessed by the analysis of urine. A complete 24-hour urine sample is the ideal but it is inconvenient and unreliable. Thus, spot urine sampling with creatinine adjustment is widely used. Stratification for age and gender is recommended. Still, ethnicity may influence creatinine excretion. We collected 104 24-h urine samples among Inuit and non-Inuit living in Greenland. Completeness of sampling was checked by using para-amino benzoic acid (PABA) that also allowed for compensation of creatinine excretion when sampling was incomplete. We measured creatinine using the Jaffe method and PABA by the HPLC method. Participants were recruited from the capital city, a major town and a settlement (n = 36/48/20). They were aged 30-69 years with 78 Inuit and 26 non-Inuit. Inuit were smaller than non-Inuit (Caucasians): height, 163 vs. 177 cm, p < 0.001; weight, 71 vs. 84 kg, p = 0.001 with similar BMI. Creatinine excretion was lower in Inuit compared to non-Inuit (men, 1344/1807 mg/24 h; women 894/1259 mg/24 h; p = 0.002; 0.02). It was influenced by age (p < 0.001), gender (p < 0.001), weight (p = 0.001) and ethnicity (p = 0.030) while not by the intake of the protein-rich Inuit diet in the adjusted analysis. Creatinine excretion was described by: Inuit men, 1925 mg - (13.1 × age); Inuit women, 1701 mg - (17.0 × age). Inuit and Caucasians have different creatinine excretion. It is recommended to stratify by ethnicity in addition to adjustment for age and gender when using creatinine correction of spot urine samples.

Whole body acid-base modeling revisited.

PubMed

Ring, Troels; Nielsen, Søren

2017-04-01

The textbook account of whole body acid-base balance in terms of endogenous acid production, renal net acid excretion, and gastrointestinal alkali absorption, which is the only comprehensive model around, has never been applied in clinical practice or been formally validated. To improve understanding of acid-base modeling, we managed to write up this conventional model as an expression solely on urine chemistry. Renal net acid excretion and endogenous acid production were already formulated in terms of urine chemistry, and we could from the literature also see gastrointestinal alkali absorption in terms of urine excretions. With a few assumptions it was possible to see that this expression of net acid balance was arithmetically identical to minus urine charge, whereby under the development of acidosis, urine was predicted to acquire a net negative charge. The literature already mentions unexplained negative urine charges so we scrutinized a series of seminal papers and confirmed empirically the theoretical prediction that observed urine charge did acquire negative charge as acidosis developed. Hence, we can conclude that the conventional model is problematic since it predicts what is physiologically impossible. Therefore, we need a new model for whole body acid-base balance, which does not have impossible implications. Furthermore, new experimental studies are needed to account for charge imbalance in urine under development of acidosis. Copyright © 2017 the American Physiological Society.

Mechanism of Hyperkalemia-Induced Metabolic Acidosis.

PubMed

Harris, Autumn N; Grimm, P Richard; Lee, Hyun-Wook; Delpire, Eric; Fang, Lijuan; Verlander, Jill W; Welling, Paul A; Weiner, I David

2018-05-01

Background Hyperkalemia in association with metabolic acidosis that are out of proportion to changes in glomerular filtration rate defines type 4 renal tubular acidosis (RTA), the most common RTA observed, but the molecular mechanisms underlying the associated metabolic acidosis are incompletely understood. We sought to determine whether hyperkalemia directly causes metabolic acidosis and, if so, the mechanisms through which this occurs. Methods We studied a genetic model of hyperkalemia that results from early distal convoluted tubule (DCT)-specific overexpression of constitutively active Ste20/SPS1-related proline-alanine-rich kinase (DCT-CA-SPAK). Results DCT-CA-SPAK mice developed hyperkalemia in association with metabolic acidosis and suppressed ammonia excretion; however, titratable acid excretion and urine pH were unchanged compared with those in wild-type mice. Abnormal ammonia excretion in DCT-CA-SPAK mice associated with decreased proximal tubule expression of the ammonia-generating enzymes phosphate-dependent glutaminase and phosphoenolpyruvate carboxykinase and overexpression of the ammonia-recycling enzyme glutamine synthetase. These mice also had decreased expression of the ammonia transporter family member Rhcg and decreased apical polarization of H + -ATPase in the inner stripe of the outer medullary collecting duct. Correcting the hyperkalemia by treatment with hydrochlorothiazide corrected the metabolic acidosis, increased ammonia excretion, and normalized ammoniagenic enzyme and Rhcg expression in DCT-CA-SPAK mice. In wild-type mice, induction of hyperkalemia by administration of the epithelial sodium channel blocker benzamil caused hyperkalemia and suppressed ammonia excretion. Conclusions Hyperkalemia decreases proximal tubule ammonia generation and collecting duct ammonia transport, leading to impaired ammonia excretion that causes metabolic acidosis. Copyright © 2018 by the American Society of Nephrology.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beyer, K.H. Jr.; Fehr, D.M.; Gelarden, R.T.

Salt intake is restricted under clinical conditions for which thiazide diuretics are customarily used. Dietary iodide intake offsets any effect of thiazide on iodide loss. However, our correlation coefficients relating Na+ to Cl- to I- excretion indicate that as thiazide administration or sodium chloride intake increases renal Na+ and Cl- excretion, I- reabsorption by the nephron coordinately decreases. Increased sodium chloride and water intake by the dog doubled I-excretion rates. Hydrochlorothiazide increased the sodium chloride and water enhanced I-excretion rate as much as eight-fold. Without added NaCl, hydrochlorothiazide increased the excretion rate of 131I by three- to eightfold, acutely. Withinmore » five to seven days after 131I oral administration, hydrochlorothiazide (1 or 2 mg/kg twice daily) doubled the rate of 131I disappearance from plasma, reduced the fecal output of 131I, and increased its rate of renal excretion. When hydrochlorothiazide was administered, as much 131I was excreted in the first 24 hours as occurred in 48 hours when sodium chloride and water were given without hydrochlorothiazide. Thiazide administration in customary clinical dosage twice a day with substantial sodium chloride and water for the first two days after exposure to 131I, should therefore facilitate the safe excretion of 131I. This accelerated removal of 131I might be enhanced even more if thyroid uptake of 131I is blocked by administration of potassium iodide, as judged by the greater 131I recovery from thyroidectomized dogs.« less

Assessment of genotoxic exposure in Swedish coke-oven work by different methods of biological monitoring.

PubMed

Reuterwall, C; Aringer, L; Elinder, C G; Rannug, A; Levin, J O; Juringe, L; Onfelt, A

1991-04-01

This study evaluated the results of several biological methods used simultaneously to monitor coke-oven work. Blood samples from 44 male coke-oven workers and 48 male referents, matched for age and smoking/snuff consumption, were examined for cytogenetic damage in lymphocytes. Urinary thioether excretion was determined for 62, and urine mutagenicity for 31, of the subjects, who followed a standardized diet during the urine sampling. Exposure to polycyclic aromatic hydrocarbons varied with work task, the ambient air levels of benzo[a]pyrene sometimes exceeding 5 micrograms/m3. Cytogenetic damage, urine mutagenicity, and thioether excretion did not differ between the groups. The smokers, however, had significantly higher sister chromatid exchange frequencies, urine mutagenicity, and thioether excretion than the nonsmokers. The absence of biological indications of genotoxic exposure was unexpected and indicates that the studied methods are not adequate to assess the carcinogenic risks of Swedish coke-oven workers.

Development and evaluation of adsorption sheet (HD safe sheet-U) using active carbon for the purpose of the preventing the contamination diffusion of urinary excreted anticancer drug.

PubMed

Sato, Junya; Ohkubo, Haruka; Sasaki, Yuki; Yokoi, Makoto; Hotta, Yasunori; Kudo, Kenzo

2017-01-01

Certain amount of anticancer drugs is excreted in the urine of patients receiving anticancer drugs, and urinary scattering including anticancer drugs at excretion has become a route of anticancer drug contamination. Therefore, we developed an active carbon sheet (HD safe sheet-U) that prevented diffusion by adsorbing anticancer drugs including that excreted in urine. The present study conducted a performance evaluation of this sheet. The adsorption performance of active carbon to anticancer drug in the urine was evaluated by determining concentration changes in the active carbon suspension (5 mg/mL) of 14 kinds of anticancer drugs (cyclophosphamide, ifosfamide, carboplatin, cisplatin, methotrexate, 5-fluorouracil, cytarabine, gemcitabine, doxorubicin, epirubicin, paclitaxel, docetaxel, etoposide, and irinotecan) diluted with artificial urine. Adhesion of the anticancer drug dropping on the sheet to a slipper sole was evaluated because urine including anticancer drugs is scattered on the floor, which can spread by adhering to shoe soles of patients and healthcare workers. The performance of the active carbon sheet was compared with two other types of medical adsorption sheets used as control sheets. Anticancer drugs diluted with artificial urine (1 mL) were dropped on the active carbon sheet and the two control sheets. The sheets were trod with slippers made by polyvinyl chloride. The adhered anticancer drug was wiped off and its quantity was determined. A remarkable decrease in anticancer drug concentrations, except for cisplatin, was detected by mixture of active carbon in the artificial urine (0-79.6%). The quantity of anticancer drug adhesion to slipper soles from the active carbon sheet was significantly lower compared with that observed for the two control sheets for eight kinds of anticancer drugs (cyclophosphamide, ifosfamide, carboplatin, methotrexate, cytarabine, gemcitabine, doxorubicin, and docetaxel). There was no adhesion in cyclophosphamide and docetaxel. Furthermore, the quantities of adhesion in cytarabine, gemcitabine, doxorubicin, paclitaxel, and irinotecan were lower than determination limit. Active carbon might be effective in adsorbing urinary anticancer drugs. The active carbon sheet adsorbed urinary excreted anticancer drugs, and use of such sheets might prevent diffusion of contamination due to urinary excreted anticancer drugs.

Diagnostic value of potassium level in a spot urine sample as an index of 24-hour urinary potassium excretion in unselected patients hospitalized in a hypertension unit

PubMed Central

Symonides, Bartosz; Wojciechowska, Ewa; Gryglas, Adam; Gaciong, Zbigniew

2017-01-01

Background Primary hyperaldosteronism may be associated with elevated 24-hour urinary potassium excretion. We evaluated the diagnostic value of spot urine (SU) potassium as an index of 24-hour urinary potassium excretion. Methods We measured SU and 24-hour urinary collection potassium and creatinine in 382 patients. Correlations between SU and 24-hour collections were assessed for potassium levels and potassium/creatinine ratios. We used the PAHO formula to estimate 24-hour urinary potassium excretion based on SU potassium level. The agreement between estimated and measured 24-hour urinary potassium excretion was evaluated using the Bland-Altman method. To evaluate diagnostic performance of SU potassium, we calculated areas under the curve (AUC) for SU potassium/creatinine ratio and 24-hour urinary potassium excretion estimated using the PAHO formula. Results Strongest correlation between SU and 24-hour collection was found for potassium/creatinine ratio (r = 0.69, P<0.001). The PAHO formula underestimated 24-hour urinary potassium excretion by mean 8.3±18 mmol/d (95% limits of agreement -28 to +44 mmol/d). Diagnostic performance of SU potassium/creatinine ratio was borderline good only if 24-hour urinary potassium excretion was largely elevated (AUC 0.802 for 120 mmol K+/24 h) but poor with lower values (AUC 0.696 for 100 mmol K+/24 h, 0.636 for 80 mmol K+/24 h, 0.675 for 40 mmol K+/24 h). Diagnostic performance of 24-hour urinary potassium excretion estimated by the PAHO formula was excellent with values above 120 mmol/d and good with lower values (AUC 0.941 for 120 mmol K+/24 h, 0.819 for 100 mmol K+/24 h, 0.823 for 80 mmol K+/24 h, 0.836 for 40 mmol K+/24 h). Conclusions Spot urine potassium/creatinine ratio might be a marker of increased 24-hour urinary potassium excretion and a potentially useful screening test when reliable 24-hour urine collection is not available. The PAHO formula allowed estimation of the 24-hour urinary potassium excretion based on SU measurements with reasonable clinical accuracy. PMID:28662194

Alteration of renal function of rats following spaceflight.

PubMed

Wade, C E; Morey-Holton, E

1998-10-01

Following spaceflight, changes in renal function of humans have been suggested. To assess the effects of readaptation on renal function, urine was collected from male rats ( approximately 245 g) over a 2-wk period following a 14-day spaceflight. Rats were assigned to three groups: flight animals (n = 6), flight controls (n = 6) housed in the flight cages on the ground, and vivarium controls (n = 5) housed in standard shoe box cages. Animals were placed into individual metabolic cages for urine collection. Urine output was significantly increased for 3 days following flight. Excretion rates of Na+ and K+ were increased, resulting in an increased osmotic excretion rate. Creatinine excretion rate increased over the first two postflight days. Glomerular filtration rate increased immediately following spaceflight without changes in plasma creatinine, Na+, K+, or osmolality. Increased excretion of solute was thus the result of increased delivery and a decreased percent reabsorption of the filtered load. Osmolal clearance was increased immediately postflight while free water clearance was decreased. In growing rats, the diuresis after short-duration spaceflight is the result of an increase in solute excretion with an accompanying reduction in free water clearance.

Alteration of renal function of rats following spaceflight

NASA Technical Reports Server (NTRS)

Wade, C. E.; Morey-Holton, E.

1998-01-01

Following spaceflight, changes in renal function of humans have been suggested. To assess the effects of readaptation on renal function, urine was collected from male rats ( approximately 245 g) over a 2-wk period following a 14-day spaceflight. Rats were assigned to three groups: flight animals (n = 6), flight controls (n = 6) housed in the flight cages on the ground, and vivarium controls (n = 5) housed in standard shoe box cages. Animals were placed into individual metabolic cages for urine collection. Urine output was significantly increased for 3 days following flight. Excretion rates of Na+ and K+ were increased, resulting in an increased osmotic excretion rate. Creatinine excretion rate increased over the first two postflight days. Glomerular filtration rate increased immediately following spaceflight without changes in plasma creatinine, Na+, K+, or osmolality. Increased excretion of solute was thus the result of increased delivery and a decreased percent reabsorption of the filtered load. Osmolal clearance was increased immediately postflight while free water clearance was decreased. In growing rats, the diuresis after short-duration spaceflight is the result of an increase in solute excretion with an accompanying reduction in free water clearance.

Creatinine as a normalization factor to estimate the representativeness of urine sample - Intra-subject and inter-subject variability studies.

PubMed

Sawant, Pramilla D; Kumar, Suja Arun; Wankhede, Sonal; Rao, D D

2018-06-01

In-vitro bioassay monitoring generally involves analysis of overnight urine samples (~12 h) collected from radiation workers to estimate the excretion rate of radionuclides from the body. The unknown duration of sample collection (10-16 h) adds to the overall uncertainty in computation of internal dose. In order to minimize this, IAEA recommends measurement of specific gravity or creatinine excretion rate in urine. Creatinine is excreted at a steady rate with normally functioning kidneys therefore, can be used as a normalization factor to infer the duration of collection and/or dilution of the sample, if any. The present study reports the chemical procedure standardized and its application for the estimation of creatinine as well as creatinine co-efficient in normal healthy individuals. Observations indicate higher inter-subject variability and lower constancy in daily excretion of creatinine for the same subject. Thus creatinine excretion rate may not be a useful indicator for extrapolating to 24 h sample collection. Copyright © 2018 Elsevier Ltd. All rights reserved.

Factors Associated With High Sodium Intake Based on Estimated 24-Hour Urinary Sodium Excretion: The 2009-2011 Korea National Health and Nutrition Examination Survey.

PubMed

Hong, Jae Won; Noh, Jung Hyun; Kim, Dong-Jun

2016-03-01

Although reducing dietary salt consumption is the most cost-effective strategy for preventing progression of cardiovascular and renal disease, policy-based approaches to monitor sodium intake accurately and the understanding factors associated with excessive sodium intake for the improvement of public health are lacking. We investigated factors associated with high sodium intake based on the estimated 24-hour urinary sodium excretion, using data from the 2009 to 2011 Korea National Health and Nutrition Examination Survey (KNHANES). Among 21,199 adults (≥19 years of age) who participated in the 2009 to 2011 KNHANES, 18,000 participants (weighted n = 33,969,783) who completed urinary sodium and creatinine evaluations were analyzed in this study. The 24-hour urinary sodium excretion was estimated using Tanaka equation. The mean estimated 24-hour urinary sodium excretion level was 4349 (4286-4413) mg per day. Only 18.5% (weighted n = 6,298,481/3,396,973, unweighted n = 2898/18,000) of the study participants consumed less the 2000 mg sodium per day. Female gender (P < 0.001), older age (P < 0.001), total energy intake ≥50 percentile (P < 0.005), and obesity (P < 0.001) were associated with high sodium intake, even after adjusting for potential confounders. Senior high school/college graduation in education and managers/professionals in occupation were associated with lower sodium intake (P < 0.001). According to hypertension management status, those who had hypertension without medication consumed more sodium than those who were normotensive. However, those who receiving treatment for hypertension consumed less sodium than those who were normotensive (P < 0.001). The number of family members, household income, and alcohol drinking did not affect 24-hour urinary sodium excretion. The logistic regression analysis for the highest estimated 24-hour urinary sodium excretion quartile (>6033 mg/day) using the abovementioned variables as covariates yielded identical results. Our data suggest that age, sex, education level, occupation, total energy intake, obesity, and hypertension management status are associated with excessive sodium intake in Korean adults using nationally representative data. Factors associated with high sodium intake should be considered in policy-based interventions to reduce dietary salt consumption and prevent cardiovascular disease as a public health target.

Dietary Sodium Consumption Predicts Future Blood Pressure and Incident Hypertension in the Japanese Normotensive General Population

PubMed Central

Takase, Hiroyuki; Sugiura, Tomonori; Kimura, Genjiro; Ohte, Nobuyuki; Dohi, Yasuaki

2015-01-01

Background Although there is a close relationship between dietary sodium and hypertension, the concept that persons with relatively high dietary sodium are at increased risk of developing hypertension compared with those with relatively low dietary sodium has not been studied intensively in a cohort. Methods and Results We conducted an observational study to investigate whether dietary sodium intake predicts future blood pressure and the onset of hypertension in the general population. Individual sodium intake was estimated by calculating 24-hour urinary sodium excretion from spot urine in 4523 normotensive participants who visited our hospital for a health checkup. After a baseline examination, they were followed for a median of 1143 days, with the end point being development of hypertension. During the follow-up period, hypertension developed in 1027 participants (22.7%). The risk of developing hypertension was higher in those with higher rather than lower sodium intake (hazard ratio 1.25, 95% CI 1.04 to 1.50). In multivariate Cox proportional hazards regression analysis, baseline sodium intake and the yearly change in sodium intake during the follow-up period (as continuous variables) correlated with the incidence of hypertension. Furthermore, both the yearly increase in sodium intake and baseline sodium intake showed significant correlations with the yearly increase in systolic blood pressure in multivariate regression analysis after adjustment for possible risk factors. Conclusions Both relatively high levels of dietary sodium intake and gradual increases in dietary sodium are associated with future increases in blood pressure and the incidence of hypertension in the Japanese general population. PMID:26224048

Quantitative determination of five metabolites of aspirin by UHPLC-MS/MS coupled with enzymatic reaction and its application to evaluate the effects of aspirin dosage on the metabolic profile.

PubMed

Li, Jian-Ping; Guo, Jian-Ming; Shang, Er-Xin; Zhu, Zhen-Hua; Liu, Yang; Zhao, Bu-Chang; Zhao, Jing; Tang, Zhi-Shu; Duan, Jin-Ao

2017-05-10

Acetylsalicylic acid (Aspirin, ASA) is a famous drug for cardiovascular diseases in recent years. Effects of ASA dosage on the metabolic profile have not been fully understood. The purpose of our study is to establish a rapid and reliable method to quantify ASA metabolites in biological matrices, especially for glucuronide metabolites whose standards are not commercially available. Then we applied this method to evaluate the effects of ASA dosage on the metabolic and excretion profile of ASA metabolites in rat urine. Salicylic acid (SA), gentisic acid (GA) and salicyluric acid (SUA) were determined directly by UHPLC-MS/MS, while salicyl phenolic glucuronide (SAPG) and salicyluric acid phenolic glucuronide (SUAPG) were quantified indirectly by measuring the released SA and SUA from SAPG and SUAPG after β-glucuronidase digestion. SUA and SUAPG were the major metabolites of ASA in rat urine 24h after ASA administration, which accounted for 50% (SUA) and 26% (SUAPG). When ASA dosage was increased, the contributions dropped to 32% and 18%, respectively. The excretion of other three metabolites (GA, SA and SAPG) however showed remarkable increases by 16%, 6% and 4%, respectively. In addition, SUA and SUAPG were mainly excreted in the time period of 12-24h, while GA was excreted in the earlier time periods (0-4h and 4-8h). SA was mainly excreted in the time period of 0-4h and 12-24h. And the excretion of SAPG was equally distributed in the four time periods. We went further to show that the excretion of five metabolites in rat urine was delayed when ASA dosage was increased. In conclusion, we have developed a rapid and sensitive method to determine the five ASA metabolites (SA, GA, SUA, SAPG and SUAPG) in rat urine. We showed that ASA dosage could significantly influence the metabolic and excretion profile of ASA metabolites in rat urine. Copyright © 2016 Elsevier B.V. All rights reserved.

Correlation of random urine protein creatinine (P-C) ratio with 24-hour urine protein and P-C ratio, based on physical activity: a pilot study.

PubMed

Sadjadi, Seyed-Ali; Jaipaul, Navin

2010-09-07

Quantification of proteinuria is usually predicated upon 24-hour urine collection. Multiple factors influence urine collection and the rate of protein and creatinine excretion. Urine collection is often incomplete, and therefore creatinine and protein excretion rates are underestimated. A random urine protein-creatinine (P-C) ratio has been shown over the years to be a reliable alternative to the 24-hour collection for detection and follow up of proteinuria. However, urine protein excretion may be influenced by physical activity. We studied 48 patients with proteinuria and varying levels of physical activity to determine the correlation between the measures of urine protein excretion. The correlation coefficient (r) between 24-hour urine total protein and random urine P-C ratio was 0.75 (P < 0.01) in the overall study population, but varied according to the level of proteinuria and physical activity in a stratified analysis: r = 0.99 (P < 0.001) and r = 0.95 (P < 0.01) in bedridden patients; r = 0.44 (P = not significant [NS]) and r = 0.54 (P = NS) in semiactive patients; and r = 0.44 (P = NS) and r = 0.58 (P < 0.05) in active patients with nephrotic- (>3500 mg/day) and non-nephrotic (<3500 mg/day) range proteinuria, respectively. The correlation appeared to be stronger between random urine and 24-hour urine P-C ratio for the overall study population (r = 0.84; P < 0.001), and when stratified according to the level of proteinuria and physical activity: r = 0.99 (P < 0.001) and r = 0.92 (P < 0.01) in bedridden patients; r = 0.61 (P = NS) and r = 0.54 (P = NS) in semiactive patients; and r = 0.64 (P < 0.02) and r = 0.52 (P < 0.05) in active patients with nephrotic and non-nephrotic range proteinuria, respectively. We conclude that the random urine P-C ratio is a reliable and practical way of estimating and following proteinuria, but its precision and accuracy may be affected by the level of patient physical activity.

Correlation of random urine protein creatinine (P-C) ratio with 24-hour urine protein and P-C ratio, based on physical activity: a pilot study

PubMed Central

Sadjadi, Seyed-Ali; Jaipaul, Navin

2010-01-01

Quantification of proteinuria is usually predicated upon 24-hour urine collection. Multiple factors influence urine collection and the rate of protein and creatinine excretion. Urine collection is often incomplete, and therefore creatinine and protein excretion rates are underestimated. A random urine protein-creatinine (P-C) ratio has been shown over the years to be a reliable alternative to the 24-hour collection for detection and follow up of proteinuria. However, urine protein excretion may be influenced by physical activity. We studied 48 patients with proteinuria and varying levels of physical activity to determine the correlation between the measures of urine protein excretion. The correlation coefficient (r) between 24-hour urine total protein and random urine P-C ratio was 0.75 (P < 0.01) in the overall study population, but varied according to the level of proteinuria and physical activity in a stratified analysis: r = 0.99 (P < 0.001) and r = 0.95 (P < 0.01) in bedridden patients; r = 0.44 (P = not significant [NS]) and r = 0.54 (P = NS) in semiactive patients; and r = 0.44 (P = NS) and r = 0.58 (P < 0.05) in active patients with nephrotic- (>3500 mg/day) and non-nephrotic (<3500 mg/day) range proteinuria, respectively. The correlation appeared to be stronger between random urine and 24-hour urine P-C ratio for the overall study population (r = 0.84; P < 0.001), and when stratified according to the level of proteinuria and physical activity: r = 0.99 (P < 0.001) and r = 0.92 (P < 0.01) in bedridden patients; r = 0.61 (P = NS) and r = 0.54 (P = NS) in semiactive patients; and r = 0.64 (P < 0.02) and r = 0.52 (P < 0.05) in active patients with nephrotic and non-nephrotic range proteinuria, respectively. We conclude that the random urine P-C ratio is a reliable and practical way of estimating and following proteinuria, but its precision and accuracy may be affected by the level of patient physical activity. PMID:20856681

Effect of Diuretics on Urinary Excretion of Cephalothin in Humans

PubMed Central

Tice, Alan D.; Barza, Michael; Bergeron, Michel G.; Brusch, John L.; Weinstein, Louis

1975-01-01

Diuretics and antibiotics are frequently used concomitantly. The possibility of drug interactions led us to study the effects of several diuretics on the renal elimination of cephalothin. Five healthy volunteers received a constant infusion of 500 mg of sodium cephalothin per h for 9 h on 4 consecutive days. Each day, after the third hour of infusion, the subjects were given one of the following in varying order: (i) furosemide (1 mg/kg, intravenous), (ii) mercaptomerin (250 mg, intramuscular), (iii) mannitol (25 g, intravenous), or (iv) no diuretic (control day). Fluid losses were replaced hourly. Serum and complete urine collections were obtained each hour and assayed for creatinine and cephalothin (bioassay). Clearances (milliliter per minute) and urinary excretions (milligram per hour) of cephalothin did not differ either when the diuretic day values were compared with control day, or when pre- and postdiuretic results on the same day were compared. Creatinine clearances were not affected by diuretics except for a transient rise after furosemide. PMID:1137368

Meta-analysis to estimate the load of Leptospira excreted in urine: beyond rats as important sources of transmission in low-income rural communities.

PubMed

Barragan, Veronica; Nieto, Nathan; Keim, Paul; Pearson, Talima

2017-01-28

Leptospirosis is a major zoonotic disease with widespread distribution and a large impact on human health. Carrier animals excrete pathogenic Leptospira primarily in their urine. Infection occurs when the pathogen enters a host through mucosa or small skin abrasions. Humans and other animals are exposed to the pathogen by direct contact with urine, contaminated soil or water. While many factors influence environmental cycling and the transmission of Leptospira to humans, the load of pathogenic Leptospira in the environment is likely to play a major role. Peridomestic rats are often implicated as a potential source of human disease; however exposure to other animals is a risk factor as well. The aim of this report is to highlight the importance of various carrier animals in terms of the quantity of Leptospira shed into the environment. For this, we performed a systematic literature review and a meta-analysis of the amount of pathogen that various animal species shed in their urine. The quantity of pathogen has been reported for cows, deer, dogs, humans, mice, and rats, in a total of 14 research articles. We estimated the average Leptospira per unit volume shed by each animal species, and the daily environmental contribution by considering the total volume of urine excreted by each carrier animal. Rats excrete the highest quantity of Leptospira per millilitre of urine (median = 5.7 × 10 6  cells), but large mammals excrete much more urine and thus shed significantly more Leptospira per day (5.1 × 10 8 to 1.3 × 10 9  cells). Here we illustrate how, in a low-income rural Ecuadorian community, host population demographics, and prevalence of Leptospira infection can be integrated with estimates of shed Leptospira to suggest that peridomestic cattle may be more important than rats in environmental cycling and ultimately, transmission to humans.

Diuretic effects of medetomidine compared with xylazine in healthy dogs

PubMed Central

Talukder, Md. Hasanuzzaman; Hikasa, Yoshiaki

2009-01-01

This study aimed to investigate and compare the effects of medetomidine and xylazine on diuretic and hormonal variables in healthy dogs. Five dogs, used in each of 11 groups, were injected intramuscularly with physiological saline solution (control), 5, 10, 20, 40, and 80 μg/kg of medetomidine, and 0.25, 0.5, 1, 2, and 4 mg/kg of xylazine. Urine and blood samples were taken 11 times over 24 h. Both medetomidine and xylazine increased urine production in a dose-dependent manner up to 4 h after injection, but the increase was much less with medetomidine than with xylazine at the tested doses. Urine specific gravity, pH, osmolality, and concentrations of creatinine, sodium, potassium, chloride, and arginine vasopressin (AVP) were decreased in a dose-dependent manner with both medetomidine and xylazine. Plasma osmolality and concentrations of sodium, potassium, and chloride were increased significantly with both drugs. Total amounts of urine AVP excreted and plasma AVP concentrations were significantly decreased by higher doses of medetomidine but were not significantly decreased by xylazine. Higher doses of both drugs significantly increased the plasma concentration of atrial natriuretic peptide (ANP), but the effect was greater with medetomidine than with xylazine. The results revealed that both drugs induce a profound diuresis, but medetomidine’s effect is less dose-dependent than xylazine’s effect. Although changes in plasma concentrations of AVP and ANP may partially influence the diuresis induced by medetomidine, other factors may be involved in the mechanism of the diuretic response to both drugs. Thus, both agents can be used clinically for transient but effective diuresis accompanied by sedation. PMID:19794896

Changes in urine parameters after desert exposure: assessment of stone risk in United States Marines transiently exposed to a desert environment.

PubMed

Masterson, James H; Jourdain, Victor J; Collard, Daniel A; Choe, Chong H; Christman, Matthew S; L'Esperance, James O; Auge, Brian K

2013-01-01

Living in a desert environment has been associated with a higher incidence of kidney stone formation, likely because of concentrated urine output, higher production of vitamin D and genetic predisposition. We determined the changes in urinary parameters after a group of United States Marines temporarily transitioned from a temperate environment to a desert environment. A total of 50 Marines completed a questionnaire and performed 3, 24-hour urine collections before mobilization to the desert, after 30 days in the desert and 2 weeks after returning from the desert. Daily urine output decreased 68% to 0.52 L despite marked increased fluid intake (17 L per day). Total daily urinary excretion of calcium, uric acid, sodium, magnesium and potassium in the desert decreased by 70%, 41%, 53%, 22% and 36%, respectively. Urinary pH decreased from 6.1 to 5.6 while in the desert, and citrate and oxalate had minimal changes. After their return from the desert, apart from a decrease of 22% in oxalate, there were no statistically significant differences from baseline. While in the desert, relative supersaturation risks of uric acid and sodium urate were increased 153% and 56%, respectively. Brushite relative supersaturation decreased 24%. After their return there was no statistical difference from baseline. Our findings suggest that the kidneys preserved water and electrolytes while the Marines were subjected to the desert environment. Despite this conservation, relative saturations indicate increased risk of stones in healthy men exposed to a desert environment with rapid resolution upon return. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Assessment of sodium status in large ruminants by measuring the sodium-to-potassium ratio in muzzle secretions.

PubMed

Singh, S P; Rani, D

1999-09-01

To develop a simple diagnostic test to assess sodium status in large ruminants on the basis of the sodium-to-potassium ratio (Na:K) and to determine its relevance. 7 buffalo heifers and 21 lactating, pregnant, and nonpregnant dairy cows and heifers. Buffalo heifers were subjected in 2 experiments to variable dietary sodium intake or sodium depletion and changes in sodium and potassium concentrations; Na:K was simultaneously monitored in various body fluids to study its value for indicating sodium status. Validity of the muzzle secretion test was assessed. Muzzle secretion and urinary Na:K and sodium concentration, but not serum electrolyte concentrations, reflected the sodium status of buffalo heifers in response to the widely variable intake of sodium (0.03 to 0.16% of dry matter [DM]). Progressive sodium depletion during an 11-day period, using saliva deprivation caused reciprocal changes in sodium and potassium concentrations in saliva and muzzle secretion, but not in urine. Decreasing urine sodium concentration was associated with decreasing urine potassium concentration. Saliva, urine, and muzzle secretion Na:K closely reflected the degree of sodium deficit. Buffaloes or dairy cows maintained on optimal sodium intake had muzzle secretion and urine Na:K > 0.30. Muzzle secretion or urine Na:K < 0.20 or < 0.10, respectively, was indicative of sodium deficiency. Analysis of muzzle secretion Na:K, and to a large extent urine Na:K, may be used as a convenient diagnostic tool to assess sodium status in large ruminants. It has accuracy similar to that of saliva Na:K.

