Effects of Alpha-Lipoic Acid on Oxidative Stress and Kinin Receptor Expression in Obese Zucker Diabetic Fatty Rats.

PubMed

Midaoui, Adil El; Talbot, Sébastien; Lahjouji, Karim; Dias, Jenny Pena; Fantus, I George; Couture, Réjean

2015-06-01

To investigate the impact of alpha-lipoic acid on superoxide anion production and NADPH oxidase activity as well as on the expression of kinin B1 and B2 receptors in key organs of obese Zucker Diabetic Fatty rats. Superoxide anion production was measured by lucigenin chemiluminescence. Kinin B1 and B2 receptors expression was measured at protein and mRNA levels by western blot and qRT-PCR in key organs of Zucker Diabetic Fatty and Zucker lean control rats treated for a period of 6 weeks with a standard diet or a diet containing the antioxidant α-lipoic acid (1 g/kg). Superoxide anion production and NADPH oxidase activity were significantly enhanced in aorta and adipose tissue of Zucker Diabetic Fatty rats. Kinin B1 and B2 receptors expression levels were also significantly increased in the liver and the gastrocnemius muscle of Zucker Diabetic Fatty rats. Expression of both receptors was not altered in the pancreas of Zucker Diabetic Fatty rats and was undetectable in white retroperitoneal adipose tissue. Alpha-lipoic acid prevented the rise in NADPH oxidase activity in aorta and epididymal adipose tissue of Zucker Diabetic Fatty rats and the upregulation of kinin B1 receptor in liver and gastrocnemius muscle and that of kinin B2 receptor in the liver. Alpha-lipoic acid treatment was found to prevent the final body weight increase without affecting significantly hyperglycemia, hyperinsulinemia and insulin resistance index in Zucker Diabetic Fatty rats. Findings support the hypothesis that oxidative stress is implicated in the induction of kinin B1 receptor in Zucker Diabetic Fatty rats. The ability of α-lipoic acid to blunt the body weight gain appears to be mediated in part by preventing NADPH oxidase activity rise in adipose tissue and reversing the hepatic upregulation of kinin B1 receptor in Zucker Diabetic Fatty rats.

Regulation of palmitoyl-CoA chain elongation by clofibric acid in the liver of Zucker fa/fa rats.

PubMed

Toyama, Tomoaki; Kudo, Naomi; Mitsumoto, Atsushi; Kawashima, Yoichi

2005-05-01

The regulation of palmitoyl-CoA chain elongation (PCE) by clofibric acid [2-(4-chlorophenoxy)-2-methylpropionic acid] was investigated in comparison with stearoyl-CoA desaturase (SCD) in the liver of obese Zucker fa/fa rats. The proportion of oleic acid in the hepatic lipids of Zucker obese rats is 2.7 times higher than that of lean littermates. The activities of PCE and SCD in the liver of Zucker obese rats were markedly higher than in lean rats, and the hepatic uptake of 2-deoxyglucose (2-DG) was also higher in Zucker obese rats compared with lean rats. The increased activities of SCD and PCE in Zucker obese rats were due to the enhanced expression of mRNA of both SCD1 and rat FA elongase 2 (rELO2), but not SCD2 or rELO1. The proportion of oleic acid in the liver was significantly increased by the administration of clofibric acid to Zucker obese rats, and the hepatic PCE activity and rELO2 mRNA expression, but not the SCD activity or SCD1 mRNA expression, were increased in response to clofibric acid treatment. By contrast, the activities of both PCE and SCD and the mRNA expression of SCD1 and rELO2 in the liver were increased by the treatment of Zucker lean rats with clofibric acid. Multiple regression analysis, which was performed to determine the relationships involving PCE activity, SCD activity, and the proportion of oleic acid, revealed that the three parameters were significantly correlated and that the standardized partial regression coefficient of PCE was higher than that of SCD. These results indicate that oleic acid is synthesized by the concerted action of PCE and SCD and that PCE plays a crucial role in the formation of oleic acid when Zucker fa/fa rats are given clofibric acid.

Obese and Lean Zucker Rats Demonstrate Differential Sensitivity to Rates of Food Reinforcement in a Choice Procedure

PubMed Central

Buckley, Jessica L.; Rasmussen, Erin B.

2012-01-01

The obese Zucker rat carries two recessive fa alleles that result in the expression of an obese phenotype. Obese Zuckers have higher food intake than lean controls in free-feed studies in which rats have ready access to a large amount of one type of food. The present study examined differences in obese and lean Zucker rats using concurrent schedules of reinforcement, which more ecologically models food selection using two food choices that have limited, but generally predictable, availability. Lever-pressing of ten lean (Fa/Fa or Fa/fa) and ten obese (fa/fa) Zucker rats was placed under three concurrent variable interval variable interval (conc VI VI) schedules of sucrose and carrot reinforcement, in which the reinforcer ratios for 45-mg food pellets were 5:1, 1:1, and 1:5. Allocation of responses to the two food alternatives was characterized using the generalized matching equation, which allows sensitivity to reinforcer rates (a) and bias toward one alternative (log k) to be quantified. All rats showed a bias to sucrose, though there were no differences between lean and obese Zucker rats. In addition, obese Zucker rats exhibited higher sensitivity to reinforcement rates than lean rats. This efficient pattern of responding was related to overall higher deliveries of food pellets. Effective matching for food, then, may be another behavioral pattern that contributes to an obese phenotype. PMID:23046726

Impulsive-choice patterns for food in genetically lean and obese Zucker rats

PubMed Central

Boomhower, Steven R.; Rasmussen, Erin B.; Doherty, Tiffany S.

2012-01-01

Behavioral-economic studies have shown that differences between lean and obese Zuckers in food consumption depend on the response requirement for food. Since a response requirement inherently increases the delay to reinforcement, differences in sensitivity to delay may also be a relevant mechanism of food consumption in the obese Zucker rat. Furthermore, the endocannabinoid neurotransmitter system has been implicated in impulsivity, but studies that attempt to characterize the effects of cannabinoid drugs (e.g., rimonabant) on impulsive choice may be limited by floor effects. The present study aimed to characterize impulsive-choice patterns for sucrose using an adjusting-delay procedure in genetically lean and obese Zuckers. Ten lean and ten obese Zucker rats chose between one lever that resulted in one pellet after a standard delay (either 1 s or 5 s) and a second lever that resulted in two or three pellets after an adjusting delay. After behavior stabilized under baseline, rimonabant (0–10 mg/kg) was administered prior to some choice sessions in the two-pellet condition. Under baseline, obese Zuckers made more impulsive choices than leans in three of the four standard-delay/pellet conditions. Additionally, in the 2-pellet condition, rimonabant increased impulsive choice in lean rats in the 1-s standard-delay condition; however, rimonabant decreased impulsive choice in obese rats in the 1-s and 5-s standard-delay conditions. These data suggest that genetic factors that influence impulsive choice are stronger in some choice conditions than others, and that the endocannabinoid system may be a relevant neuromechanism. PMID:23261877

Impulsive-choice patterns for food in genetically lean and obese Zucker rats.

PubMed

Boomhower, Steven R; Rasmussen, Erin B; Doherty, Tiffany S

2013-03-15

Behavioral-economic studies have shown that differences between lean and obese Zuckers in food consumption depend on the response requirement for food. Since a response requirement inherently increases the delay to reinforcement, differences in sensitivity to delay may also be a relevant mechanism of food consumption in the obese Zucker rat. Furthermore, the endocannabinoid neurotransmitter system has been implicated in impulsivity, but studies that attempt to characterize the effects of cannabinoid drugs (e.g., rimonabant) on impulsive choice may be limited by floor effects. The present study aimed to characterize impulsive-choice patterns for sucrose using an adjusting-delay procedure in genetically lean and obese Zuckers. Ten lean and ten obese Zucker rats chose between one lever that resulted in one pellet after a standard delay (either 1 s or 5 s) and a second lever that resulted in two or three pellets after an adjusting delay. After behavior stabilized under baseline, rimonabant (0-10 mg/kg) was administered prior to some choice sessions in the two-pellet condition. Under baseline, obese Zuckers made more impulsive choices than leans in three of the four standard-delay/pellet conditions. Additionally, in the 2-pellet condition, rimonabant increased impulsive choice in lean rats in the 1-s standard-delay condition; however, rimonabant decreased impulsive choice in obese rats in the 1-s and 5-s standard-delay conditions. These data suggest that genetic factors that influence impulsive choice are stronger in some choice conditions than others, and that the endocannabinoid system may be a relevant neuromechanism. Copyright © 2012 Elsevier B.V. All rights reserved.

Anti-Obesity Effects of Onion Extract in Zucker Diabetic Fatty Rats

PubMed Central

Yoshinari, Orie; Shiojima, Yoshiaki; Igarashi, Kiharu

2012-01-01

Anti-obesity effects of onion extract were determined in obesity and diabetes-prone Zucker diabetic fatty rats by measuring the efficacy of markers concerned with diabetes and obesity. Body and adipose tissue weights in 5% of onion extract-fed group were found to be significantly lower than the control group without onion extract. Fasting blood glucose and HOMA-IR levels were also improved, although the serum insulin and leptin levels did not show any remarkable difference. Serum triglyceride and free fatty acid levels in both the 3% and 5%-fed group were found to be reduced compared to the control group. Additionally the feeding of the onion extract increased the glucose tolerance. These results suggest that dietary onion extract is beneficial for improving diabetes by decreasing lipid levels. We also examined differentiation ability of rat white preadipocyte cells using the onion extract and its sulfur-containing components. Cycloalliin, S-methyl-L-cysteine, S-propyl-L-cysteine sulfoxide, dimethyl trisulfide, especially S-methyl-L-cysteine sulfoxide were reported to be effective in inhibiting formation of oil drop in the cells, suggesting that these compounds may be involved in the anti-obesity effect of the onion extract. PMID:23201769

Resistant Starch but Not Enzymatically Modified Waxy Maize Delays Development of Diabetes in Zucker Diabetic Fatty Rats.