Time to Consider Use of the Sodium-to-Potassium Ratio for Practical Sodium Reduction and Potassium Increase

PubMed Central

Miura, Katsuyuki; Ueshima, Hirotsugu

2017-01-01

Pathogenetic studies have demonstrated that the interdependency of sodium and potassium affects blood pressure. Emerging evidences on the sodium-to-potassium ratio show benefits for a reduction in sodium and an increase in potassium compared to sodium and potassium separately. As presently there is no known review, this article examined the practical use of the sodium-to-potassium ratio in daily practice. Epidemiological studies suggest that the urinary sodium-to-potassium ratio may be a superior metric as compared to separate sodium and potassium values for determining the relation to blood pressure and cardiovascular disease risks. Higher correlations and better agreements are seen for the casual urine sodium-to-potassium ratio than for casual urine sodium or potassium alone when compared with the 24-h urine values. Repeated measurements of the casual urine provide reliable estimates of the 7-day 24-h urine value with less bias for the sodium-to-potassium ratio as compared to the common formulas used for estimating the single 24-h urine from the casual urine for sodium and potassium separately. Self-monitoring devices for the urinary sodium-to-potassium ratio measurement makes it possible to provide prompt onsite feedback. Although these devices have been evaluated with a view to support an individual approach for sodium reduction and potassium increase, there has yet to be an accepted recommended guideline for the sodium-to-potassium ratio. This review concludes with a look at the practical use of the sodium-to-potassium ratio for assistance in practical sodium reduction and potassium increase. PMID:28678188

Reference intervals for 24 laboratory parameters determined in 24-hour urine collections.

PubMed

Curcio, Raffaele; Stettler, Helen; Suter, Paolo M; Aksözen, Jasmin Barman; Saleh, Lanja; Spanaus, Katharina; Bochud, Murielle; Minder, Elisabeth; von Eckardstein, Arnold

2016-01-01

Reference intervals for many laboratory parameters determined in 24-h urine collections are either not publicly available or based on small numbers, not sex specific or not from a representative sample. Osmolality and concentrations or enzymatic activities of sodium, potassium, chloride, glucose, creatinine, citrate, cortisol, pancreatic α-amylase, total protein, albumin, transferrin, immunoglobulin G, α1-microglobulin, α2-macroglobulin, as well as porphyrins and their precursors (δ-aminolevulinic acid and porphobilinogen) were determined in 241 24-h urine samples of a population-based cohort of asymptomatic adults (121 men and 120 women). For 16 of these 24 parameters creatinine-normalized ratios were calculated based on 24-h urine creatinine. The reference intervals for these parameters were calculated according to the CLSI C28-A3 statistical guidelines. By contrast to most published reference intervals, which do not stratify for sex, reference intervals of 12 of 24 laboratory parameters in 24-h urine collections and of eight of 16 parameters as creatinine-normalized ratios differed significantly between men and women. For six parameters calculated as 24-h urine excretion and four parameters calculated as creatinine-normalized ratios no reference intervals had been published before. For some parameters we found significant and relevant deviations from previously reported reference intervals, most notably for 24-h urine cortisol in women. Ten 24-h urine parameters showed weak or moderate sex-specific correlations with age. By applying up-to-date analytical methods and clinical chemistry analyzers to 24-h urine collections from a large population-based cohort we provide as yet the most comprehensive set of sex-specific reference intervals calculated according to CLSI guidelines for parameters determined in 24-h urine collections.

Identification of leptospiral 3-hydroxyacyl-CoA dehydrogenase released in the urine of infected hamsters

PubMed Central

2014-01-01

Background Leptospirosis is a global zoonosis caused by pathogenic Leptospira. The non-specific clinical signs and symptoms of leptospirosis lead to its misdiagnosis. To date, there is still no reliable rapid test kit that can accurately diagnose leptospirosis at bedside or in field. In this research, with the ultimate goal of formulating a rapid and accurate diagnostic tool for leptospirosis, we aimed to identify leptospiral proteins excreted in urine of infected hamsters, which are thought to mimic Weil’s disease. Results Hamsters were subcutaneously infected with leptospires, and the general attributes of urine as well as the proteins excreted in it were examined. Some leptospiral proteins were found to be excreted in the urine from the early phase of infection. The most important finding of this study was the detection of the lipid-metabolizing enzyme, 3-hydroxyacyl-CoA dehydrogenase (HADH), before the onset of illness, when leptospires were not yet detected in the urine of infected hamsters. Conclusions This is the first report on the detection of leptospiral HADH in the host urine, which may be a possible candidate leptospiral antigen that can be used in the early diagnosis of human and animal leptospirosis. PMID:24884439

Urinary spot albumin:creatinine ratio for documenting proteinuria in women with preeclampsia.

PubMed

Huang, Qitao; Gao, Yunfei; Yu, Yanhong; Wang, Wei; Wang, Shuoshi; Zhong, Mei

2012-01-01

To assess whether a single urinary spot urinary albumin:creatinine ratio (ACR) can be used to estimate 24-hour urinary protein excretion in women with preeclampsia. ACR and 24-hour urinary protein excretion were measured in 50 consecutive patients with preeclampsia. ACR was determined in a spot midstream urine sample and the amount of protein excretion was quantified in a 24-hour urine collection performed the following day. The correlation between the spot ACR and 24-hour urine protein excretion was assessed, and the diagnostic value of ACR was expressed in terms of specificity and sensitivity. Receiver operating characteristic curve analysis was used to determine the best cutoff values of the spot ACR for mild preeclampsia (proteinuria ≥ 0.3 g/24 h) and severe preeclampsia (defined in China as proteinuria ≥ 2 g/24 h). A strong correlation was evident between the spot ACR and 24-hour urinary protein excretion (r = .938; P < .001). The optimal spot ACR cutoff point was 22.8 mg/mmol for 0.3 g/24 h of protein excretion (mild preeclampsia) with a sensitivity and specificity of 82.4% and 99.4%, respectively, and 155.6 mg/mmol for 2 g/24 h of protein excretion (severe preeclampsia) with a sensitivity and specificity of 90.6% and 99.6%, respectively. Compared with 24-hour urinary protein excretion, the spot urinary ACR may be a simple, convenient, and accurate indicator of significant proteinuria in women with preeclampsia.

Defective renal water handling in transgenic mice over-expressing human CD39/NTPDase1

PubMed Central

Zhang, Yue; Morris, Kaiya L.; Sparrow, Shannon K.; Dwyer, Karen M.; Enjyoji, Keiichi; Robson, Simon C.

2012-01-01

Ectonucleoside triphosphate diphosphohydrolase-1 hydrolyzes extracellular ATP and ADP to AMP. Previously, we showed that CD39 is expressed at several sites within the kidney and thus may impact the availability of type 2 purinergic receptor (P2-R) ligands. Because P2-Rs appear to regulate urinary concentrating ability, we have evaluated renal water handling in transgenic mice (TG) globally overexpressing hCD39. Under basal conditions, TG mice exhibited significantly impaired urinary concentration and decreased protein abundance of AQP2 in the kidney compared with wild-type (WT) mice. Urinary excretion of total nitrates/nitrites was significantly higher in TG mice, but the excretion of AVP or PGE2 was equivalent to control WT mice. There were no significant differences in electrolyte-free water clearance or fractional excretion of sodium. Under stable hydrated conditions (gelled diet feeding), the differences between the WT and TG mice were negated, but the decrease in urine osmolality persisted. When water deprived, TG mice failed to adequately concentrate urine and exhibited impaired AVP responses. However, the increases in urinary osmolalities in response to subacute dDAVP or chronic AVP treatment were similar in TG and WT mice. These observations suggest that TG mice have impaired urinary concentrating ability despite normal AVP levels. We also note impaired AVP release in response to water deprivation but that TG kidneys are responsive to exogenous dDAVP or AVP. We infer that heightened nucleotide scavenging by increased levels of CD39 altered the release of endogenous AVP in response to dehydration. We propose that ectonucleotidases and modulated purinergic signaling impact urinary concentration and indicate potential utility of targeted therapy for the treatment of water balance disorders. PMID:22622462

Renal excretion of water in men under hypokinesia and physical exercise with fluid and salt supplementation

NASA Astrophysics Data System (ADS)

Zorbas, Yan G.; Federenko, Youri F.; Togawa, Mitsui N.

It has been suggested that under hypokinesia (reduced number of steps/day) and intensive physical exercise, the intensification of fluid excretion in men is apparently caused as a result of the inability of the body to retain optimum amounts of water. Thus, to evaluate this hypothesis, studies were performed with the use of fluid and sodium chloride (NaCl) supplements on 12 highly trained physically healthy male volunteers aged 19-24 years under 364 days of hypokinesis (HK) and a set of intensive physical exercises (PE). They were divided into two groups with 6 volunteers per group. The first group of subjects were submitted to HK and took daily fluid and salt supplements in very small doses and the second group of volunteers were subjected to intensive PE and fluid-salt supplements. For the simulation of the hypokinetic effect, both groups of subjects were kept under an average of 4000 steps/day. During the prehypokinetic period of 60 days and under the hypokinetic period of 364 days water consumed and eliminated in urine by the men, water content in blood, plasma volume, rate of glomerular filtration, renal blood flow, osmotic concentration of urine and blood were measured. Under HK, the rate of renal excretion of water increased considerably in both groups. The additional fluid and salt intake failed to normalize water balance adequately under HK and PE. It was concluded that negative water balance evidently resulted not from shortage of water in the diet but from the inability of the body to retain optimum amounts of fluid under HK and a set of intensive PEs.

Assessment of murine bladder permeability with fluorescein: validation with cyclophosphamide and protamine.

PubMed

Eichel, L; Scheidweiler, K; Kost, J; Shojaie, J; Schwarz, E; Messing, E; Wood, R

2001-07-01

Bladder hyperpermeability should result in elevated blood levels of intravesically administered agents. Reabsorption from a hyperpermeable bladder should result in prolonged urinary excretion of an agent after parenteral administration. To test these hypotheses, urinary clearance and plasma levels of sodium fluorescein (NaF) were measured in mice before and during cyclophosphamide (CYP) and protamine-induced hemorrhagic cystitis. To measure the plasma uptake of NaF from the bladder, 10 mg/mL NaF was instilled, either by catheter or retrograde urethral infusion, 15 minutes before retro-orbital or ventricular sampling. The plasma levels were measured 24 hours and 14 days after exposure to CYP 300 mg/kg or 15 minutes after instillation of protamine 10 mg/mL. Hourly urine concentrations were measured immediately after intraperitoneal administration of 10 mg/kg NaF. Pretreatment samples were compared with those obtained 24 hours after intraperitoneal administration of 300 mg/kg CYP. Urinary NaF excretion was delayed in CYP-exposed mice. A bi-exponential model provided an appropriate fit of the data, both before and after CYP administration. The plasma levels of NaF were significantly elevated at 24 hours and 14 days after CYP exposure when sampled by ventricular nick or retro-orbitally. The median concentration of fluorescein in the protamine-treated mice was significantly higher than in the control mice. Fluorescein can be used to measure alterations in bladder permeability after bladder mucosal injury in mice. Urinary excretion of NaF is a bi-exponential process that is delayed after bladder mucosal injury, presumably because of increased mucosal permeability and resorption from the urine into the bloodstream.

Dapagliflozin Aggravates Renal Injury via Promoting Gluconeogenesis in db/db Mice.

PubMed

Jia, Yingli; He, Jinzhao; Wang, Liang; Su, Limin; Lei, Lei; Huang, Wei; Geng, Xiaoqiang; Zhang, Shun; Meng, Xiaolu; Zhou, Hong; Yang, Baoxue

2018-01-01

A sodium-glucose co-transporter-2 inhibitor dapagliflozin is widely used for lowering blood glucose and its usage is limited in type 2 diabetes mellitus patients with moderate renal impairment. As its effect on kidney function is discrepant and complicated, the aim of this study is to determine the effect of dapagliflozin on the progression of diabetic nephropathy and related mechanisms. Twelve-week-old male C57BL/6 wild-type and db/db mice were treated with vehicle or 1 mg/kg dapagliflozin for 12 weeks. Body weight, blood glucose, insulin tolerance, glucose tolerance, pyruvate tolerance and 24-hour urine were measured every 4 weeks. At 24 weeks of age, renal function was evaluated by blood urea nitrogen level, creatinine clearance, urine output, urinary albumin excretion, Periodic Acid-Schiff staining, Masson's trichrome staining and electron microscopy. Changes in insulin signaling and gluconeogenic key regulatory enzymes were detected using Western blot analysis. Dapagliflozin did not alleviate but instead aggravated diabetic nephropathy manifesting as increased levels of microalbuminuria, blood urea nitrogen, and glomerular and tubular damage in db/db mice. Despite adequate glycemic control by dapagliflozin, urinary glucose excretion increased after administration before 24 weeks of age and was likely associated with renal impairment. Increased urinary glucose excretion was mainly derived from the disturbance of glucose homeostasis with elevated hepatic and renal gluconeogenesis induced by dapagliflozin. Although it had no effect on insulin sensitivity and glucose tolerance, dapagliflozin further induced the expression of gluconeogenic key rate-limiting enzymes through increasing the expression levels of FoxO1 in the kidney and liver. These experimental results indicate that dapagliflozin aggravates diabetes mellitus-induced kidney injury, mostly through increasing gluconeogenesis. © 2018 The Author(s). Published by S. Karger AG, Basel.

Eclampsia despite strict dietary sodium restriction.

PubMed

Delemarre, F M; Steegers, E A; Berendes, J N; de Jong PA

2001-01-01

The classic indication for prescribing dietary sodium restriction in pregnancy has been the prevention of eclampsia. We describe a case of intrapartum eclampsia in a 24-year-old nulliparous woman. A strongly sodium restricted diet was prescribed because of pre-eclampsia. Compliance to the diet was checked with 24-hour urinary sodium excretion. This report, describing the first case of eclampsia despite neglectable urinary sodium excretion, adds to the view that sodium restriction in pregnancy is obsolete. Copyright 2001 S. Karger AG, Basel.

Sodium urine test

MedlinePlus

... or monitor many types of kidney diseases. Normal Results For adults, normal urine sodium values are generally ... meaning of your specific test result. What Abnormal Results Mean A higher than normal urine sodium level ...

The salt-taste threshold in untreated hypertensive patients.

PubMed

Kim, Chang-Yeon; Ye, Mi-Kyung; Lee, Young Soo

2017-01-01

The salt-taste threshold can influence the salt appetite, and is thought to be another marker of sodium intake. Many studies have mentioned the relationship between the sodium intake and blood pressure (BP). The aim of this study was to evaluate the relationship between the salt-taste threshold and urinary sodium excretion in normotensive and hypertensive groups. We analyzed 199 patients (mean age 52 years, male 47.3%) who underwent 24-h ambulatory BP monitoring (ABPM). Hypertension was diagnosed as an average daytime systolic BP of ≥135 mmHg or diastolic BP of ≥85 mmHg by the ABPM. We assessed the salt-taste threshold using graded saline solutions. The salt-taste threshold, 24-h urinary sodium and potassium excretion, and echocardiographic data were compared between the control and hypertensive groups. The detection and recognition threshold of the salt taste did not significantly differ between the control and hypertensive groups. The 24-h urinary sodium excretion of hypertensive patients was significantly higher than that of the control group (140.9 ± 59.8 vs. 117.9 ± 57.2 mEq/day, respectively, p  = 0.011). Also, the urinary sodium-potassium ratio was significantly higher in the hypertensive patients. There was no correlation between the salt-taste threshold and 24-h urinary sodium excretion. The salt-taste threshold might not be related to the BP status as well as the 24-h urinary sodium excretion.

The relationship between sodium intake and some bone minerals and osteoporosis risk assessment instrument in postmenopausal women.

PubMed

Vafa, Mohammadreza; Soltani, Sepideh; Zayeri, Farid; Niroomand, Mahtab; Najarzadeh, Azadeh

2016-01-01

The results of the studies on the effects of sodium on bone metabolism have been inconsistent. There is no definitive answer to the question of whether sodium restriction can be associated with a lower incidence of osteoporosis. What reinforces the necessity of designing this study is the lack of findings with the approach of examining the effects of sodium on bone in our country. This was a cross-sectional study conducted on 185 retired female teachers aged 45 to 70. Sodium intake was evaluated using two methods: A 24-hour recall and a 12-hour urine sample. To assess bone health, ORAI index was calculated for each individual. Urinary calcium, phosphorus, potassium and serum vitamin D and PTH were measured as laboratory variables. To compare the general characteristics of the participants across tertiles of urinary sodium, the analysis of variance (ANOVA) was used for quantitative variables and the Chi-square test for categorical variables. Phosphorous, calcium and potassium urinary excretion rate increased with the increase in urinary sodium (p<0.05). However, the changes in serum vitamin D, and PTH levels across tertiles of urinary sodium were not significant. Changes in urinary sodium levels were not significant (p=0.933) in ORAI groups (sorted by rating). The relationship between urinary calcium and sodium was apparent in low calcium intake (r=0.415, p<0.001), but not in higher calcium intake (r=0.144, p=0.177). Although urinary calcium and potassium increased with the increase in sodium intake, no relationship was found between sodium and ORAI.

Fractional excretion of urea in pre-eclampsia: a clinical observation.

PubMed

Zar, Tausif; Kohn, Orly F; Kaplan, Andre A

2011-11-01

Pre-eclampsia is one of the leading causes of maternal and fetal mortality and morbidity. It occurs in 7% of all the pregnancies and accounts for 80% of the cases of pregnancy-induced hypertension. Diagnosis of pre-eclampsia in patients with pre-existing chronic kidney disease, proteinuria, and hypertension is a dilemma. The fractional excretion of urea has been described as a marker for renal perfusion. Since pre-eclampsia is associated with a marked decline in renal perfusion, we explored the utility of the fractional excretion of urea as a marker for pre-eclampsia. Urine and serum chemistries were evaluated in 6 pregnant women with pre-eclampsia on their first visit, immediately prior to delivery, and postpartum. For each of these three measurements, the fractional excretion of urea was calculated and proteinuria was assessed by random urine protein-creatinine ratio or 24-hour urine protein studies. In patients diagnosed with pre-eclampsia, the fractional excretion of urea decreased substantially from higher values obtained during the 3rd trimester to values consistent with renal hypoperfusion (< 35%) just prior to delivery, and it rapidly normalized immediately after delivery. Alterations in fractional excretion of urea, which suggest a decreased renal perfusion, may be a useful tool in supporting the diagnosis of preeclampsia.

Systemic PPARγ deletion causes severe disturbance in fluid homeostasis in mice

PubMed Central

Zhou, Li; Panasiuk, Alexandra; Downton, Maicy; Zhao, Daqiang; Yang, Baoxue; Jia, Zhanjun

2015-01-01

The pharmacological action of peroxisome proliferator-activated receptor (PPAR)γ in promoting sodium and water retention is well documented as highlighted by the major side-effect of body weight gain and edema associated with thiazolidinedione use. However, a possible physiological role of PPARγ in regulation of fluid metabolism has not been reported by previous studies. Here we analyzed fluid metabolism in inducible whole-body PPARγ knockout mice. The null mice developed severe polydipsia and polyuria, reduced urine osmolality, and modest hyperphagia. The phenomenon persisted during 3 days of pair feeding and pair drinking, accompanied by progressive weight loss. After 24 h water deprivation, the null mice had a lower urine osmolality, a higher urine volume, a greater weight loss, and a greater rise in hematocrit than the floxed control. Urinary vasopressin (AVP) excretion was not different between the genotypes under basal condition or after WD. The response of urine osmolality to acute and chronic 1-desamino-8-d-arginine vasopressin treatment was attenuated in the null mice, but the total abundance or phosphorylation of aquaporin 2 (AQP2) in the kidney or AVP-induced cAMP production in inner medullary collecting duct suspensions was unaffected. Overall, PPARγ participates in physiological control of fluid homeostasis through an unknown mechanism involving cAMP/AQP2-independent enhancement of AVP response. PMID:26330489

Effect of 14 days of bed rest on urine metabolite excretion and plasma enzyme levels

NASA Technical Reports Server (NTRS)

Pace, N.; Grunbaum, B. W.; Kodama, A. M.; Rahlmann, D. F.; Newsom, B. D.

1974-01-01

After 1 week of ambulatory base-line measurement, a group of 8 men 19-26 years of age remained continuously recumbent for 14 days. Studies were continued for 1 week following the prolonged recumbency. Urine excretion rates for a number of constituents were determined 2 days before bed rest, on day 14 of bed rest, and day 6 after bed rest. Blood plasma samples were also obtained at these times, and analyzed for several enzymes. On day 14 of bed rest significant increases were observed in urine excretion of total osmotically-active substances, magnesium, calcium, phosphate, creatinine, hydroxyproline, and 17-OH corticosteroids. A decrease occurred in urinary glucose excretion. Plasma levels of alkaline phosphatase and LDH-3 were depressed, while plasma GPT was elevated. Many of these changes persisted on day 6 after bed rest, and are interpreted as concomitants of the disuse atrophy of the musculoskeletal system that characterizes prolonged bed rest and weightlessness.

Importance of inhibiting sodium-glucose cotransporter and its compelling indication in type 2 diabetes: pathophysiological hypothesis.

PubMed

Kimura, Genjiro

2016-03-01

Primarily the sodium-glucose cotransporter 2 (SGLT2) inhibitors suppress the cotransport of glucose and sodium from the tubular lumen of proximal tubules to the blood and enhance the glucose excretion into urine. Therefore, glucose and caloric balances become negative, making the blood glucose level as well as insulin secretion both reduced. On the other hand, the proximal tubular fluid, constituting with low chloride concentration because of SGLT2 inhibition, is transferred to the loop of Henle. On the low chloride conditions, the reabsorption mechanisms in the loop of Henle do not work, as if loop diuretics are given. Finally, blood pressure is also lowered secondarily due to the loop diuretic action by SGLT2 inhibitions. Thus, the metabolic and hemodynamic combined systems synergistically interact further to suppress the risks leading to atherosclerosis and organs damage. Precise mechanisms for SGLT2 inhibitors to work in various aspects especially in preventing organ damage and cardiovascular events must be clarified further. Copyright © 2016 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Nephrotic syndrome complicated by idiopathic central diabetes insipidus.

PubMed

Konomoto, Takao; Tanaka, Etsuko; Imamura, Hideaki; Orita, Mayuko; Sawada, Hirotake; Nunoi, Hiroyuki

2014-05-01

There is ongoing discussion regarding the mechanisms underlying edema formation in nephrotic syndrome (NS). Many studies published in the last decade reported that primary renal sodium retention was a major factor in edema formation. However, many of the factors influencing edema formation in NS remain unclear, including the role of arginine vasopressin (AVP). We report a 12-year-old boy with steroid-dependent NS complicated by idiopathic central diabetes insipidus (CDI). He did not develop edema during his first relapse of NS after developing CDI, despite having hypoalbuminemia. He had polydipsia, polyuria, low urine osmolality, and a low serum arginine AVP level. His fractional excretion of sodium was only slightly low. Endocrinological testing and magnetic resonance imaging revealed idiopathic CDI. After starting desmopressin therapy, he developed edema when his NS relapsed. This is the first known reported case of NS in a patient with CDI. The findings suggest that appropriate AVP secretion in response to an increase in serum osmolality caused by renal sodium retention is necessary for excess extracellular fluid accumulation in NS. Further investigation is needed to more fully understand the role of AVP in edema formation in NS.

[13C]Nandrolone excretion in trained athletes: interindividual variability in metabolism.

PubMed

Baume, Norbert; Avois, Lidia; Schweizer, Carine; Cardis, Christine; Dvorak, Jiri; Cauderay, Michel; Mangin, Patrice; Saugy, Martial

2004-02-01

Nandrolone is one of the most abused anabolic steroids, and its use in doping is increasing, as revealed by numerous positive cases during recent years in various sports. Different authors have reported the possible natural production of nandrolone metabolites in humans, and some of these authors argued that exhaustive exercise could increase nandrolone production in the body or induce dehydration and consequently lead to an increase of nandrolone metabolites in urine. Volunteers (n = 22) ingested two 25-mg doses of [(13)C]nandrolone at 24-h intervals and collected urine specimens for 5 days. The labeled nandrolone metabolites 19-norandrosterone and 19-noretiocholanolone were identified and quantified by gas chromatography-mass spectrometry. Interindividual variability was observed in nandrolone excretion patterns and kinetics, as well as for the noretiocholanolone:norandrosterone ratio. The amounts of nandrolone metabolites measured at the excretion peak varied between 1180 and 38 661 microg/L for norandrosterone and 576 and 12 328 microg/L for noretiocholanolone. At the end of the excretion period, the noretiocholanolone:norandrosterone ratio was sometimes >1. The analysis of numerous spot-urine samples allowed the determination of an acceptable correlation between urinary creatinine and specific gravity for placebo- and steroid-treated individuals: y = 0.0052ln(x) + 1.0178 (r(2) = 0.8142) and y = 0.0068ln(x) + 1.0172 (r(2) = 0.7730), respectively. The excretion kinetics and patterns of labeled nandrolone show interindividual variability. More investigations are currently underway to estimate the influence of exhaustive exercises on excretion of labeled nandrolone metabolites in urine.

Is higher sodium intake associated with elevated systemic inflammation? A population-based study.

PubMed

Fogarty, Andrew W; Lewis, Sarah A; McKeever, Tricia M; Britton, John R

2009-06-01

Observational epidemiologic studies have suggested that a low-sodium diet is associated with reduced mortality. The objective was to test the hypothesis that a higher dietary intake of sodium is associated with increased systemic inflammation--a potential risk factor for both cardiovascular disease and cancer. The study design consisted of a randomly selected, cross-sectional, population-based study of 2633 individuals surveyed in 1991, of whom 1597 participants provided paired urinary and blood samples permitting measurement of 24-h urinary sodium excretion and serum C-reactive protein (CRP) concentrations. The mean (+/-SD) 24-h sodium intake for the population was 177 +/- 69 mmol. In the basic model adjusted for age, sex, and smoking, higher levels of 24-h sodium excretion were directly associated with serum CRP, with an increase in serum CRP of 1.20 mg/L per 100-mmol increment in sodium excretion (95% CI: 1.11, 1.30). However, this association was reduced after adjustment for body mass index, with an increase in serum CRP of 1.06 mg/L per 100-mmol increment in sodium excretion (95% CI: -1.02, 1.15). We observed a linear association between an objective measure of sodium intake and serum CRP that may be influenced by confounding by body mass index. The magnitude of these associations suggests that dietary sodium consumption is unlikely to be an important modifiable risk factor for increased systemic inflammation.

Studies on the individual and combined diuretic effects of four Vietnamese traditional herbal remedies (Zea mays, Imperata cylindrica, Plantago major and Orthosiphon stamineus).

PubMed

Doan, D D; Nguyen, N H; Doan, H K; Nguyen, T L; Phan, T S; van Dau, N; Grabe, M; Johansson, R; Lindgren, G; Stjernström, N E

1992-06-01

Herbal remedies are widely used in Vietnam alongside modern drugs. We assessed the diuretic effect of four traditional Vietnamese herbal remedies from Zea mays, Imperata cylindrica, Plantago major and Orthosiphon stamineus, all claimed to produce an increase of diuresis. No influence was recorded for the 12- and 24-h urine output or on the sodium excretion for any of the drugs when tested under standardized conditions in a placebo controlled double-blind crossover model. The present study indicates the need for critical review of the present recommendations regarding therapy with plant materials in countries relying on empiric traditions.

Prediction of urinary nitrogen and urinary urea nitrogen excretion by lactating dairy cattle in northwestern Europe and North America: a meta-analysis.

PubMed

Spek, J W; Dijkstra, J; van Duinkerken, G; Hendriks, W H; Bannink, A

2013-07-01

A meta-analysis was conducted on the effect of dietary and animal factors on the excretion of total urinary nitrogen (UN) and urinary urea nitrogen (UUN) in lactating dairy cattle in North America (NA) and northwestern Europe (EU). Mean treatment data were used from 47 trials carried out in NA and EU. Mixed model analysis was used with experiment included as a random effect and all other factors, consisting of dietary and animal characteristics, included as fixed effects. Fixed factors were nested within continent (EU or NA). A distinction was made between urinary excretions based on either urine spot samples or calculated assuming a zero N balance, and excretions that were determined by total collection of urine only. Moreover, with the subset of data based on total collection of urine, a new data set was created by calculating urinary N excretion assuming a zero N balance. Comparison with the original subset of data allowed for examining the effect of such an assumption on the relationship established between milk urea N (MUN) concentration and UN. Of all single dietary and animal factors evaluated to predict N excretion in urine, MUN and dietary crude protein (CP) concentration were by far the best predictors. Urinary N excretion was best predicted by the combination of MUN, CP, and dry matter intake, whereas UUN was best predicted by the combination of MUN and CP. All other factors did not improve or only marginally improved the prediction of UN or UUN. The relationship between UN and MUN differed between NA and EU, with higher estimated regression coefficients for MUN for the NA data set. Precision of UN and UUN prediction improved substantially when only UN or UUN data based on total collection of urine were used. The relationship between UN and MUN for the NA data set, but not for the EU data set, was substantially altered when UN was calculated assuming a zero N balance instead of being based on the total collection of urine. According to results of the present meta-analysis, UN and UUN are best predicted by the combination of MUN and CP and that, in regard to precision and accuracy, prediction equations for UN and UUN should be derived from the total collection of urine. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Cardiovascular risk factors in two Ecuadorian urban and rural populations. The Ecuadorian-Japan Cooperative CARDIAC Study Group.

PubMed

Del Pozo, G; Davalos, P; Yamori, Y

1990-01-01

We examined the specific hypotheses linking the intake of sodium, potassium, calcium, magnesium, and protein to blood pressure (BP) and the relationship between dietary factors and mortality from the major cardiovascular diseases (CVD) in the Ecuadorian populations. Two Ecuadorian populations, the urban and the rural, were selected from Quito and Vilcabamba, respectively. From Quito: 87 men and 83 women; from Vilcabamba: 71 men and 91 women aged 50-54 were randomly selected for BP measurement, 24-h urine collection, and blood sampling according to the Cardiovascular Disease and Alimentary Comparison (CARDIAC) Study protocol. Samples were analyzed at CARDIAC center in Izumo, Japan. Mean systolic blood pressure (SBP) was not much different in the two populations, but mean diastolic blood pressure (DBP) and body mass index (BMI) were significantly lower in Vilcabamba (p less than 0.001). Mortality from stroke was higher in Vilcabamba, whereas coronary death rate was higher in Quito. Both sodium intake and sodium/potassium ratio were higher in Vilcabamba (p less than 0.001). Protein intake and serum cholesterol were higher in Quito (p less than 0.001). Urinary taurine excretion was higher in Quito. There was no difference in W3/W6 fatty acids ratio between the two populations. Multiple regression analyses of intracommunity correlation indicated that both SBP and DBP were highly significantly related with BMI in Quito and that urinary excretions were inversely related to SBP. Serum cholesterol was positively related to coronary death rate. Mortality from stroke was inversely related to both serum cholesterol and protein and was positively related to salt consumption.

In Vivo Cardiovascular Pharmacology of 2′,3′-cAMP, 2′-AMP, and 3′-AMP in the Rat

PubMed Central

Mi, Zaichuan

2013-01-01

The naturally occurring purine 2′,3′-cAMP is metabolized in vitro to 2′-AMP and 3′-AMP, which are subsequently metabolized to adenosine. Whether in vivo 2′,3′-cAMP, 2′-AMP, or 3′-AMP are rapidly converted to adenosine and exert rapid effects via adenosine receptors is unknown. To address this question, we compared the cardiovascular and renal effects of 2′,3′-cAMP, 2′-AMP, 3′-AMP, 3′,5′-cAMP, 5′-AMP, and adenosine in vivo in the rat. Purines were infused intravenously while monitoring mean arterial blood pressure (MABP), heart rate (HR), cardiac output, and renal and mesenteric blood flows. Total peripheral (TPR), renal vascular (RVR), and mesenteric vascular (MVR) resistances were calculated. Urine was collected for determination of urine excretion rate [urine volume (UV)]. When sufficient urine was available, the sodium excretion rate (Na+ER) and glomerular filtration rate (GFR) were determined. 2′,3′-cAMP, 2′-AMP, and 3′-AMP dose-dependently and profoundly reduced MABP, HR, TPR, and MVR with efficacy and potency similar to adenosine and 5′-AMP. These effects of 2′,3′-cAMP, 2′-AMP, and 3′-AMP were attenuated by blockade of adenosine receptors with 1,3-dipropyl-8-(p-sulfophenyl)xanthine. 2′,3′-cAMP, 2′-AMP, 3′-AMP, adenosine, and 5′-AMP variably affected RVR, but profoundly (nearly 100%) decreased UV at higher doses. GFR and Na+ER could be measured at the lower doses and were suppressed by 2′,3′-cAMP, 2′-AMP, and 3′-AMP, but not by adenosine or 5′-AMP. 2′,3′-cAMP increased urinary excretion rates of 2′-AMP, 3′-AMP, and adenosine. 3′,5′-cAMP exerted no adverse hemodynamic effects yet increased urinary adenosine as efficiently as 2′,3′-cAMP. Conclusions: In vivo 2′,3′-cAMP is rapidly converted to adenosine. Because both cAMPs increase adenosine in the urinary compartment, these agents may provide unique therapeutic opportunities. PMID:23759508

Effect of a commercial anion dietary supplement on acid-base balance, urine volume, and urinary ion excretion in male goats fed oat or grass hay diets.