PubMed

Hedemann, Mette Skou; Hermansen, Kjeld; Pedersen, Sven; Bach Knudsen, Knud Erik

2017-05-01

Background: The incidence of type 2 diabetes (T2D) is increasing worldwide, and nutritional management of circulating glucose may be a strategic tool in the prevention of T2D. Objective: We studied whether enzymatically modified waxy maize with an increased degree of branching delayed the onset of diabetes in male Zucker diabetic fatty (ZDF) rats. Methods: Forty-eight male ZDF rats, aged 5 wk, were divided into 4 groups and fed experimental diets for 9 wk that contained 52.95% starch: gelatinized corn starch (S), glucidex (GLU), resistant starch (RS), or enzymatically modified starch (EMS). Blood glucose after feed deprivation was assessed every second week; blood samples taken at run-in and at the end of the experiment were analyzed for glycated hemoglobin (HbA1c) and plasma glucose, insulin, and lipids. During weeks 2 and 8, urine was collected for metabolomic analysis. Results: Based on blood glucose concentrations in feed-deprived rats, none of the groups developed diabetes. However, in week 9, plasma glucose after feed deprivation was significantly lower in rats fed the S and RS diets (13.5 mmol/L) than in rats fed the GLU and EMS diets (17.0-18.9 mmol/L), and rats fed RS had lower HbA1c (4.9%) than rats fed the S, GLU, and EMS (5.6-6.1%) diets. The homeostasis model assessment of insulin resistance was significantly lower in rats fed RS than in rats fed the other diets (185 compared with 311-360), indicating that rats fed the S, GLU, and EMS diets were diabetic, and a 100% higher urine excretion during week 8 in rats fed the GLU and EMS diets than that of rats fed S and RS showed that they were diabetic. Urinary nontargeted metabolomics revealed that the diabetic state of rats fed S, GLU, and EMS diets influenced microbial metabolism, as well as amino acid, lipid, and vitamin metabolism. Conclusions: EMS did not delay the onset of diabetes in ZDF rats, whereas rats fed RS showed no signs of diabetes. © 2017 American Society for Nutrition.

Obesity decreases serum selenium levels in DMBA-induced mammary tumor using Obese Zucker Rat Model

USDA-ARS?s Scientific Manuscript database

Recently, we reported that obese Zucker rats had increased susceptibility to DMBA-induced mammary tumors compared to lean Zucker rats. Several studies suggest that lower serum selenium may play an important role in increasing the risk of several types of cancers (e.g, colon, breast and prostate canc...

Effect of lateral hypothalamic lesion on brown adipose tissue of Zucker lean and obese rats.

PubMed

Holt, S J; York, D A

1988-01-01

Acute (10-day) lateral hypothalamic (LH) lesion induced a reduction of food intake in both lean and obese Zucker rats which averaged about 50% over the course of the first 10 days. The aphagia associated with a fall in body weight in both genotypes which was greater than their respective pair-fed controls, indicating a change in energetic efficiency. The reduced level of BAT protein, mitochondria and GDP binding observed in the obese rat was restored after LH lesion, suggesting the reestablishment of a normal sympathetic drive to the tissue. The markedly lower plasma insulin concentration in the LH lesioned obese rat is consistent with a reduction in parasympathetic activity in these animals. Food restriction in the sham lean rat reduced BAT protein content and mitochondrial GDP binding, whereas no such changes were observed in the food restricted obese rat. This demonstrates the insensitivity of the obese rat to dietary signals and may imply that LH lesion restores diet-induced BAT thermogenesis in the obese rat.

Cardiovascular and metabolic responses to fasting and thermoneutrality are conserved in obese Zucker rats.

PubMed

Overton, J M; Williams, T D; Chambers, J B; Rashotte, M E

2001-04-01

The primary purpose of the study was to test the hypothesis that reduced leptin signaling is necessary to elicit the cardiovascular and metabolic responses to fasting. Lean (Fa/?; normal leptin receptor; n = 7) and obese (fa/fa; mutated leptin receptor; n = 8) Zucker rats were instrumented with telemetry transmitters and housed in metabolic chambers at 23 degrees C (12:12-h light-dark cycle) for continuous (24 h) measurement of metabolic and cardiovascular variables. Before fasting, mean arterial pressure (MAP) was higher (MAP: obese = 103 +/- 3; lean = 94 +/- 1 mmHg), whereas oxygen consumption (VO(2): obese = 16.5 +/- 0.3; lean = 18.6 +/- 0.2 ml. min(-1). kg(-0.75)) was lower in obese Zucker rats compared with their lean controls. Two days of fasting had no effect on MAP in either lean or obese Zucker rats, whereas VO(2) (obese = -3.1 +/- 0.3; lean = -2.9 +/- 0.1 ml. min(-1). kg(-0.75)) and heart rate (HR: obese = -56 +/- 4; lean = -42 +/- 4 beats/min) were decreased markedly in both groups. Fasting increased HR variability both in lean (+1.8 +/- 0.4 ms) and obese (+2.6 +/- 0.3 ms) Zucker rats. After a 6-day period of ad libitum refeeding, when all parameters had returned to near baseline levels, the cardiovascular and metabolic responses to 2 days of thermoneutrality (ambient temperature 29 degrees C) were determined. Thermoneutrality reduced VO(2) (obese = -2.4 +/- 0.2; lean = -3.3 +/- 0.2 ml. min(-1). kg(-0.75)), HR (obese = -46 +/- 5; lean = -55 +/- 4 beats/min), and MAP (obese = -13 +/- 6; lean = -10 +/- 1 mmHg) similarly in lean and obese Zucker rats. The results indicate that the cardiovascular and metabolic responses to fasting and thermoneutrality are conserved in Zucker rats and suggest that intact leptin signaling may not be requisite for the metabolic and cardiovascular responses to reduced energy intake.

Renoprotective mechanisms of soy protein intake in the obese Zucker rat

PubMed Central

Trujillo, Joyce; Cruz, Cristino; Tovar, Armando; Vaidya, Vishal; Zambrano, Elena; Bonventre, Joseph V.; Gamba, Gerardo; Torres, Nimbe; Bobadilla, Norma A.

2008-01-01

We previously showed that long-term consumption of a soy protein diet (SoyP) reduces renal damage in obese Zucker (ObeseZ) rats by restoring urinary NO2 and NO3 excretion (UNO2/NO3V), suggesting that nitric oxide (NO) deficiency may contribute to the renal progression observed in this model. In addition, there is compelling evidence that hyperleptinemia produced deleterious effects on the kidney through its interaction with the short leptin receptor (ObRa). This study was designed to evaluate the contribution of the NO/endothelial NO synthase (eNOS) system, renal oxidative stress, and ObRa expression to the renoprotection conferred by the consumption of a SoyP in ObeseZ rats. Ten lean and ten male ObeseZ rats were included. One-half of each group was fed with a 20% SoyP and the other half with a 20% casein protein diet (CasP) over the course of 160 days. eNOS protein levels and phosphorylation, renal lipoperoxidation (rLPO), and antioxidant enzyme activity were assessed. In addition, renal ObRa, TGF-β, and kidney injury molecule (Kim-1) mRNA levels, as well as urinary Kim-1 levels, were measured. Renal injury observed in ObeseZ rats fed with CasP was not associated with changes in eNOS expression or phosphorylation. However, this group did present with increased rLPO, reduced catalase activity, and upregulation of ObRa, TGF-β1, and Kim-1. In contrast, ObeseZ rats fed with a SoyP exhibited a reduction in NOS-Thr495 phosphorylation and rLPO, as well as an enhanced catalase activity. These findings were associated with a significant reduction of ObRa, TGF-β1, and Kim-1 mRNA levels and urinary Kim-1 protein. Our results show that renoprotection by SoyP in ObeseZ rats is in part mediated by increased NO availability secondary to a reduction in eNOS-T495 phosphorylation and oxidative stress, together with a significant reduction in ObRa and TGF-β expression. PMID:18815216

Behavioural, morphological and electrophysiological assessment of the effects of type 2 diabetes mellitus on large and small nerve fibres in Zucker diabetic fatty, Zucker lean and Wistar rats.

PubMed

Garcia-Perez, E; Schönberger, T; Sumalla, M; Stierstorfer, B; Solà, R; Doods, H; Serra, J; Gorodetskaya, N

2018-04-20

Peripheral neuropathy is a common complication in type 2 diabetes mellitus (T2DM). The most common presentation is in the form of a distal axonal sensory-motor polyneuropathy that involves large and small nerve fibres in variable proportion. Zucker Diabetic Fatty (ZDF), Zucker Lean (ZL) and Wistar Han (WH) rats were used to assess the behavioural, morphological and electrophysiological effects that T2DM have on peripheral large and small nerve fibres of 6- to 40-week-old rats. ZDF rats presented mechanical hypersensitivity that initially worsened in parallel to the progression of diabetes and eventually reverted at later stages of the disease. The reversal from hypersensitivity to hyposensitivity paralleled a reduction in the number of intraepithelial skin nerve terminals and in the nerve fibre lengths. However, no increased levels of degeneration of dorsal root ganglion neurons were observed. Nerve conduction studies showed a reduction in sensory and motor nerve conduction velocity (CV) in hyperglycaemic ZDF rats. Microneurography showed significant alterations in several parameters of activity-dependent slowing (ADS) of mechano-insensitive C-nociceptors in ZDF rats. Surprisingly, some of these changes were also observed in ZL rats. Moreover, we found spontaneous activity in all three strains implying that C-nociceptors become hyperexcitable and spontaneously active not only in ageing hyperglycaemic ZDF rats but also in age-matched and apparently normoglycaemic ZL and WH rats fed with the same diet. ZDF rats presented a diabetic neuropathy involving large and small nerve fibres; additionally, ZL and WH rats also showed early small abnormalities in C-fibres, clearly detected by microneurography SIGNIFICANCE: This study provides a functional description of large and small nerve fibre function in a diabetic model that recapitulates many of the findings observed in patients suffering from type 2 diabetes mellitus. © 2018 European Pain Federation - EFIC®.

Submandibular Gland and Caries Susceptibility in the Obese Zucker Rat

PubMed Central

Mozaffari, Mahmood S.; Abdelsayed, Rafik; Zakhary, Ibrahim; El-Salanty, Mohammed; Liu, Jun Yao; Wimborne, Hereward; El-Marakby, Ahmed

2010-01-01

Background Obesity is a prevalent disorder characterized as marked insulin resistance and low grade inflammation. We tested the hypothesis that obesity upregulates inflammatory markers in the submandibular gland in association with derangements of its architecture and predisposition to caries in obese Zucker rats. We also examined the potential impact of chromium picolinate (Cr(Pic)3), a nutritional supplement suggested to improve glycemic control, on the aforementioned parameters. Design Male obese Zucker rats (OZR) were treated with diets lacking and containing 5 or 10 mg/kg chromium (as Cr(Pic)3) from 6 weeks to about 6 months of age; lean Zucker rats (LZR) served as controls. Thereafter, glycemic status, salivary tissue architecture and levels of several inflammatory markers were determined in association with caries susceptibility. Results OZR showed reduced insulin sensitivity, increased ratio of phospho-nuclear factor kappa B (NF-κB) to total NF-κB and increased intercellular adhesion molecule-1 level but similar histological features compared to LZR. Importantly, compared to LZR, OZR displayed rampant caries and a tendency for reduced dentin mineral density. Treatment of OZR with Cr(Pic)3 attenuated upregulation of these proinflammatory indicators in association with reduced severity of caries without improving insulin sensitivity. Conclusions Obesity promotes proinflammatory changes within the submandibular gland, without affecting glandular architecture, in association with rampant caries; Cr(Pic)3 treatment provided some protective effects. PMID:20973827

Potential utility of combination therapy with nateglinide and telmisartan for metabolic derangements in Zucker Fatty rats.

PubMed

Kajioka, T; Miura, K; Kitahara, Y; Yamagishi, S

2007-12-01

The metabolic syndrome is strongly associated with insulin resistance and has been recognized as a cluster of risk factors for cardiovascular disease. Insulin resistance and/or impaired early-phase insulin secretion are major determinants of postprandial hyperglycemia. In this study, we investigated the potential utility of combination therapy with telmisartan, an angiotensin II receptor blocker and nateglinide, a rapid-onset/short-duration insulinotropic agent, for the treatment of postprandial hyperglycemia and metabolic derangements in Zucker Fatty (ZF) rats. ZF rats fed twice daily were given vehicle, 50 mg/kg of nateglinide, 5 mg/kg of telmisartan, or both for 6 weeks. Combination therapy with nateglinide and telmisartan for 2 weeks ameliorated postprandial hyperglycemia in ZF rats fed twice daily. Furthermore, 6-week treatment with nateglinide and telmisartan not only decreased fasting plasma insulin, triglycerides, and free fatty acid levels, but also improved the responses of blood glucose to insulin and subsequently reduced the decremental glucose areas under the curve in the ZF rats. Combination therapy also restored the decrease of plasma adiponectin levels in the ZF rats. Monotherapy with nateglinide or telmisartan alone didnot significantly improve these metabolic parameters. These observations demonstrate that combination therapy with nateglinide and telmisartan may improve the metabolic derangements by ameliorating early phase of insulin secretion as well as insulin resistance in ZF rats fed twice daily. Our present findings suggest that the combination therapy with nateglinide and telmisartan could be a promising therapeutic strategy for the treatment of the metabolic syndrome.

Influence of benzodiazepines on body weight and food intake in obese and lean Zucker rats.

PubMed

Blasi, C

2000-05-01

1. The gamma-aminobutyric acid (GABA)-ergic system, which is functionally altered in obese (fa/fa) Zucker rats, plays an important role in controlling energy balance within the central nervous system. 2. GABA receptors seem to be involved in the dysfunction of the hypothalamic energy homeostasis-controlling mechanisms in these animals due to a genetically-induced defect of the leptin-neuropeptide Y system. 3. To shed further light on the possible role played by the GABA system in the pathogenesis of this rat model, two benzodiazepine (BDZ) receptor agonists (diazepam and clonazepam) and one BDZ antagonist (flumazenil) were administered intraperitoneally in obese and lean Zucker rats. 4. Body weight gain was reduced by the BDZ agonists in both phenotypes, and one receptor-agonist (diazepam) lowered insulin concentration in obese rats. In GABA-antagonist-treated obese rats, the daily amount of body weight gain and food intake acquired an oscillatory rhythm similar to that of normal rodents. 5. By demonstrating the role of BDZ receptors, these findings may help clarify the pathophysiology of obesity and insulin resistance in fatty Zucker rats.

Vitamin A status affects obesity development and hepatic expression of key genes for fuel metabolism in Zucker fatty rats.

PubMed

Zhang, Yan; Li, Rui; Li, Yang; Chen, Wei; Zhao, Shi; Chen, Guoxun

2012-08-01

We hypothesized that vitamin A (VA) status may affect obesity development. Male Zucker lean (ZL) and fatty (ZF) rats after weaning were fed a synthetic VA deficient (VAD) or VA sufficient (VAS) diet for 8 weeks before their plasma parameters and hepatic genes' expression were analyzed. The body mass (BM) of ZL or ZF rats fed the VAD diet was lower than that of their corresponding controls fed the VAS diet at 5 or 2 weeks, respectively. The VAD ZL and ZF rats had less food intake than the VAS rats after 5 weeks. The VAD ZL and ZF rats had lower plasma glucose, triglyceride, insulin, and leptin levels, as well as lower liver glycogen content, net mass of epididymal fat, and liver/BM and epididymal fat/BM ratios (ZL only) than their respective VAS controls. VAD rats had lower hepatic Cyp26a1, Srebp-1c, Fas, Scd1, Me1, Gck, and Pklr (ZL and ZF); and higher Igfbp1 (ZL and ZF), Pck1(ZF only), and G6pc (ZF only) mRNA levels than their respective VAS controls. We conclude that ZL and ZF rats responded differently to dietary VA deficiency. VA status affected obesity development and altered the expression of hepatic genes for fuel metabolism in ZF rats. The mechanisms will help us to combat metabolic diseases.

Evaluation of Visceral Adipose Tissue Oxygenation by Blood Oxygen Level-Dependent MRI in Zucker Diabetic Fatty Rats.

PubMed

Shi, Hong-Jian; Li, Yan-Feng; Ji, Wen-Jie; Lin, Zhi-Chun; Cai, Wei; Chen, Tao; Yuan, Bin; Niu, Xiu-Long; Li, Han-Ying; Shu, Wen; Li, Yu-Ming; Yuan, Fei; Zhou, Xin; Zhang, Zhuoli

2018-06-01

This study aimed to investigate the feasibility of blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) to evaluate visceral adipose tissue (VAT) oxygenation in Zucker diabetic fatty (ZDF) rats and its associations with systemic metaflammation. Five-week-old ZDF rats and Zucker lean (ZL) rats were fed a high-fat diet (HFD) for 18 weeks. A baseline BOLD-MRI scan of perirenal adipose tissue was performed after 8 weeks of HFD feeding, and then the rats were randomized to receive pioglitazone or a vehicle for the following 10 weeks. At sacrifice, BOLD-MRI scan, Hypoxyprobe-1 injection, and circulating T helper 17 (Th17), regulatory T (Treg) cells, and monocyte subtype flow cytometry analysis were performed. HFD feeding led to a significant increase in VAT BOLD-MRI R2* signals (20.14 ± 0.23 per second vs. 21.53 ± 0.20 per second; P = 0.012), an indicator for decreased oxygenation. R2* signal was significantly correlated with VAT pimonidazole adduct-positive area, insulin resistance, Th17 and Treg cells, CD43 + and CD43+ + monocyte subtypes, and VAT macrophage infiltration. Pioglitazone treatment improved the insulin resistance and was associated with a delayed progression of VAT oxygenation. This work demonstrated the feasibility of BOLD-MRI for detecting the VAT oxygenation status in ZDF rats, and the BOLD-MRI signals were associated with insulin resistance and systemic metaflammation in ZDF rats during the development of obesity. © 2018 The Obesity Society.

α-Motoneurons maintain biophysical heterogeneity in obesity and diabetes in Zucker rats.

PubMed

MacDonell, Christopher W; Chopek, Jeremy W; Gardiner, Kalan R; Gardiner, Phillip F

2017-10-01

Small-diameter sensory dysfunction resulting from diabetes has received much attention in the literature, whereas the impact of diabetes on α-motoneurons (MN) has not. In addition, the chance of developing insulin resistance and diabetes is increased in obesity. No study has examined the impact of obesity or diabetes on the biophysical properties of MN. Lean Zucker rats and Zucker diabetic fatty (ZDF) rats were separated into lean, obese (ZDF fed standard chow), and diabetic (ZDF fed high-fat diet that led to diabetes) groups. Glass micropipettes recorded hindlimb MN properties from identified flexor and extensor MN. MN were separated within their groups on the basis of input conductance, which created high- and low-input conductance subpopulations for each. A significant shorter (20%) afterhyperpolarization half-decay (AHP 1/2 ) was found in low-conductance MN for the diabetic group only, whereas AHP½ tended to be shorter in the obese group (19%). Significant positive correlations were found among rheobase and input conductance for both lean and obese animals. No differences were found between the groups for afterhyperpolarization amplitude (AHP amp ), input conductance, rheobase, or any of the rhythmic firing properties (frequency-current slope and spike-frequency adaptation index). MN properties continue to be heterogeneous in obese and diabetic animals. Obesity does not seem to influence lumbar MN. Despite the resistance of MN to the impact of diabetes, the reduced AHP 1/2 decay and the tendency for a reduction in AHP amp may be the first sign of change to MN function. NEW & NOTEWORTHY Knowledge about the impact of obesity and diabetes on the biophysical properties of motoneurons is lacking. We found that diabetes reduces the duration of the afterhyperpolarization and that motoneuron function is unchanged by obesity. A reduced afterhyperpolarization may impact discharge characteristics and may be the first sign of change to motoneuron function. Copyright �

IVGTT-based simple assessment of glucose tolerance in the Zucker fatty rat: Validation against minimal models.

PubMed

Morettini, Micaela; Faelli, Emanuela; Perasso, Luisa; Fioretti, Sandro; Burattini, Laura; Ruggeri, Piero; Di Nardo, Francesco

2017-01-01

For the assessment of glucose tolerance from IVGTT data in Zucker rat, minimal model methodology is reliable but time- and money-consuming. This study aimed to validate for the first time in Zucker rat, simple surrogate indexes of insulin sensitivity and secretion against the glucose-minimal-model insulin sensitivity index (SI) and against first- (Φ1) and second-phase (Φ2) β-cell responsiveness indexes provided by C-peptide minimal model. Validation of the surrogate insulin sensitivity index (ISI) and of two sets of coupled insulin-based indexes for insulin secretion, differing from the cut-off point between phases (FPIR3-SPIR3, t = 3 min and FPIR5-SPIR5, t = 5 min), was carried out in a population of ten Zucker fatty rats (ZFR) and ten Zucker lean rats (ZLR). Considering the whole rat population (ZLR+ZFR), ISI showed a significant strong correlation with SI (Spearman's correlation coefficient, r = 0.88; P<0.001). Both FPIR3 and FPIR5 showed a significant (P<0.001) strong correlation with Φ1 (r = 0.76 and r = 0.75, respectively). Both SPIR3 and SPIR5 showed a significant (P<0.001) strong correlation with Φ2 (r = 0.85 and r = 0.83, respectively). ISI is able to detect (P<0.001) the well-recognized reduction in insulin sensitivity in ZFRs, compared to ZLRs. The insulin-based indexes of insulin secretion are able to detect in ZFRs (P<0.001) the compensatory increase of first- and second-phase secretion, associated to the insulin-resistant state. The ability of the surrogate indexes in describing glucose tolerance in the ZFRs was confirmed by the Disposition Index analysis. The model-based validation performed in the present study supports the utilization of low-cost, insulin-based indexes for the assessment of glucose tolerance in Zucker rat, reliable animal model of human metabolic syndrome.