PubMed

Stratton-Phelps, Meri; House, John K

2004-10-01

To determine whether feeding a commercial anionic dietary supplement as a urinary acidifier to male goats may be useful for management of urolithiasis. 8 adult sexually intact male Toggenburg, Saanen, and Nubian goats. Goats were randomly assigned by age-, breed-, and weight-matched pairs to an oat or grass hay diet that was fed for 12 days. On days 13 to 14 (early sample collection time before supplementation), measurements were made of blood and urine sodium, potassium, calcium, magnesium, chloride, phosphorus, and sulfur concentrations; blood and urine pH; urine production; and water consumption. During the next 28 days, the anionic dietary supplement was added to the oat and grass hay diets to achieve a dietary cation-anion difference of 0 mEq/100g of dry matter. Blood and urine samples were analyzed during dietary supplementation on days 12 to 13 (middle sample collection time) and 27 to 28 (late sample collection time). Blood bicarbonate, pH, and urine pH of goats fed grass hay and goats fed oat hay were significantly decreased during the middle and late sample collection times, compared with the early sample collection time. Water consumption and urine production in all goats increased significantly during the late sample collection time, compared with the early sample collection time. The anionic dietary supplement used in our study increases urine volume, alters urine ion concentrations, and is an efficacious urinary acidifier in goats. Goats treated with prolonged anionic dietary supplementation should be monitored for secondary osteoporosis from chronic urinary calcium loss.

The Association between Urinary Sodium Excretion and Metabolic Syndrome in Korean Adults from the 2010–2011 Korean National Health and Nutrition Examination Survey

PubMed Central

Seo, Jeong Eun; Lee, Hong Soo; Lee, Sang Wha; Shim, Kyung Won; Byun, A Ri; Kim, Jung Hwa; An, Hee Jeong

2017-01-01

Background The sodium intake of Koreans was higher than that recommended by the World Health Organization. Urinary sodium, which is correlated with sodium intake, can be easily calculated by the Tanaka's equation. This study aimed to evaluate the association between urinary sodium and metabolic syndrome in Korean adults using the 2010–2011 Korean National Health and Nutrition Examination Survey (KNHANES). Methods A total of 5,870 participants from the 2010–2011 KNHANES were included in this study. Twenty-four hour urinary sodium was calculated by the Tanaka's equation using spot urine. Participants were divided into tertiles based on urinary sodium levels. The association between urinary sodium and metabolic syndrome was analyzed using multivariate logistic regression analysis. Results The odds ratios (ORs) and 95% confidence intervals (CIs) of metabolic syndrome for the 2nd and 3rd tertile of urinary sodium levels was 1.51 (1.16–1.97) and 1.56 (1.23–1.97) compared to the lowest tertile of urinary sodium in men. The ORs and 95% CIs of metabolic syndrome in women were 1.20 (0.95–1.51) for the 2nd tertile and 2.16 (1.68–2.78) for the 3rd tertile. These associations remained statistically significant, even after adjusting for multiple covariates such as age, education, regular exercise, smoking, and alcohol consumption. Conclusion These findings indicate that urinary sodium is significantly associated with metabolic syndrome in Korean adults. PMID:28775809

Calcium EDTA toxicity: renal excretion of endogenous trace metals and the effect of repletion on collagen degradation in the rat.

PubMed

Braide, V B

1984-01-01

Studies on total hydroxyproline concentrations in urine of rats infused with toxic doses of CaEDTA at 6 mmol/kg per 24 hr for 48 hr or injected i.p. with the chelate at 4.8 mmol/kg/day for 10 days, indicate a two- to six-fold increase in urine excretion of the imino acid. This is due to increased degradation of collagen induced by CaEDTA. CaEDTA infusion was also shown to enhance urine excretion of some trace metals (Zn, Mn, Cu and Fe). Rats infused with CaEDTA for 36 hr showed a gradual fall in concentration of hydroxyproline in the urine, following cessation of chelate infusion. The decline in hydroxyproline concentrations was faster in rats receiving trace metal (Zn, Co, Mn or Ni) treatment during the post-CaEDTA infusion period; suggesting that the metals may affect collage, making the protein less susceptible to degradation in the body.

Correlation of arsenic exposure through drinking groundwater and urinary arsenic excretion among adults in Pakistan.

PubMed

Ahmed, Mubashir; Fatmi, Zafar; Ali, Arif

2014-01-01

Long-term exposure to arsenic has been associated with manifestation of skin lesions (melanosis/keratosis) and increased risk of internal cancers (lung/bladder). The objective of the study described here was to determine the relationship between exposure of arsenic through drinking groundwater and urinary arsenic excretion among adults > or =15 years of age living in Khairpur district, Pakistan. Total arsenic was determined in drinking groundwater and in spot urine samples of 465 randomly selected individuals through hydride generation-atomic absorption spectrometry. Spearman's rank correlation coefficient was calculated between arsenic in drinking groundwater and arsenic excreted in urine. The median arsenic concentration in drinking water was 2.1 microg/L (range: 0.1-350), and in urine was 28.5 microg/L (range: 0.1-848). Positive correlation was found between total arsenic in drinking water and in urine (r = .52, p < .01). Urinary arsenic may be used as a biomarker of arsenic exposure through drinking water.

New insights into the mechanism of methoxyflurane nephrotoxicity and implications for anesthetic development (part 2): Identification of nephrotoxic metabolites.

PubMed

Kharasch, Evan D; Schroeder, Jesara L; Liggitt, H Denny; Ensign, Dustin; Whittington, Dale

2006-10-01

Methoxyflurane nephrotoxicity results from its metabolism, which occurs by both dechlorination (to methoxydifluoroacetic acid [MDFA]) and O-demethylation (to fluoride and dichloroacetic acid [DCAA]). Inorganic fluoride can be toxic, but it remains unknown why other anesthetics, commensurately increasing systemic fluoride concentrations, are not toxic. Fluoride is one of many methoxyflurane metabolites and may itself cause toxicity and/or reflect formation of other toxic metabolite(s). This investigation evaluated the disposition and renal effects of known methoxyflurane metabolites. Rats were given by intraperitoneal injection the methoxyflurane metabolites MDFA, DCAA, or sodium fluoride (0.22, 0.45, 0.9, or 1.8 mmol/kg followed by 0.11, 0.22, 0.45, or 0.9 mmol/kg on the next 3 days) at doses relevant to metabolite exposure after methoxyflurane anesthesia, or DCAA and fluoride in combination. Renal histology and function (blood urea nitrogen, urine volume, urine osmolality) and metabolite excretion in urine were assessed. Methoxyflurane metabolite excretion in urine after injection approximated that after methoxyflurane anesthesia, confirming the appropriateness of metabolite doses. Neither MDFA nor DCAA alone had any effects on renal function parameters or necrosis. Fluoride at low doses (0.22, then 0.11 mmol/kg) decreased osmolality, whereas higher doses (0.45, then 0.22 mmol/kg) also caused diuresis but not significant necrosis. Fluoride and DCAA together caused significantly greater tubular cell necrosis than fluoride alone. Methoxyflurane nephrotoxicity seems to result from O-demethylation, which forms both fluoride and DCAA. Because their co-formation is unique to methoxyflurane compared with other volatile anesthetics and they are more toxic than fluoride alone, this suggests a new hypothesis of methoxyflurane nephrotoxicity. This may explain why increased fluoride formation from methoxyflurane, but not other anesthetics, is associated with toxicity. These results may have implications for the interpretation of clinical anesthetic defluorination, use of volatile anesthetics, and the laboratory methods used to evaluate potential anesthetic toxicity.

β3 adrenergic receptor in the kidney may be a new player in sympathetic regulation of renal function.

PubMed

Procino, Giuseppe; Carmosino, Monica; Milano, Serena; Dal Monte, Massimo; Schena, Giorgia; Mastrodonato, Maria; Gerbino, Andrea; Bagnoli, Paola; Svelto, Maria

2016-09-01

To date, the study of the sympathetic regulation of renal function has been restricted to the important contribution of β1- and β2-adrenergic receptors (ARs). Here we investigate the expression and the possible physiologic role of β3-adrenergic receptor (β3-AR) in mouse kidney. The β3-AR is expressed in most of the nephron segments that also express the type 2 vasopressin receptor (AVPR2), including the thick ascending limb and the cortical and outer medullary collecting duct. Ex vivo experiments in mouse kidney tubules showed that β3-AR stimulation with the selective agonist BRL37344 increased intracellular cAMP levels and promoted 2 key processes in the urine concentrating mechanism. These are accumulation of the water channel aquaporin 2 at the apical plasma membrane in the collecting duct and activation of the Na-K-2Cl symporter in the thick ascending limb. Both effects were prevented by the β3-AR antagonist L748,337 or by the protein kinase A inhibitor H89. Interestingly, genetic inactivation of β3-AR in mice was associated with significantly increased urine excretion of water, sodium, potassium, and chloride. Stimulation of β3-AR significantly reduced urine excretion of water and the same electrolytes. Moreover, BRL37344 promoted a potent antidiuretic effect in AVPR2-null mice. Thus, our findings are of potential physiologic importance as they uncover the antidiuretic effect of β3-AR stimulation in the kidney. Hence, β3-AR agonism might be useful to bypass AVPR2-inactivating mutations. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Experimental model for acute kidney injury caused by uropathogenic Escherichia coli.

PubMed

Skowron, Beata; Baranowska, Agnieszka; Kaszuba-Zwoińska, Jolanta; Więcek, Grażyna; Malska-Woźniak, Anna; Heczko, Piotr; Strus, Magdalena

2017-06-19

Acute kidney injury (AKI) is the rapid deterioration of renal function, diagnosed on the basis of an increase in serum creatinine and abnormal urinary parameters. AKI is associated with increased risk of mortality or chronic kidney disease (CKD). The aim of the study was to develop an experimental model for AKI resulting from Escherichia coli-induced pyelonephritis. E. coli was isolated from a patient with clinical symptoms of urinary tract infection (UTI). The study included three groups of female Wistar rats (groups 1, 2 and 3), in which pyelonephritis was induced by transurethral inoculation with highly virulent E. coli (105, 107 and 109 cfu/ml, respectively). Urine and blood samples for analysis were obtained prior to the inoculation (day 0), as well as 7, 14 and 21 days thereafter. Aside from a microbiological examination of urine samples, daily urine output, serum creatinine (CreaS), creatinine clearance (CrCl), interleukin 6 (IL-6), fractional excretion of sodium (FENa) and fractional excretion of urea (FEUrea) were determined. A histopathological examination of kidney and urinary bladder specimens was conducted as well. While UTI-related pyelonephritis developed irrespective of E. coli inoculum size, AKI was observed only following transurethral administration of E. coli at the intermediate and high dose, i.e. 107 and 109 cfu/ml, respectively (group 2 and 3). An increase in CreaS and abnormal diuresis were accompanied by changes in parameters specific for various forms of AKI, i.e. FENa and FEUrea. Based on these changes, administration of E. coli at 107 cfu/ml was demonstrated to induce renal AKI, whereas inoculation with 109 cfu/ml seemed to cause not only ascending pyelonephritis, but perhaps also bacteremia and urosepsis (prerenal component of AKI).

Sodium intake, RAAS-blockade and progressive renal disease.

PubMed

de Borst, Martin H; Navis, Gerjan

2016-05-01

Pharmacological blockade of the renin-angiotensin-aldosterone system (RAAS) by angiotensin converting enzyme inhibitors or angiotensin receptor blockers is the current standard treatment to prevent progressive renal function loss in patients with chronic kidney disease. Yet in many patients the renal protective effect of RAAS-blockade is incomplete. Short-term clinical studies have demonstrated that dietary sodium restriction potentiates the antiproteinuric effect of RAAS-blockade. More recently, it was shown that this effect is accompanied by a lower risk of end-stage renal disease and adverse cardiovascular outcomes. The modulation of RAAS-blockade efficacy by sodium intake is likely multifactorial, and is mediated by effects of sodium on local tissue RAAS in kidney, vasculature and brain, and by effects on the immune system. Despite the evidence showing the beneficial effects of even a moderate sodium restriction (∼2.5g/d), it remains difficult to realize in clinical practice. In an analysis based on 24-h urinary sodium excretion data from more than 10,000 CKD patients and renal transplant recipients, we found that sodium intake in these patients is on average 3.8g/d, closely resembling the global general population (3.95g/d). Behavioral approaches including the use of online dietary coaching (ehealth) and feedback using data from 24-h urine collections may be useful to successfully lower dietary sodium intake, aiming to improve cardio-renal outcomes in patients with CKD. Copyright © 2016 Elsevier Ltd. All rights reserved.

Congenital erythropoietic porphyria in an African hedgehog (Atelerix albiventris).

PubMed

Wolff, Carlos; Corradini, Paulina; Cortés, Galaxia

2005-06-01

A 6-mo-old, male African hedgehog (Atelerix albiventris) presented with a history of pink urine and demonstrating pink-colored teeth and mild hepatomegaly on examination. Urinalysis revealed no physical, chemical, or cellular abnormalities other than a pink color and fluorescence under ultraviolet light (UV). Also under UV, intense fluorescence of teeth, feet, and spines was noted. Porphyria was suspected. Spectrophotometric evaluation of urine showed extremely elevated levels of copro- and uroporphyrins. Analysis of the urine by thin-layer chromatography showed an abnormal pattern of excreted porphyrin intermediates. Urine high-performance thin-layer chromatography showed that excreted porphyrins were 90-95% of the type-I isomeric form, suggestive of congenital erythropoietic porphyria.

Do You Have Symptoms of a Kidney Stone?

MedlinePlus

... to a veterinarian if you see blood or crystals in the urine or signs of painful urination. Pets with stones often try to urinate frequently, but excrete only a tiny amount of urine most of the time. They will squat and strain but either nothing ...

Glycerophosphate is interchangeable with inorganic phosphate in terms of safety and serum pharmacokinetics.

PubMed

Topp, Heinrich; Hochfeld, Olena; Bark, Staffan; Grossmann, Matthias; Joukhadar, Christian; Westphal, Martin; Straatsma, Harald; Rothenburger, Markus

2011-01-01

The primary aim of the present investigation was to determine and compare the pharmacokinetic (PK) profiles of inorganic phosphate in serum and urine after intravenous administration of sodium glycerophosphate and inorganic sodium phosphate. Additionally, study product safety profiles were evaluated. In total, 27 healthy, white volunteers (17 male/10 female) were enrolled in this double-blinded, randomized, 2-sequence, crossover study and were assigned to receive an organic test drug (sodium glycerophosphate) and an inorganic reference preparation (sodium phosphate) on 2 occasions. Validated analytical methods were used, and concentrations of total inorganic phosphate in serum and urine were determined over 24 h following a single 4-hour continuous intravenous infusion of test and reference drugs at a dose of 80 mmol. Study days were separated by washout periods of 7 days. An analysis of variance, based on population means and 90% confidence intervals (CIs), was used for testing bioequivalence (BE; range 0.8-1.25) between investigational products. The geometric means of the ratio of the point estimates and corresponding 90% CIs for the area under the concentration-versus-time curve of inorganic serum phosphate from 0 to 24 h (AUC(0-24)), the phosphate's maximum concentration in serum (C(max)) and the total amount of inorganic phosphate excreted in urine over 24 h corrected for individual baseline values (Ae(0-24 bc)) were estimated. The test/reference ratios for inorganic phosphate were 1.04 (CI 1.00-1.07), 0.85 (CI 0.84-0.87) and 0.84 (CI 0.77-0.92) for AUC(0-24), C(max) in serum and Ae(0-24 bc) in urine, respectively. Hence, standard BE criteria were met for AUC(0-24) and C(max) in serum, while Ae(0-24 bc) marginally failed to demonstrate BE. After drug administration, a total of 15 subjects reported the occurrence of at least 1 treatment emergent adverse event (AE). All AEs were classified as mild to moderate in severity, and the two treatment groups were equally affected. No serious AEs occurred. The serum PK profiles of inorganic phosphate were almost superimposable following intravenous administration of equimolar doses of test and reference drugs. Thus, we conclude that the two study drugs are essentially similar in terms of serum PK profiles, safety and tolerability. Copyright © 2011 S. Karger AG, Basel.

Quantification of acetylcholine, choline, betaine, and dimethylglycine in human plasma and urine using stable-isotope dilution ultra performance liquid chromatography-tandem mass spectrometry.

PubMed

Kirsch, Susanne H; Herrmann, Wolfgang; Rabagny, Yannick; Obeid, Rima

2010-12-15

Disorders in choline metabolism are related to disease conditions. We developed a stable-isotope dilution ultra performance liquid chromatography-mass spectrometry (UPLC-MS/MS) method for the simultaneous quantification of acetylcholine (ACh), betaine, choline, and dimethylglycine (DMG). We used this method to measure concentrations of the analytes in plasma and urine in addition to other biological fluids after a protein precipitation by acetonitrile. The detection limits were between 0.35 nmol/L (for ACh in urine) and 0.34 μmol/L (for betaine in urine). ACh concentrations were not detectable in plasma. Intraassay and interassay coefficient of variation (CVs) were all <10.0% in biological fluids, except for DMG in cerebrospinal fluid (CV=12.44%). Mean recoveries in urine pool samples were between 99.2% and 103.9%. The urinary excretion of betaine, choline, and DMG was low, with approximately 50.0% higher excretion of choline in females compared to males. Median urinary excretion of ACh were 3.44 and 3.92 μmol/mol creatinine in males and females, respectively (p=0.689). Plasma betaine concentrations correlated significantly with urinary excretions of betaine (r=0.495, p=0.027) and choline (r=0.502, p=0.024) in females. Plasma choline concentrations correlated significantly with urinary excretion of ACh in males (r=0.419, p=0.041) and females (r=0.621, p=0.003). The new method for the simultaneous determination of ACh, betaine, choline, and DMG is sensitive, precise, and fast enough to be used in clinical investigations related to the methylation pathway. Copyright © 2010 Elsevier B.V. All rights reserved.

Toxicokinetics of 1,2-diethylbenzene in male Sprague-Dawley rats-part 1: excretion and metabolism of [(14)C]1,2-diethylbenzene.

PubMed

Payan, J P; Beydon, D; Cossec, B; Ensminger, A; Fabry, J P; Ferrari, E

1999-12-01

The excretion and metabolism of neurotoxic 1,2-diethylbenzene (1, 2-DEB) was studied in male Sprague-Dawley rats after i.v. (1 mg/kg) or oral (1 or 100 mg/kg) administration of 1,2-diethyl[U-(14)C]benzene ([(14)C]1,2-DEB). Whatever the treatment, radioactivity was mainly excreted in urine (65-76% of the dose) and to a lower extent in feces (15-23% of the dose), or via exhaled air (3-5% of the dose). However, experiments with rats fitted with a biliary cannula demonstrated that about 52 to 64% of the administered doses (1 or 100 mg/kg) were initially excreted in bile. Biliary metabolites were extensively reabsorbed from the gut and ultimately excreted in urine after several enterohepatic circulations. Insignificant amounts of unchanged 1,2-DEB were recovered in the different excreta (urine, bile, and feces). As reported previously, presence of 1-(2'-ethylphenyl)ethanol (EPE) was confirmed in urine and demonstrated in bile and feces. The two main [(14)C]1,2-DEB metabolites accounted for 57 to 79% of urinary and biliary radioactivity, respectively. Beta-Glucuronidase hydrolysis and electron impact mass spectra results strongly supported their glucuronide structure. Additionally, these two main metabolites were thought to be the glucuronide conjugates of the two potential enantiomers of EPE. The results indicate that the main initial conversion step of the primary metabolic pathway of 1,2-DEB appears to be the hydroxylation of the alpha-carbon atom of the side chain. The presence of two glucuronide conjugates of EPE in the urine in a ratio different from one suggests that the metabolic conversion of 1, 2-DEB is under stereochemical control.

Uric acid, an important screening tool to detect inborn errors of metabolism: a case series.

PubMed

Jasinge, Eresha; Kularatnam, Grace Angeline Malarnangai; Dilanthi, Hewa Warawitage; Vidanapathirana, Dinesha Maduri; Jayasena, Kandana Liyanage Subhashinie Priyadarshika Kapilani Menike; Chandrasiri, Nambage Dona Priyani Dhammika; Indika, Neluwa Liyanage Ruwan; Ratnayake, Pyara Dilani; Gunasekara, Vindya Nandani; Fairbanks, Lynette Dianne; Stiburkova, Blanka

2017-09-06

Uric acid is the metabolic end product of purine metabolism in humans. Altered serum and urine uric acid level (both above and below the reference ranges) is an indispensable marker in detecting rare inborn errors of metabolism. We describe different case scenarios of 4 Sri Lankan patients related to abnormal uric acid levels in blood and urine. CASE 1: A one-and-half-year-old boy was investigated for haematuria and a calculus in the bladder. Xanthine crystals were seen in microscopic examination of urine sediment. Low uric acid concentrations in serum and low urinary fractional excretion of uric acid associated with high urinary excretion of xanthine and hypoxanthine were compatible with xanthine oxidase deficiency. CASE 2: An 8-month-old boy presented with intractable seizures, feeding difficulties, screaming episodes, microcephaly, facial dysmorphism and severe neuro developmental delay. Low uric acid level in serum, low fractional excretion of uric acid and radiological findings were consistent with possible molybdenum cofactor deficiency. Diagnosis was confirmed by elevated levels of xanthine, hypoxanthine and sulfocysteine levels in urine. CASE 3: A 3-year-10-month-old boy presented with global developmental delay, failure to thrive, dystonia and self-destructive behaviour. High uric acid levels in serum, increased fractional excretion of uric acid and absent hypoxanthine-guanine phosphoribosyltransferase enzyme level confirmed the diagnosis of Lesch-Nyhan syndrome. CASE 4: A 9-year-old boy was investigated for lower abdominal pain, gross haematuria and right renal calculus. Low uric acid level in serum and increased fractional excretion of uric acid pointed towards hereditary renal hypouricaemia which was confirmed by genetic studies. Abnormal uric acid level in blood and urine is a valuable tool in screening for clinical conditions related to derangement of the nucleic acid metabolic pathway.

Renal distal tubule proliferation and increased aquaporin 2 level but decreased urine osmolality in db/db mouse: treatment with chromium picolinate.

PubMed

Mozaffari, Mahmood S; Abdelsayed, Rafik; Liu, Jun Yao; Zakhary, Ibrahim; Baban, Babak

2012-02-01

Hallmark features of type 2 diabetes mellitus include glucosuria and polyuria. Further, renal aquaporin 2 is pivotal to regulation of fluid excretion and urine osmolality. Accordingly, we tested the hypothesis that the db/db mouse displays increased glucosuria and fluid excretion but reduced urine osmolality in association with decreased renal aquaporin 2 level. In addition, we examined the effect of chromium picolinate (Cr(pic)3) which is purported to improve glycemic control. The db/db mice excreted more urine in association with marked glucose excretion but lower urine osmolality than db/m control group. Light microscopic examination of renal tissue revealed proliferation of tubular structures in db/db compared to the db/m mice, a feature validated with Ki67 immunostaining. Further, these tubules showed generally similar immunostaining intensity and pattern for aquaporin 2 indicating that proliferated tubules are of distal origin. On the other hand, renal aquaporin 2 protein level was significantly higher in the db/db than db/m group. Treatment of db/db mice with Cr(pic)3 reduced plasma glucose and hemoglobin A1c (~15-17%, p<0.05) and Ki67 positive cells but other parameters were similar to their untreated counterparts. Collectively, these findings suggest that proliferation of renal distal tubules and increased aquaporin 2 level likely represent an adaptive mechanism to regulate fluid excretion to prevent dehydration in the setting of marked glucosuria in the db/db mouse, features not affected by Cr(pic)3 treatment. These observations are of relevance to increasing interest in developing therapeutic agents that facilitate renal glucose elimination. Copyright © 2011 Elsevier Inc. All rights reserved.

Renal distal tubule proliferation and increased aquaporin 2 level but decreased urine osmolality in db/db mouse: treatment with chromium picolinate

PubMed Central

Mozaffari, Mahmood S.; Abdelsayed, Rafik; Liu, Jun Yao; Zakhary, Ibrahim; Baban, Babak

2011-01-01

Hallmark features of type 2 diabetes mellitus include glucosuria and polyuria. Further, renal aquaporin 2 is pivotal to regulation of fluid excretion and urine osmolality. Accordingly, we tested the hypothesis that the db/db mouse displays increased glucosuria and fluid excretion but reduced urine osmolality in association with decreased renal aquaporin 2 level. In addition, we examined the effect of chromium picolinate (Cr(pic)3) which is purported to improve glycemic control. The db/db mice excreted more urine in association with marked glucose excretion but lower urine osmolality than db/m control group. Light microscopic examination of renal tissue revealed proliferation of tubular structures in db/db compared to the db/m mice, a feature validated with Ki67 immunostaining. Further, these tubules showed generally similar immunostaining intensity and pattern for aquaporin 2 indicating that proliferated tubules are of distal origin. On the other hand, renal aquaporin 2 protein level was significantly higher in the db/db than db/m group. Treatment of db/db mice with Cr(pic)3 reduced plasma glucose and hemoglobin A1c (~ 15–17%, p<0.05) and Ki67 positive cells but other parameters were similar to their untreated counterparts. Collectively, these findings suggest that proliferation of renal distal tubules and increased aquaporin 2 level likely represent an adaptive mechanism to regulate fluid excretion to prevent dehydration in the setting of marked glucosuria in the db/db mouse, features not affected by Cr(pic)3 treatment. These observations are of relevance to increasing interest in developing therapeutic agents that facilitate renal glucose elimination. PMID:21983138

Urinary excretion of purine derivatives as an index of microbial protein synthesis in the camel (Camelus dromedarius).

PubMed

Guerouali, Abdelhai; El Gass, Youssef; Balcells, Joaquim; Belenguer, Alvaro; Nolan, John

2004-08-01

Five experiments were carried out to extend knowledge of purine metabolism in the camel (Camelus dromedarius) and to establish a model to enable microbial protein outflow from the forestomachs to be estimated from the urinary excretion of purine derivatives (PD; i.e. xanthine, hypoxanthine, uric acid, allantoin). In experiment 1, four camels were fasted for five consecutive days to enable endogenous PD excretion in urine to be determined. Total PD excretion decreased during the fasting period to 267 (SE 41.5) micromol/kg body weight (W)0.75 per d. Allantoin and xanthine + hypoxanthine were consistently 86 and 6.1 % of total urinary PD during this period but uric acid increased from 3.6 % to 7.4 %. Xanthine oxidase activity in tissues (experiment 2) was (micromol/min per g fresh tissue) 0.038 in liver and 0.005 in gut mucosa but was not detected in plasma. In experiment 3, the duodenal supply of yeast containing exogenous purines produced a linear increase in urinary PD excretion rate with the slope indicating that 0.63 was excreted in urine. After taking account of endogenous PD excretion, the relationship can be used to predict purine outflow from the rumen. From the latter prediction, and also the purine:protein ratio in bacteria determined in experiment 5, we predicted the net microbial outflow from the rumen. In experiment 4, with increasing food intake, the rate of PD excretion in the urine increased linearly by about 11.1 mmol PD/kg digestible organic matter intake (DOMI), equivalent to 95 g microbial protein/kg DOMI.

Dietary Sodium Consumption Predicts Future Blood Pressure and Incident Hypertension in the Japanese Normotensive General Population.

PubMed

Takase, Hiroyuki; Sugiura, Tomonori; Kimura, Genjiro; Ohte, Nobuyuki; Dohi, Yasuaki

2015-07-29

Although there is a close relationship between dietary sodium and hypertension, the concept that persons with relatively high dietary sodium are at increased risk of developing hypertension compared with those with relatively low dietary sodium has not been studied intensively in a cohort. We conducted an observational study to investigate whether dietary sodium intake predicts future blood pressure and the onset of hypertension in the general population. Individual sodium intake was estimated by calculating 24-hour urinary sodium excretion from spot urine in 4523 normotensive participants who visited our hospital for a health checkup. After a baseline examination, they were followed for a median of 1143 days, with the end point being development of hypertension. During the follow-up period, hypertension developed in 1027 participants (22.7%). The risk of developing hypertension was higher in those with higher rather than lower sodium intake (hazard ratio 1.25, 95% CI 1.04 to 1.50). In multivariate Cox proportional hazards regression analysis, baseline sodium intake and the yearly change in sodium intake during the follow-up period (as continuous variables) correlated with the incidence of hypertension. Furthermore, both the yearly increase in sodium intake and baseline sodium intake showed significant correlations with the yearly increase in systolic blood pressure in multivariate regression analysis after adjustment for possible risk factors. Both relatively high levels of dietary sodium intake and gradual increases in dietary sodium are associated with future increases in blood pressure and the incidence of hypertension in the Japanese general population. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Urinary Netrin-1: A New Biomarker for the Early Diagnosis of Renal Damage in Obese Children.

PubMed

Övünç Hacıhamdioğlu, Duygu; Hacıhamdioğlu, Bülent; Altun, Demet; Müftüoğlu, Tuba; Karademir, Ferhan; Süleymanoğlu, Selami

2016-09-01

Urinary netrin-1 is a new marker to demonstrate early tubular damage. The aim of this study was to determine whether urinary netrin-1 is increased in obese children. A total of 68 normoalbuminuric and normotensive obese patients and 65 controls were included in the study. Urine samples were collected for assessment of urinary phosphorus, sodium, potassium, creatinine, albumin, and netrin-1. Blood samples were collected for measurements of fasting glucose, insulin, lipid, phosphorus, sodium, potassium, and creatinine levels. Homeostatic model assessment insulin resistance index was calculated. Gender and age were similar between obese and control groups (12.01±3.03 vs. 11.7±3.2 years, p=0.568 and 33 vs. 35 girls, p=0.543, respectively). Obese patients had significantly higher netrin-1 excretion than the controls (841.68±673.17 vs. 228.94±137.25 pg/mg creatinine, p=0.000). Urinary netrin-1 level was significantly higher in obese subjects with insulin resistance compared to those without insulin resistance (1142±1181 vs. 604.9±589.91 pg/mg creatinine, p=0.001). In normotensive and normoalbuminuric obese children, urinary netrin-1 level can increase before onset of albuminuria. Urinary netrin-1 excretion appears to be affected predominantly by insulin resistance and hyperinsulinemia. Urinary netrin-1 may be a new biomarker for determining early tubular injury in obese children.

Effect of dipeptidyl peptidase-4 inhibition on circadian blood pressure during the development of salt-dependent hypertension in rats

PubMed Central

Sufiun, Abu; Rafiq, Kazi; Fujisawa, Yoshihide; Rahman, Asadur; Mori, Hirohito; Nakano, Daisuke; Kobori, Hiroyuki; Ohmori, Koji; Masaki, Tsutomu; Kohno, Masakazu; Nishiyama, Akira

2015-01-01

A growing body of evidence has indicated that dipeptidyl peptidase-4 (DPP-4) inhibitors have antihypertensive effects. Here, we aim to examine the effect of vildagliptin, a DPP-4-specific inhibitor, on blood pressure and its circadian-dipping pattern during the development of salt-dependent hypertension in Dahl salt-sensitive (DSS) rats. DSS rats were treated with a high-salt diet (8% NaCl) plus vehicle or vildagliptin (3 or 10 mg kg−1 twice daily by oral gavage) for 7 days. Blood pressure was measured by the telemetry system. High-salt diet for 7 days significantly increased the mean arterial pressure (MAP), systolic blood pressure (SBP) and were also associated with an extreme dipping pattern of blood pressure in DSS rats. Treatment with vildagliptin dose-dependently decreased plasma DPP-4 activity, increased plasma glucagon-like peptide 1 (GLP-1) levels and attenuated the development of salt-induced hypertension. Furthermore, vildagliptin significantly increased urine sodium excretion and normalized the dipping pattern of blood pressure. In contrast, intracerebroventricular infusion of vildagliptin (50, 500 or 2500 μg) did not alter MAP and heart rate in DSS rats. These data suggest that salt-dependent hypertension initially develops with an extreme blood pressure dipping pattern. The DPP-4 inhibitor, vildagliptin, may elicit beneficial antihypertensive effects, including the improvement of abnormal circadian blood pressure pattern, by enhancing urinary sodium excretion. PMID:25588850

Salt Intake and the Association with Blood Pressure in Young Iranian Children: First Report From the Middle East and North Africa

PubMed Central

Kelishadi, Roya; Gheisari, Alaleh; Zare, Narges; Farajian, Sanam; Shariatinejad, Keyvan

2013-01-01

Background: This study aimed to assess the salt intake of Iranian children, and to assess the correlation of urinary electrolytes excretion with blood pressure. Methods: This cross-sectional study was conducted in 2011-2012 among 3-10-year-old children, selected by multi-stage cluster sampling from urban and rural areas of Isfahan, Iran. The sodium (Na), potassium (K), and creatinine (Cr) were measured in a random sample of the children's first morning fasting urine. Three-day averages of dietary intakes were analyzed by the Nutritionist-4 software. Results: The mean (SD) of urinary Na was 177.17 (28.68) mEq/day without significant difference according to gender and living area. The mean (SD) dietary intakes of Na and K were 2017.76 (117.94) and 1119.06 (76.03) mg/day, respectively. Children of urban and rural areas consumed similar sources of salty foods (bread, cheese, and snacks) and had low intake of vegetables. No significant association was documented between urinary electrolytes excretions and blood pressure. Conclusions: This study, which to the best of our knowledge is the first of its kind in the Middle East and North Africa region, revealed that Iranian young children consume a large amount of sodium and small amount of potassium. The non-significant associations of electrolyte excretions with blood pressure may be because of the very young age group of participants. Given the development of preference to salt taste from early childhood, and the tracking of risk factors of chronic diseases from this age, reducing salt intake of young children should be emphasized. PMID:23671781

Maladjustment of kidneys to microgravity: Design of measures to reduce the loss of calcium

NASA Technical Reports Server (NTRS)

Nechay, Bohdan R.