Rice endosperm protein slows progression of fatty liver and diabetic nephropathy in Zucker diabetic fatty rats.

PubMed

Kubota, Masatoshi; Watanabe, Reiko; Yamaguchi, Miki; Hosojima, Michihiro; Saito, Akihiko; Fujii, Mikio; Fujimura, Shinobu; Kadowaki, Motoni

2016-10-01

We previously reported that rice endosperm protein (REP) has renoprotective effects in Goto-Kakizaki rats, a non-obese diabetic model. However, whether these effects occur in obese diabetes remains unclear. This study aimed to clarify the effects of REP on obese diabetes, especially on fatty liver and diabetic nephropathy, using the obese diabetic model Zucker diabetic fatty (ZDF) rats. In total, 7-week-old male ZDF rats were fed diets containing 20 % REP or casein (C) for 8 weeks. Changes in fasting blood glucose levels and urinary markers were monitored during the experimental period. Hepatic lipids and metabolites were measured and renal glomeruli were observed morphologically. HbA1c levels were significantly lower in rats fed REP, compared with C (P<0·05). Compared with C in the liver, REP prevented lipid accumulation (total lipid, TAG and total cholesterol, P<0·01). Liver metabolome analysis indicated that levels of metabolites associated with glycolysis, the pentose phosphate pathway and carnitine metabolism were significantly greater in the REP group than in the C group (P<0·05), suggesting activation of both glucose catabolism and fatty acid oxidation. The metabolite increases promoted by REP may contribute to suppression of liver lipid accumulation. Urinary excretion of albumin and N-acetyl-β-d-glucosaminidase was significantly reduced in rats fed REP for 8 weeks (P<0·01). In addition, there was a distinct suppression of mesangial matrix expansion and glomerular hypertrophy in response to REP (P<0·01). Thus, REP had preventive effects on obese diabetes, fatty liver and diabetic nephropathy.

Peroxisomal palmitoyl-CoA oxidation in the Zucker rat.

PubMed Central

Brady, P S; Hoppel, C L

1983-01-01

The effects of 3 or 6 days of starvation on hepatic peroxisomal palmitoyl-CoA oxidation were examined in adult lean and obese Zucker rats. When expressed either per mg of DNA or per total liver, obese rats had almost 2-fold higher oxidation rates than the lean rats. Within 6 days of starvation rates fell by 50% among both phenotypes. When data were expressed per 100 g body wt., lean and obese rats had similar rates, falling from a mean of 0.57 to 0.28 mumol/min per 100 g body wt. within 6 days of starvation. Peroxisomal oxidative changes paralleled mitochondrial beta-oxidative changes. PMID:6882399

Microvascular disorders in obese Zucker rats are restored by a rice bran diet.

PubMed

Justo, M L; Claro, C; Vila, E; Herrera, M D; Rodriguez-Rodriguez, R

2014-05-01

Nutritional-based approaches aimed to prevent microvascular dysfunction associated to obesity present potential advantages over pharmacological strategies. Our aim was to test whether a rice bran enzymatic extract (RBEE)-supplemented diet could attenuate microvascular alterations in obese rats. Lean and obese Zucker rats were fed standard diet supplemented or not with 1% and 5% RBEE for 20 weeks. Functional studies were performed in small mesenteric arteries in isometric myograph. Immunoblotting and fluorescence studies were made in arterial homogenates and arterial sections, respectively. RBEE-supplementation restored microvascular function in obese rats through a marked increase in NO and endothelial-derived hyperpolarizing factor contribution by up-regulation of eNOS and calcium-activated potassium channels expression, respectively, in association to a substantial reduction of microvascular inflammation and superoxide anion formation. These data agrees with the beneficial actions of RBEE on dyslipidemia, hyperinsulinemia and hypertension in obesity. The multi-factorial properties of RBEE-diet, especially for restoring the function of small resistance arteries shows this dietary-based approach to be a promising candidate for prevention of microvascular alterations in obesity, which are crucial in cardiovascular events in obese subjects. Copyright © 2013 Elsevier B.V. All rights reserved.

Long-term physical exercise and atrial natriuretic peptide in obese Zucker rats.

PubMed

Pörsti, Ilkka; Kähönen, Mika; Wu, Xiumin; Arvola, Pertti; Ruskoaho, Heikki

2002-07-01

Endurance training increases natriuretic peptide synthesis in the hypertrophied myocardium of spontaneously hypertensive rats. We examined the effects of 22-week-long treadmill exercise on plasma and tissue atrial natriuretic peptide in Zucker rats, a model of genetic obesity and moderate hypertension without clear cardiac hypertrophy. The blood pressures of the animals were measured by the tail-cuff method, and plasma and tissue samples for the peptide determinations were taken at the end of the study. The training increased heart weight to body weight ratio, while atrial natriuretic peptide contents in the right and left atrium, ventricular tissue, and plasma did not change. The exercise prevented the elevation of blood pressure, which was observed in non-exercised obese Zucker rats, and also reduced blood pressure in the lean rats. In conclusion, these results suggest that in the absence of preceding myocardial hypertrophy, the long-term exercise-induced workload is not deleterious to the heart in experimental obesity, since no changes in plasma and tissue atrial natriuretic peptide were detected.

LKB1-AMPK signaling in muscle from obese insulin-resistant Zucker rats and effects of training.

PubMed

Sriwijitkamol, Apiradee; Ivy, John L; Christ-Roberts, Christine; DeFronzo, Ralph A; Mandarino, Lawrence J; Musi, Nicolas

2006-05-01

AMPK is a key regulator of fat and carbohydrate metabolism. It has been postulated that defects in AMPK signaling could be responsible for some of the metabolic abnormalities of type 2 diabetes. In this study, we examined whether insulin-resistant obese Zucker rats have abnormalities in the AMPK pathway. We compared AMPK and ACC phosphorylation and the protein content of the upstream AMPK kinase LKB1 and the AMPK-regulated transcriptional coactivator PPARgamma coactivator-1 (PGC-1) in gastrocnemius of sedentary obese Zucker rats and sedentary lean Zucker rats. We also examined whether 7 wk of exercise training on a treadmill reversed abnormalities in the AMPK pathway in obese Zucker rats. In the obese rats, AMPK phosphorylation was reduced by 45% compared with lean rats. Protein expression of the AMPK kinase LKB1 was also reduced in the muscle from obese rats by 43%. In obese rats, phosphorylation of ACC and protein expression of PGC-1alpha, two AMPK-regulated proteins, tended to be reduced by 50 (P = 0.07) and 35% (P = 0.1), respectively. There were no differences in AMPKalpha1, -alpha2, -beta1, -beta2, and -gamma3 protein content between lean and obese rats. Training caused a 1.5-fold increase in AMPKalpha1 protein content in the obese rats, although there was no effect of training on AMPK phosphorylation and the other AMPK isoforms. Furthermore, training also significantly increased LKB1 and PGC-1alpha protein content 2.8- and 2.5-fold, respectively, in the obese rats. LKB1 protein strongly correlated with hexokinase II activity (r = 0.75, P = 0.001), citrate synthase activity (r = 0.54, P = 0.02), and PGC-1alpha protein content (r = 0.81, P < 0.001). In summary, obese insulin-resistant rodents have abnormalities in the LKB1-AMPK-PGC-1 pathway in muscle, and these abnormalities can be restored by training.

Effects of clenbuterol on insulin resistance in conscious obese Zucker rats.

PubMed

Pan, S J; Hancock, J; Ding, Z; Fogt, D; Lee, M; Ivy, J L

2001-04-01

The present study was conducted to determine the effect of chronic administration of the long-acting beta(2)-adrenergic agonist clenbuterol on rats that are genetically prone to insulin resistance and impaired glucose tolerance. Obese Zucker rats (fa/fa) were given 1 mg/kg of clenbuterol by oral intubation daily for 5 wk. Controls received an equivalent volume of water according to the same schedule. At the end of the treatment, rats were catheterized for euglycemic-hyperinsulinemic (15 mU insulin. kg(-1). min(-1)) clamping. Clenbuterol did not change body weight compared with the control group but caused a redistribution of body weight: leg muscle weights increased, and abdominal fat weight decreased. The glucose infusion rate needed to maintain euglycemia and the rate of glucose disappearance were greater in the clenbuterol-treated rats. Furthermore, plasma insulin levels were decreased, and the rate of glucose uptake into hindlimb muscles and abdominal fat was increased in the clenbuterol-treated rats. This increased rate of glucose uptake was accompanied by a parallel increase in the rate of glycogen synthesis. The increase in muscle glucose uptake could not be ascribed to an increase in the glucose transport protein GLUT-4 in clenbuterol-treated rats. We conclude that chronic clenbuterol treatment reduces the insulin resistance of the obese Zucker rat by increasing insulin-stimulated muscle and adipose tissue glucose uptake. The improvements noted may be related to the repartitioning of body weight between tissues.

Dietary fish protein hydrolysates containing bioactive motifs affect serum and adipose tissue fatty acid compositions, serum lipids, postprandial glucose regulation and growth in obese Zucker fa/fa rats.

PubMed

Drotningsvik, Aslaug; Mjøs, Svein A; Pampanin, Daniela M; Slizyte, Rasa; Carvajal, Ana; Remman, Tore; Høgøy, Ingmar; Gudbrandsen, Oddrun A

2016-10-01

The world's fisheries and aquaculture industries produce vast amounts of protein-containing by-products that can be enzymatically hydrolysed to smaller peptides and possibly be used as additives to functional foods and nutraceuticals targeted for patients with obesity-related metabolic disorders. To investigate the effects of fish protein hydrolysates on markers of metabolic disorders, obese Zucker fa/fa rats consumed diets with 75 % of protein from casein/whey (CAS) and 25 % from herring (HER) or salmon (SAL) protein hydrolysate from rest raw material, or 100 % protein from CAS for 4 weeks. The fatty acid compositions were similar in the experimental diets, and none of them contained any long-chain n-3 PUFA. Ratios of lysine:arginine and methionine:glycine were lower in HER and SAL diets when compared with CAS, and taurine was detected only in fish protein hydrolysate diets. Motifs with reported hypocholesterolemic or antidiabetic activities were identified in both fish protein hydrolysates. Rats fed HER diet had lower serum HDL-cholesterol and LDL-cholesterol, and higher serum TAG, MUFA and n-3:n-6 PUFA ratio compared with CAS-fed rats. SAL rats gained more weight and had better postprandial glucose regulation compared with CAS rats. Serum lipids and fatty acids were only marginally affected by SAL, but adipose tissue contained less total SFA and more total n-3 PUFA when compared with CAS. To conclude, diets containing hydrolysed rest raw material from herring or salmon proteins may affect growth, lipid metabolism, postprandial glucose regulation and fatty acid composition in serum and adipose tissue in obese Zucker rats.

Effects of 2-AG on the reinforcing properties of wheel activity in obese and lean Zucker rats.

PubMed

Smith, Shilo L; Rasmussen, Erin B

2010-07-01

The endocannabinoid system plays a role in obesity, primarily by its role in food reward. Activity, also involved in obesity, seems to be at least partially controlled by the endocannabinoid system, but the relevant behavioral and neurochemical mechanisms have not been well established. This study represents an attempt to begin elucidating these mechanisms by examining the effects of an endogenous cannabinoid ligand, 2-arachidonoylglycerol (2-AG), on the reinforcing properties of exercise reinforcement in lean and obese Zucker rats. Ten obese and 10 lean Zucker rats pressed a locked door under a progressive ratio schedule of reinforcement that, when unlocked, provided access to a running wheel for 2-min periods. After baseline breakpoints were established, doses of 2-AG (0.3-3 mg/kg) were administered before experimental sessions. Obese rats exhibited lower breakpoints for wheel activity, lower response rates, and fewer revolutions compared with lean rats. 2-AG decreased breakpoints, response rates, and revolutions for obese rats, and revolutions only for lean rats. These data suggest that 2-AG may reduce the reinforcing properties of activity, and that obese Zuckers may show a greater sensitivity to 2-AG. The data also suggest that endocannabinoids may play a role in the reinforcing properties of exercise.

Tesaglitazar, a dual PPAR{alpha}/{gamma} agonist, ameliorates glucose and lipid intolerance in obese Zucker rats.

PubMed

Oakes, Nicholas D; Thalén, Pia; Hultstrand, Therese; Jacinto, Severina; Camejo, Germán; Wallin, Boel; Ljung, Bengt

2005-10-01

Insulin resistance, impaired glucose tolerance, high circulating levels of free fatty acids (FFA), and postprandial hyperlipidemia are associated with the metabolic syndrome, which has been linked to increased risk of cardiovascular disease. We studied the metabolic responses to an oral glucose/triglyceride (TG) (1.7/2.0 g/kg lean body mass) load in three groups of conscious 7-h fasted Zucker rats: lean healthy controls, obese insulin-resistant/dyslipidemic controls, and obese rats treated with the dual peroxisome proliferator-activated receptor alpha/gamma agonist, tesaglitazar, 3 mumol.kg(-1).day(-1) for 4 wk. Untreated obese Zucker rats displayed marked insulin resistance, as well as glucose and lipid intolerance in response to the glucose/TG load. The 2-h postload area under the curve values were greater for glucose (+19%), insulin (+849%), FFA (+53%), and TG (+413%) compared with untreated lean controls. Treatment with tesaglitazar lowered fasting plasma glucose, improved glucose tolerance, substantially reduced fasting and postload insulin levels, and markedly lowered fasting TG and improved lipid tolerance. Fasting FFA were not affected, but postprandial FFA suppression was restored to levels seen in lean controls. Mechanisms of tesaglitazar-induced lowering of plasma TG were studied separately using the Triton WR1339 method. In anesthetized, 5-h fasted, obese Zucker rats, tesaglitazar reduced hepatic TG secretion by 47%, increased plasma TG clearance by 490%, and reduced very low-density lipoprotein (VLDL) apolipoprotein CIII content by 86%, compared with obese controls. In conclusion, the glucose/lipid tolerance test in obese Zucker rats appears to be a useful model of the metabolic syndrome that can be used to evaluate therapeutic effects on impaired postprandial glucose and lipid metabolism. The present work demonstrates that tesaglitazar ameliorates these abnormalities and enhances insulin sensitivity in this animal model.

Gene expression and adiposity are modified by soy protein in male Zucker diabetic fatty rats.

PubMed

Banz, William J; Davis, Jeremy; Peterson, Richard; Iqbal, Muhammad J

2004-12-01

It has earlier been demonstrated that soy protein diets ameliorate the diabetic phenotype in obese Zucker rats. In this study, we further investigated physiological changes related to adiposity in male Zucker diabetic fatty rats consuming soy-based diets and compared these diets with the insulin-sensitizing drug, rosiglitazone. Transcript abundance of known genes was assessed in the livers to identify potential molecular connections between soy diets and adiposity. Male Zucker diabetic fatty rats were assigned to casein (C) protein, low-isoflavone soy (LIS) protein, high-isoflavone soy (HIS) protein, or C + rosiglitazone (CR) diets. Compared with the C diet, the LIS diet decreased plasma lipids and increased body weight, but did not change liver weight or carcass adiposity. HIS decreased plasma lipids, liver weight, and body weight. CR decreased plasma lipids and increased carcass adiposity and body weight with no effect on liver weight. In LIS livers, 15 genes involved in signaling and lipid metabolism were up-regulated 2-fold or higher. In HIS livers, seven genes had a 2-fold or higher change in abundance. However, in CR livers, none of the genes was significantly changed compared with the C diet. There appears to be a distinct change in gene expression associated with soy diets as compared with C-based diets and rosiglitazone treatment.

Development of a sleeve gastrectomy weight loss model in obese Zucker rats.

PubMed

Lopez, Peter P; Nicholson, Susannah E; Burkhardt, Gabriel E; Johnson, Robert A; Johnson, Fruzsina K

2009-12-01

Obesity promotes the development of diabetes and cardiovascular disease. The most effective weight loss treatment is bariatric surgery, but results greatly vary depending on the procedure. Sleeve gastrectomy (SG) has recently emerged as a reduced risk weight loss procedure for super obese patients. However, the mechanism of weight loss from SG and its effects on obesity-induced complications are yet to be determined. Our goal was to develop an experimental model of SG in genetically obese rats. Male obese Zucker rats (400-500 g, leptin-insensitive) were anesthetized with isoflurane. After a midline laparotomy, the stomach was clamped, the greater curvature was excised, and a triple suture line was used to close the gastric remnant. Sham rats underwent laparotomy only. Metabolic parameters were followed for 14 d after surgery. Caloric intake and body weight decreased in SG rats over 14 d by 98 +/- 10 kcal/d and 74 +/- 14 g, respectively. Blood total cholesterol levels were lower in rats that lost weight. Furthermore, blood glucose levels were lower in rats that lost weight. Active ghrelin levels were unchanged in SG rats 14 d after surgery. These results show that SG promotes weight loss in obese Zucker rats. Furthermore, SG-induced weight loss is accompanied by improved plasma cholesterol and glucose profile. However, SG does not promote a prolonged decrease in ghrelin levels. These results suggest that SG is an effective weight loss procedure in leptin insensitivity to improve the lipid profile and decrease insulin resistance and these effects might be independent of changes in ghrelin levels.

Azilsartan improves glycemic status and reduces kidney damage in zucker diabetic fatty rats.

PubMed

Hye Khan, Md Abdul; Neckář, Jan; Haines, Jasmine; Imig, John D

2014-08-01

Azilsartan medoxomil (AZL-M), an angiotensin II receptor blocker, demonstrates antihypertensive and organ protective effects in hypertension. We investigated the efficacy of AZL-M to ameliorate metabolic syndrome and kidney damage associated with type 2 diabetes using Zucker diabetic fatty (ZDF) rats. ZDF rats were treated with vehicle or AZL-M for 8 weeks. Zucker diabetic lean (ZDL) rats were used as controls. Urine and plasma samples were collected for biochemical analysis, and kidney tissues were used for histopathological and immunohistopathological examination at the end of the 8-week protocol. ZDF rats were diabetic with hyperglycemia and impaired glucose tolerance, and AZL-M ameliorated the diabetic phenotype. ZDF rats were hypertensive compared with ZDL rats (181±6 vs. 129±7mm Hg), and AZL-M decreased blood pressure in ZDF rats (116±7mm Hg). In ZDF rats, there was marked renal damage with elevated proteinuria, albuminuria, nephrinuria, 2-4-fold higher tubular cast formation, and glomerular injury compared with ZDL rats. AZL-M treatment reduced renal damage in ZDF rats. ZDF rats demonstrated renal inflammation and oxidative stress with elevated urinary monocyte chemoattractant protein 1 excretion, renal infiltration of macrophages, and elevated kidney malondialdehyde levels. AZL-M reduced oxidative stress and inflammation in ZDF rats. Overall, we demonstrate that AZL-M attenuates kidney damage in type 2 diabetes. We further demonstrate that anti-inflammatory and antioxidative activities of AZL-M contribute to its kidney protective action. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Increased adipogenic conversion of muscle satellite cells in obese Zucker rats.

PubMed

Scarda, A; Franzin, C; Milan, G; Sanna, M; Dal Prà, C; Pagano, C; Boldrin, L; Piccoli, M; Trevellin, E; Granzotto, M; Gamba, P; Federspil, G; De Coppi, P; Vettor, R

2010-08-01

Visceral and intermuscular adipose tissue (IMAT) depots account for most obesity-related metabolic and cardiovascular complications. Muscle satellite cells (SCs) are mesenchymal stem cells giving rise to myotubes and also to adipocytes, suggesting their possible contribution to IMAT origin and expansion. We investigated the myogenic differentiation of SCs and the adipogenic potential of both preadipocytes and SCs from genetically obese Zucker rats (fa/fa), focusing on the role of Wnt signaling in these differentiation processes. SCs were isolated by single-fiber technique from flexor digitorum brevis muscle and preadipocytes were extracted from subcutaneous adipose tissue (AT). Morphological features and gene expression profile were evaluated during in vitro myogenesis and adipogenesis. Wingless-type MMTV integration site family member 10b (Wnt10b) expression was quantified by quantitative PCR in skeletal muscle and AT. We did not observe any difference in the proliferation rate and in the myogenic differentiation of SCs from obese and lean rats. However, a decreased insulin-induced glucose uptake was present in myotubes originating from fa/fa rats. Under adipogenic conditions, preadipocytes and SCs of obese animals displayed an enhanced adipogenesis. Wnt10b expression was reduced in obese rats in both muscle and AT. Our data suggest that the increase in different fat depots including IMAT and the reduced muscle insulin sensitivity, the major phenotypical alteration of obese Zucker rats, could be ascribed to an intrinsic defect, either genetically determined or acquired, still present in both muscle and fat precursors. The involvement of Wnt10b as a regulator of both adipogenesis and muscle-to-fat conversion is suggested.