1989-01-01

Losses of skeletal calcium and body fluids occur during prolonged exposure to microgravity. The kidney plays a major role in regulating the physiological functions involved. Relative to this regulatory function, the kidney performs three operations: filtration of blood plasma through the glomeruli, reabsorption, and secretion of fluid and electrolytes so that needed components are retained and only waste is eliminated in the urine. Using data published in Biomedical Results from Skylab, researchers performed new calculations that reflect more directly the operations of the kidney in the handling of calcium, sodium, chloride, potassium and phosphate during space flight. These calculations revealed that the fraction of filtered calcium that was rejected by renal tubules and excreted in the urine increased by 71 percent, from 1.77 percent (preflight) to 3.02 percent (inflight) of the filtered load. This represents a large absolute increase because the total filtered amount is huge. Because the tubular rejection fraction of other ions increased relatively less than that of calcium, researchers postulate the inflight development of a specific renal defect that causes an excessive loss of calcium in urine and thereby contributes to the weakening of bones.

Effects of Fatty Liver Induced by Excess Orotic Acid on B-Group Vitamin Concentrations of Liver, Blood, and Urine in Rats.

PubMed

Shibata, Katsumi; Morita, Nobuya; Kawamura, Tomoyo; Tsuji, Ai; Fukuwatari, Tsutomu

2015-01-01

Fatty liver is caused when rats are given orotic acid of the pyrimidine base in large quantities. The lack of B-group vitamins suppresses the biosynthesis of fatty acids. We investigated how orotic acid-induced fatty liver affects the concentrations of liver, blood, and urine B-group vitamins in rats. The vitamin B6 and B12 concentrations of liver, blood, and urine were not affected by orotic acid-induced fatty liver. Vitamin B2 was measured only in the urine, but was unchanged. The liver, blood, and urine concentrations of niacin and its metabolites fell dramatically. Niacin and its metabolites in the liver, blood, and urine were affected as expected. Although the concentrations of vitamin B1, pantothenic acid, folate, and biotin in liver and blood were decreased by orotic acid-induced fatty liver, these urinary excretion amounts showed a specific pattern toward increase. Generally, as for the typical urinary excretion of B-group vitamins, these are excreted when the body is saturated. However, the ability to sustain vitamin B1, pantothenic acid, folate, and biotin decreased in fatty liver, which is hypothesized as a specific phenomenon. This metabolic response might occur to prevent an abnormally increased biosynthesis of fatty acids by orotic acid.

Flavonol glycosides of sea buckthorn (Hippophaë rhamnoides ssp. sinensis) and lingonberry (Vaccinium vitis-idaea) are bioavailable in humans and monoglucuronidated for excretion.

PubMed

Lehtonen, Henna-Maria; Lehtinen, Outi; Suomela, Jukka-Pekka; Viitanen, Matti; Kallio, Heikki

2010-01-13

Glucuronidation and excretion of sea buckthorn and lingonberry flavonols were investigated in a postprandial trial by analyzing the intact forms of flavonol glycosides as well as glucuronides in plasma, urine, and feces. Four study subjects consumed sea buckthorn (study day 1) and lingonberry (study day 2) breakfasts, and blood, urine, and fecal samples were collected for 8, 24, and 48 h, respectively. Both glycosides and glucuronides of the flavonol quercetin as well as kaempferol glucuronides were detected in urine and plasma samples after the consumption of lingonberries; 14% of flavonols in urine were glycosides, and 86% were glucuronidated forms (wt %). After the consumption of sea buckthorn, 5% of flavonols excreted in urine were detected intact, and 95% as the glucuronides (wt %). Solely glucuronides of flavonols isorhamnetin and quercetin were found in plasma after the consumption of sea buckthorn berries. Only glycosides were detected in the feces after each berry trial. Flavonol glycosides and glucuronides remained in blood and urine quite long, and the peak concentrations appeared slightly later than previously described. The berries seemed to serve as a good flavonol supply, providing steady flavonol input for the body for a relatively long time.

Sodium Excretion and the Risk of Cardiovascular Disease in Patients With Chronic Kidney Disease

PubMed Central

Mills, Katherine T.; Chen, Jing; Yang, Wei; Appel, Lawrence J.; Kusek, John W.; Alper, Arnold; Delafontaine, Patrice; Keane, Martin G.; Mohler, Emile; Ojo, Akinlolu; Rahman, Mahboob; Ricardo, Ana C.; Soliman, Elsayed Z.; Steigerwalt, Susan; Townsend, Raymond; He, Jiang

2016-01-01

IMPORTANCE Patients with chronic kidney disease (CKD) are at an increased risk of cardiovascular disease (CVD) compared with the general population. Prior studies have produced contradictory results on the association of dietary sodium intake with risk of CVD, and this relationship has not been investigated in patients with CKD. OBJECTIVE To evaluate the association between urinary sodium excretion and clinical CVD events among patients with CKD. DESIGN, SETTING, AND PARTICIPANTS A prospective cohort study of patients with CKD from 7 locations in the United States enrolled in the Chronic Renal Insufficiency Cohort Study and followed up from May 2003 to March 2013. EXPOSURES The cumulative mean of urinary sodium excretion from three 24-hour urinary measurements and calibrated to sex-specific mean 24-hour urinary creatinine excretion. MAIN OUTCOMES AND MEASURES A composite of CVD events defined as congestive heart failure, stroke, ormyocardial infarction. Events were reported every 6 months and confirmed by medical record adjudication. RESULTS Among 3757 participants (mean age, 58 years; 45% women), 804 composite CVD events (575 heart failure, 305 myocardial infarction, and 148 stroke) occurred during a median 6.8 years of follow-up. From lowest (<2894 mg/24 hours) to highest (≥4548 mg/24 hours) quartile of calibrated sodium excretion, 174, 159, 198, and 273 composite CVD events occurred, and the cumulative incidence was 18.4%, 16.5%, 20.6%, and 29.8% at median follow-up. In addition, the cumulative incidence of CVD events in the highest quartile of calibrated sodium excretion compared with the lowest was 23.2% vs 13.3% for heart failure, 10.9% vs 7.8% for myocardial infarction, and 6.4% vs 2.7% for stroke at median follow-up. Hazard ratios of the highest quartile compared with the lowest quartile were 1.36 (95% CI, 1.09–1.70; P = .007) for composite CVD events, 1.34 (95% CI, 1.03–1.74; P = .03) for heart failure, and 1.81 (95% CI, 1.08–3.02; P = .02) for stroke after multivariable adjustment. Restricted cubic spline analyses of the association between sodium excretion and composite CVD provided no evidence of a nonlinear association (P = .11) and indicated a significant linear association (P < .001). CONCLUSIONS AND RELEVANCE Among patients with CKD, higher urinary sodium excretion was associated with increased risk of CVD. PMID:27218629

Human Excretion of Polybrominated Diphenyl Ether Flame Retardants: Blood, Urine, and Sweat Study

PubMed Central

Genuis, Shelagh K.; Birkholz, Detlef

2017-01-01

Commonly used as flame retardants, polybrominated diphenyl ethers (PBDEs) are routinely detected in the environment, animals, and humans. Although these persistent organic pollutants are increasingly recognized as having serious health implications, particularly for children, this is the first study, to our knowledge, to investigate an intervention for human elimination of bioaccumulated PBDEs. Objectives. To determine the efficacy of blood, urine, and perspiration as PBDE biomonitoring mediums; assess excretion of five common PBDE congeners (28, 47, 99, 100, and 153) in urine and perspiration; and explore the potential of induced sweating for decreasing bioaccumulated PBDEs. Results. PBDE congeners were not found in urine samples; findings focus on blood and perspiration. 80% of participants tested positive in one or more body fluids for PBDE 28, 100% for PBDE 47, 95% for PBDE 99, and 90% for PBDE 100 and PBDE 153. Induced perspiration facilitated excretion of the five congeners, with different rates of excretion for different congeners. Conclusion. Blood testing provides only a partial understanding of human PBDE bioaccumulation; testing of both blood and perspiration provides a better understanding. This study provides important baseline evidence for regular induced perspiration as a potential means for therapeutic PBDE elimination. Fetotoxic and reproductive effects of PBDE exposure highlight the importance of further detoxification research. PMID:28373979

Spot Urine-guided Salt Reduction in Chronic Kidney Disease Patients.

PubMed

Uchiyama, Kiyotaka; Yanai, Akane; Ishibashi, Yoshitaka

2017-09-01

Dietary salt restriction is important in patients with chronic kidney disease (CKD) to reduce hypertension, cardiovascular events, progression of CKD, and mortality. However, recommending salt reduction for patients is difficult without knowing their actual sodium intake. This study evaluated the effectiveness of spot urine-guided salt reduction in CKD outpatients. A prospective cohort study was used. This study included a total of 127 adult outpatients (aged 60 ± 18 years, 80 males) with CKD. Their baseline estimated glomerular filtration rate was 51.4 ± 25.1 (mL/minute/1.73 m 2 ), and 64 (50%) of them were with CKD stage 3a or 3b (both 32 [25%]). We informed the patients of their individual spot urine-estimated salt intake every time they visited the outpatient clinic. Based on the data, the nephrologist encouraged the patients to achieve their salt restriction goal. The primary outcome was the estimated salt excretion, and the secondary outcome was the urinary protein-to-Cr ratio (UPCR). Multiple regression analyses were performed to clarify the contributing factors of changes in both outcomes. Over a follow-up of 12 months, the median number of patients' visits was 7 (5-8). The estimated salt intake was significantly reduced from 7.98 ± 2.49 g/day to 6.77 ± 1.77 g/day (P < .0001). The median UPCR was also reduced from 0.20 (0.10-0.80) to 0.10 (0.10-0.48) (P < .0001). On multiple regression analysis, a reduction in UPCR was positively associated with the baseline UPCR and a reduction in systolic blood pressure significantly (P < .0001 and P < .01, respectively) as well as positively correlated with a reduction in the estimated salt intake, with borderline significance (P = .08). Providing spot urine-estimated salt intake feedback effectively motivated CKD patients to reduce their salt intake. Spot urine-guided salt reduction may slow CKD progression through decreased urinary protein excretion. Copyright © 2017 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Variability of plasma and urine betaine in diabetes mellitus and its relationship to methionine load test responses: an observational study

PubMed Central

2012-01-01

Background Since betaine is an osmolyte and methyl donor, and abnormal betaine loss is common in diabetes mellitus (>20% patients), we investigated the relationship between betaine and the post-methionine load rise in homocysteine, in diabetes and control subjects. The post-methionine load test is reported to be both an independent vascular risk factor and a measure of betaine sufficiency. Methods Patients with type 2 diabetes (n = 34) and control subjects (n = 17) were recruited. We measured baseline fasting plasma and 4-hour post-methionine load (L-methionine, 0.1 mg/kg body weight) concentrations of homocysteine, betaine, and the betaine metabolite N,N-dimethylglycine. Baseline urine excretions of betaine, dimethylglycine and glucose were measured on morning urine samples as the ratio to urine creatinine. Statistical determinants of the post-methionine load increase in homocysteine were identified in multiple linear regression models. Results Plasma betaine concentrations and urinary betaine excretions were significantly (p < 0.001) more variable in the subjects with diabetes compared with the controls. Dimethylglycine excretion (p = 0.00014) and plasma dimethylglycine concentrations (p = 0.039) were also more variable. In diabetes, plasma betaine was a significant negative determinant (p < 0.001) of the post-methionine load increase in homocysteine. However, it was not conclusive that this was different from the relationship in the controls. In the patients with diabetes, a strong relationship was found between urinary betaine excretion and urinary glucose excretion (but not with plasma glucose). Conclusions Both high and low plasma betaine concentrations, and high and low urinary betaine excretions, are more prevalent in diabetes. The availability of betaine affects the response in the methionine load test. The benefits of increasing betaine intake should be investigated. PMID:22510294

The effect of ascorbic acid ingestion on the biochemical and physicochemical risk factors associated with calcium oxalate kidney stone formation.

PubMed

Auer, B L; Auer, D; Rodgers, A L

1998-03-01

The present study was undertaken to determine the effect of ingestion of large doses of vitamin C on urinary oxalate excretion and on a number of other biochemical and physicochemical risk factors associated with calcium oxalate urolithiasis. A further objective was to determine urinary ascorbate excretion and to relate it qualitatively to ingested levels of the vitamin and oxalate excretion. Ten healthy males participated in a protocol in which 4 g ascorbic acid was ingested for 5 days. Urines (24 h) were collected prior to, during and after the protocol. The urine collection procedure was designed to allow for the analysis of oxalate in the presence and absence of an EDTA preservative and for the analysis of ascorbic acid by manual titration using 2,6 dichlorophenolindophenol. Physicochemical risk factors such as the calcium oxalate relative supersaturation and Tiselius risk index were calculated from urine composition. The results showed that erroneously high analytical oxalate levels occur in the asence of preservative. In the preserved samples there was no significant increase in oxalate excretion at any stage of the protocol. Ascorbate excretion increased when vitamin C ingestion commenced but levelled out after 24 hours suggesting that saturation of the metabolic pool is reached within 24 hours after which ingested ascorbic acid is excreted unmetabolized in the urine. While transient statistically significant changes occurred in some of the biochemical risk factors, they were not regarded as being clinically significant. There were no changes in either the calcium oxalate relative supersaturation or Tiselius risk index. It is concluded that ingestion of large doses of ascorbic acid does not affect the principal risk factors associated with calcium oxalate kidney stone formation.

Minimum urine flow rate during water deprivation: importance of the nonurea versus total osmolality in the inner medulla.

PubMed

Soroka, S D; Chayaraks, S; Cheema-Dhadli, S; Myers, J A; Rubin, S; Sonnenberg, H; Halperin, M L

1997-06-01

Antidiuretic hormone leads to an increase in the permeability for water and urea in the inner medullary collecting duct. Hence, urea may not be an "effective" osmole in the inner medulla during maximal renal water conservation. Accordingly, the purpose of this study was to evaluate whether differences in the rate of urea excretion would influence maximum renal water conservation in humans. In water-deprived rats, the concentration of urea and total osmolality were somewhat higher in the urine exiting the inner medullary collecting duct than in interstitial fluid obtained from the entire papillary tip. Nevertheless, the "nonurea" (total osmolality minus urea in millimolar terms) osmolality was virtually identical in both locations. Chronically fasted human subjects that were water-deprived for 16 h had a lower rate of urea excretion (71 +/- 7 versus 225 +/- 14 mumol/min) and a somewhat lower urine osmolality (745 +/- 53 versus 918 +/- 20 mosmol/kg H2O). Nevertheless, they had identical urine flow rates (0.5 +/- 0.01 and 0.5 +/- 0.02 ml/min, respectively), and their nonurea osmolality also was similar (587 +/- 25 and 475 +/- 14 mosmol/kg H2O, respectively) to the water-deprived normal subjects. The composition of their urine differed in that the principal nonurea osmoles became NH4+ and beta-hydroxybutyrate rather than Na and C1. During water deprivation in normal subjects, the ingestion of urea caused a twofold rise in urine flow rate, a fall in the nonurea osmolality, and a rise in the rate of excretion of nonurea osmoles. The nonurea osmolality of the urine, and presumably the medullary interstitial fluid as well, was inversely related to the urea excretion rate. In chronic fasting, the nature, but not the quantity, of nonurea osmoles changed. The similar minimum urine volume was predictable from an analysis based on nonurea osmole considerations.

Sodium Restriction in Patients With CKD: A Randomized Controlled Trial of Self-management Support.

PubMed

Meuleman, Yvette; Hoekstra, Tiny; Dekker, Friedo W; Navis, Gerjan; Vogt, Liffert; van der Boog, Paul J M; Bos, Willem Jan W; van Montfrans, Gert A; van Dijk, Sandra

2017-05-01

To evaluate the effectiveness and sustainability of self-managed sodium restriction in patients with chronic kidney disease. Open randomized controlled trial. Patients with moderately decreased kidney function from 4 hospitals in the Netherlands. Regular care was compared with regular care plus an intervention comprising education, motivational interviewing, coaching, and self-monitoring of blood pressure (BP) and sodium. Primary outcomes were sodium excretion and BP after the 3-month intervention and at 6-month follow-up. Secondary outcomes were protein excretion, kidney function, antihypertensive medication, self-efficacy, and health-related quality of life (HRQoL). At baseline, mean sodium excretion rate was 163.6±64.9 (SD) mmol/24 h; mean estimated glomerular filtration rate was 49.7±25.6mL/min/1.73m 2 ; median protein excretion rate was 0.8 (IQR, 0.4-1.7) g/24 h; and mean 24-hour ambulatory systolic and diastolic BPs were 129±15 and 76±9mmHg, respectively. Compared to regular care only (n=71), at 3 months, the intervention group (n=67) showed reduced sodium excretion rate (mean change, -30.3 [95% CI, -54.7 to -5.9] mmol/24 h), daytime ambulatory diastolic BP (mean change, -3.4 [95% CI, -6.3 to -0.6] mmHg), diastolic office BP (mean change, -5.2 [95% CI, -8.4 to -2.1] mmHg), protein excretion (mean change, -0.4 [95% CI, -0.7 to -0.1] g/24h), and improved self-efficacy (mean change, 0.5 [95% CI, 0.1 to 0.9]). At 6 months, differences in sodium excretion rates and ambulatory BPs between the groups were not significant, but differences were detected in systolic and diastolic office BPs (mean changes of -7.3 [95% CI, -12.7 to -1.9] and -3.8 [95% CI, -6.9 to -0.6] mmHg, respectively), protein excretion (mean changes, -0.3 [95% CI, -0.6 to -0.1] g/24h), and self-efficacy (mean change, 0.5 [95% CI, 0.0 to 0.9]). No differences in kidney function, medication, and HRQoL were observed. Nonblinding, relatively low response rate, and missing data. Compared to regular care only, this self-management intervention modestly improved outcomes, although effects on sodium excretion and ambulatory BP diminish over time. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Exogenous L-Arginine Attenuates the Effects of Angiotensin II on Renal Hemodynamics and the Pressure Natriuresis-Diuresis Relationship

PubMed Central

Das, Satarupa; Mattson, David L.

2014-01-01

SUMMARY Administration of exogenous L-Arginine (L-Arg) attenuates Angiotensin II (AngII)-mediated hypertension and kidney disease in rats. The present study assessed renal hemodynamics and pressure-diuresis-natriuresis in anesthetized rats infused with vehicle, AngII (20 ng/kg/min, iv) or AngII + L-Arg (300 µg/kg/min, iv). Increasing renal perfusion pressure (RPP) from approximately 100 to 140 mmHg resulted in a 9–10 fold increase in urine flow and sodium excretion rate in control animals. In comparison, AngII infusion significantly reduced renal blood flow (RBF) and glomerular filtration rate (GFR) by 40–42% and blunted the pressure-dependent increase in urine flow and sodium excretion rate by 54–58% at elevated RPP. Supplementation of L-Arg reversed the vasoconstrictor effects of AngII and restored pressure-dependent diuresis to levels not significantly different from control rats. Experiments in isolated aortic rings were performed to assess L-Arg effects on the vasculature. Dose-dependent contraction to AngII (10−10M to 10−7M) was observed with a maximal force equal to 27±3% of the response to 10−5M phenylephrine. Contraction to 10−7M AngII was blunted by 75±3% with 10−4M L-Arg. The influence of L-Arg to blunt AngII mediated contraction was eliminated by endothelial denudation or incubation with nitric oxide synthase inhibitors. Moreover, the addition of 10−3M cationic or neutral amino acids, which compete with L-Arg for cellular uptake, blocked the effect of L-Arg. Anionic amino acids did not influence the effects of L-Arg on AngII-mediated contraction. These studies indicate that L-Arg blunts AngII-mediated vascular contraction by an endothelial- and NOS-dependent mechanism involving cellular uptake of L-Arg. PMID:24472006

Potassium handling with dual renin-angiotensin system inhibition in diabetic nephropathy.

PubMed

Van Buren, Peter N; Adams-Huet, Beverley; Nguyen, Mark; Molina, Christopher; Toto, Robert D

2014-02-01

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are the cornerstones of pharmacologic therapy in diabetic nephropathy. Mineralocorticoid receptor blockers reduce proteinuria as single agents or add-on therapy to other renin-angiotensin-aldosterone system-inhibiting drugs in these patients. The long-term benefits and ultimate role of mineralocorticoid receptor blockers in diabetic nephropathy remain unknown. A clinical trial previously showed that the kalemic effect of spironolactone is higher than losartan when added to lisinopril in patients with diabetic nephropathy. The purpose of this study was to investigate if renal potassium handling was primarily responsible for that observation. In a blinded, randomized, three-arm placebo-controlled clinical trial, 80 participants with diabetic nephropathy taking lisinopril (80 mg) were randomized to spironolactone (25 mg daily), losartan (100 mg daily), or placebo (trial dates from July of 2003 to December of 2006). Serum potassium, aldosterone, and 24-hour urine sodium, potassium, and creatinine were measured over 48 weeks. Differences were analyzed with repeated measures mixed models. Mean follow-up serum potassium was 5.0 mEq/L for spironolactone, 4.7 mEq/L for losartan (P=0.05 versus spironolactone), and 4.5 mEq/L for placebo (P<0.001 versus spironolactone; P=0.03 versus losartan). The difference in serum potassium was 0.23 mEq/L for losartan versus placebo (P=0.02), 0.43 mEq/L for spironolactone versus placebo (P<0.001), and 0.2 mEq/L for spironolactone versus losartan (P=0.05). Serum and urine potassium excretion and secretion rates were similar between groups throughout the study. Spironolactone raised serum potassium more than losartan in patients with diabetic nephropathy receiving lisinopril, despite similar renal sodium and potassium excretion. This finding suggests that extrarenal potassium homeostasis contributes to hyperkalemia in these patients. A better understanding of extrarenal potassium homeostasis will provide an opportunity to use this drug more safely in patients with diabetic nephropathy as well as other patient populations.

The Presence Of Strange Males' Odor Induces Behavioral Responses And Elevated Levels Of Low Molecular Weight Proteins Excreted In The Urine Of Mature Water Vole Males (Arvicola amphibius L).

PubMed

Nazarova, Galina G; Proskurniak, Lyudmila P; Yuzhik, Ekaterina I

2016-03-01

We hypothesized that low molecular weight urinary proteins play a role in male-male chemical communication in the water vole, Arvicola ampibius L. We studied the effect of placing soiled litter from strange males into the cage of another sexually mature male on the intensity of its digging and scattering, urination on the litter, and alteration in the levels of low molecular weight proteins (15-25 kDa) excreted in the urine before and after 4 days of exposure as determined by chip electrophoresis. The intensity of digging and scattering was positively correlated with levels of testosterone in serum of males exposed to strange male odors (r = 0.56; P < 0.01), as well as with the concentration of low molecular weight proteins in the donor's urine (r = 0.52, P < 0.05). At the end of the experiment, the level of low molecular weight protein in excreted urine was elevated in the males exposed to the strange male's litter. These results highlight the importance of quantitative inter-individual variation of low molecular weight urinary proteins in the modulation of the physiology and behavior of conspecifics.

S-phenyl-N-acetylcysteine in urine of rats and workers after exposure to benzene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jongeneelen, F.J.; Dirven, H.A.; Leijdekkers, C.M.

1987-05-01

An HPLC method for the determination of S-phenyl-N-acetylcysteine in urine is described. The sensitivity is 6 mumol/L (CV = 9%) urine. Exposure of rats to six different concentrations of benzene, ranging from 0-30 ppm, was highly associated with urinary excretion of S-phenyl-N-acetylcysteine (r = 0.86) and with total phenol (r = 0.81). A background level of phenol was found in urine of both non-exposed rats and of non-exposed referents. However, no background excretion of S-phenyl-N-acetylcysteine was found, either in rats or in humans. In urine of exposed rats, the level of S-phenyl-N-acetylcysteine was approximately five times lower than the phenolmore » level. Workers occupationally exposed to benzene, showing high levels of urinary phenol, revealed low concentrations of urinary S-phenyl-N-acetylcysteine. The biological monitoring of industrial exposure to benzene by determination of S-phenyl-N-acetylcysteine in urine is not better than the determination of phenol in urine.« less

AMINO ACIDURIA IN PRIMATES FOLLOWING IRRADIATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hunter, C.G.

The daily urine amino N excretion of 4 monkeys was followed before and after whole body irradiation with doses in the lower lethal range. In 2 non- survivors, there was little change in the daily quantity excreted until terminally. In 2 survivors given the same food intakes as in the irradiated study and sham irradiated, the daily urine amino N excretion during the first week differed but slightly from the values after irradiation, but in the second week more amino N was excreted after irradiation in one animal and less in the other. It would appear that amino aciduria inmore » primates irradiated with doses in the lower lethal range is inseparable from the natural response of the over-all protein metabolism associated with any injury. (auth)« less

Fenofibrate causes elevation of betaine excretion but not excretion of other osmolytes by healthy adults.

PubMed

Lever, Michael; McEntyre, Christopher J; George, Peter M; Slow, Sandy; Chambers, Stephen T; Foucher, Christelle

2014-01-01

Cross-sectional data suggest that bezafibrate increases betaine excretion in dyslipidemic patients. We aimed to demonstrate that fenofibrate induces increased betaine excretion in normal subjects and explore whether other 1-carbon metabolites and osmolytes are similarly affected. Urine was collected from 26 healthy adults before and after treatment with fenofibrate (145 mg/day for 6 weeks). Excretions of betaine, N,N-dimethylglycine, free choline, myo-inositol, taurine, trimethylamine-N-oxide, carnitine, and acetylcarnitine were measured by liquid chromatography with mass spectrometric detection. Fenofibrate increased the median betaine excretion from 7.5 to 25.8 mmol/mole creatinine (median increase 3-fold), P < .001. The median increase in N,N-dimethylglycine excretion was 2-fold (P < .001). Median choline excretion increased 12% (significant, P = .029). Participants with higher initial excretions tended to have larger increases (P < .001 in all 3 cases). Fenofibrate did not significantly change the median excretions of myo-inositol, taurine, trimethylamine-N-oxide, and carnitine. The excretion of acetylcarnitine decreased 4-fold on treatment, with no correlation between the baseline and after-treatment excretions. Changes in all urine components tested, except trimethylamine-N-oxide, positively correlated with changes in betaine excretion even when the median excretions before and after were not significantly different. Fibrates increase betaine, and to a lesser extent N,N-dimethylglycine and choline, excretion. Other osmolytes are not elevated. Because the increase in betaine excretion depends on the baseline excretion, large increases in excretion in the metabolic syndrome and diabetes (where baseline excretions are high) could be expected. Replacement with betaine supplements may be considered. Copyright © 2014 National Lipid Association. Published by Elsevier Inc. All rights reserved.

A major urinary protein of the domestic cat regulates the production of felinine, a putative pheromone precursor.

PubMed

Miyazaki, Masao; Yamashita, Tetsuro; Suzuki, Yusuke; Saito, Yoshihiro; Soeta, Satoshi; Taira, Hideharu; Suzuki, Akemi

2006-10-01

Domestic cats spray urine with species-specific odor for territorial marking. Felinine (2-amino-7-hydroxy-5,5-dimethyl-4-thiaheptanoic acid), a putative pheromone precursor, is excreted in cat urine. Here, we report that cauxin, a carboxylesterase excreted as a major urinary component, regulates felinine production. In vitro enzyme assays indicated that cauxin hydrolyzed the felinine precursor 3-methylbutanol-cysteinylglycine to felinine and glycine. Cauxin and felinine were excreted age dependently after 3 months of age. The age-dependent increases in cauxin and felinine excretion were significantly correlated. In mature cats, cauxin and felinine levels were sex-dependently correlated and were higher in males than in females. In headspace gas of cat urine, 3-mercapto-3-methyl-1-butanol, 3-mercapto-3-methylbutyl formate, 3-methyl-3-methylthio-1-butanol, and 3-methyl-3-(2-methyldisulfanyl)-1-butanol were identified as candidates for felinine derivatives. These findings demonstrate that cauxin-dependent felinine production is a cat-specific metabolic pathway, and they provide information for the biosynthetic mechanisms of species-specific molecules in mammals.

Drinking Water Salinity and Maternal Health in Coastal Bangladesh: Implications of Climate Change

PubMed Central

Ireson, Andrew; Kovats, Sari; Mojumder, Sontosh Kumar; Khusru, Amirul; Rahman, Atiq; Vineis, Paolo

2011-01-01

Background: Drinking water from natural sources in coastal Bangladesh has become contaminated by varying degrees of salinity due to saltwater intrusion from rising sea levels, cyclone and storm surges, and upstream withdrawal of freshwater. Objective: Our objective was to estimate salt intake from drinking water sources and examine environmental factors that may explain a seasonal excess of hypertension in pregnancy. Methods: Water salinity data (1998–2000) for Dacope, in rural coastal Bangladesh, were obtained from the Centre for Environment and Geographic Information System in Bangladesh. Information on drinking water sources, 24-hr urine samples, and blood pressure was obtained from 343 pregnant Dacope women during the dry season (October 2009 through March 2010). The hospital-based prevalence of hypertension in pregnancy was determined for 969 pregnant women (July 2008 through March 2010). Results: Average estimated sodium intakes from drinking water ranged from 5 to 16 g/day in the dry season, compared with 0.6–1.2 g/day in the rainy season. Average daily sodium excretion in urine was 3.4 g/day (range, 0.4–7.7 g/day). Women who drank shallow tube-well water were more likely to have urine sodium > 100 mmol/day than women who drank rainwater [odds ratio (OR) = 2.05; 95% confidence interval (CI), 1.11–3.80]. The annual hospital prevalence of hypertension in pregnancy was higher in the dry season (OR = 12.2%; 95% CI, 9.5–14.8) than in the rainy season (OR = 5.1%; 95% CI, 2.91–7.26). Conclusions: The estimated salt intake from drinking water in this population exceeded recommended limits. The problem of saline intrusion into drinking water has multiple causes and is likely to be exacerbated by climate change–induced sea-level rise. PMID:21486720

Renal handling of sodium and water in the hypothyroid rat

PubMed Central

Michael, Ulrich F.; Barenberg, Robert L.; Chavez, Rafaelita; Vaamonde, Carlos A.; Papper, Solomon

1972-01-01

Hypothyroid rats were examined with conventional renal clearance and micropuncture techniques to elicit the mechanism and site within the nephron responsible for the increased salt and water excretion observed in these animals. When compared with age-matched control rats, a decrease in inulin clearance of 30% (P < 0.001) and in Hippuran clearance of 32% (P < 0.005) was observed in the hypothyroid rats. Absolute excretion of sodium and water was increased 3-fold (P < 0.02) and 2-fold (P < 0.025), respectively, while fractional excretion of sodium and water was increased 4.3-fold (P < 0.02) and 2.9-fold (P < 0.05), respectively, in the hypothyroid animals. Fractional proximal reabsorption of sodium as assessed from proximal tubular fluid to plasma ratios of inulin ([TF/P]IN) was found to be decreased by 28% (P < 0.001) in the hypothyroid rats. Superficial single nephron filtration rate was reduced proportionately to the decrease in total filtration rate in the hypothyroid rats. These data indicate that the proximal tubule is one of the sites of diminished sodium and water reabsorption in the hypothyroid rat. The data also suggest that the observed decrease in glomerular filtration rate in the hypothyroid animals is not caused by a decrease in the number of functioning nephrons and that the observed increase in sodium and water excretion is not caused by a redistribution of filtrate from juxtamedullary to superficial nephrons. Although the exact mechanisms of the observed changes in proximal tubular function remain unknown, the data suggest that they are probably related to the lack of thyroid hormone. Whatever their mechanism, it appears that the enhanced sodium and water excretion observed in the hypothyroid animals must be determined by further reduction in tubular sodium reabsorption in the distal nephron. PMID:5024038

Hydration Status and Sodium Balance of Endurance Runners Consuming Postexercise Supplements of Varying Nutrient Content.

PubMed

Pryor, J Luke; Johnson, Evan C; Del Favero, Jeffery; Monteleone, Andrew; Armstrong, Lawrence E; Rodriguez, Nancy R

2015-10-01

Postexercise protein and sodium supplementation may aid recovery and rehydration. Preserved beef provides protein and contains high quantities of sodium that may alter performance related variables in runners. The purpose of this study was to determine the effects of consuming a commercial beef product postexercise on sodium and water balance. A secondary objective was to characterize effects of the supplementation protocols on hydration, blood pressure, body mass, and running economy. Eight trained males (age = 22 ± 3 y, VO2max = 66.4 ± 4.2 ml·kg-1·min-1) completed three identical weeks of run training (6 run·wk-1, 45 ± 6 min·run-1, 74 ± 5% HRR). After exercise, subjects consumed either, a beef nutritional supplement (beef jerky; [B]), a standard recovery drink (SRD), or SRD+B in a randomized counterbalanced design. Hydration status was assessed via urinary biomarkers and body mass. No main effects of treatment were observed for 24 hr urine volume (SRD, 1.7 ± 0.5; B, 1.8 ± 0.6; SRD+B, 1.4 ± 0.4 L·d-1), urine specific gravity (1.016 ± 0.005, 1.018 ± 0.006, 1.017 ± 0.006) or body mass (68.4 ± 8.2, 68.3 ± 7.7, 68.2 ± 8.1 kg). No main effect of treatment existed for sodium intake-loss (-713 ± 1486; -973 ± 1123; -980 ± 1220 mg·d-1). Mean arterial pressure (81.0 ± 4.6, 81.1 ± 7.3, 83.8 ± 5.4 mm Hg) and average exercise running economy (VO2: SRD, 47.9 ± 3.2; B, 47.2 ± 2.6; SRD+B, 46.2 ± 3.4 ml·kg-1·min-1) was not affected. Urinary sodium excretion accounted for the daily sodium intake due to the beef nutritional supplement. Findings suggest the commercial beef snack is a viable recovery supplement following endurance exercise without concern for hydration status, performance decrements, or cardiovascular consequences.

Arsenic drinking water exposure and urinary excretion among adults in the Yaqui Valley, Sonora, Mexico.

PubMed

Meza, Maria Mercedes; Kopplin, Michael J; Burgess, Jefferey L; Gandolfi, A Jay

2004-10-01

The objective of this study was to determine arsenic exposure via drinking water and to characterize urinary arsenic excretion among adults in the Yaqui Valley, Sonora, Mexico. A cross-sectional study was conducted from July 2001 to May 2002. Study subjects were from the Yaqui Valley, Sonora, Mexico, residents of four towns with different arsenic concentrations in their drinking water. Arsenic exposure was estimated through water intake over 24 h. Arsenic excretion was assessed in the first morning void urine. Total arsenic concentrations and their species arsenate (As V), arsenite (As III), monomethyl arsenic (MMA), and dimethyl arsenic (DMA) were determined by HPLC/ICP-MS. The town of Esperanza with the highest arsenic concentration in water had the highest daily mean intake of arsenic through drinking water, the mean value was 65.5 microg/day. Positive correlation between total arsenic intake by drinking water/day and the total arsenic concentration in urine (r = 0.50, P < 0.001) was found. Arsenic excreted in urine ranged from 18.9 to 93.8 microg/L. The people from Esperanza had the highest geometric mean value of arsenic in urine, 65.1 microg/L, and it was statistically significantly different from those of the other towns (P < 0.005). DMA was the major arsenic species in urine (47.7-67.1%), followed by inorganic arsenic (16.4-25.4%), and MMA (7.5-15%). In comparison with other reports the DMA and MMA distribution was low, 47.7-55.6% and 7.5-9.7%, respectively, in the urine from the Yaqui Valley population (except the town of Cocorit). The difference in the proportion of urinary arsenic metabolites in those towns may be due to genetic polymorphisms in the As methylating enzymes of these populations.

Effect of a 30-day isolation stress on calcium, phosphorus and other excretory products in an unrestrained chimpanzee.

NASA Technical Reports Server (NTRS)

Sabbot, I. M.; Mcnew, J. J.; Hoshizaki, T.; Sedgwick, C. J.; Adey, W. R.

1972-01-01

An unrestrained chimpanzee was studied in an isolation chamber and in his home cage environment. The study consisted of 49 urine collection days (14 days pre-, 5 days post- and 30 days of isolation), and then of 10 days in the home cage. Dietary intake, urine and fecal data were obtained. The effect of isolation on various excretory parameters was studied. Urine samples were analyzed for volume, osmolarity, creatinine, creatine, urea-N, 17-hydroxy corticosteroids, VMA, calcium and inorganic phosphorus. One way analyses of variance performed on the urinary excretion parameters showed all except creatinine excretion to vary significantly during periods of the study. The changes observed in calcium and phosphorus were highly significant. The data suggests that the calcium to phosphorus excretion ratio might serve as a physiological stress indicator of Selye's adaptation syndrome (period of resistance).

Comparison of urinary excretion of radon from the human body before and after radon bath therapy.

PubMed

Kávási, Norbert; Kovács, Tibor; Somlai, János; Jobbágy, Viktor; Nagy, Katalin; Deák, Eszter; Berhés, István; Bender, Tamás; Ishikawa, Tetsuo; Tokonami, Shinji

2011-07-01

Theoretically, the human body absorbs radon through the lungs and the skin and excretes it through the lungs and the excretory organs during radon bath therapy. To check this theory, the radon concentrations in urine samples were compared before and after radon bath therapy. During the therapy, the geometric mean (GM) and the geometric standard deviation of the radon concentration in air and in the bath water were 979 Bq m(-3), 1.58 and 73.6 Bq dm(-3), 1.1, respectively. Since radon was detected in each urine sample (GM around 3.0 Bq dm(-3)), urinary excretion of radon was confirmed. The results of this study can neither reject nor confirm the hypothesis of radon absorption through the skin. A 15 times higher increment of inhaled radon level did not cause significant changes in radon of urine samples.

Contribution of dietary oxalate to urinary oxalate excretion

NASA Technical Reports Server (NTRS)

Holmes, R. P.; Goodman, H. O.; Assimos, D. G.

2001-01-01

BACKGROUND: The amount of oxalate excreted in urine has a significant impact on calcium oxalate supersaturation and stone formation. Dietary oxalate is believed to make only a minor (10 to 20%) contribution to the amount of oxalate excreted in urine, but the validity of the experimental observations that support this conclusion can be questioned. An understanding of the actual contribution of dietary oxalate to urinary oxalate excretion is important, as it is potentially modifiable. METHODS: We varied the amount of dietary oxalate consumed by a group of adult individuals using formula diets and controlled, solid-food diets with a known oxalate content, determined by a recently developed analytical procedure. Controlled solid-food diets were consumed containing 10, 50, and 250 mg of oxalate/2500 kcal, as well as formula diets containing 0 and 180 mg oxalate/2500 kcal. Changes in the content of oxalate and other ions were assessed in 24-hour urine collections. RESULTS: Urinary oxalate excretion increased as dietary oxalate intake increased. With oxalate-containing diets, the mean contribution of dietary oxalate to urinary oxalate excretion ranged from 24.4 +/- 15.5% on the 10 mg/2500 kcal/day diet to 41.5 +/- 9.1% on the 250 mg/2500 kcal/day diet, much higher than previously estimated. When the calcium content of a diet containing 250 mg of oxalate was reduced from 1002 mg to 391 mg, urinary oxalate excretion increased by a mean of 28.2 +/- 4.8%, and the mean dietary contribution increased to 52.6 +/- 8.6%. CONCLUSIONS: These results suggest that dietary oxalate makes a much greater contribution to urinary oxalate excretion than previously recognized, that dietary calcium influences the bioavailability of ingested oxalate, and that the absorption of dietary oxalate may be an important factor in calcium oxalate stone formation.

Defective renal dopamine function and sodium-sensitive hypertension in adult ovariectomized Wistar rats: role of the cytochrome P-450 pathway.

PubMed

Di Ciano, Luis A; Azurmendi, Pablo J; Colombero, Cecilia; Levin, Gloria; Oddo, Elisabet M; Arrizurieta, Elvira E; Nowicki, Susana; Ibarra, Fernando R

2015-06-15

We have previously shown that ovariectomy in adult Wistar rats under normal sodium (NS) intake results in an overexpression of the total Na(+)-K(+)-ATPase (NKA) α1-subunit (Di Ciano LA, Azurmendi PJ, Toledo JE, Oddo EM, Zotta E, Ochoa F, Arrizurieta EE, Ibarra FR. Clin Exp Hypertens 35: 475-483, 2013). Upon high sodium (HS) intake, ovariectomized (oVx) rats developed defective NKA phosphorylation, a decrease in sodium excretion, and an increment in mean blood pressure (MBP). Since NKA phosphorylation is modulated by dopamine (DA), the aim of this study was to compare the intracellular response of the renal DA system leading to NKA phosphorylation upon sodium challenge in intact female (IF) and oVx rats. In IF rats, HS caused an increase in urinary DA and sodium, in NKA phosphorylation state, in cytochrome P-4504A (CYP4A) expression, and in 20-HETE production, while MBP kept normal. Blockade of the D1 receptor (D1R) with the D1-like receptor antagonist SCH 23390 in IFHS rats shifted NKA into a more dephosphorylated state, decreased sodium excretion by 50%, and increased MBP. In oVxNS rats, D1R expression was reduced and D3R expression was increased, and under HS intake sodium excretion was lower and MBP higher than in IFHS rats (both P < 0.05), NKA was more dephosphorylated than in IFHS, and CYP4A expression or 20-HETE production did not change. Blockade of D1R in oVxHS rats changed neither NKA phosphorylation state nor sodium excretion or MBP. D2R and PKCα expression did not vary among groups. The alteration of the renal DA system produced by ovariectomy could account for the defective NKA phosphorylation, the inefficient excretion of sodium load, and the development of salt-sensitive hypertension. Copyright © 2015 the American Physiological Society.

Protective effects of Tribulus terrestris L extract against acute kidney injury induced by reperfusion injury in rats.

PubMed

Najafi, Houshang; Firouzifar, Mohammad Reza; Shafaat, Omid; Changizi Ashtiyani, Saeed; Hosseini, Nasser

2014-07-01

This study aimed to investigate the protective effect of aerial parts of the Tribulus terrestris L extract on acute kidney injury (AKI) induced by ischemia for 30 minutes and reperfusion for 24 hours in rats. Ten male Sprague-Dawley rats in the AKI and 10 in the Tribulus terrestris groups received the extract solvent and extract of the plant (11 mg/kg), respectively, for 13 days (oral administration). On day 14, ischemia for 30 minutes and reperfusion for 24 hours were induced on the rats. In the last 6 hours of the reperfusion period (24 hours), urine samples were collected in metabolic cages. At the end of this period, blood samples were also taken to determine plasma urea nitrogen, creatinine, and electrolyte concentrations. The kidney tissues were collected for measuring the level of oxidative stress and histological studies. They were compared with the sham operation group and a control group with normal diet and no operation. In the Tribulus terrestris group, the increase in plasma creatinine and urea nitrogen concentrations was significantly less following reperfusion, and their values reached the same level as that in the sham group. Creatinine clearance and urine osmolarity in the Tribulus terrestris group was higher in comparison with the AKI group, whereas sodium absolute excretion, fractional excretion of potassium, oxidative stress, and cellular damages were less. Oral administration of Tribulus terrestris extract for 2 weeks can decrease kidney functional disturbance, oxidative stress, and cellular damages following reperfusion injury in rats.

A Pilot Study: The importance of inter-individual differences in inorganic arsenic metabolism for birth weight outcome

PubMed Central

Gelmann, Elyssa R; Gurzau, Eugen; Gurzau, Anca; Goessler, Walter; Kunrath, Julie

2013-01-01

Inorganic arsenic (iAs) exposure is detrimental to birth outcome. We lack information regarding the potential for iAs metabolism to affect fetal growth. Our pilot study evaluated postpartum Romanian women with known birth weight outcome for differences in iAs metabolism. Subjects were chronically exposed to low-to-moderate drinking water iAs. We analyzed well water, arsenic metabolites in urine, and toenail arsenic. Urine iAs and metabolites, toenail iAs, and secondary methylation efficiency increased as an effect of exposure (p<0.001). Urine iAs and metabolites showed a significant interaction effect between exposure and birth weight. Moderately exposed women with low compared to normal birth weight outcome had greater metabolite excretion (p<0.03); 67% with low compared to 10% with normal birth weight outcome presented urine iAs >9μg/L (p=0.019). Metabolic partitioning of iAs toward excretion may impair fetal growth. Prospective studies on iAs excretion before and during pregnancy may provide a biomarker for poor fetal growth risk. PMID:24211595

Fish Oil Supplementation and Urinary Oxalate Excretion in Normal Subjects on a Low-oxalate Diet

PubMed Central

Lange, Jessica N.; Mufarrij, Patrick W.; Easter, Linda; Knight, John; Holmes, Ross P.; Assimos, Dean G.

2014-01-01

OBJECTIVE To determine if fish oil supplementation reduces endogenous oxalate synthesis in healthy subjects. MATERIALS AND METHODS Fifteen healthy non–stone-forming adults participated in this study. Subjects first abstained from using vitamins, medications, or foods enriched in omega-3 fatty acids for 30 days. Next, they collected two 24-hour urine specimens while consuming a self-selected diet. Subjects consumed an extremely low-oxalate and normal-calcium diet for 5 days and collected 24-hour urine specimens on the last 3 days of this diet. Next, the subjects took 2 fish oil capsules containing 650-mg eicosapentaenoic acid and 450-mg docosahexaenoic acid twice daily for 30 days. They consumed a self-selected diet on days 1–25 and the controlled diet on days 26–30. Twenty-four-hour urine samples were collected on days 28–30. Excretion levels of urinary analytes including oxalate and glycolate were analyzed. RESULTS Although there was a significant reduction in urinary oxalate, magnesium, and potassium excretions and an increase in uric acid excretion during the controlled dietary phases compared with the self-selected diet, there were no significant differences in their excretion during controlled diet phases with and without fish oil supplementation. CONCLUSION These results suggest that fish oil supplementation does not reduce endogenous oxalate synthesis or urinary oxalate excretion in normal adults during periods of extremely low oxalate intake. However, these results do not challenge the previously described reduction in urinary oxalate excretion demonstrated in normal subjects consuming a moderate amount of oxalate in conjunction with fish oil. PMID:25102784

Renal outcomes and dietary potassium: the overshadowed electrolyte?

PubMed

Jablonski, Kristen L; Kendrick, Jessica B

2014-12-01

Smyth et al. examined the association between urinary sodium and potassium excretion and adverse renal outcomes in adults at high cardiovascular risk. They found no association between urinary sodium excretion and adverse renal outcomes, but a reduced odds of adverse renal outcomes with higher urinary potassium excretion. It will be important to ascertain whether this finding holds true in individuals free from vascular disease and diabetes, as well as in patients with chronic kidney disease.

Renal responses of trout to chronic respiratory and metabolic acidoses and metabolic alkalosis.

PubMed

Wood, C M; Milligan, C L; Walsh, P J

1999-08-01

Exposure to hyperoxia (500-600 torr) or low pH (4.5) for 72 h or NaHCO(3) infusion for 48 h were used to create chronic respiratory (RA) or metabolic acidosis (MA) or metabolic alkalosis in freshwater rainbow trout. During alkalosis, urine pH increased, and [titratable acidity (TA) - HCO(-)(3)] and net H(+) excretion became negative (net base excretion) with unchanged NH(+)(4) efflux. During RA, urine pH did not change, but net H(+) excretion increased as a result of a modest rise in NH(+)(4) and substantial elevation in [TA - HCO(-)(3)] efflux accompanied by a large increase in inorganic phosphate excretion. However, during MA, urine pH fell, and net H(+) excretion was 3.3-fold greater than during RA, reflecting a similar increase in [TA - HCO(-)(3)] and a smaller elevation in phosphate but a sevenfold greater increase in NH(+)(4) efflux. In urine samples of the same pH, [TA - HCO(-)(3)] was greater during RA (reflecting phosphate secretion), and [NH(+)(4)] was greater during MA (reflecting renal ammoniagenesis). Renal activities of potential ammoniagenic enzymes (phosphate-dependent glutaminase, glutamate dehydrogenase, alpha-ketoglutarate dehydrogenase, alanine aminotransferase, phosphoenolpyruvate carboxykinase) and plasma levels of cortisol, phosphate, ammonia, and most amino acids (including glutamine and alanine) increased during MA but not during RA, when only alanine aminotransferase increased. The differential responses to RA vs. MA parallel those in mammals; in fish they may be keyed to activation of phosphate secretion by RA and cortisol mobilization by MA.

Blood pressure, ethnic group, and salt intake in Belize.

PubMed

Simmons, D

1983-03-01

A total of 1316 individuals were studied in seven villages in Belize, Central America. This represented 92% of the area population aged over 18. Generally, they were members of three ethnic groups--Maya, Spanish, and Creole. The systolic and diastolic IV and V blood pressures were recorded using standardised procedure. Significant differences in blood pressure, weight, and obesity were found between ethnic groups in both sexes, Creoles having higher means than the other groups. Significant relationships with blood pressure were found with obesity, age, and number of children. An early morning urine specimen was obtained from a random 50% of the men, and only in Creoles was there an association between raised blood pressure and sodium/potassium urinary excretion ratio.

The abuse of diuretics as performance-enhancing drugs and masking agents in sport doping: pharmacology, toxicology and analysis

PubMed Central

Cadwallader, Amy B; de la Torre, Xavier; Tieri, Alessandra; Botrè, Francesco

2010-01-01

Diuretics are drugs that increase the rate of urine flow and sodium excretion to adjust the volume and composition of body fluids. There are several major categories of this drug class and the compounds vary greatly in structure, physicochemical properties, effects on urinary composition and renal haemodynamics, and site and mechanism of action. Diuretics are often abused by athletes to excrete water for rapid weight loss and to mask the presence of other banned substances. Because of their abuse by athletes, diuretics have been included on The World Anti-Doping Agency's (WADA) list of prohibited substances; the use of diuretics is banned both in competition and out of competition and diuretics are routinely screened for by anti-doping laboratories. This review provides an overview of the pharmacology and toxicology of diuretics and discusses their application in sports. The most common analytical strategies currently followed by the anti-doping laboratories accredited by the WADA are discussed along with the challenges laboratories face for the analysis of this diverse class of drugs. PMID:20718736

[Is the renal excretion of orally applied diatrizoate (Gastrografin) a reliable marker of gastrointestinal perforation or dehiscence of a gastrointestinal anastomosis?].

PubMed

Born, M; Axmann, C; Kader, R; von Falkenhausen, M; Manka, C; Willinek, W A; Schild, H

2004-11-01

Renal excretion of orally or rectally applied Gastrografin is reported to be a reliable indicator of a perforation or a postoperative anastomotic dehiscence of the GI-tract. The study was conducted to determine whether increased attenuation of the urine measured by CT after oral or rectal application of Gastrografin can give reliable evidence of any leakage from the gastrointestinal tract. Urine samples of 33 patients, who underwent a Gastrografin-enhanced fluoroscopic examination of the esophagus or the GI-tract for different clinical reasons, were examined by CT. The samples had been taken immediately before and 60 to 90 minutes after application of 100 ml Gastrografin. The results were compared with those of 5 healthy volunteers, who took urine samples before, 30, 60, 90, and 120 minutes after drinking 100 ml of Gastrografin. Maximal attenuation of the volunteers' urine samples was achieved 60 to 90 minutes after Gastrografin application with a mean of 50 Hounsfield units (HU), SD = 17 HU. The urine of three patients with radiologically proven fistula or dehiscence of a GI-tract anastomosis had no relevant increase in attenuation. Three other cases without any clinical or radiological evidence of an anastomotic leak had a substantial increase in the attenuation of the urine probes (87, 110, and 290 HU, respectively). The CT-measured urine samples as evidence of renal excretion of orally or rectally applied Gastrografin are not reliable for the detection of leaks from the GI-tract.

Antigravity suit inflation: kidney function and cardiovascular and hormonal responses in men.

PubMed

Geelen, G; Kravik, S E; Hadj-Aissa, A; Leftheriotis, G; Vincent, M; Bizollon, C A; Sem-Jacobsen, C W; Greenleaf, J E; Gharib, C

1989-02-01

To investigate the effects of lower body positive pressure (LBPP) on kidney function while controlling certain cardiovascular and endocrine responses, seven men [35 +/- 2 (SE) yr] underwent 30 min of sitting and then 4.5 h of 70 degrees head-up tilt. An antigravity suit was applied (60 Torr legs, 30 Torr abdomen) during the last 3 h of tilt. A similar noninflation experiment was conducted where the suited subjects were tilted for 3.5 h. To provide adequate urine flow, the subjects were hydrated during the course of both experiments. Immediately after inflation, mean arterial pressure increased by 8 +/- 3 Torr and pulse rate decreased by 16 +/- 3 beats/min. Plasma renin activity and aldosterone were maximally suppressed (P less than 0.05) after 2.5 h of inflation. Plasma vasopressin decreased by 40-50% (P less than 0.05) and plasma sodium and potassium remained unchanged during both experiments. Glomerular filtration rate was not increased significantly by inflation, whereas inflation induced marked increases (P less than 0.05) in effective renal plasma flow (ERPF), urine flow, osmolar and free water clearances, and total and fractional sodium excretion. No such changes occurred during control. Thus, LBPP induces 1) a significant increase in ERPF and 2) significant changes in kidney excretory patterns similar to those observed during water immersion or the early phase of bed rest, situations that also result in central vascular volume expansion.

THE PHYSIOLOGICAL AND MORPHOLOGICAL BASIS FOR OLFACTORY PERCEPTION OF STEROIDS DURING AGONISITC BEHAVIOR IN LOBSTER

EPA Science Inventory

During fighting, American lobsters urinate on each other with antennule flicking highest during this period. Blocking excretion of urine obliterates previously established dominance relationships, suggesting that individual recognition requires a urine signal (Breithaupt et al.,...

76 FR 6335 - Sodium and Potassium Salts of N-alkyl (C8

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-04

...): Solvents such as alcohols and hydrocarbons; surfactants such as polyoxyethylene polymers and fatty acids... metabolites are not systemically toxic and would be rapidly conjugated and excreted. The SSNA surfactants (mono and di-sodium propionates) may be conjugated and excreted directly. Alternatively, the tertiary...

Clinical utility of spot urine protein-to-creatinine ratio modified by estimated daily creatinine excretion in children.

PubMed

Yang, Eun Mi; Yoon, Bo Ae; Kim, Soo Wan; Kim, Chan Jong

2017-06-01

The spot urine protein-to-creatinine ratio (UPCR) is widely used to predict 24-h urine protein (24-h UP) excretion. In patients with low daily urine creatinine excretion (UCr), however, the UPCR may overestimate 24-h UP. The aim of this study was to predict 24-h UP using UPCR adjusted by estimated 24-h UCr in children. This study included 442 children whose 24-h UP and spot UPCR were measured concomitantly. Estimated 24-h UCr was calculated using three previously existing equations. We estimated the 24-h UP excretion from UPCR by multiplying the estimated UCr. The results were compared with the measured 24-h UP. There was a strong correlation between UPCR and 24-h UP (r = 0.801, P < 0.001), and the correlation improved after multiplying the UPCR by the measured UCr (r = 0.847, P < 0.001). Using the estimated UCr rather than the measured UCr, there was high accuracy and strong correlation between the estimated UPCR weighted by the Cockcroft-Gault equation and 24-h UP. Improvement was also observed in the subgroup (proteinuria vs. non-proteinuria) analysis, particularly in the proteinuria group. The spot UPCR multiplied by the estimated UCr improved the accuracy of prediction of the 24-h UP in children.

Biological monitoring of isocyanates and related amines. I. Determination of 1,6-hexamethylene diamine (HDA) in hydrolysed human urine after oral administration of HDA.

PubMed

Brorson, T; Skarping, G; Sandström, J F; Stenberg, M

1990-01-01

1,6-Hexamethylene diamine (HDA), used as raw material in industrial manufacturing operations, was orally administered to six healthy volunteers. After acid hydrolysis of the urine by hydrochloric acid, HDA and the metabolite 6-aminohexanoic acid were quantified. HDA was determined as an ethyl-chloroformate derivative by capillary gas chromatography using thermionic specific detection (TSD), and 6-aminohexanoic acid was quantified by ion chromatography using the ninhydrin reaction. In nonhydrolysed urine, monoacetylated HDA (N-acetyl-1,6-hexamethylene diamine) and HDA, were verified as heptafluorobutyric anhydride derivatives by gas chromatography-mass spectrometry (GC-MS), in a chemical ionization mode using isobutane and ammonia as reagent gases. In hydrolysed urine, a mean of 0.28 mg (range 1-6%) of the administered dose (8.2 mg) was recovered as HDA, and a mean of 0.8 mg (range less than 1-27%) as 6-aminohexanoic acid. The urinary excretion of both the determined compounds was rapid, and the principal part (greater than 90%) of the elimination was completed within 10 h. There was a considerable inter-individual variation in the excreted amounts, but the intra-individual variation in the excretion of HDA was limited. The subjects N-acetylator phenotype was determined by a dapsone test. Three slow acetylators excreted lower amounts (mean 2% of given dose) of HDA than three rapid ones (mean 5%).

One-year enzyme-linked immunosorbent assay follow-up of human interleukin for Da cells/leukemia inhibitory factor in blood and urine of 22 kidney transplant recipients.

PubMed

Morel, D; Taupin, J L; Combe, C; Potaux, L; Gualde, N; Moreau, J F

1994-12-15

The cytokine human interleukin for Da cells/leukemia inhibitory factor (HILDA/LIF) exerts multiple biological effects in vitro. In mice, high circulating levels of HILDA/LIF induce a wide range of pathophysiological events, some of them closely involved with immunological and inflammatory responses. Using a sandwich ELISA recognizing the natural human HILDA/LIF molecule with a threshold of 50 pg/ml in urine and 150 pg/ml in plasma, we monitored the urine and plasma HILDA/LIF levels of 22 patients in their first year after a kidney transplant. HILDA/LIF urine excretion is increased during acute rejection, and infections also trigger heavy HILDA/LIF plasma concentrations or urine excretion. In addition, this study raises the question of HILDA/LIF involvement in post-kidney-transplant phenomena such as hypercalcemia, osteoporosis, or the reversal of anemia.

Urinary prostaglandin excretion in pregnancy: the effect of dietary sodium restriction.

PubMed

Delemarre, F M; Thomas, C M; van den Berg, R J; Jongsma, H W; Steegers, E A

2000-10-01

Dietary sodium restriction results in activation of the renin-angiotensin-aldosterone-system. In the non-pregnant situation renin release in response to a low sodium diet is mediated by prostaglandins. We studied the effect of dietary sodium restriction on urinary prostaglandin metabolism in pregnancy. In a randomized, longitudinal study the excretion of urinary metabolites of prostacyclin (6-keto-PGF(1 alpha)and 2,3-dinor-6-keto-PGF(1 alpha)) and thromboxane A(2)(TxB(2)and 2,3-dinor-TxB(2)) was determined throughout pregnancy and post partum in 12 women on a low sodium diet and in 12 controls. In pregnancy the excretion of all urinary prostaglandins is increased. The 6-keto-PGF(1 alpha)/ TxB(2)-ratio as well as the 2, 3-dinor-6-keto-PGF(1 alpha)/ 2,3-dinor-TxB(2)-ratio did not significantly change in pregnancy. CONCLUISION Prostacyclin and thromboxane do not seem to play an important role in sodium balance during pregnancy. Copyright 2000 Harcourt Publishers Ltd.

Evidence against bicarbonate reabsorption in the ascending limb, particularly as disclosed by free-water clearance studies.

PubMed Central

Seldin, D. W.; Rosin, J. M.; rector, F. C.

1975-01-01

Bicarbonate reabsorption in the thick ascending limb of Henle's loop was examined by studies of free-water clearance (CH2O) and free-water reabsorption (TcH2O). During maximal water diuresis in the dog, CH2O/GFR was taken as an indes of sodium reabsorption in, and urine flow (V/GFR) as an index of delivery of filtrate to, this scarbonate, infusion of a nonreabsorbable solute (hypotonic mannitol) and administration of an inhibitor of bicarbonate reabsorption (acetaent, but less than that achieved with hypotonic saline infusion. This suggests that sodium that sodium bicarbonate is not reabsorbed in the ascending limb. Rather, it is the sodium chloride, swept out of the proximal tubule by osmotic diuresis due to nonreabsorbed mannitol or sodium bicarbonate, that is reabsorbed in the ascending limb thereby increasing CH2O, whereas the nonreabsorption of mannitol and sodium bicarbonate results in a depressed CH20 per unit V when compared with hypotonic saline. V/GFR is not a satisfactory index of delivery to the ascending limb during osmotic diuresis, since it includes water obligated by nonreabsorbable solutes. When a better index of delivery, the sum of the clearances of chloride (CC1) and free-water (CH2O) is used, hypotonic bicarbonate infusion, hypotonic mannitol infusion and acetazolamide administration increase CH2O/GFR per unit delivery to the same extent as odes hypotonic saline infusion. Studies in dogs and rats on TcH2O also indicate that sodium bicarbonate is an impermeant solute in the ascending limb. Osmotic diuresis due to sodium bicarbonate diuresis, produced either by inhibition of sodium bicarbonate reabsorption (acetazolamide, L-lysine mono-hydrochloride) or infusion of sodium bicarbonate, or mannitol diuresis both produced marked chloruresis and increased TcH2O to the same extent as did hypertonic saline infusion. If chloride excretion was almost eliminated by hemodialysis against a chloride-free dialysate (dogs) or prolonged feeding of a salt-free diet (rats), TcH2O formation was unimpaired if hypertonic saline was infused but virtually obliterated during mannitol or sodium bicarbonate diuresis. Sodium reabsorption in the ascending limb, therefore, appears to be dependent upon chloride as the accompanying anion. At any given rate of bicarbonate excretion, more cloride is delivered out of the proximal tubule (as estimated from CC1 + CH2O) with hypotonic sodium bicarbonate infusion than with acetazolamide administration. This suggests that magnitude of the chlorutesis accompanying bicarbonate diuresis depends, not only on osmotic diuresis due to nonreabsorbed sodium bicarbonate, but also on the extent to which concomitant changes in effective extracellular volume influence overall sodium chloride reabsorption. PMID:1202762

Catecholamine, Corticosteroid and Ketone Excretion in Exercise and Hypoxia,

DTIC Science & Technology

OHCS excretion tended to be higher during the experimental period and subsequently lower overnight during the hypoxia week. Ketosis occurred in two...subjects. In one of these it could be readily related to previous extraneous stress. Excretion of unidentified ketones in overnight urines was sometimes suspected and occurred beyond doubt following gross ketosis . (Author)

Sodium and potassium urinary excretion and their ratio in the elderly: results from the Nutrition UP 65 study

PubMed Central

Moreira, Pedro; Sousa, Ana S.; Guerra, Rita S.; Santos, Alejandro; Borges, Nuno; Afonso, Cláudia; Amaral, Teresa F.; Padrão, Patrícia

2018-01-01

Background We aimed to describe urinary sodium and potassium excretion and their ratio in a representative sample of Portuguese elderly population, according to sociodemographic characteristics and weight status. Methods A cluster sampling approach was used, representing older Portuguese adults (≥65 years) according to age, sex, education level, and regional area within the Nutrition UP 65 study. This cross-sectional evaluation was conducted in 2015 and 2016. From a sample size of 1,500 participants, 1,318 were eligible for the present analysis, 57.3% were women, and 23.5% were aged ≥80 years. Sodium and potassium consumption was evaluated through one 24 h urinary excretion. Inadequate sodium intake was defined as ≥2,000 mg/day, inadequate potassium intake was considered as <3,510 mg/day, and inadequate sodium-to-potassium ratio was defined as >1, according to the World Health Organization cutoffs. Results The proportion of the participants with an inadequate intake was 80.0% in women and 91.5% in men (sodium), 96.2% of women and 79.4% of men (potassium), and 98.4% of women and 99.1% of men (sodium-to-potassium ratio). Higher sodium adequacy was observed among the older elderly, unmarried, with lower household income, and underweight/normal weight. Higher potassium adequacy was observed in the younger elderly, married, and with higher income. Conclusion The majority of the Portuguese elderly population was classified as having inadequate sodium, potassium, and sodium-to-potassium ratio urinary excretion. Therefore, strategies for reducing sodium and increasing potassium intake are priorities in the Portuguese elderly population. PMID:29545733

Ozone Therapy on Rats Submitted to Subtotal Nephrectomy: Role of Antioxidant System

PubMed Central

Calunga, José Luis; Zamora, Zullyt B.; Borrego, Aluet; del Río, Sarahí; Barber, Ernesto; Menéndez, Silvia; Hernández, Frank; Montero, Teresita; Taboada, Dunia

2005-01-01

Chronic renal failure (CRF) represents a world health problem. Ozone increases the endogenous antioxidant defense system, preserving the cell redox state. The aim of this study is to evaluate the effect of ozone/oxygen mixture in the renal function, morphology, and biochemical parameters, in an experimental model of CRF (subtotal nephrectomy). Ozone/oxygen mixture was applied daily, by rectal insufflation (0.5 mg/kg) for 15 sessions after the nephrectomy. Renal function was evaluated, as well as different biochemical parameters, at the beginning and at the end of the study (10 weeks). Renal plasmatic flow (RPF), glomerular filtration rate (GFR), the urine excretion index, and the sodium and potassium excretions (as a measurement of tubular function) in the ozone group were similar to those in Sham group. Nevertheless, nephrectomized rats without ozone (positive control group) showed the lowest RPF, GFR, and urine excretion figures, as well as tubular function. Animals treated with ozone showed systolic arterial pressure (SAP) figures lower than those in the positive control group, but higher values compared to Sham group. Serum creatinine values and protein excretion in 24 hours in the ozone group were decreased compared with nephrectomized rats, but were still higher than normal values. Histological study demonstrated that animals treated with ozone showed less number of lesions in comparison with nephrectomized rats. Thiobarbituric acid reactive substances were significantly increased in nephrectomized and ozone-treated nephrectomized rats in comparison with Sham group. In the positive control group, superoxide dismutase (SOD) and catalase (CAT) showed the lowest figures in comparison with the other groups. However, ozone/oxygen mixture induced a significant stimulation in the enzymatic activity of CAT, SOD, and glutathione peroxidase, as well as reduced glutathione in relation with Sham and positive control groups. In this animal model of CRF, ozone rectal administrations produced a delay in the advance of the disease, protecting the kidneys against vascular, hemorheological, and oxidative mechanisms. This behavior suggests ozone therapy has a protective effect on renal tissue by downregulation of the oxidative stress shown in CRF. PMID:16192672

Ammonia Transporters and Their Role in Acid-Base Balance

PubMed Central

2017-01-01

Acid-base homeostasis is critical to maintenance of normal health. Renal ammonia excretion is the quantitatively predominant component of renal net acid excretion, both under basal conditions and in response to acid-base disturbances. Although titratable acid excretion also contributes to renal net acid excretion, the quantitative contribution of titratable acid excretion is less than that of ammonia under basal conditions and is only a minor component of the adaptive response to acid-base disturbances. In contrast to other urinary solutes, ammonia is produced in the kidney and then is selectively transported either into the urine or the renal vein. The proportion of ammonia that the kidney produces that is excreted in the urine varies dramatically in response to physiological stimuli, and only urinary ammonia excretion contributes to acid-base homeostasis. As a result, selective and regulated renal ammonia transport by renal epithelial cells is central to acid-base homeostasis. Both molecular forms of ammonia, NH3 and NH4+, are transported by specific proteins, and regulation of these transport processes determines the eventual fate of the ammonia produced. In this review, we discuss these issues, and then discuss in detail the specific proteins involved in renal epithelial cell ammonia transport. PMID:28151423

Food label education does not reduce sodium intake in people with type 2 diabetes mellitus. A randomised controlled trial.