Leucine and Protein Metabolism in Obese Zucker Rats

PubMed Central

She, Pengxiang; Olson, Kristine C.; Kadota, Yoshihiro; Inukai, Ayami; Shimomura, Yoshiharu; Hoppel, Charles L.; Adams, Sean H.; Kawamata, Yasuko; Matsumoto, Hideki; Sakai, Ryosei; Lang, Charles H.; Lynch, Christopher J.

2013-01-01

Branched-chain amino acids (BCAAs) are circulating nutrient signals for protein accretion, however, they increase in obesity and elevations appear to be prognostic of diabetes. To understand the mechanisms whereby obesity affects BCAAs and protein metabolism, we employed metabolomics and measured rates of [1-14C]-leucine metabolism, tissue-specific protein synthesis and branched-chain keto-acid (BCKA) dehydrogenase complex (BCKDC) activities. Male obese Zucker rats (11-weeks old) had increased body weight (BW, 53%), liver (107%) and fat (∼300%), but lower plantaris and gastrocnemius masses (−21–24%). Plasma BCAAs and BCKAs were elevated 45–69% and ∼100%, respectively, in obese rats. Processes facilitating these rises appeared to include increased dietary intake (23%), leucine (Leu) turnover and proteolysis [35% per g fat free mass (FFM), urinary markers of proteolysis: 3-methylhistidine (183%) and 4-hydroxyproline (766%)] and decreased BCKDC per g kidney, heart, gastrocnemius and liver (−47–66%). A process disposing of circulating BCAAs, protein synthesis, was increased 23–29% by obesity in whole-body (FFM corrected), gastrocnemius and liver. Despite the observed decreases in BCKDC activities per gm tissue, rates of whole-body Leu oxidation in obese rats were 22% and 59% higher normalized to BW and FFM, respectively. Consistently, urinary concentrations of eight BCAA catabolism-derived acylcarnitines were also elevated. The unexpected increase in BCAA oxidation may be due to a substrate effect in liver. Supporting this idea, BCKAs were elevated more in liver (193–418%) than plasma or muscle, and per g losses of hepatic BCKDC activities were completely offset by increased liver mass, in contrast to other tissues. In summary, our results indicate that plasma BCKAs may represent a more sensitive metabolic signature for obesity than BCAAs. Processes supporting elevated BCAA]BCKAs in the obese Zucker rat include increased dietary intake, Leu and

Endothelin antagonism improves hepatic insulin sensitivity associated with insulin signaling in Zucker fatty rats.

PubMed

Berthiaume, Nathalie; Carlson, Christian J; Rondinone, Cristina M; Zinker, Bradley A

2005-11-01

In the present study, we investigated the effects of long-term treatment with the endothelin (ET) antagonist atrasentan, an ET(A)-selective antagonist, on whole body glucose metabolism and insulin signaling in a commonly used model of insulin resistance, the Zucker fatty rat. Zucker lean and fatty rats were maintained for 6 weeks on either control or atrasentan-treated water. Euglycemic-hyperinsulinemic clamps (4 mU/kg per minute) were performed at the end of the 6-week treatment on a subset of rats (n=10/treatment). In another subset (n=5/treatment), an insulin tolerance test was performed; liver and muscle tissues were harvested 10 minutes following the challenge for further analysis. Results of the clamps demonstrated that long-term atrasentan treatment significantly increased whole body glucose metabolism in fatty rats compared with vehicle control subjects. Insulin-induced insulin receptor substrate 1 tyrosine and protein kinase B serine phosphorylation were significantly reduced in the liver and muscle of fatty animals compared with their lean littermates. This reduction was overcome with atrasentan treatment in the liver but not in the muscle. There was no difference between lean and fatty animals, however, in insulin receptor substrate 1 and protein kinase B protein expression in the liver and muscle and no effect by atrasentan. In contrast, expression of the regulatory subunit of PI-3 kinase (p85alpha) was significantly increased in the liver but not in the muscle of fatty animals compared with their lean littermates and this was normalized to levels of lean animals with atrasentan treatment. These findings indicate that long-standing ET antagonism improves whole body glucose metabolism in Zucker fatty rats through improvements in insulin signaling in the liver. These results indicate that therapeutic ET antagonism may assist in correcting the insulin-resistant state.

Branched-chain amino acid restriction in Zucker-fatty rats improves muscle insulin sensitivity by enhancing efficiency of fatty acid oxidation and acyl-glycine export.

PubMed

White, Phillip J; Lapworth, Amanda L; An, Jie; Wang, Liping; McGarrah, Robert W; Stevens, Robert D; Ilkayeva, Olga; George, Tabitha; Muehlbauer, Michael J; Bain, James R; Trimmer, Jeff K; Brosnan, M Julia; Rolph, Timothy P; Newgard, Christopher B

2016-07-01

A branched-chain amino acid (BCAA)-related metabolic signature is strongly associated with insulin resistance and predictive of incident diabetes and intervention outcomes. To better understand the role that this metabolite cluster plays in obesity-related metabolic dysfunction, we studied the impact of BCAA restriction in a rodent model of obesity in which BCAA metabolism is perturbed in ways that mirror the human condition. Zucker-lean rats (ZLR) and Zucker-fatty rats (ZFR) were fed either a custom control, low fat (LF) diet, or an isonitrogenous, isocaloric LF diet in which all three BCAA (Leu, Ile, Val) were reduced by 45% (LF-RES). We performed comprehensive metabolic and physiologic profiling to characterize the effects of BCAA restriction on energy balance, insulin sensitivity, and glucose, lipid and amino acid metabolism. LF-fed ZFR had higher levels of circulating BCAA and lower levels of glycine compared to LF-fed ZLR. Feeding ZFR with the LF-RES diet lowered circulating BCAA to levels found in LF-fed ZLR. Activity of the rate limiting enzyme in the BCAA catabolic pathway, branched chain keto acid dehydrogenase (BCKDH), was lower in liver but higher in skeletal muscle of ZFR compared to ZLR and was not responsive to diet in either tissue. BCAA restriction had very little impact on metabolites studied in liver of ZFR where BCAA content was low, and BCKDH activity was suppressed. However, in skeletal muscle of LF-fed ZFR compared to LF-fed ZLR, where BCAA content and BCKDH activity were increased, accumulation of fatty acyl CoAs was completely normalized by dietary BCAA restriction. BCAA restriction also normalized skeletal muscle glycine content and increased urinary acetyl glycine excretion in ZFR. These effects were accompanied by lower RER and improved skeletal muscle insulin sensitivity in LF-RES fed ZFR as measured by hyperinsulinemic-isoglycemic clamp. Our data are consistent with a model wherein elevated circulating BCAA contribute to development of

Feeding butter with elevated content of trans-10, cis-12 conjugated linoleic acid to obese-prone rats impairs glucose and insulin tolerance.

PubMed

Hamilton, Melissa; Hopkins, Loren E; AlZahal, Ousama; MacDonald, Tara L; Cervone, Daniel T; Wright, David C; McBride, Brian W; Dyck, David J

2015-09-28

We recently demonstrated that feeding a natural CLAt10,c12-enriched butter to lean female rats resulted in small, but significant increases in fasting glucose and insulin concentrations, and impaired insulin tolerance. Our goal was to extend these findings by utilizing the diabetes-prone female fatty Zucker rat. Rats were fed custom diets containing 45 % kcal of fat derived from control and CLAt10,c12-enriched butter for 8 weeks. CLA t10,c12-enriched butter was prepared from milk collected from cows fed a high fermentable carbohydrate diet to create subacute rumen acidosis (SARA); control (non-SARA) butter was collected from cows fed a low grain diet. Female fatty Zucker rats (10 weeks old) were randomly assigned to one of four diet treatments: i) low fat (10 % kcal), ii) 45 % kcal lard, iii) 45 % kcal SARA butter, or iv) 45 % kcal non-SARA butter. A low fat fed lean Zucker group was used as a control group. After 8 weeks, i) glucose and insulin tolerance tests, ii) insulin signaling in muscle, adipose and liver, and iii) metabolic caging measurements were performed. Glucose and insulin tolerance were significantly impaired in all fatty Zucker groups, but to the greatest extent in the LARD and SARA conditions. Insulin signaling (AKT phosphorylation) was impaired in muscle, visceral (perigonadal) adipose tissue and liver in fatty Zucker rats, but was generally similar across dietary groups. Physical activity, oxygen consumption, food intake and weight gain were also similar amongst the various fatty Zucker groups. Increasing the consumption of a food naturally enriched with CLAt10,c12 significantly worsens glucose and insulin tolerance in a diabetes-prone rodent model. This outcome is not explained by changes in tissue insulin signaling, physical activity, energy expenditure, food intake or body mass.

Cyclosporine A administered during reperfusion fails to restore cardioprotection in prediabetic Zucker obese rats in vivo.

PubMed

Huhn, R; Heinen, A; Hollmann, M W; Schlack, W; Preckel, B; Weber, N C

2010-12-01

Hyperglycaemia blocks sevoflurane-induced postconditioning, and cardioprotection in hyperglycaemic myocardium can be restored by inhibition of the mitochondrial permeability transition pore (mPTP). We investigated whether sevoflurane-induced postconditioning is also blocked in the prediabetic heart and if so, whether cardioprotection could be restored by inhibiting mPTP. Zucker lean (ZL) and Zucker obese (ZO) rats were assigned to one of seven groups. Animals underwent 25 min of ischaemia and 120 min of reperfusion. Control (ZL-/ZO Con) animals were not further treated. postconditioning groups (ZL-/ZO Sevo-post) received sevoflurane for 5 min starting 1min prior to the onset of reperfusion. The mPTP inhibitor cyclosporine A (CsA) was administered intravenously in a concentration of 5 (ZO CsA and ZO CsA+Sevo-post) or 10 mg/kg (ZO CsA10+Sevo-post) 5 min before the onset of reperfusion. At the end of reperfusion, infarct sizes were measured by TTC staining. Blood samples were collected to measure plasma levels of insulin, cholesterol and triglycerides. Sevoflurane postconditioning reduced infarct size in ZL rats to 35±12% (p<0.05 vs. ZL Con: 60±6%). In ZO rats sevoflurane postconditioning was abolished (ZO Sevo-post: 59±12%, n.s. vs. ZO Con: 58±6%). 5 mg and 10 mg CsA could not restore cardioprotection (ZO CsA+Sevo-post: 59±7%, ZO CsA10+Sevo-post: 57±14%; n.s. vs. ZO Con). In ZO rats insulin, cholesterol and triglyceride levels were significant higher than in ZL rats (all p<0.05). Inhibition of mPTP with CsA failed to restore cardioprotection in the prediabetic but normoglycaemic heart of Zucker obese rats in vivo. Copyright © 2009 Elsevier B.V. All rights reserved.

Effects of glucomannan/spirulina-surimi on liver oxidation and inflammation in Zucker rats fed atherogenic diets.

PubMed

Vázquez-Velasco, Miguel; González-Torres, Laura; López-Gasco, Patricia; Bastida, Sara; Benedí, Juana; González-Muñoz, María José; Sánchez-Muniz, Francisco J

2015-12-01

Cholesterolemia is associated with pro-oxidative and proinflammatory effects. Glucomannan- or glucomannan plus spirulina-enriched surimis were included in cholesterol-enriched high-saturated diets to test the effects on lipemia; antioxidant status (glutathione status, and antioxidant enzymatic levels, expressions and activities); and inflammation biomarkers (endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α)) in Zucker fa/fa rats. Groups of eight rats each received diet containing squid-surimi (C), squid-surimi cholesterol-enriched diet (HC), glucomannan-squid-surimi cholesterol-enriched diet (HG), or glucomannan-spirulina-squid-surimi cholesterol-enriched diet (HGS) over a period of 7 weeks. HC diet induced severe hyperlipemia, hepatomegalia, increased inflammation markers, and impaired antioxidant status significantly (at least p < 0.05) vs. C diet. HG diet decreased lipemia and liver size and normalized antioxidant status to C group levels, but increased TNF-α with respect to HC diet (p < 0.05). In general terms, 3 g/kg of spirulina in diet maintained the positive results observed in the HG diet but, in addition, increased inflammation index [eNOS/(eNOS + iNOS)] and decreased plasma TNF-α (both p < 0.05). In conclusion, glucomannan plus a small amount of spirulina blocks negative effects promoted by hypercholesterolemic diets. Although more studies are needed, present results suggest the utility of including glucomannan and/or spirulina as functional ingredients into fish derivates to be consumed by people on metabolic syndrome risk.

Remote ischemic preconditioning fails to reduce infarct size in the Zucker fatty rat model of type-2 diabetes: role of defective humoral communication.

PubMed

Wider, Joseph; Undyala, Vishnu V R; Whittaker, Peter; Woods, James; Chen, Xuequn; Przyklenk, Karin

2018-03-09

Remote ischemic preconditioning (RIPC), the phenomenon whereby brief ischemic episodes in distant tissues or organs render the heart resistant to infarction, has been exhaustively demonstrated in preclinical models. Moreover, emerging evidence suggests that exosomes play a requisite role in conveying the cardioprotective signal from remote tissue to the myocardium. However, in cohorts displaying clinically common comorbidities-in particular, type-2 diabetes-the infarct-sparing effect of RIPC may be confounded for as-yet unknown reasons. To investigate this issue, we used an integrated in vivo and in vitro approach to establish whether: (1) the efficacy of RIPC is maintained in the Zucker fatty rat model of type-2 diabetes, (2) the humoral transfer of cardioprotective triggers initiated by RIPC are transported via exosomes, and (3) diabetes is associated with alterations in exosome-mediated communication. We report that a standard RIPC stimulus (four 5-min episodes of hindlimb ischemia) reduced infarct size in normoglycemic Zucker lean rats, but failed to confer protection in diabetic Zucker fatty animals. Moreover, we provide novel evidence, via transfer of serum and serum fractions obtained following RIPC and applied to HL-1 cardiomyocytes subjected to hypoxia-reoxygenation, that diabetes was accompanied by impaired humoral communication of cardioprotective signals. Specifically, our data revealed that serum and exosome-rich serum fractions collected from normoglycemic rats attenuated hypoxia-reoxygenation-induced HL-1 cell death, while, in contrast, exosome-rich samples from Zucker fatty rats did not evoke protection in the HL-1 cell model. Finally, and unexpectedly, we found that exosome-depleted serum from Zucker fatty rats was cytotoxic and exacerbated hypoxia-reoxygenation-induced cardiomyocyte death.

The influence of sleep deprivation and obesity on DNA damage in female Zucker rats.

PubMed

Tenorio, Neuli M; Ribeiro, Daniel A; Alvarenga, Tathiana A; Fracalossi, Ana Carolina C; Carlin, Viviane; Hirotsu, Camila; Tufik, Sergio; Andersen, Monica L

2013-01-01

The aim of this study was to evaluate overall genetic damage induced by total sleep deprivation in obese, female Zucker rats of differing ages. Lean and obese Zucker rats at 3, 6, and 15 months old were randomly distributed into two groups for each age group: home-cage control and sleep-deprived (N = 5/group). The sleep-deprived groups were deprived sleep by gentle handling for 6 hours, whereas the home-cage control group was allowed to remain undisturbed in their home-cage. At the end of the sleep deprivation period, or after an equivalent amount of time for the home-cage control groups, the rats were brought to an adjacent room and decapitated. The blood, brain, and liver tissue were collected and stored individually to evaluate DNA damage. Significant genetic damage was observed only in 15-month-old rats. Genetic damage was present in the liver cells from sleep-deprived obese rats compared with lean rats in the same condition. Sleep deprivation was associated with genetic damage in brain cells regardless of obesity status. DNA damage was observed in the peripheral blood cells regardless of sleep condition or obesity status. Taken together, these results suggest that obesity was associated with genetic damage in liver cells, whereas sleep deprivation was associated with DNA damage in brain cells. These results also indicate that there is no synergistic effect of these noxious conditions on the overall level of genetic damage. In addition, the level of DNA damage was significantly higher in 15-month-old rats compared to younger rats.

Genetic profiling of two phenotypically distinct outbred rats derived from a colony of the Zucker fatty rats maintained at Tokyo Medical University

PubMed Central

Nakanishi, Satoshi; Kuramoto, Takashi; Kashiwazaki, Naomi; Yokoi, Norihide

2016-01-01

The Zucker fatty (ZF) rat is an outbred rat and a well-known model of obesity without diabetes, harboring a missense mutation (fatty, abbreviated as fa) in the leptin receptor gene (Lepr). Slc:Zucker (Slc:ZF) outbred rats exhibit obesity while Hos:ZFDM-Leprfa (Hos:ZFDM) outbred rats exhibit obesity and type 2 diabetes. Both outbred rats have been derived from an outbred ZF rat colony maintained at Tokyo Medical University. So far, genetic profiles of these outbred rats remain unknown. Here, we applied a simple genotyping method using Ampdirect reagents and FTA cards (Amp-FTA) in combination with simple sequence length polymorphisms (SSLP) markers to determine genetic profiles of Slc:ZF and Hos:ZFDM rats. Among 27 SSLP marker loci, 24 loci (89%) were fixed for specific allele at each locus in Slc:ZF rats and 26 loci (96%) were fixed in Hos:ZFDM rats, respectively. This indicates the low genetic heterogeneity in both colonies of outbred rats. Nine loci (33%) showed different alleles between the two outbred rats, suggesting considerably different genetic profiles between the two outbred rats in spite of the same origin. Additional analysis using 72 SSLP markers further supported these results and clarified the profiles in detail. This study revealed that genetic profiles of the Slc:ZF and Hos:ZFDM outbred rats are different for about 30% of the SSLP marker loci, which is the underlying basis for the phenotypic difference between the two outbred rats. PMID:27795491

Effects of 2 G on adiposity, leptin, lipoprotein lipase, and uncoupling protein-1 in lean and obese Zucker rats

NASA Technical Reports Server (NTRS)

Warren, L. E.; Horwitz, B. A.; Hamilton, J. S.; Fuller, C. A.

2001-01-01

Male Zucker rats were exposed to 2 G for 8 wk to test the hypothesis that the leptin regulatory pathway contributes to recovery from effects of 2 G on feeding, growth, and nutrient partitioning. After initial hypophagia, body mass-independent food intake of the lean rats exposed to 2 G surpassed that of the lean rats maintained at 1 G, but food intake of the obese rats exposed to 2 G remained low. After 8 wk at 2 G, body mass and carcass fat were less in both genotypes. Leptin and percent fat were lower in lean rats exposed to 2 G vs. 1 G but did not differ in obese rats exposed to 2 G vs. 1 G. Although exposure to 2 G did not alter uncoupling protein-1 levels, it did elicit white fat pad-specific changes in lipoprotein lipase activity in obese but not lean rats. We conclude that 2 G affects both genotypes but that the lean Zucker rats recover their food intake and growth rate and retain "normal" lipoprotein lipase activity to a greater degree than do the obese rats, emphasizing the importance of a functional leptin regulatory pathway in this acclimation.

Rimonabant reduces the essential value of food in the genetically obese Zucker rat: an exponential demand analysis.

PubMed

Rasmussen, Erin B; Reilly, William; Buckley, Jessica; Boomhower, Steven R

2012-02-01

Research on free-food intake suggests that cannabinoids are implicated in the regulation of feeding. Few studies, however, have characterized how environmental factors that affect food procurement interact with cannabinoid drugs that reduce food intake. Demand analysis provides a framework to understand how cannabinoid blockers, such as rimonabant, interact with effort in reducing demand for food. The present study examined the effects rimonabant had on demand for sucrose in obese Zucker rats when effort to obtain food varied and characterized the data using the exponential ("essential value") model of demand. Twenty-nine male (15 lean, 14 obese) Zucker rats lever-pressed under eight fixed ratio (FR) schedules of sucrose reinforcement, in which the number of lever-presses to gain access to a single sucrose pellet varied between 1 and 300. After behavior stabilized under each FR schedule, acute doses of rimonabant (1-10mg/kg) were administered prior to some sessions. The number of food reinforcers and responses in each condition was averaged and the exponential and linear demand equations were fit to the data. These demand equations quantify the value of a reinforcer by its sensitivity to price (FR) increases. Under vehicle conditions, obese Zucker rats consumed more sucrose pellets than leans at smaller fixed ratios; however, they were equally sensitive to price increases with both models of demand. Rimonabant dose-dependently reduced reinforcers and responses for lean and obese rats across all FR schedules. Data from the exponential analysis suggest that rimonabant dose-dependently increased elasticity, i.e., reduced the essential value of sucrose, a finding that is consistent with graphical depictions of normalized demand curves. Copyright © 2011 Elsevier Inc. All rights reserved.

Voluntary running exercise prevents β-cell failure in susceptible islets of the Zucker diabetic fatty rat.