PubMed

Petersen, Kristina S; Torpy, David J; Chapman, Ian M; Guha, Sanghamitra; Clifton, Peter M; Turner, Kirsty; Keogh, Jennifer B

2013-09-01

Sodium intake is high in people with type 2 diabetes (T2DM). The aim of this study was to investigate whether urinary sodium excretion can be reduced by educating people with T2DM to read food labels and choose low sodium products. In a 3 month randomised controlled trial, 78 men (n=49) and women (n=29) with T2DM were recruited from a Diabetes Centre at a University teaching hospital. The intervention group was educated in a single session to use the nutrition information panel on food labels to choose products which complied with the Food Standards Australia New Zealand (FSANZ) guideline of <120 mg sodium/100 g food. The control group continued on their usual diet. The primary outcome measure was 24h urinary sodium excretion which was performed at baseline and 3 months. Data was analysed using repeated measures analysis of variance, independent samples t-test and Pearson's correlations. At 3 months mean urinary sodium excretion was unchanged in the intervention (174±13 mmol/24 h and 175±13 mmol/24 h) and control group (167±15mmol/24h and 161±13 mmol/24 h), and there was no between group difference (p>0.05). Sodium excretion was not reduced following the label reading education provided to this group of people with T2DM. Copyright © 2013 Elsevier Ltd. All rights reserved.

Neonatal handling reduces renal function in adult rats.

PubMed

Donadio, Márcio Vinícius Fagundes; Jacobs, Silvana; Corezola, Kizzy Ludnila; Melo, Denizar Alberto da Silva; Dias, Henrique Bregolin; Reichel, Carlos Luiz; Franci, Celso Rodrigues; Jeckel-Neto, Emilio Antonio; Lulhier, Francisco; Lucion, Aldo Bolten; de Oliveira, Jarbas Rodrigues; Sanvitto, Gilberto Luiz

2009-01-01

To evaluate the effects of neonatal handling on hydroelectrolytic balance in adult rats. The litters were divided into two groups: nonhandled and handled. The procedure consisted of handling the pups for 1 min/day in the first 10 days postnatally. When adults, animals had their body weight verified and were housed in individual metabolic cages. After a 24-hour period, urine samples were collected and the urinary and water intake volumes measured. Blood samples to determine osmolality, aldosterone, corticosterone, angiotensin II, creatinine, urea, sodium and potassium levels were collected. The kidneys were removed for histological assessment. Urinary osmolality, sodium, urea and creatinine were also measured and the creatinine clearance (CC) calculated. No difference between groups was found in the body weight. Handled animals showed a reduction in the total kidney wet weight, water intake, urinary volume, CC, plasma angiotensin II, corticosterone and aldosterone when compared to the nonhandled and an increase in the urinary osmolality and sodium excretion fraction. No differences in serum potassium and no evidence of structural changes were demonstrated by histological analysis. Neonatal handling induced long-lasting effects decreasing renal function without evidence of kidney structural changes. (c) 2009 S. Karger AG, Basel.

Impact of dose on the bioavailability of coffee chlorogenic acids in humans.

PubMed

Stalmach, Angélique; Williamson, Gary; Crozier, Alan

2014-08-01

Single servings of coffee beverage containing low (412 μmol), medium (635 μmol) and high (795 μmol) amounts of chlorogenic acids were administered to eleven healthy volunteers in a double-blind randomised controlled trial. Analysis of plasma and urine collected for 24 h revealed the presence of 12 metabolites in plasma and 16 metabolites in urine, principally in the form of sulphates, and to a lesser extent glucuronides of caffeic, ferulic, dihydrocaffeic and dihydroferulic acids, as well as intact feruloylquinic and caffeoylquinic acids, and sulphated caffeoylquinic acid lactones. Median values of peak plasma concentrations after increasing doses of chlorogenic acids were 1088, 1526 and 1352 nM. In urine the median amounts of metabolites excreted after 24 h following consumption of the three coffees were 101, 160 and 125 μmol, accounting for 24%, 25% and 16% of the doses ingested. Peak plasma concentration and urinary excretion values showed trends towards a reduced bioavailability of chlorogenic acids associated with the highest dose ingested, when expressed as percentages of intake. Potential biomarkers of coffee intake were identified as feruloylquinic acids and sulphated caffeoylquinic acid lactones in plasma and urine with positive moderate to strong coefficients of determination for peak plasma concentrations (0.60-0.81) and amounts excreted in urine (0.36-0.73) (P < 0.05).

Urinary proteomics in renal pathophysiology: Impact of proteinuria.

PubMed

Sancho-Martínez, Sandra M; Prieto-García, Laura; Blanco-Gozalo, Víctor; Fontecha-Barriuso, Miguel; López-Novoa, José M; López-Hernández, Francisco J

2015-06-01

Urinary differential proteomics is used to study renal pathophysiological mechanisms, find novel markers of biological processes and renal diseases, and stratify patients according to proteomic profiles. The proteomic procedure determines the pathophysiological meaning and clinical relevance of results. Urine samples for differential proteomic studies are usually normalized by protein content, regardless of its pathophysiological characteristics. In the field of nephrology, this approach translates into the comparison of a different fraction of the total daily urine output between proteinuric and nonproteinuric samples. Accordingly, alterations in the level of specific proteins found by this method reflect the relative presence of individual proteins in the urine; but they do not necessarily show alterations in their daily excretion, which is a key parameter for the understanding of the pathophysiological meaning of urinary components. For renal pathophysiology studies and clinical biomarker identification or determination, an alternative proteomic concept providing complementary information is based on sample normalization by daily urine output, which directly informs on changes in the daily excretion of individual proteins. This is clinically important because daily excretion (rather than absolute or relative concentration) is the only self-normalized way to evaluate the real meaning of urinary parameters, which is also independent of urine concentration. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

21 CFR 862.1285 - Etiocholanolone test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... intended to measure etiocholanolone in serum and urine. Etiocholanolone is a metabolic product of the hormone testosterone and is excreted in the urine. Etiocholanolone measurements are used in the diagnosis...

A novel double-tracer technique to characterize absorption, distribution, metabolism and excretion (ADME) of [14C]tofogliflozin after oral administration and concomitant intravenous microdose administration of [13C]tofogliflozin in humans.

PubMed

Schwab, Dietmar; Portron, Agnes; Backholer, Zoe; Lausecker, Berthold; Kawashima, Kosuke

2013-06-01

Human mass balance studies and the assessment of absolute oral bioavailability (F) are usually assessed in separate studies. Intravenous microdose administration of an isotope tracer concomitant to an unlabeled oral dose is an emerging technique to assess F. We report a novel double-tracer approach implemented for tofogliflozin combining oral administration of a radiolabel tracer with concomitant intravenous administration of a stable isotope tracer. Tofogliflozin is a potent and selective sodium/glucose cotransporter 2 inhibitor for the treatment of type 2 diabetes mellitus currently in clinical development. The objectives of the present study were to assess the systemic exposure of major circulating metabolites, excretion balance, F and contribution of renal clearance (CLR) to total clearance (CL) of tofogliflozin in healthy subjects within one study applying a novel double-tracer technique. Six healthy male subjects received 20 mg [(12)C/(14)C]tofogliflozin (3.73 MBq) orally and a concomitant microdose of 0.1 mg [(13)C]tofogliflozin intravenously. Pharmacokinetics of tofogliflozin were determined for the oral and intravenous route; the pharmacokinetics of the metabolites M1 and M5 were determined for the oral route. Quantification of [(12)C]tofogliflozin in plasma and urine and [(13)C]tofogliflozin in plasma was performed by selective LC-MS/MS methods. For the pre-selected metabolites of tofogliflozin, M1 and M5, a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) was applied to plasma and urine samples. Total radioactivity was assessed in plasma, urine and feces. Pharmacokinetic analysis was conducted by non-compartmental methods. The pharmacokinetics of tofogliflozin in healthy subjects were characterized by an F of 97.5 ± 12.3 %, CL of 10.0 ± 1.3 l/h and volume of distribution at steady-state (V(ss)) of 50.6 ± 6.7 l. The main route of elimination of total drug-related material was by excretion into urine (77.0 ± 4.1 % of the dose). The observed CL(R) of 25.7 ± 5.0 ml/min was higher than the product of the estimated glomerular filtration rate (eGFR) and fraction unbound in plasma (f(u)) (eGFR × f(u) 15 ml/min), indicating the presence of net active tubular secretion in the renal elimination of tofogliflozin. However, CLR contributed only 15.5 % to the CL of tofogliflozin, suggesting that reductions in CLR by renal impairment won't significantly affect systemic exposure to tofogliflozin. Tofogliflozin and its metabolite M1 were the only major circulating entities accounting for 46 ± 8.6 and 50 ± 8.2 %, respectively, of total circulating drug-related material, while the metabolite M5 was a minor circulating metabolite accounting for 3.0 ± 0.3 % of total circulating drug-related material. Both the M1 and M5 metabolites were excreted into urine and the major metabolite M1 did not exhibit active tubular secretion. These results demonstrate the utility of the double-tracer approach to provide essential pharmacokinetic data and excretion data for drug-related material in one study at the same dosing occasion. The data obtained allowed the characterization of absorption, distribution, metabolism and excretion of tofogliflozin. Tofogliflozin exhibited highly favorable pharmacokinetic properties as demonstrated by its high F, low CL and a low V(ss. The presence of only one major circulating metabolite of tofogliflozin was unambiguously demonstrated. As a drug targeting the kidney, luminal exposure of the kidney is achieved by renal filtration and active tubular secretion.

Increased salt consumption induces body water conservation and decreases fluid intake.

PubMed

Rakova, Natalia; Kitada, Kento; Lerchl, Kathrin; Dahlmann, Anke; Birukov, Anna; Daub, Steffen; Kopp, Christoph; Pedchenko, Tetyana; Zhang, Yahua; Beck, Luis; Johannes, Bernd; Marton, Adriana; Müller, Dominik N; Rauh, Manfred; Luft, Friedrich C; Titze, Jens

2017-05-01

The idea that increasing salt intake increases drinking and urine volume is widely accepted. We tested the hypothesis that an increase in salt intake of 6 g/d would change fluid balance in men living under ultra-long-term controlled conditions. Over the course of 2 separate space flight simulation studies of 105 and 205 days' duration, we exposed 10 healthy men to 3 salt intake levels (12, 9, or 6 g/d). All other nutrients were maintained constant. We studied the effect of salt-driven changes in mineralocorticoid and glucocorticoid urinary excretion on day-to-day osmolyte and water balance. A 6-g/d increase in salt intake increased urine osmolyte excretion, but reduced free-water clearance, indicating endogenous free water accrual by urine concentration. The resulting endogenous water surplus reduced fluid intake at the 12-g/d salt intake level. Across all 3 levels of salt intake, half-weekly and weekly rhythmical mineralocorticoid release promoted free water reabsorption via the renal concentration mechanism. Mineralocorticoid-coupled increases in free water reabsorption were counterbalanced by rhythmical glucocorticoid release, with excretion of endogenous osmolyte and water surplus by relative urine dilution. A 6-g/d increase in salt intake decreased the level of rhythmical mineralocorticoid release and elevated rhythmical glucocorticoid release. The projected effect of salt-driven hormone rhythm modulation corresponded well with the measured decrease in water intake and an increase in urine volume with surplus osmolyte excretion. Humans regulate osmolyte and water balance by rhythmical mineralocorticoid and glucocorticoid release, endogenous accrual of surplus body water, and precise surplus excretion. Federal Ministry for Economics and Technology/DLR; the Interdisciplinary Centre for Clinical Research; the NIH; the American Heart Association (AHA); the Renal Research Institute; and the TOYOBO Biotechnology Foundation. Food products were donated by APETITO, Coppenrath und Wiese, ENERVIT, HIPP, Katadyn, Kellogg, Molda, and Unilever.

Increased salt consumption induces body water conservation and decreases fluid intake

PubMed Central

Rakova, Natalia; Kitada, Kento; Lerchl, Kathrin; Dahlmann, Anke; Birukov, Anna; Daub, Steffen; Kopp, Christoph; Pedchenko, Tetyana; Zhang, Yahua; Beck, Luis; Marton, Adriana; Müller, Dominik N.; Rauh, Manfred; Luft, Friedrich C.

2017-01-01

BACKGROUND. The idea that increasing salt intake increases drinking and urine volume is widely accepted. We tested the hypothesis that an increase in salt intake of 6 g/d would change fluid balance in men living under ultra-long-term controlled conditions. METHODS. Over the course of 2 separate space flight simulation studies of 105 and 205 days’ duration, we exposed 10 healthy men to 3 salt intake levels (12, 9, or 6 g/d). All other nutrients were maintained constant. We studied the effect of salt-driven changes in mineralocorticoid and glucocorticoid urinary excretion on day-to-day osmolyte and water balance. RESULTS. A 6-g/d increase in salt intake increased urine osmolyte excretion, but reduced free-water clearance, indicating endogenous free water accrual by urine concentration. The resulting endogenous water surplus reduced fluid intake at the 12-g/d salt intake level. Across all 3 levels of salt intake, half-weekly and weekly rhythmical mineralocorticoid release promoted free water reabsorption via the renal concentration mechanism. Mineralocorticoid-coupled increases in free water reabsorption were counterbalanced by rhythmical glucocorticoid release, with excretion of endogenous osmolyte and water surplus by relative urine dilution. A 6-g/d increase in salt intake decreased the level of rhythmical mineralocorticoid release and elevated rhythmical glucocorticoid release. The projected effect of salt-driven hormone rhythm modulation corresponded well with the measured decrease in water intake and an increase in urine volume with surplus osmolyte excretion. CONCLUSION. Humans regulate osmolyte and water balance by rhythmical mineralocorticoid and glucocorticoid release, endogenous accrual of surplus body water, and precise surplus excretion. FUNDING. Federal Ministry for Economics and Technology/DLR; the Interdisciplinary Centre for Clinical Research; the NIH; the American Heart Association (AHA); the Renal Research Institute; and the TOYOBO Biotechnology Foundation. Food products were donated by APETITO, Coppenrath und Wiese, ENERVIT, HIPP, Katadyn, Kellogg, Molda, and Unilever. PMID:28414302

High sodium chloride intake is associated with low bone density in calcium stone-forming patients.

PubMed

Martini, L A; Cuppari, L; Colugnati, F A; Sigulem, D M; Szejnfeld, V L; Schor, N; Heilberg, I P

2000-08-01

Although renal stone disease has been associated with reduced bone mass, the impact of nutrient intake on bone loss is unknown. The present study was undertaken to investigate the influence of nutrient intake on bone density of 85 calcium stone-forming (CSF) patients (47 male and 38 premenopausal females) aged 41+/-11 years (X+/-SD). Bone mineral density (BMD) was measured using dual energy X-ray absorptiometry at the lumbar spine (L2-L4) and femoral neck sites, and low BMD was defined as a T score < -1 (WHO criteria). A 4-day dietary record and a 24-hour urine sample were obtained from each patient for the assessment of nutrient intake and urinary calcium (U(Ca)), sodium (U(Na)), phosphate and creatinine excretion. Forty-eight patients (56%) presented normal BMD and 37 (44%) low BMD. There were no statistical differences regarding age, weight, height, body mass index, protein, calcium and phosphorus intakes between both groups. The mean U(Ca), phosphorus and nitrogen appearance also did not differ between groups. However, there was a higher percentage of hypercalciuria among low vs normal BMD patients (62 vs 33%, p < 0.05). Low BMD patients presented a higher mean sodium chloride (NaCl) intake and excretion (UNa) than normal BMD (14+/-5 vs 12+/-4 g/day and 246+/-85 vs 204+/-68 mEq/day, respectively p < 0.05). The percentage of patients presenting NaCl intake > or = 16 g/day was also higher among low vs normal BMD patients (35 vs 12%, p < 0.05). After adjustment for calcium and protein intakes, age, weight, body mass index, urinary calcium, citrate and uric acid excretion, and duration of stone disease, multiple-regression analysis showed that a high NaCl intake (> or = 16 g/day) was the single variable that was predictive of risk of low bone density in CSF patients (odds ratio = 3.8). These data suggest that reducing salt intake should be recommended for CSF patients presenting hypercalciuria and osteopenia.

The impact of intrarenal nitric oxide synthase inhibition on renal blood flow and function in mild and severe hyperdynamic sepsis.

PubMed

Ishikawa, Ken; Bellomo, Rinaldo; May, Clive N

2011-04-01

In experimental hyperdynamic sepsis, renal function deteriorates despite renal vasodilatation and increased renal blood flow. Because nitric oxide is increased in sepsis and participates in renal blood flow control, we investigated the effects of intrarenal Nω-nitro-L-arginine methyl ester, a nonspecific nitric oxide synthase inhibitor, in mild and severe sepsis. Prospective crossover and randomized control interventional studies. University-affiliated research institute. Thirty-two merino ewes. Examination of responses to intrarenal infusion of Nω-nitro-L-arginine methyl ester for 8 hrs in unilaterally nephrectomized normal sheep and in sheep administered Escherichia coli. : In normal sheep, Nω-nitro-L-arginine methyl ester decreased renal blood flow (301 ± 30 to 228 ± 26 mL/min) and creatinine clearance (40.0 ± 5.8 to 31.1 ± 2.8 mL/min), whereas plasma creatinine increased, but fractional excretion of sodium was unchanged. In sheep with nonhypotensive hyperdynamic sepsis, plasma creatinine increased and there were decreases in creatinine clearance (34.5 ± 4.6 to 20.1 ± 3.7 mL/min) and fractional excretion of sodium despite increased renal blood flow. Infusion of Nω-nitro-L-arginine methyl ester normalized renal blood flow and increased urine output, but creatinine clearance did not improve and plasma creatinine and fractional excretion of sodium increased. In sheep with severe hypotensive sepsis, creatinine clearance decreased further (31.1 ± 5.4 to 16.0 ± 1.7 mL/min) despite increased renal blood flow. Infusion of Nω-nitro-L-arginine methyl ester restored mean arterial pressure and reduced renal blood flow but did not improve plasma creatinine or creatinine clearance. In hyperdynamic sepsis, with or without hypotension, creatinine clearance decreased despite increasing renal blood flow. Intrarenal Nω-nitro-L-arginine methyl ester infusion reduced renal blood flow but did not improve creatinine clearance. These data indicate that septic acute kidney injury is not the result of decreased renal blood flow nor is it improved by nonspecific nitric oxide synthase inhibition.

Diagnostic Accuracy of Urine Protein/Creatinine Ratio Is Influenced by Urine Concentration

PubMed Central

Yang, Chih-Yu; Chen, Fu-An; Chen, Chun-Fan; Liu, Wen-Sheng; Shih, Chia-Jen; Ou, Shuo-Ming; Yang, Wu-Chang; Lin, Chih-Ching; Yang, An-Hang

2015-01-01

Background The usage of urine protein/creatinine ratio to estimate daily urine protein excretion is prevalent, but relatively little attention has been paid to the influence of urine concentration and its impact on test accuracy. We took advantage of 24-hour urine collection to examine both urine protein/creatinine ratio (UPCR) and daily urine protein excretion, with the latter as the reference standard. Specific gravity from a concomitant urinalysis of the same urine sample was used to indicate the urine concentration. Methods During 2010 to 2014, there were 540 adequately collected 24h urine samples with protein concentration, creatinine concentration, total volume, and a concomitant urinalysis of the same sample. Variables associated with an accurate UPCR estimation were determined by multivariate linear regression analysis. Receiver operating characteristic (ROC) curves were generated to determine the discriminant cut-off values of urine creatinine concentration for predicting an accurate UPCR estimation in either dilute or concentrated urine samples. Results Our findings indicated that for dilute urine, as indicated by a low urine specific gravity, UPCR is more likely to overestimate the actual daily urine protein excretion. On the contrary, UPCR of concentrated urine is more likely to result in an underestimation. By ROC curve analysis, the best cut-off value of urine creatinine concentration for predicting overestimation by UPCR of dilute urine (specific gravity ≦ 1.005) was ≦ 38.8 mg/dL, whereas the best cut-off values of urine creatinine for predicting underestimation by UPCR of thick urine were ≧ 63.6 mg/dL (specific gravity ≧ 1.015), ≧ 62.1 mg/dL (specific gravity ≧ 1.020), ≧ 61.5 mg/dL (specific gravity ≧ 1.025), respectively. We also compared distribution patterns of urine creatinine concentration of 24h urine cohort with a concurrent spot urine cohort and found that the underestimation might be more profound in single voided samples. Conclusions The UPCR in samples with low or high specific gravity is more likely to overestimate or underestimate actual daily urine protein amount, respectively, especially in a dilute urine sample with its creatinine below 38.8 mg/dL or a concentrated sample with its creatinine above 61.5 mg/dL. In particular, UPCR results should be interpreted with caution in cases that involve dilute urine samples because its overestimation may lead to an erroneous diagnosis of proteinuric renal disease or an incorrect staging of chronic kidney disease. PMID:26353117

Diagnostic Accuracy of Urine Protein/Creatinine Ratio Is Influenced by Urine Concentration.

PubMed

Yang, Chih-Yu; Chen, Fu-An; Chen, Chun-Fan; Liu, Wen-Sheng; Shih, Chia-Jen; Ou, Shuo-Ming; Yang, Wu-Chang; Lin, Chih-Ching; Yang, An-Hang

2015-01-01

The usage of urine protein/creatinine ratio to estimate daily urine protein excretion is prevalent, but relatively little attention has been paid to the influence of urine concentration and its impact on test accuracy. We took advantage of 24-hour urine collection to examine both urine protein/creatinine ratio (UPCR) and daily urine protein excretion, with the latter as the reference standard. Specific gravity from a concomitant urinalysis of the same urine sample was used to indicate the urine concentration. During 2010 to 2014, there were 540 adequately collected 24h urine samples with protein concentration, creatinine concentration, total volume, and a concomitant urinalysis of the same sample. Variables associated with an accurate UPCR estimation were determined by multivariate linear regression analysis. Receiver operating characteristic (ROC) curves were generated to determine the discriminant cut-off values of urine creatinine concentration for predicting an accurate UPCR estimation in either dilute or concentrated urine samples. Our findings indicated that for dilute urine, as indicated by a low urine specific gravity, UPCR is more likely to overestimate the actual daily urine protein excretion. On the contrary, UPCR of concentrated urine is more likely to result in an underestimation. By ROC curve analysis, the best cut-off value of urine creatinine concentration for predicting overestimation by UPCR of dilute urine (specific gravity ≦ 1.005) was ≦ 38.8 mg/dL, whereas the best cut-off values of urine creatinine for predicting underestimation by UPCR of thick urine were ≧ 63.6 mg/dL (specific gravity ≧ 1.015), ≧ 62.1 mg/dL (specific gravity ≧ 1.020), ≧ 61.5 mg/dL (specific gravity ≧ 1.025), respectively. We also compared distribution patterns of urine creatinine concentration of 24h urine cohort with a concurrent spot urine cohort and found that the underestimation might be more profound in single voided samples. The UPCR in samples with low or high specific gravity is more likely to overestimate or underestimate actual daily urine protein amount, respectively, especially in a dilute urine sample with its creatinine below 38.8 mg/dL or a concentrated sample with its creatinine above 61.5 mg/dL. In particular, UPCR results should be interpreted with caution in cases that involve dilute urine samples because its overestimation may lead to an erroneous diagnosis of proteinuric renal disease or an incorrect staging of chronic kidney disease.

Elimination kinetics of metals after an accidental exposure to welding fumes.

PubMed

Schaller, Karl H; Csanady, György; Filser, Johannes; Jüngert, Barbara; Drexler, Hans

2007-07-01

We had the opportunity to study the kinetics of metals in blood and urine samples of a flame-sprayer exposed to high accident-prone workplace exposure. We measured over 1 year, the nickel, aluminium, and chromium concentrations in blood and urine specimens after exposure. On this basis, we evaluated the corresponding half-lives. Blood and urine sampling were carried out five times after accidental exposure over a period of 1 year. The metals were analysed by graphite furnace atomic absorption spectrometry and Zeeman compensation with reliable methods. Either a mono-exponential or a bi-exponential function was fitted to the concentration-time courses of selected metals using weighted least squares non-linear regression analysis. The amount excreted in urine was calculated integrating the urinary decay curve and multiplying with the daily creatinine excretion. The first examination was carried out 15 days after exposure. The mean aluminium concentration in plasma was 8.2 microg/l and in urine, 58.4 microg/g creatinine. The mean nickel concentration in blood was 59.6 microg/l and the excretion in urine 700 microg/g creatinine. The mean chromium level in blood was 1.4 microg/l in urine, 7.4 microg/g creatinine. For the three elements, the metal concentrations in blood and urine exceeded the reference values at least in the initial phase. For nickel, the German biological threshold limit values (EKA) were exceeded. Aluminium showed a mono-exponential decay, whereas the elimination of chromium and nickel was biphasic in biological fluids of the accidentally exposed welder. The half-lives were as follows: for aluminium 140 days (urine) and 160 days (plasma); for chromium 40 and 730 days (urine); for nickel 25 and 610 days (urine) as well as 30 and 240 days (blood). The renal clearance of aluminium and nickel was about 2 l/h estimated for the last monitoring day.

Muzzle secretion electrolytes as a possible indicator of sodium status in buffalo (Bubalus bubalis) calves: effects of sodium depletion and aldosterone administration.

PubMed

Kumar, S; Singh, S P

1981-01-01

In two separate experiments, the effects of sodium depletion and aldosterone administration on sodium and potassium concentrations in muzzle secretion, saliva and urine were studied in buffalo calves. Sodium deficiency in the animals was experimentally produced by unilateral parotid saliva deprivation for 18 days. During sodium depletion, the sodium levels in saliva and muzzle secretion gradually fell while the potassium level gradually rose. The concentrations of both of these cations in urine gradually fell during the course of sodium depletion. Aldosterone administration in normal (sodium-replete) animals simulated the effects of sodium depletion as far as cationic changes in saliva were concerned. However, aldosterone did not affect sodium and potassium concentration in the urine and in muzzle secretion in a manner similar to that caused by sodium depletion. Though the hormone decreased urinary sodium without affecting urinary potassium, it did not affect the muzzle sodium or potassium. Results suggest that aldosterone affects the composition of saliva and urine in buffaloes as it does in sheep and other ruminants. Similar changes in composition of muzzle secretion and saliva during sodium depletion indicate that the concentration of sodium in muzzle secretion could possibly be used to evaluate the sodium status of animals.

Measurement of Menadione in urine by HPLC

USDA-ARS?s Scientific Manuscript database

Menadione may be an important metabolite of vitamin K that is excreted in urine. A high performance liquid chromatography (HPLC) method with a C30 column, fluorescence detection and post-column zinc reduction was developed to measure menadione in urine. The mobile phase was composed of 95% methanol...

Enhanced renal prostaglandin production in the dog. I. Effects on renal function.

PubMed

Tannenbaum, J; Splawinski, J A; Oates, J A; Nies, A S

1975-01-01

The changes in renal function produced by endogenous synthesis of prostaglandins by the kidney were evaluated by infusing sodium arachidonate, the prescursor of the prostaglandins, into one renal artery of the dog. These changes were compared with those produced by similar infusions on performed prostaglandin (PG) E2 and F2alpha.PGE2given at 0.01-0.3 mug/kg min--1 produced dose-related increases in urine flow, sodium and potassium excretion, free water clearance, and renal blood flow. The glomerular filtration rage increased only at the lowest dose and the calculated filtration fraction fell. Arachidonic acid at 1.0-30.0 mug/kg min--1 similarly produced dose-related increases in electrolyte excretion, but the increase in renal blood flow was much less than that produced by PGE2 and there were no changes in glomerular filtration rate, filtration fraction, or free water clearances. PGF2alpha had essentially no effects at infusion rates of 0.03-1.0 mug/kg min--1. All renal effects of arachidonic acid were inhibited by simultaneous infusions of an inhibitor of prostaglandin synthetase, 5, 8, 11,14-eicosatetraynoic acid (20:4). None of the effects produced by PGE2 were inhibited by 20:4. These results indicate that enhanced endogenous renal prostaglandin synthesis, which can be produced by arachidonate infusion, results in significant alterations of renal function. This finding strengthens the hypothesis that renal prostaglandins formed in vivo have physiological importance as regulators of renal function.

Low Response of Renin-Angiotensin System to Sodium Intake Intervention in Chinese Hypertensive Patients.

PubMed

Feng, Weijing; Cai, Qingqing; Yuan, Woliang; Liu, Yu; Bardeesi, Adham Sameer A; Wang, Jingfeng; Chen, Jie; Huang, Hui

2016-02-01

The interactions of sodium balance and response of renin-angiotensin-aldosterone system are important for maintaining the hemodynamic stability in physiological conditions. However, the influence of short-term sodium intake intervention in the response of renin-angiotensin system (RAS) on hypertensive patients is still unclear. Thus, we conducted a clinical trial to investigate the effects of short-term sodium intake intervention on the response of RAS in hypertensive patients.One hundred twenty-five primary Chinese hypertensive patients were divided into high, moderate, and low sodium groups by 24-hour urinary sodium excretion (UNa). All the patients received a 10-day dietary sodium intake intervention with standardized sodium (173.91mmol/day) and potassium (61.53mmol/day). Blood pressure, urinary sodium, urinary potassium, plasma sodium, potassium, creatinine, the levels of plasma renin activity, plasma angiotensin II concentrations (AT-II), and plasma aldosterone concentrations were detected before and after the intervention.Before the intervention, no differences were found in blood pressure and RAS among 3 groups. After standardized dietary sodium intake intervention, both UNa excretion and systolic pressure decreased in high-sodium group, while they increased in moderate and low-sodium groups. Intriguingly, there were no changes in the levels of plasma renin activity, AT-II, and plasma aldosterone concentrations among 3 groups during the intervention.The present study demonstrated that the influenced sodium excretion and blood pressure by short-term sodium intake intervention were independent of RAS quick response in Chinese hypertensive patients.

Low Response of Renin–Angiotensin System to Sodium Intake Intervention in Chinese Hypertensive Patients

PubMed Central

Feng, Weijing; Cai, Qingqing; Yuan, Woliang; Liu, Yu; Bardeesi, Adham Sameer A.; Wang, Jingfeng; Chen, Jie; Huang, Hui

2016-01-01

Abstract The interactions of sodium balance and response of renin–angiotensin–aldosterone system are important for maintaining the hemodynamic stability in physiological conditions. However, the influence of short-term sodium intake intervention in the response of renin–angiotensin system (RAS) on hypertensive patients is still unclear. Thus, we conducted a clinical trial to investigate the effects of short-term sodium intake intervention on the response of RAS in hypertensive patients. One hundred twenty-five primary Chinese hypertensive patients were divided into high, moderate, and low sodium groups by 24-hour urinary sodium excretion (UNa+). All the patients received a 10-day dietary sodium intake intervention with standardized sodium (173.91mmol/day) and potassium (61.53mmol/day). Blood pressure, urinary sodium, urinary potassium, plasma sodium, potassium, creatinine, the levels of plasma renin activity, plasma angiotensin II concentrations (AT-II), and plasma aldosterone concentrations were detected before and after the intervention. Before the intervention, no differences were found in blood pressure and RAS among 3 groups. After standardized dietary sodium intake intervention, both UNa+ excretion and systolic pressure decreased in high-sodium group, while they increased in moderate and low-sodium groups. Intriguingly, there were no changes in the levels of plasma renin activity, AT-II, and plasma aldosterone concentrations among 3 groups during the intervention. The present study demonstrated that the influenced sodium excretion and blood pressure by short-term sodium intake intervention were independent of RAS quick response in Chinese hypertensive patients. PMID:26871780

Loxoprofen sodium treatment for elderly men with refractory nocturia: effect on night-time urine production.

PubMed

Okada, Shinsuke; Watanabe, Hideki; Kojima, Yoshiyuki; Yanai, Yoshimasa; Sasaki, Shoichi; Kohri, Kenjiro

2008-05-01

We evaluated the efficacy of loxoprofen sodium for refractory nocturia. Twelve men (mean age, 75.1 +/- 5.7) with nocturia were enrolled in this study. All patients received 60 mg loxoprofen sodium prior to sleeping at night for 14 days. Nine of 12 patients (75%) felt more satisfaction than previous treatments. Patients were grouped into a loxoprofen sodium-effective (n = 7) and ineffective groups (n = 5) based on the results of the frequency-volume chart. In the effective group, interestingly, night-time urine volume showed significant reduction (P < 0.05). On the other hand, the average single voided volume at night and 24-h urine volume showed no significant change. There was a statistically significant difference in the night-time urine volume after treatment between groups (P < 0.01). Loxoprofen sodium is an effective treatment for some patients with refractory nocturia. The main effect mechanism of loxoprofen sodium may involve the reduction of night-time urine production.

Metabolism and elimination of methyl, iso- and n-butyl paraben in human urine after single oral dosage.

PubMed

Moos, Rebecca K; Angerer, Jürgen; Dierkes, Georg; Brüning, Thomas; Koch, Holger M

2016-11-01

Parabens are used as preservatives in personal care and consumer products, food and pharmaceuticals. Their use is controversial because of possible endocrine disrupting properties. In this study, we investigated metabolism and urinary excretion of methyl paraben (MeP), iso-butyl paraben (iso-BuP) and n-butyl paraben (n-BuP) after oral dosage of deuterium-labeled analogs (10 mg). Each volunteer received one dosage per investigated paraben separately and at least 2 weeks apart. Consecutive urine samples were collected over 48 h. In addition to the parent parabens (free and conjugated) which are already used as biomarkers of internal exposure and the known but non-specific metabolites, p-hydroxybenzoic acid (PHBA) and p-hydroxyhippuric acid (PHHA), we identified new, oxidized metabolites with hydroxy groups on the alkyl side chain (3OH-n-BuP and 2OH-iso-BuP) and species with oxidative modifications on the aromatic ring. MeP represented 17.4 % of the dose excreted in urine, while iso-BuP represented only 6.8 % and n-BuP 5.6 %. Additionally, for iso-BuP, about 16 % was excreted as 2OH-iso-BuP and for n-BuP about 6 % as 3OH-n-BuP. Less than 1 % was excreted as ring-hydroxylated metabolites. In all cases, PHHA was identified as the major but non-specific metabolite (57.2-63.8 %). PHBA represented 3.0-7.2 %. For all parabens, the majority of the oral dose captured by the above metabolites was excreted in the first 24 h (80.5-85.3 %). Complementary to the parent parabens excreted in urine, alkyl-chain-oxidized metabolites of the butyl parabens are introduced as valuable and contamination-free biomarkers of exposure.

Studies on absorption and elimination of dietary maillard reaction products.

PubMed

Förster, Anke; Kühne, Yvonne; Henle, Thomas

2005-06-01

A nine-day dietary study involving 18 healthy volunteers was performed in order to investigate the influence of nutrition on the urinary excretion of the Maillard reaction products (MRPs) fructoselysine, pyrraline, and pentosidine. From day two through day eight, most types of Maillard product-containing food had to be avoided. On day five, participants were divided into four groups, three of them receiving a test meal (pretzel sticks, brewed coffee, or custard) containing defined amounts of MRPs. The fourth group served as a control. Urine samples taken over a 24-h period were analyzed for MRPs using chromatographic means. As a result of the MRP-free diet, urinary excretion of free pyrraline and fructoselysine, which was calculated from furosine analysis, were lowered about 90%. Excretion of pentosidine decreased about 40%. Consumption of pretzel sticks and coffee on day five resulted in increased amounts of pyrraline and pentosidine in urine samples on days five to seven. Related to the supplied amounts of pyrraline, about 50% were recovered in the urine samples after ingestion of the pretzel sticks. For pentosidine, 60% of the ingested free derivative from coffee brew and 2% of the peptide-bound amino acid ingested with the bakery product were recovered in the urine samples, indicating a better bioavailability for free pentosidine compared to the protein-bound form. For peptide-bound Amadori products, no influence on the excretion was observed after ingestion of the test foods, indicating degradation in the intestine or plasma to yet-unknown metabolites. In conclusion, differences concerning the excretion rate of individual MRPs point to individual resorption and metabolic pathways. These results are of importance for the discussion of a possible (patho)physiological role of dietary advanced glycation end products (AGEs).

Pharmacokinetics of intravenous pan-class I phosphatidylinositol 3-kinase (PI3K) inhibitor [14C]copanlisib (BAY 80-6946) in a mass balance study in healthy male volunteers.

PubMed

Gerisch, Michael; Schwarz, Thomas; Lang, Dieter; Rohde, Gabriele; Reif, Stefanie; Genvresse, Isabelle; Reschke, Susanne; van der Mey, Dorina; Granvil, Camille

2017-09-01

To determine the pharmacokinetics of radiolabeled copanlisib (BAY 80-6946) in healthy male volunteers and to investigate the disposition and biotransformation of copanlisib. A single dose of 12 mg copanlisib containing 2.76 MBq [ 14 C]copanlisib was administered as a 1-h intravenous infusion to 6 volunteers with subsequent sampling up to 34 days. Blood, plasma, urine and feces were collected to monitor total radioactivity, parent compound and metabolites. Copanlisib treatment was well tolerated. Copanlisib was rapidly distributed throughout the body with a volume distribution of 1870 L and an elimination half-life of 52.1-h (range 40.4-67.5-h). Copanlisib was the predominant component in human plasma (84% of total radioactivity AUC) and the morpholinone metabolite M1 was the only circulating metabolite (about 5%). Excretion of drug-derived radioactivity based on all 6 subjects was 86% of the dose within a collection interval of 20-34 days with 64% excreted into feces as major route of elimination and 22% into urine. Unchanged copanlisib was the main component excreted into urine (15% of dose) and feces (30% of dose). Excreted metabolites (41% of dose) of copanlisib resulted from oxidative biotransformation. Copanlisib was eliminated predominantly in the feces compared to urine as well as by hepatic biotransformation, suggesting that the clearance of copanlisib would more likely be affected by hepatic impairment than by renal dysfunction. The dual mode of elimination via unchanged excretion of copanlisib and oxidative metabolism decreases the risk of clinically relevant PK-related drug-drug interactions.

Metabolite profiling of bendamustine in urine of cancer patients after administration of [14C]bendamustine.

PubMed

Dubbelman, Anne-Charlotte; Jansen, Robert S; Rosing, Hilde; Darwish, Mona; Hellriegel, Edward; Robertson, Philmore; Schellens, Jan H M; Beijnen, Jos H

2012-07-01

Bendamustine is an alkylating agent consisting of a mechlorethamine derivative, a benzimidazole group, and a butyric acid substituent. A human mass balance study showed that bendamustine is extensively metabolized and subsequently excreted in urine. However, limited information is available on the metabolite profile of bendamustine in human urine. The objective of this study was to elucidate the metabolic pathways of bendamustine in humans by identification of its metabolites excreted in urine. Human urine samples were collected up to 168 h after an intravenous infusion of 120 mg/m(2) (80-95 μCi) [(14)C]bendamustine. Metabolites of [(14)C]bendamustine were identified using liquid chromatography (high-resolution)-tandem mass spectrometry with off-line radioactivity detection. Bendamustine and a total of 25 bendamustine-related compounds were detected. Observed metabolic conversions at the benzimidazole and butyric acid moiety were N-demethylation and γ-hydroxylation. In addition, various other combinations of these conversions with modifications at the mechlorethamine moiety were observed, including hydrolysis (the primary metabolic pathway), cysteine conjugation, and subsequent biotransformation to mercapturic acid and thiol derivatives, N-dealkylation, oxidation, and conjugation with phosphate, creatinine, and uric acid. Bendamustine-derived products containing phosphate, creatinine, and uric acid conjugates were also detected in control urine incubated with bendamustine. Metabolites that were excreted up to 168 h after the infusion included products of dihydrolysis and cysteine conjugation of bendamustine and γ-hydroxybendamustine. The range of metabolic reactions is generally consistent with those reported for rat urine and bile, suggesting that the overall processes involved in metabolic elimination are qualitatively the same in rats and humans.

Uptake, metabolism and excretion of orally and intravenously administered, 14C- and 3H-labeled N-acetylneuraminic acid mixture in the mouse and rat.

PubMed

Nöhle, U; Schauer, R

1981-11-01

N-Acetyl-D-[2-14C,9-3H]neuraminic acid, enzymically prepared from sodium [2-14C]-pyruvate and N-acetyl-D-[6-3H]mannosamine by N-acetylneuraminate lyase in 75% yield, was orally administered to 20 day old fasted mice. 90% of the administered neuraminic acid was absorbed from the intestine in the course of 4 h, at a rate depending on the retention time of neuraminic acid in the intestine and the mental conditions of the animals. Between 60 and 90% of the neuraminic acid was excreted in the urine without chemical alteration within the first 6 h. Four hours after administration 10% of the 3H- and 1.3% of the 14C-radioactivity were recovered in the whole blood and in liver, spleen, kidney and brain. After 3 days 0.5% of 3H- and 0.01% of 14C-radioactivity still remained in these tissues. The discrepancy of the 14C-amount relative to the 3H-quantity was accounted for by exhaled 14CO2. After intravenous injection of N-acetylneuraminic acid into rats, 90% of the radioactivity corresponding to the original substance was excreted in the urine within 10 min. Four hours after administration only 5% of the applied 3H- and 1.2% of the 14C-radioactivity were left in the blood and in liver, spleen, kidney and brain. The experiments show that neither orally nor intravenously applied N-acetylneuraminic acid can penetrate cell membranes to a large extent, with the exception of the intestine. The isotopic ratio and N-acetylneuraminate lyase activity suggest that the small amount of the neuraminic acid retained in tissues was largely cleaved by the lyase, followed by metabolism of the reaction products. It may be concluded from these observations that neuraminic acid occurring in food cannot directly be used for the biosynthesis of glycoconjugates on a large scale.

Absorption and metabolism of milk thistle flavanolignans in humans.

PubMed

Calani, Luca; Brighenti, Furio; Bruni, Renato; Del Rio, Daniele

2012-12-15

This study evaluated the absorption and metabolism of milk thistle flavonolignans silychristin, silydianin, silybin and isosilybin isomers (all together known as silymarin) in humans. Fourteen volunteers consumed an extract of milk thistle and urine was collected up to 48 h after consumption. Thirty-one metabolites were identified in urine by means of HPLC-MS/MS, monoglucuronides being the most common excreted form, followed by sulphate-glucuronides and diglucuronides, respectively. The excretion of monoglucuronides peaked 2 h after consumption, whereas sulphate-glucuronide and diglucuronide excretion peaked at 8 h. The bioavailability of milk thistle flavanolignans was 0.45±0.28% (mean±SD). In conclusion, milk thistle flavonolignans are extensively modified after ingestion and recovered in urine as sulpho- and glucuronyl-conjugates, indicating a strong affinity for hepatic phase II enzymes. All future studies (in vitro and in vivo) dealing with the effects of milk thistle should start by considering the modification of its flavonolignans after ingestion by humans. Copyright © 2012 Elsevier GmbH. All rights reserved.

[Metabolism of various biogenic amines in diabetes mellitus].

PubMed

Stoilov, L D; Perelygina, A A

1981-01-01

Serotonin (5-HT) and histamine metabolism was studied in 50 patients with diabetes melitus. Simultaneously the blood and urine content of their precursors and metabolites tryptophane, 5-hydroxytryptophane (5-HTP), 5-hydroxyindolylacetic acid (5-HIAA) and histidine was examined. An increase in 5-HT metabolism intensification (the augmented 5-HTP and 5-HT blood levels and enhanced 5-HTP and 5-HIAA excretion with the urine) was determined, whereas the blood and urine contents of histamine and histadine were within normal. Moreover, significantly higher increase in 5-HT blood level and enhanced 5-HIAA excretion with the urine were seen in patients with juvenile diabetes mellitus comparatively to those with insulin-depending type of the disease. Possible significance of changes, being discovered in 5-HT metabolism of patients with diabetes mellitus, in the disease pathogenesis is discussed.

Hyponatremia in visceral leishmaniasis.

PubMed

Verde, Frederico A Lima; Verde, Francisco A A Lima; Veronese, Francisco José V; Neto, Augusto S; Fuc, Galdino; Verde, Emir M Lima

2010-01-01

There are few reports linking hyponatremia and visceral leishmaniasis (kala-azar). This is a study of 55 consecutive kala-azar patients and 20 normal individuals as a control group. Hyponatremia and serum hypo-osmolality were detected in 100% of kala-azar patients. High first morning urine osmolality (750.0 ± 52.0 vs. 894.5 ± 30.0mOsm/kg H₂O, p < 0.05), and high 24-hour urine osmolality (426.0 ± 167.0 vs. 514.6 ± 132.0 mOsm/kg H₂O, p < 0.05) demonstrated persistent antidiuretic hormone secretion. Urinary sodium was high (82.3 ± 44.2 vs.110.3 ± 34.7 mEq/L, p < 0.05). Low seric uric acid occurred in 61.8% of patients and increased fractional urinary uric acid excretion was detected in 74.5% of them. Increased glomerular filtration rate was present in 25.4% of patients. There was no evidence of extracellular volume depletion. Normal plasma ADH levels were observed in kala-azar patients. No endocrine or renal dysfunction was detected. It is possible that most hyponatremic kala-azar patients present the syndrome of inappropriate antidiuretic hormone secretion.

Aldosterone Is Not Associated With Metabolic and Microvascular Insulin Sensitivity in Abdominally Obese Men.

PubMed

Schütten, Monica T J; Kusters, Yvo H A M; Houben, Alfons J H M; Scheijen, Jean L J M; van de Waarenburg, Marjo P H; Schalkwijk, Casper G; Joris, Peter J; Plat, Jogchum; Mensink, Ronald P; de Leeuw, Peter W; Stehouwer, Coen D A

2018-02-01

Impaired insulin-mediated muscle microvascular recruitment (IMMR) may add to the development of insulin resistance and hypertension. Increased aldosterone levels have been linked to these obesity-related complications in severely to morbidly obese individuals and to impaired microvascular function in experimental studies. To investigate whether aldosterone levels are associated with IMMR, insulin sensitivity, and blood pressure in lean and moderately abdominally obese men, and to study the effect of weight loss. In 25 lean and 53 abdominally obese men, 24-hour blood pressure measurement was performed, and aldosterone levels were measured using ultra-performance liquid chromatography tandem mass spectrometry. Insulin sensitivity was assessed by determining whole-body glucose disposal during a hyperinsulinemic clamp. IMMR in forearm skeletal muscle was measured with contrast-enhanced ultrasonography. These assessments were repeated in the abdominally obese men following an 8-week weight loss or weight stable period. Sodium excretion and aldosterone levels were similar in lean and abdominally obese participants, but sodium excretion was inversely associated with aldosterone concentration only in the lean individuals [lean, β/100 mmol sodium excretion (adjusted for age and urinary potassium excretion) = -0.481 (95% confidence interval, -0.949 to -0.013); abdominally obese, β/100 mmol sodium excretion = -0.081 (95% confidence interval, -0.433 to 0.271); P for interaction = 0.02]. Aldosterone was not associated with IMMR, insulin sensitivity, or blood pressure and was unaffected by weight loss. In moderately abdominally obese men, the inverse relationship between sodium excretion and aldosterone concentration is less than that in lean men but does not translate into higher aldosterone levels. The absolute aldosterone level does not explain differences in microvascular and metabolic insulin sensitivity and blood pressure between lean and moderately abdominally obese men. Copyright © 2017 Endocrine Society

A phase I study to assess the mass balance, excretion, and pharmacokinetics of [14C]-ixazomib, an oral proteasome inhibitor, in patients with advanced solid tumors.

PubMed

Gupta, Neeraj; Zhang, Steven; Pusalkar, Sandeepraj; Plesescu, Mihaela; Chowdhury, Swapan; Hanley, Michael J; Wang, Bingxia; Xia, Cindy; Zhang, Xiaoquan; Venkatakrishnan, Karthik; Shepard, Dale R

2018-06-01

This two-part, phase I study evaluated the mass balance, excretion, pharmacokinetics (PK), and safety of ixazomib in patients with advanced solid tumors. In Part A of the study, patients received a single 4.1 mg oral solution dose of [ 14 C]-ixazomib containing ~500 nCi total radioactivity (TRA), followed by non-radiolabeled ixazomib (4 mg capsule) on days 14 and 21 of the 35-day PK cycle. Patients were confined to the clinic for the first 168 h post dose and returned for 24 h overnight clinic visits on days 14, 21, 28, and 35. Blood, urine, and fecal samples were collected during Part A to assess the mass balance (by accelerator mass spectrometry), excretion, and PK of ixazomib. During Part B of the study, patients received non-radiolabeled ixazomib (4 mg capsules) on days 1, 8, and 15 of 28-day cycles. After oral administration, ixazomib was rapidly absorbed with a median plasma T max of 0.5 h and represented 70% of total drug-related material in plasma. The mean total recovery of administered TRA was 83.9%; 62.1% in urine and 21.8% in feces. Only 3.23% of the administered dose was recovered in urine as unchanged drug up to 168 h post dose, suggesting that most of the TRA in urine was attributable to metabolites. All patients experienced a treatment-emergent adverse event, which most commonly involved the gastrointestinal system. These findings suggest that ixazomib is extensively metabolized, with urine representing the predominant route of excretion of drug-related material.Trial ID: ClinicalTrials.gov # NCT01953783.

Therapeutic and diagnostic potential of a vasopressin-2 antagonist for impaired water handling in cirrhosis.

PubMed

Inoue, T; Ohnishi, A; Matsuo, A; Kawai, B; Kunihiro, N; Tada, Y; Koizumi, F; Chau, T; Okada, K; Yamamura, Y; Tanaka, T

1998-05-01

Progressive cirrhosis is associated with increasing difficulty to handle free water. We examined the therapeutic potential of an orally active nonpeptide vasopressin-2 receptor antagonist (OPC-31260) in the management of edema and ascites in patients with cirrhosis. By means of its chemical blockade of the vasopressin-2 receptor in the kidney, we also assessed the ability of renal water handling in the early stage of cirrhosis. A single 30 mg dose of OPC-31260 was administered orally to eight biopsy-proven patients with cirrhosis who had ascites or peripheral edema. The aquaretic responses were compared with those in six healthy subjects. In the patients with cirrhosis, OPC-31260 significantly (p < 0.01) increased the urinary excretion rate at 0 to 2 hours, and significantly (p < 0.01) lowered urine osmolality at 2 to 4 hours after administration. Free water clearance increased from -0.48 +/- 0.14 to +0.19 +/- 0.21 ml/min (p < 0.05) at 0 to 4 hours after administration. However, these aquaretic responses in the patients with cirrhosis were only approximately half the responses observed in the healthy subjects. A significant (p < 0.05) inverse relationship was observed between indocyanine green retention at 15 minutes after administration and the maximal free water clearance after administration to the patients with cirrhosis. Urinary sodium excretion did not change significantly in the patients, whereas it increased twofold in the healthy subjects. Urinary vasopressin excretion tended to increase in the patients, whereas it increased twofold to threefold (p < 0.01 to 0.05) from the baseline in the healthy subjects. Urinary prostaglandin E2 excretion was not increased, and serum sodium and plasma vasopressin levels were elevated only slightly in both groups. Even though a hyporesponsiveness was observed in the group of patients with cirrhosis compared with the healthy group, the novel vasopressin-2 antagonist induced hypotonic diuresis in patients with cirrhosis, suggesting a therapeutic potential in managing water excess. This drug response may be a new index to assess impairment of water handling in patients with cirrhosis.

The epidemiology of hypernatraemia in hospitalised children in Lothian: a 10-year study showing differences between dehydration, osmoregulatory dysfunction and salt poisoning.

PubMed

Forman, Sarah; Crofton, Patricia; Huang, Hian; Marshall, Tom; Fares, Katia; McIntosh, Neil

2012-06-01

The relative frequencies of the causes of hypernatraemia in children after the neonatal period are unknown. Salt poisoning and osmoregulatory dysfunction are extremely rare and potentially fatal. In this retrospective 10-year study, the incidence, causes and differential biochemistry of hypernatraemia in children is examined. Children with hypernatraemia (sodium ≥ 150 mmol/litre) aged >2 weeks to 17 years were identified from laboratory data of two paediatric departments serving the Lothian region of Scotland. A review of patient notes established time of onset and cause. Denominator data were available from the Scottish Health Service. On admission to hospital, 1 in 2288 children (1:1535 admitted as an emergency) had hypernatraemia. This is 1 in 30 563 Lothian children <17 years. Overall 0.04% hospital stays had an episode of hypernatraemia. In 45 children admitted with 64 separate episodes (11 from a case of salt poisoning), the commonest cause was dehydration secondary to either gastroenteritis or systemic infection; 31% had an underlying chronic neurological disorder. A total of 177 further cases developed hypernatraemia after admission. The commonest causes were dehydration secondary to severe systemic infection and postoperative cardiac surgery. Urine sodium:creatinine ratio and fractional excretion of sodium were both much higher in the salt poisoning case than in a child with osmoregulatory dysfunction or children with simple dehydration. Hypernatraemia after 2 weeks of age is uncommon, and on admission is usually associated with dehydration. Salt poisoning and osmoregulatory dysfunction are rare but should be considered in cases of repeated hypernatraemia without obvious cause. Routine measurement of urea, creatinine and electrolytes on paired urine and plasma on admission will differentiate these rare causes.

Renal water handling in rats with decompensated liver cirrhosis.

PubMed

Jonassen, T E; Christensen, S; Kwon, T H; Langhoff, S; Salling, N; Nielsen, S

2000-12-01

The present study was performed to investigate the renal handling of water in rats with decompensated liver cirrhosis. Liver cirrhosis was induced by intraperitoneal administration of carbon tetrachloride twice weekly for 16 wk. Control rats were treated with vehicle. The cirrhotic rats developed severe disturbances in water homeostasis: urine production was decreased and hyperosmotic, the rats had significantly decreased plasma sodium concentration and ascites, and the ability to excrete an intravenous water load was significantly impaired. Plasma concentrations of vasopressin and aldosterone were increased. Mean arterial pressure, glomerular filtration rate (GFR), and fractional lithium excretion were decreased. Acute vasopressin type 2-receptor blockade with the selective nonpeptide antagonist OPC-31260 (800 microg. kg(-1). h(-1)) was performed during conditions whereby volume depletion was prevented by computer-driven, servo-controlled intravenous volume replacement with 150 mM glucose. The aquaretic response to OPC-31260 was similar in cirrhotic and control rats. However, the OPC 31260-induced rises in fractional water excretion (delta V/GFR; +24%) and fractional distal water excretion (delta V/C(Li); +46%) were significantly increased in the cirrhotic rats, where V is flow rate and delta is change. This suggests that vasopressin-mediated renal water reabsorption capacity was increased in the cirrhotic rats. Semiquantitative immunoblotting revealed that the expression of the vasopressin-regulated water channel aquaporin-2 was unchanged in membrane fractions of both whole kidney and inner medulla from cirrhotic rats. Together, these results suggest a relative escape from vasopressin on collecting duct water reabsorption in rats with decompensated liver cirrhosis.

Bisphenol A Concentration in Breast Milk following Consumption of a Canned Coffee Drink.

PubMed

Tateoka, Yumiko

2015-08-01

Bisphenol A (BPA) is generally considered to be an endocrine disruptor. Previous reports indicate that the BPA content in breast milk is higher than that in serum; however, BPA is considered to be excreted in the urine and not to accumulate in the body. The current study aimed at evaluating the migration of BPA from a commercially available canned coffee drink in a container that was coated with vinyl chloride resin into breast milk. Ten women who had breastfed for ≥12 months, were ready to cease breastfeeding, and drank commercially available canned coffee drinks daily were approached to participate. A canned coffee drink in which the can contained vinyl chloride resin was chosen. Samples (5 mL each) of urine and breast milk were collected prior to and after ingestion (1 h, 2 h, 4 h, and 6 h) of a 190-mL canned coffee drink. BPA measurements were conducted using an ELISA kit. Each 190-mL can of coffee contained 196.9 ng/mL BPA, resulting in 37.4 μg that was consumed in each drink. In breast milk, peak BPA excretion occurred at 1 hour; in urine, excretion occurred rapidly during the first hour, remaining relatively unchanged at 2 hours. The present results indicate that BPA is excreted into the breast milk in addition to the urine and feces. Therefore, it is important to reduce both direct and indirect dietary BPA intake. © The Author(s) 2014.

Metabolism of. cap alpha. -C/sup 14/-histidine in the intact rat. II. Radioactive excretion products in urine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolf, G.; Wu, P.H.L.; Heck, W.W.

1956-09-01

The normal metabolic pathways in the intact rat was investigated via the radioactive urinary excretion products following administration of a physiological dose of a radioactive compound such as ..cap alpha..-C/sup 14/-DL-histidine. The major metabolites, except one, excreted in the urine 5 hours after administration of ..cap alpha..-C/sup 14/-DL-histidine were isolated and identified. Glutamic acid and urocanic acids had simlar and low activities, whereas carboxyl-labeled imidazoacetic acid was found to be the principal metabolite with a high level of activity. It was concluded that the main end-product of the catabolism of DL-histidine is imidazoleacetic acid probably formed through imidazolepyruvic acid.

Renal sodium reabsorption following induction of and recovery from volume expansion

NASA Technical Reports Server (NTRS)

Knight, T. F.; Weinman, E. J.

1977-01-01

In the rat, infusion of a volume of isotonic saline equal to 2% of body weight resulted in an 82% increase in the delivery of filtrate out of the proximal tubule but little or, in some animals, no change in the urinary excretion of sodium. By contrast, further degrees of volume expansion resulted in lesser increases in the distal delivery of filtrate, but were associated with a marked increase in the urinary excretion of sodium. Sixty minutes following completion of volume expansion, while the animals were still in positive sodium balance, the urinary excretion of sodium decreased 52% compared to a decrease of only 24% in the distal delivery of filtrate. During the course of progressive volume expansion and during the recovery phase, there was a dissociation between alterations in sodium reabsorption in the proximal convoluted tubule and in the whole kidney. These studies indicate that although the proximal tubule is more sensitive to changes in the extracellular fluid volume, distal nephron sites are ultimately responsible both for the natriuresis of volume expansion and the relative antinatriuresis of the recovery periods.

Reference limits for urinary fractional excretion of electrolytes in adult non-racing Greyhound dogs.

PubMed

Bennett, S L; Abraham, L A; Anderson, G A; Holloway, S A; Parry, B W

2006-11-01

To determine reference limits for urinary fractional excretion of electrolytes in Greyhound dogs. Urinary fractional excretion was calculated using a spot clearance method preceded by a 16 to 20 hour fast in 48 Greyhound dogs. Raw data analysed using the bootstrap estimate was used to calculate the reference limits. The observed range for urinary fractional excretion in Greyhound dogs was 0.0 to 0.77% for sodium, 0.9 to 14.7% for potassium, 0 to 0.66% for chloride, 0.03 to 0.22% for calcium and 0.4 to 20.1% for phosphate. Expressed as percentages, the suggested reference limits for fractional excretion in Greyhound dogs are as follows: sodium < or = 0.72, potassium < or = 12.2, chloride < or = 0.55, calcium < or = 0.13 and phosphate < or = 16.5. Veterinary practitioners may use these reference limits for urinary electrolyte fractional excretion when investigating renal tubular disease in Greyhound dogs.

Influence of BMI in nephrolithiasis in an Appalachian pediatric population: A single-center experience.

PubMed

Murphy, Margaret O; Erpelding, Scott G; Chishti, Aftab S; Dugan, Adam; Ziada, Ali; Kiessling, Stefan G

2018-06-07

The prevalence of pediatric nephrolithiasis has increased significantly in the past 20 years. Metabolic abnormalities predisposing adults to nephrolithiasis in obese patients include increased urinary sodium and uric acid excretion as well as low urine pH; however, limited data are available in the pediatric population. The aim was to investigate whether obese pediatric patients presenting with nephrolithiasis have a unique metabolic profile similar to reported findings in obese adults with nephrolithiasis. A retrospective chart review was performed in children aged 1-18 years seen at Kentucky Children's Hospital between 2010 and 2016. Inclusion criteria included all patients with documented stones confirmed by ultrasonography or computed tomography. A total of 111 patient charts were reviewed in the study with a mean age of 11.8 ± 4.2 years. Seventy patients (63%) had a normal BMI and 41 patients (37%) were considered overweight/obese. There was no statistically significant relationship between BMI and stone recurrence. Obese patients had significantly decreased levels of urinary citrate, oxalate, magnesium, and potassium with significant elevations of urinary urea nitrogen, ammonia, and low urine pH compared with normal weight patients (Summary Figure). Several groups have reported on metabolic findings within obese and non-obese pediatric patients. A Turkish study reported increased oxalate excretion and hypocitraturia in obese patients while a Korean study also reported increased rates of hypocitraturia in recurrent stone formers. Similar to these studies, we did find significant differences in citrate within our study population; however, we found significantly lower levels of urinary oxalate in obese patients. The majority of these studies do not report an association with BMI and urine pH although this has been reported in the adult population and our findings support an inverse relationship between body mass index (BMI) and pH. Our group found a higher level of calcium phosphate stones, supporting of Eisner's findings that high BMI is associated with increased supersaturation of calcium phosphate. Limitations of our study include being a single center and retrospective in nature. Our study demonstrates differences in types of stones and urinary metabolites in an obese pediatric population suggestive of different metabolic profiles contributing to stone disease. We report similar association between BMI and urine pH, urinary potassium, and citrate. This study confirmed our primary hypothesis that obese pediatric patients would have a different urinary mineral profile as evidenced by lower levels of citrate and potassium and low urine pH; however, obese patients did not exhibit significantly elevated urinary sodium and uric acid when normalized to weight, as described in the adult population. Our study did not confirm our secondary hypothesis that stone composition would be associated with BMI status or stone recurrence. Copyright © 2018 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Potent aquaretic agent. A novel nonpeptide selective vasopressin 2 antagonist (OPC-31260) in men.

PubMed Central

Ohnishi, A; Orita, Y; Okahara, R; Fujihara, H; Inoue, T; Yamamura, Y; Yabuuchi, Y; Tanaka, T

1993-01-01

Solute-free water diuretics (aquaretics) by antagonizing hydrosmotic vasopressin receptors (V2) may be useful in treating water-retaining diseases. The effects of intravenous administration of a newly developed nonpeptide, selective V2 antagonist, OPC-31260, at doses ranging from 0.017 to 1.0 mg/kg to groups of healthy, normally hydrated men were compared with those of 0.33 mg/kg furosemide and placebo. OPC-31260 increased the hypotonic urine volume dose dependently for the first 4 h, while furosemide induced sodium diuresis for 2 h. The absolute increase in the cumulative response in the urine to the highest doses of OPC-31260 was not significantly different from that to furosemide. The higher doses of OPC-31260 rapidly lowered urine osmolality for 2 h, particularly between minutes 15 and 45 (e.g., 1.0-mg/kg dose: 63 +/- 2 mOsm/kg in urine collected between minutes 30 and 45). In a marked hypotonic diuresis, mean free water clearance of the 4-h urine increased dose proportionally into the positive range, reaching 1.80 +/- 0.21 ml/min at 1.0 mg/kg. Whereas furosemide induced marked Na and K diuresis, OPC-31260 increased urinary Na excretion only slightly. At 4 h, 0.75 and 1.0 mg/kg of OPC-31260 almost doubled the plasma arginine vasopressin; and the higher doses increased plasma osmolality and plasma Na slightly, but did not alter plasma K, blood pressure, or heart rate. OPC-31260 thus safely induced a potent aquaretic effect in men. Images PMID:8254021

Serum and ascitic fluid serotonin levels and 5-hydroxyindoleacetic acid urine excretion in the liver of cirrhotic patients with encephalopathy.

PubMed

Chojnacki, C; Walecka-Kapica, E; Stepien, A; Pawlowicz, M; Wachowska-Kelly, P; Chojnacki, J

2013-01-01

The excess and deficit of serotonin can be the cause of somatic and mental disorders. The aim of this study was to evaluate serotonin levels in blood and ascitic fluid as well as excretion of 5-hydroxyindoleacetic acid (5-HIAA) in urine in patients with hepatic encephalopathy (HE). The study included 75 alcoholic cirrhotic patients divided into 3 groups (HE1, HE2, HE3), 25 patients each, with grade 1, 2 and 3 of hepatic encephalopathy according to West-Haven classification. The control group (C) included 25 clinically healthy volunteers. Venous blood and ascitic fluid were collected in fasting. On the same day a 24-hour urine collection was performed. Immunoenzymatic method was used to determine the serotonin level in serum and ascitic fluid, and 5-HIAA in urine (IBL-RE-59121, RE-59131). In the control group, mean serum serotonin level (ng/ml) was 155.5 ± 38.1 and in the 3 study groups: HE1 - 175.2 ± 32.4 (NS), HE2 - 137.2 ± 28.6 (NS), HE3 - 108.3 ± 46.3 (p<0.001). Serotonin concentration in ascitic fluid was on the average about 25% of its level in serum. The excretion of 5-HIAA in urine (mg/24h) in all groups, was: C - 5.9 ± 2.1, HE1 - 5.8 ± 1.8 (NS), HE2 - 4.8 ± 1.2(NS), HE3 - 4.3 ± 1.3 (p<0.05). The results of our study indicate that serum and ascitic fluid level of serotonin and urine excretion of 5-HIAA depends on the grade of hepatic encephalopathy. In patients with severe hepatic encephalopathy serotonin concentration in blood is decreased which can affect some clinical manifestation of this disease.

Does Replacing Sodium Excreted in Sweat Attenuate the Health Benefits of Physical Activity?

PubMed

Turner, Martin J; Avolio, Alberto P

2016-08-01

International guidelines suggest limiting sodium intake to 86-100 mmol/day, but average intake exceeds 150 mmol/day. Participants in physical activities are, however, advised to increase sodium intake before, during and after exercise to ensure euhydration, replace sodium lost in sweat, speed rehydration and maintain performance. A similar range of health benefits is attributable to exercise and to reduction in sodium intake, including reductions in blood pressure (BP) and the increase of BP with age, reduced risk of stroke and other cardiovascular diseases, and reduced risk of osteoporosis and dementia. Sweat typically contains 40-60 mmol/L of sodium, leading to approximately 20-90 mmol of sodium lost in one exercise session with sweat rates of 0.5-1.5 L/h. Reductions in sodium intake of 20-90 mmol/day have been associated with substantial health benefits. Homeostatic systems reduce sweat sodium as low as 3-10 mmol/L to prevent excessive sodium loss. "Salty sweaters" may be individuals with high sodium intake who perpetuate their "salty sweat" condition by continual replacement of sodium excreted in sweat. Studies of prolonged high intensity exercise in hot environments suggest that sodium supplementation is not necessary to prevent hyponatremia during exercise lasting up to 6 hr. We examine the novel hypothesis that sodium excreted in sweat during physical activity offsets a significant fraction of excess dietary sodium, and hence may contribute part of the health benefits of exercise. Replacing sodium lost in sweat during exercise may improve physical performance, but may attenuate the long-term health benefits of exercise.

Urea and Ammonia Metabolism and the Control of Renal Nitrogen Excretion.

PubMed

Weiner, I David; Mitch, William E; Sands, Jeff M

2015-08-07

Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea transport proteins, mediates a central role in the urine concentrating mechanism. Renal ammonia excretion, although often considered only in the context of acid-base homeostasis, accounts for approximately 10% of total renal nitrogen excretion under basal conditions, but can increase substantially in a variety of clinical conditions. Because renal ammonia metabolism requires intrarenal ammoniagenesis from glutamine, changes in factors regulating renal ammonia metabolism can have important effects on glutamine in addition to nitrogen balance. This review covers aspects of protein metabolism and the control of the two major molecules involved in renal nitrogen excretion: urea and ammonia. Both urea and ammonia transport can be altered by glucocorticoids and hypokalemia, two conditions that also affect protein metabolism. Clinical conditions associated with altered urine concentrating ability or water homeostasis can result in changes in urea excretion and urea transporters. Clinical conditions associated with altered ammonia excretion can have important effects on nitrogen balance. Copyright © 2015 by the American Society of Nephrology.

Urea and Ammonia Metabolism and the Control of Renal Nitrogen Excretion

PubMed Central

Mitch, William E.; Sands, Jeff M.

2015-01-01

Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea transport proteins, mediates a central role in the urine concentrating mechanism. Renal ammonia excretion, although often considered only in the context of acid-base homeostasis, accounts for approximately 10% of total renal nitrogen excretion under basal conditions, but can increase substantially in a variety of clinical conditions. Because renal ammonia metabolism requires intrarenal ammoniagenesis from glutamine, changes in factors regulating renal ammonia metabolism can have important effects on glutamine in addition to nitrogen balance. This review covers aspects of protein metabolism and the control of the two major molecules involved in renal nitrogen excretion: urea and ammonia. Both urea and ammonia transport can be altered by glucocorticoids and hypokalemia, two conditions that also affect protein metabolism. Clinical conditions associated with altered urine concentrating ability or water homeostasis can result in changes in urea excretion and urea transporters. Clinical conditions associated with altered ammonia excretion can have important effects on nitrogen balance. PMID:25078422

Human urinary excretion profile after smoking and oral administration of ( sup 14 C)delta 1-tetrahydrocannabinol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johansson, E.; Gillespie, H.K.; Halldin, M.M.

The urinary excretion profiles of delta 1-tetrahydrocannabinol (delta 1-THC) metabolites have been evaluated in two chronic and two naive marijuana users after smoking and oral administration of ({sup 14}C)delta 1-THC. Urine was collected for five days after each administration route and analyzed for total delta 1-THC metabolites by radioactivity determination, for delta 1-THC-7-oic acid by high-performance liquid chromatography, and for cross-reacting cannabinoids by the EMIT d.a.u. cannabinoid assay. The average urinary excretion half-life of {sup 14}C-labeled delta 1-THC metabolites was calculated to be 18.2 +/- 4.9 h (+/- SD). The excretion profiles of delta 1-THC-7-oic acid and EMIT readings weremore » similar to the excretion profile of {sup 14}C-labeled metabolites in the naive users. However, in the chronic users the excretion profiles of delta 1-THC-7-oic acid and EMIT readings did not resemble the radioactive excretion due to the heavy influence from previous Cannabis use. Between 8-14% of the radioactive dose was recovered in the urine in both user groups after oral administration. Lower urinary recovery was obtained both in the chronic and naive users after smoking--5 and 2%, respectively.« less

Iodine Intakes of Victorian Schoolchildren Measured Using 24-h Urinary Iodine Excretion

PubMed Central

Beckford, Kelsey; Margerison, Claire; Skeaff, Sheila A.

2017-01-01

Mandatory fortification of bread with iodized salt was introduced in Australia in 2009, and studies using spot urine collections conducted post fortification indicate that Australian schoolchildren are now replete. However an accurate estimate of daily iodine intake utilizing 24-h urinary iodine excretion (UIE μg/day) has not been reported and compared to the estimated average requirement (EAR). This study aimed to assess daily total iodine intake and status of a sample of primary schoolchildren using 24-h urine samples. Victorian primary school children provided 24-h urine samples between 2011 and 2013, from which urinary iodine concentration (UIC, μg/L) and total iodine excretion (UIE, μg/day) as an estimate of intake was determined. Valid 24-h urine samples were provided by 650 children, mean (SD) age 9.3 (1.8) years (n = 359 boys). The mean UIE of 4–8 and 9–13 year olds was 94 (48) and 111 (57) μg/24-h, respectively, with 29% and 26% having a UIE below the age-specific EAR. The median (IQR) UIC was 124 (83,172) μg/L, with 36% of participants having a UIC < 100 μg/L. This convenience sample of Victorian schoolchildren were found to be iodine replete, based on UIC and estimated iodine intakes derived from 24-h urine collections, confirming the findings of the Australian Health Survey. PMID:28867787

The diurnal variation in urine acidification differs between normal individuals and uric acid stone formers

PubMed Central

Cameron, Mary Ann; Maalouf, Naim M.; Poindexter, John; Adams-Huet, Beverley; Sakhaee, Khashayar; Moe, Orson W.

2012-01-01

Many biologic functions follow circadian rhythms driven by internal and external cues that synchronize and coordinate organ physiology to diurnal changes in the environment and behavior. Urinary acid-base parameters follow diurnal patterns and it is thought these changes are due to periodic surges in gastric acid secretion. Abnormal urine pH is a risk factor for specific types of nephrolithiasis and uric acid stones are typical of excessively low urine pH. Here we placed 9 healthy volunteers and 10 uric acid stone formers on fixed metabolic diets to study the diurnal pattern of urinary acidification. All showed clear diurnal trends in urinary acidification but none of the patterns were affected by inhibitors of the gastric proton pump. Uric acid stone formers had similar patterns of change through the day but their urine pH was always lower compared to healthy volunteers. Uric acid stone formers excreted more acid (normalized to acid ingestion) with the excess excreted primarily as titratable acid rather than ammonium. Urine base excretion was also lower in uric acid stone formers (normalized to base ingestion) along with lower plasma bicarbonate concentrations during part of the day. Thus, increased net acid presentation to the kidney and the preferential use of buffers, other than ammonium, result in much higher concentrations of un-dissociated uric acid throughout the day and consequently an increased risk of uric acid stones. PMID:22297671

Caffeine intake antagonizes salt sensitive hypertension through improvement of renal sodium handling

PubMed Central

Yu, Hao; Yang, Tao; Gao, Peng; Wei, Xing; Zhang, Hexuan; Xiong, Shiqiang; Lu, Zongshi; Li, Li; Wei, Xiao; Chen, Jing; Zhao, Yu; Arendshorst, William J.; Shang, Qianhui; Liu, Daoyan; Zhu, Zhiming

2016-01-01

High salt intake is a major risk factor for hypertension. Although acute caffeine intake produces moderate diuresis and natriuresis, caffeine increases the blood pressure (BP) through activating sympathetic activity. However, the long-term effects of caffeine on urinary sodium excretion and blood pressure are rarely investigated. Here, we investigated whether chronic caffeine administration antagonizes salt sensitive hypertension by promoting urinary sodium excretion. Dahl salt-sensitive (Dahl-S) rats were fed with high salt diet with or without 0.1% caffeine in drinking water for 15 days. The BP, heart rate and locomotor activity of rats was analyzed and urinary sodium excretion was determined. The renal epithelial Na+ channel (ENaC) expression and function were measured by in vivo and in vitro experiments. Chronic consumption of caffeine attenuates hypertension induced by high salt without affecting sympathetic nerve activity in Dahl-S rats. The renal α-ENaC expression and ENaC activity of rats decreased after chronic caffeine administration. Caffeine increased phosphorylation of AMPK and decrease α-ENaC expression in cortical collecting duct cells. Inhibiting AMPK abolished the effect of caffeine on α-ENaC. Chronic caffeine intake prevented the development of salt-sensitive hypertension through promoting urinary sodium excretion, which was associated with activation of renal AMPK and inhibition of renal tubular ENaC. PMID:27173481

Vitamin C modulates lead excretion in rats.

PubMed

Lihm, Hoseob; Kim, Hyun; Chang, Heekyung; Yoon, Myunghee; Lee, Kayoung; Choi, Jongsoon

2013-12-01

Lead, one of the most toxic heavy metals, takes longer time to be excreted from the body than other heavy metals. The purpose of this study is, by measuring lead excretion via urine and feces, to find out the effect of vitamin C in lead chelation. Thirty-six rats were randomly assorted into four groups. All 33 rats except for the control group were administered with lead, before orally administered with different doses of vitamin C per kilogram of body weight. The lead excretion levels in urine and feces as well as the survival rate were then measured for each group. The rats with lead administrations (10/13, 76.9%) with lead administrations only, 10/11 rats (90.9%) with lead administrations and low dose of vitamin C, 9/9 rats (100%) with lead administrations and high dose of vitamin C survived. Among the 29 surviving rats, low vitamin C intake group exhibited higher urinary excretion than the lead only group. The urinary excretion level in high dose vitamin C intakegroup was significantly higher than the lead only group. In addition, fecal lead excretion seemed to be increased in the high dose vitamin C intake group, compared to the group with lead administrations only with statistical significance. Through animal experiment, it was found out that administrating high dose of vitamin C accelerated the excretion of lead in body compared to low dose of vitamin C.

P1,P4-diadenosine tetraphosphate (Ap4A) inhibits proximal tubular reabsorption of sodium in rats.

PubMed

Stiepanow-Trzeciak, Anna; Jankowski, Maciej; Angielski, Stefan; Szczepanska-Konkel, Miroslawa

2007-01-01

P1,P4-diadenosine tetraphosphate (Ap4A) is a vasoactive dinucleotide possessing natriuretic activity. It is unclear, however, which part of the nephron is the target site of action for Ap4A. We evaluated the tubular sites of Ap4A action using the lithium clearance technique. Ap4A at a priming dose of 2 micromol/kg with subsequent infusion at 20 nmol/kg/min increased fractional water and sodium excretion 2.5- and 5.6-fold, respectively. Moreover, Ap4A increased lithium clearance 1.9-fold and fractional lithium excretion 2.8-fold. Fractional water and sodium excretion from distal nephron segments was not significantly affected by Ap4A. These results suggest that Ap4A induces natriuresis mainly through inhibition of proximal tubular reabsorption of sodium. Copyright 2007 S. Karger AG, Basel.

Excretion of sodium and methylglucamine diatrizoate after longtime unilateral ureteric stasis in the rabbit.

PubMed

Owman, T

1979-01-01

The excretion of sodium and meglumine diatrizoate was examined following one or two weeks of unilateral ureteric occlusion. No difference between the two diatrizoate salts was found. A slow compensatory increase of the function of the intact kidney occurred, but after two weeks it was still insufficient at high blood concentration levels.

Involvement of Glucagon-Like Peptide-1 in the Regulation of Selective Excretion of Sodium or Chloride Ions by the Kidneys.

PubMed

Marina, A S; Kutina, A V; Shakhmatoba, E I; Natochin, Yu V

2017-02-01

An increase of total glucagon-like peptide-1 (GLP-1) concentration in the plasma in rats was revealed 5 min after oral, but not intraperitoneal administration of NaCl or Trizma HCl solutions. The increase in GLP-1 level was similar to that after oral glucose administration. After intraperitoneal administration of 2.5% NaCl, GLP-1 mimetic exenatide accelerated natriuresis and urinary chloride excretion. Under conditions of normonatriemia and hyperchloremia induced by injection of 6.7% Trizma HCl, exenatide stimulated chloride excretion and reabsorption of sodium ions in the kidneys. These findings suggest that GLP-1 participates in selective regulation of the balance of sodium and chloride ions.

Percutaneous absorption of selenium sulfide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farley, J.; Skelly, E.M.; Weber, C.B.

1986-01-01

The purpose of this study was to determine selenium levels in the urine of Tinea patients before and after overnight application of a 2.5% selenium sulfide lotion. Selenium was measured by atomic absorption spectroscopy (AAS). Hydride generation and carbon rod atomization were studied. It was concluded from this study that selenium is absorbed through intact skin. Selenium is then excreted, at least partially, in urine, for at least a week following treatment. The data show that absorption and excretion of selenium vary on an individual basis. Selenium levels in urine following a single application of selenium sulfide lotion do notmore » indicate that toxic amounts of selenium are being absorbed. Repeated treatments with SeS/sub 2/ result in selenium concentrations in urine which are significantly higher than normal. Significant matrix effects are observed in the carbon rod atomization of urine samples for selenium determinations, even in the presence of a matrix modifier such as nickel. The method of standard additions is required to obtain accurate results in the direct determination of selenium in urine by carbon rod AAS.« less

Hypertension prevalence, awareness, treatment, and control and sodium intake in Shandong Province, China: baseline results from Shandong-Ministry of Health Action on Salt Reduction and Hypertension (SMASH), 2011.

PubMed

Bi, Zhenqiang; Liang, Xiaofeng; Xu, Aiqiang; Wang, Linghong; Shi, Xiaoming; Zhao, Wenhua; Ma, Jixiang; Guo, Xiaolei; Zhang, Xiaofei; Zhang, Jiyu; Ren, Jie; Yan, Liuxia; Lu, Zilong; Wang, Huicheng; Tang, Junli; Cai, Xiaoning; Dong, Jing; Zhang, Juan; Chu, Jie; Engelgau, Michael; Yang, Quanhe; Hong, Yuling; Wang, Yu

2014-05-22

In China, population-based blood pressure levels and prevalence of hypertension are increasing. Meanwhile, sodium intake, a major risk factor for hypertension, is high. In 2011, to develop intervention priorities for a salt reduction and hypertension control project in Shandong Province (population 96 million), a cross-sectional survey was conducted to collect information on sodium intake and hypertension prevalence, awareness, treatment, and control. Complex, multistage sampling methods were used to select a provincial-representative adult sample. Blood pressure was measured and a survey conducted among all participants; condiments were weighed in the household, a 24-hour dietary recall was conducted, and urine was collected. Hypertension was determined by blood pressure measured on a single occasion and self-reported use of antihypertension medications. Overall, 23.4% (95% confidence interval [CI], 20.9%-26.0%) of adults in Shandong were estimated to have hypertension. Among those classified as having hypertension, approximately one-third (34.5%) reported having hypertension, approximately one-fourth (27.5%) reported taking medications, and one-seventh (14.9%) had their blood pressure controlled (<140/<90 mm Hg). Estimated total average daily dietary sodium intake was 5,745 mg (95% CI, 5,428 mg-6,063 mg). Most dietary sodium (80.8%) came from salt and high-salt condiments added during cooking: a sodium intake of 4,640 mg (95% CI, 4,360 mg-4,920 mg). The average daily urinary sodium excretion was 5,398 mg (95% CI, 5,112 mg-5,683 mg). Hypertension and excessive sodium intake in adults are major public health problems in Shandong Province, China.

Hypertension Prevalence, Awareness, Treatment, and Control and Sodium Intake in Shandong Province, China: Baseline Results From Shandong–Ministry of Health Action on Salt Reduction and Hypertension (SMASH), 2011

PubMed Central

Bi, Zhenqiang; Liang, Xiaofeng; Xu, Aiqiang; Wang, Linghong; Shi, Xiaoming; Zhao, Wenhua; Ma, Jixiang; Guo, Xiaolei; Zhang, Xiaofei; Zhang, Jiyu; Ren, Jie; Yan, Liuxia; Lu, Zilong; Wang, Huicheng; Tang, Junli; Cai, Xiaoning; Dong, Jing; Zhang, Juan; Chu, Jie; Engelgau, Michael; Yang, Quanhe; Hong, Yuling

2014-01-01

Introduction In China, population-based blood pressure levels and prevalence of hypertension are increasing. Meanwhile, sodium intake, a major risk factor for hypertension, is high. In 2011, to develop intervention priorities for a salt reduction and hypertension control project in Shandong Province (population 96 million), a cross-sectional survey was conducted to collect information on sodium intake and hypertension prevalence, awareness, treatment, and control. Methods Complex, multistage sampling methods were used to select a provincial-representative adult sample. Blood pressure was measured and a survey conducted among all participants; condiments were weighed in the household, a 24-hour dietary recall was conducted, and urine was collected. Hypertension was determined by blood pressure measured on a single occasion and self-reported use of antihypertension medications. Results Overall, 23.4% (95% confidence interval [CI], 20.9%–26.0%) of adults in Shandong were estimated to have hypertension. Among those classified as having hypertension, approximately one-third (34.5%) reported having hypertension, approximately one-fourth (27.5%) reported taking medications, and one-seventh (14.9%) had their blood pressure controlled (<140/<90 mm Hg). Estimated total average daily dietary sodium intake was 5,745 mg (95% CI, 5,428 mg–6,063 mg). Most dietary sodium (80.8%) came from salt and high-salt condiments added during cooking: a sodium intake of 4,640 mg (95% CI, 4,360 mg–4,920 mg). The average daily urinary sodium excretion was 5,398 mg (95% CI, 5,112 mg–5,683 mg). Conclusion Hypertension and excessive sodium intake in adults are major public health problems in Shandong Province, China. PMID:24854239

Ammonia excretion increased and urea excretion decreased in urine of a new world nectarivorous bat with decreased nitrogen intake.

PubMed

Herrera M, L Gerardo; Ramirez P, Nicte; Miron M, Leticia

2006-01-01

We determined the effect of water and nitrogen intake on nitrogenous waste composition in the nectarivorous Pallas's long-tongued bat Glossophaga soricina (Phyllostomidae) to test the hypothesis that bats reduce excretion of urea nitrogen and increase the excretion of ammonia nitrogen as nitrogen intake decreases and water intake decreases. Because changes in urine nitrogen composition are expected only in animals whose natural diets are low in nitrogen and high in water content, we also measured maintenance nitrogen requirements (MNR). We hypothesized that, similar to other plant-eating vertebrates, nectarivorous bats have low MNR. Our nitrogen excretion hypothesis was partly proved correct. There was an increase in the proportion of N excreted as ammonia and a decrease in the proportion excreted as urea in low-nitrogen diets. The proportion of N excreted as ammonia and urea was independent of water intake. Most individuals were ureotelic (n = 28), and only a few were ureo-ammonotelic (n = 3) or ammonotelic (n = 2). According to our nitrogen requirement hypothesis, apparent MNR (60 mg kg(-0.75) d(-1)) and truly digestible MNR (54 mg N kg(-0.75) d(-1)) were low. A decrease in urea excretion in low-nitrogen diets may result from urea recycling from liver to the gut functioning as a nitrogen salvage system in nectarivorous bats. This mechanism probably contributes to the low MNR found in Pallas's long-tongued bats.

Renal Outcomes and Dietary Potassium: The Overshadowed Electrolyte?

PubMed Central

Jablonski, Kristen L.; Kendrick, Jessica

2014-01-01

Smyth et al. examined the association between urinary sodium and potassium excretion and adverse renal outcomes in adults at high cardiovascular risk. They found no association between urinary sodium excretion and adverse renal outcomes, but a reduced odds of adverse renal outcomes with higher urinary potassium excretion. This finding is quite interesting and a major advancement from this study. It will be important to ascertain whether this finding holds true in individuals free from vascular disease and diabetes, as well as in patients with chronic kidney disease. PMID:25427082

Comparison of hormone and electrolyte circadian rhythms in male and female humans

NASA Technical Reports Server (NTRS)

Vernikos-Danellis, J.; Winget, C. M.; Goodwin, A. E.; Reilly, T.

1977-01-01

Circadian rhythm characteristics in healthy male and female humans were studied at 4-hour intervals for urine volume, cortisol, 5-hydroxyindoleacetic acid (5-HIAA), Na, K, Na/K ratios in the urine, as well as plasma cortisol. While plasma and urinary cortisol rhythms were very similar in both sexes, the described rhythms in urine volume, electrolyte, and 5-HIAA excretion differ for the two sexes. The results suggest that sex differences exist in the circadian patterns of important hormone and metabolic functions and that the internal synchrony of circadian rhythms differs for the two sexes. The results seem to indicate that the rhythmical secretion of cortisol does not account for the pattern of Na and K excretion.

An analysis of workers' tritium concentration in urine samples as a function of time after intake at Korean pressurised heavy water reactors.

PubMed

Kim, Hee Geun; Kong, Tae Young

2012-12-01

In general, internal exposure from tritium at pressurised heavy water reactors (PHWRs) accounts for ∼20-40 % of the total radiation dose. Tritium usually reaches the equilibrium concentration after a few hours inside the body and is then excreted from the body with an effective half-life in the order of 10 d. In this study, tritium metabolism was reviewed using its excretion rate in urine samples of workers at Korean PHWRs. The tritium concentration in workers' urine samples was also measured as a function of time after intake. On the basis of the monitoring results, changes in the tritium concentration inside the body were then analysed.

Dietary sodium restriction for mild hypertension in general practice.

PubMed Central

Watt, G C; Edwards, C; Hart, J T; Hart, M; Walton, P; Foy, C J

1983-01-01

Eighteen patients with stable mild hypertension (mean blood pressure 144/93 mm Hg) restricted their sodium intake for eight weeks while taking part in a double blind randomised crossover trial of slow sodium and placebo tablets. Mean 24 hour urinary sodium excretion was 143 mmol(mEq) during the period on slow sodium and 87 mmol during the period on placebo. Five patients were unable to reduce their sodium intake below 120 mmol, but the others had a mean 24 hour urinary sodium excretion of 59 mmol during the period on placebo. There was no significant difference in blood pressure between the slow sodium and placebo treatment periods, although the study had a power of 99% to detect a difference of 5 mm Hg in mean arterial pressure between the two periods. Moderate dietary sodium restriction does not lower blood pressure in patients with this degree of hypertension. PMID:6401551

Detox agents do not affect the pharmacokinetics of methamphetamine in the rat.

PubMed

Lee, Sang Kyu; Kim, Yoon; Suh, Sungill; Suh, Yong Jun; In, Moon Kyo; Kim, Dong-Hyun; Jin, Changbae; Yoo, Hye Hyun

2009-04-15

Recently, 'detox' agents have been popularly used as forms of diets or nutritional supplements. Especially, several cases have been reported that these detox agents have been used to mask drug tests among drug abusers. In the present study, capsule and drink types of detox agents were evaluated for their ability to alter the elimination of methamphetamine (MA) in rats. For this study, MA and its major metabolite, amphetamine (AP) in urine samples were determined using LC-tandem mass spectrometry after administration of the detox agents to MA-treated rats. As a result, significant differences were not shown between control and detox-dosed groups in the amounts of MA and AP excreted into urine as well as the volume of excreted urine. This result suggests that the detox agents tested may not affect the metabolism or elimination of MA and further might have minimal effect on narcotics detection in the urine samples of drug abusers.

Renal ammonia metabolism and transport.

PubMed

Weiner, I David; Verlander, Jill W

2013-01-01

Renal ammonia metabolism and transport mediates a central role in acid-base homeostasis. In contrast to most renal solutes, the majority of renal ammonia excretion derives from intrarenal production, not from glomerular filtration. Renal ammoniagenesis predominantly results from glutamine metabolism, which produces 2 NH4(+) and 2 HCO3(-) for each glutamine metabolized. The proximal tubule is the primary site for ammoniagenesis, but there is evidence for ammoniagenesis by most renal epithelial cells. Ammonia produced in the kidney is either excreted into the urine or returned to the systemic circulation through the renal veins. Ammonia excreted in the urine promotes acid excretion; ammonia returned to the systemic circulation is metabolized in the liver in a HCO3(-)-consuming process, resulting in no net benefit to acid-base homeostasis. Highly regulated ammonia transport by renal epithelial cells determines the proportion of ammonia excreted in the urine versus returned to the systemic circulation. The traditional paradigm of ammonia transport involving passive NH3 diffusion, protonation in the lumen and NH4(+) trapping due to an inability to cross plasma membranes is being replaced by the recognition of limited plasma membrane NH3 permeability in combination with the presence of specific NH3-transporting and NH4(+)-transporting proteins in specific renal epithelial cells. Ammonia production and transport are regulated by a variety of factors, including extracellular pH and K(+), and by several hormones, such as mineralocorticoids, glucocorticoids and angiotensin II. This coordinated process of regulated ammonia production and transport is critical for the effective maintenance of acid-base homeostasis.

Urinary excretion of uranium in adult inhabitants of the Czech Republic.

PubMed

Malátová, Irena; Bečková, Věra; Kotík, Lukáš

2016-02-01

The main aim of this study was to determine and evaluate urinary excretion of uranium in the general public of the Czech Republic. This value should serve as a baseline for distinguishing possible increase in uranium content in population living near legacy sites of mining and processing uranium ores and also to help to distinguish the proportion of the uranium content in urine among uranium miners resulting from inhaled dust. The geometric mean of the uranium concentration in urine of 74 inhabitants of the Czech Republic was 0.091 mBq/L (7.4 ng/L) with the 95% confidence interval 0.071-0.12 mBq/L (5.7-9.6 ng/L) respectively. The geometric mean of the daily excretion was 0.15 mBq/d (12.4 ng/d) with the 95% confidence interval 0.12-0.20 mBq/d (9.5-16.1 ng/d) respectively. Despite the legacy of uranium mines and plants processing uranium ore in the Czech Republic, the levels of uranium in urine and therefore, also human body content of uranium, is similar to other countries, esp. Germany, Slovenia and USA. Significant difference in the daily urinary excretion of uranium was found between individuals using public supply and private water wells as a source of drinking water. Age dependence of daily urinary excretion of uranium was not found. Mean values and their range are comparable to other countries, esp. Germany, Slovenia and USA. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bioaccessibility and excretion of arsenic in Niu Huang Jie Du Pian pills

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koch, Iris; Sylvester, Steven; Lai, Vivian W.-M.

2007-08-01

Traditional Chinese medicines (TCMs) often contain significant levels of potentially toxic elements, including arsenic. Niu Huang Jie Du Pian pills were analyzed to determine the concentration, bioaccessibility (arsenic fraction soluble in the human gastrointestinal system) and chemical form (speciation) of arsenic. Arsenic excretion in urine (including speciation) and facial hair were studied after a one-time ingestion. The pills contained arsenic in the form of realgar, and although the total arsenic that was present in a single pill was high (28 mg), the low bioaccessibility of this form of arsenic predicted that only 4% of it was available for absorption intomore » the bloodstream (1 mg of arsenic per pill). The species of arsenic that were solubilized were inorganic arsenate (As(V)) and arsenite (As(III)) but DMAA and MMAA were detected in urine. Two urinary arsenic excretion peaks were observed: an initial peak several (4-8) hours after ingestion corresponding to the excretion of predominantly As(III), and a larger peak at 14 h corresponding predominantly to DMAA and MMAA. No methylated As(III) species were observed. Facial hair analysis revealed that arsenic concentrations did not increase significantly as a result of the ingestion. Arsenic is incompletely soluble under human gastrointestinal conditions, and is metabolized from the inorganic to organic forms found in urine. Bioaccessible arsenic is comparable to the quantity excreted. Facial hair as a bio-indicator should be further tested.« less

Pilot biomonitoring of adults and children following use of chlorpyrifos shampoo and flea collars on dogs.

PubMed

Dyk, Melinda Bigelow; Chen, Zhenshan; Mosadeghi, Sasan; Vega, Helen; Krieger, Robert

2011-01-01

Pesticide handlers and pet owners who use products such as shampoos and dips and insecticide-impregnated collars to treat and control fleas on companion animals are exposed to a variety of active ingredients. Chlorpyrifos exposures of adults and children were measured using urine biomonitoring following use of over-the-counter products on dogs. Age and gender-specific measurements of urinary 3, 5, 6-trichloro-2-pyridinol (TCPy) revealed modest elevations of biomarker excretion following shampoo/dips. Smaller TCPy increments were measured following application of impregnated dog collars. The extent of indoor activity and potential pet contact were important determinants of urine biomarker level. Children without direct pet contact excreted more TCPy following collar application. Pet collars may be a source of indoor surface contamination and human exposure. Children excreted up to 4 times more TCPy than adults when urine volumes were adjusted using age-specific creatinine excretion levels. Although chlorpyrifos is no longer used in the United States in pet care products, results of this research provide perspective on the extent of human exposure from similar pet care products. These pilot studies demonstrated that pet care products such as insecticidal shampoos and dips and impregnated collars may expose family members to low levels of insecticide relative to toxic levels of concern.