PubMed

Delghingaro-Augusto, Viviane; Décary, Simon; Peyot, Marie-Line; Latour, Martin G; Lamontagne, Julien; Paradis-Isler, Nicolas; Lacharité-Lemieux, Marianne; Akakpo, Huguette; Birot, Olivier; Nolan, Christopher J; Prentki, Marc; Bergeron, Raynald

2012-01-15

Physical activity improves glycemic control in type 2 diabetes (T2D), but its contribution to preserving β-cell function is uncertain. We evaluated the role of physical activity on β-cell secretory function and glycerolipid/fatty acid (GL/FA) cycling in male Zucker diabetic fatty (ZDF) rats. Six-week-old ZDF rats engaged in voluntary running for 6 wk (ZDF-A). Inactive Zucker lean and ZDF (ZDF-I) rats served as controls. ZDF-I rats displayed progressive hyperglycemia with β-cell failure evidenced by falling insulinemia and reduced insulin secretion to oral glucose. Isolated ZDF-I rat islets showed reduced glucose-stimulated insulin secretion expressed per islet and per islet protein. They were also characterized by loss of the glucose regulation of fatty acid oxidation and GL/FA cycling, reduced mRNA expression of key β-cell genes, and severe reduction of insulin stores. Physical activity prevented diabetes in ZDF rats through sustaining β-cell compensation to insulin resistance shown in vivo and in vitro. Surprisingly, ZDF-A islets had persistent defects in fatty acid oxidation, GL/FA cycling, and β-cell gene expression. ZDF-A islets, however, had preserved islet insulin mRNA and insulin stores compared with ZDF-I rats. Physical activity did not prevent hyperphagia, dyslipidemia, or obesity in ZDF rats. In conclusion, islets of ZDF rats have a susceptibility to failure that is possibly due to altered β-cell fatty acid metabolism. Depletion of pancreatic islet insulin stores is a major contributor to islet failure in this T2D model, preventable by physical activity.

Relationship between lipogenesis, ketogenesis, and malonyl-CoA content in isolated hepatocytes from the obese Zucker rat adapted to a high-fat diet.

PubMed

Malewiak, M I; Griglio, S; Le Liepvre, X

1985-07-01

The relationship between lipogenesis and ketogenesis and the concentration of malonyl coenzyme A (CoA) was investigated in hepatocytes from adult obese Zucker rats and their lean littermates fed either a control low-fat diet or a high-fat diet (30% lard in weight). With the control diet, lipogenesis--although strongly inhibited in the presence of either 1 mmol/L oleate, 10(-6) mol/L glucagon or 0.1 mmol/L TOFA (a hypolipidemic drug)--remained about fifteen-fold higher in the obese rats than in the lean rats. In contrast, ketogenesis under some conditions (oleate + TOFA) was not significantly lower (30%) as compared with the lean rats. After adaptation to the high-fat diet, lipogenesis was depressed fourfold in the lean rats and ninefold in the obese ones; however its magnitude remained significantly higher in the latter, namely at a value close to that measured in control-fed lean rats. Ketogenesis was comparable in lean and obese rats and much higher in the presence of 1 mmol/L oleate than of 0.3 mmol/L oleate, whereas lipogenesis did not vary with increasing oleate concentration in the medium. Acetyl-CoA carboxylase activity measured in liver homogenates was higher in the obese group, but was stepwise inhibited by increasing concentrations of oleyl-CoA regardless of the diet for both lean and obese rats, thus showing no abnormality of in vitro responsiveness to this inhibitor. With the control diet, hepatocyte malonyl-CoA levels were significantly higher in the obese rats, both in the basal state and after inhibition of lipogenesis by oleate and TOFA.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of fourteen novel obesity-related genes in Zucker diabetic fatty rats.

PubMed

Schmid, Peter M; Heid, Iris; Buechler, Christa; Steege, Andreas; Resch, Markus; Birner, Christoph; Endemann, Dierk H; Riegger, Guenter A; Luchner, Andreas

2012-07-13

Genome-wide association studies (GWAS) are useful to reveal an association between single nucleotide polymorphisms and different measures of obesity. A multitude of new loci has recently been reported, but the exact function of most of the according genes is not known. The aim of our study was to start elucidating the function of some of these genes. We performed an expression analysis of fourteen genes, namely BDNF, ETV5, FAIM2, FTO, GNPDA2, KCTD15, LYPLAL1, MCR4, MTCH2, NEGR1, NRXN3, TMEM18, SEC16B and TFAP2B, via real-time RT-PCR in adipose tissue of the kidney capsule, the mesenterium and subcutaneum as well as the hypothalamus of obese Zucker diabetic fatty (ZDF) and Zucker lean (ZL) rats at an age of 22 weeks. All of our target genes except for SEC16B showed the highest expression in the hypothalamus. This suggests a critical role of these obesity-related genes in the central regulation of energy balance. Interestingly, the expression pattern in the hypothalamus showed no differences between obese ZDF and lean ZL rats. However, LYPLAL1, TFAP2B, SEC16B and FAIM2 were significantly lower expressed in the kidney fat of ZDF than ZL rats. NEGR1 was even lower expressed in subcutaneous and mesenterial fat, while MTCH2 was higher expressed in the subcutaneous and mesenterial fat of ZDF rats. The expression pattern of the investigated obesity genes implies for most of them a role in the central regulation of energy balance, but for some also a role in the adipose tissue itself. For the development of the ZDF phenotype peripheral rather than central mechanisms of the investigated genes seem to be relevant.

Resistance training inhibits the elevation of skeletal muscle derived-BDNF level concomitant with improvement of muscle strength in zucker diabetic rat

PubMed Central

Kim, Hee-Jae; So, Byunghun; Son, Jun Seok; Song, Han Sol; Oh, Seung Lyul; Seong, Je Kyung; Lee, Hoyoung; Song, Wook

2015-01-01

[Purpose] In the present study, we investigated the effects of 8 weeks of progressive resistance training on the level of skeletal muscle derived BDNF as well as glucose intolerance in Zucker diabetic rats. [Methods] Six week-old male Zucker diabetic fatty (ZDF) and Zucker lean control (ZLC) rats were randomly divided into 3 groups: sedentary ZLC (ZLC-Con), sedentary ZDF (ZDF-Con), and exercised ZDF (ZDF-Ex). Progressive resistance training using a ladder and tail weights was performed for 8 weeks (3 days/week). [Results] After 8 weeks of resistance training, substantial reduction in body weight was observed in ZDF-Ex compared to ZDF-Con. Though the skeletal muscle volume did not change, grip strength grip strength was significantly higher in ZDF-Ex compared to ZDF-Con. In the soleus, the level of BDNF was increased in ZDF-Con, but was significantly decreased (p<0.05) in ZDF-Ex, showing a training effect. Moreover, we found that there was a negative correlation (r=-0.657; p=0.004) between grip strength and BDNF level whereas there was a positive correlation (r=0.612; p=0.008) between plasma glucose level and BDNF level in skeletal muscle. [Conclusion] Based upon our results, we demonstrated that resistance training inhibited the elevation of skeletal muscle derived-BDNF expression concomitant with the improvement of muscle strength in zucker diabetic rats. In addition, muscle-derived BDNF might be a potential mediator for the preventive effect of resistance training on the progress of type 2 diabetes. PMID:27274460

Remodeling of the skeletal muscle microcirculation increases resistance to perfusion in obese Zucker rats.

PubMed

Frisbee, Jefferson C

2003-07-01

Whereas previous studies have demonstrated that the development of syndrome X in obese Zucker rats (OZR) is associated with impaired arteriolar reactivity to vasoactive stimuli, additional results from these studies indicate that the passive diameter of skeletal muscle arterioles is reduced in OZR versus lean Zucker rats (LZR). On the basis of these prior observations, the present study evaluated structural alterations to the skeletal muscle microcirculation as potential contributors to an elevated vascular resistance. Isolated skeletal muscle resistance arterioles exhibited a reduced passive diameter at all levels of intralumenal pressure and a left-shifted stress-strain curve in OZR versus LZR, indicative of structural remodeling of individual arterioles. Histological analyses using Griffonia simplicifolia I lectin-stained sections of skeletal muscle demonstrated reduced microvessel density (rarefaction) in OZR versus LZR, suggesting remodeling of entire microvascular networks. Finally, under maximally dilated conditions, constant flow-perfused skeletal muscle of OZR exhibited significant elevations in perfusion pressure versus LZR, indicative of an increased resistance to perfusion within the microcirculation. These data suggest that developing structural alterations to the skeletal muscle microcirculation in OZR result in elevated vascular resistance, which may, acting in concert with impaired arteriolar reactivity, contribute to blunted active hyperemic responses and compromised performance of in situ skeletal muscle with elevated metabolic demand.

Joint feedback analysis modeling of nonesterified fatty acids in obese Zucker rats and normal Sprague-Dawley rats after different routes of administration of nicotinic acid.

PubMed

Tapani, Sofia; Almquist, Joachim; Leander, Jacob; Ahlström, Christine; Peletier, Lambertus A; Jirstrand, Mats; Gabrielsson, Johan

2014-08-01

Data were pooled from several studies on nicotinic acid (NiAc) intervention of fatty acid turnover in normal Sprague-Dawley and obese Zucker rats in order to perform a joint PKPD of data from more than 100 normal Sprague-Dawley and obese Zucker rats, exposed to several administration routes and rates. To describe the difference in pharmacodynamic parameters between obese and normal rats, we modified a previously published nonlinear mixed effects model describing tolerance and oscillatory rebound effects of NiAc on nonesterified fatty acids plasma concentrations. An important conclusion is that planning of experiments and dose scheduling cannot rely on pilot studies on normal animals alone. The obese rats have a less-pronounced concentration-response relationship and need higher doses to exhibit desired response. The relative level of fatty acid rebound after cessation of NiAc administration was also quantified in the two rat populations. Building joint normal-disease models with scaling parameter(s) to characterize the "degree of disease" can be a useful tool when designing informative experiments on diseased animals, particularly in the preclinical screen. Data were analyzed using nonlinear mixed effects modeling, for the optimization, we used an improved method for calculating the gradient than the usually adopted finite difference approximation. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

Brown Norway and Zucker Lean Rats Demonstrate Circadian Variation in Ventilation and Sleep Apnea

PubMed Central

Fink, Anne M.; Topchiy, Irina; Ragozzino, Michael; Amodeo, Dionisio A.; Waxman, Jonathan A.; Radulovacki, Miodrag G.; Carley, David W.

2014-01-01

Study Objectives: Circadian rhythms influence many biological systems, but there is limited information about circadian and diurnal variation in sleep related breathing disorder. We examined circadian and diurnal patterns in sleep apnea and ventilatory patterns in two rat strains, one with high sleep apnea propensity (Brown Norway [BN]) and the other with low sleep apnea propensity (Zucker Lean [ZL]). Design/Setting: Chronically instrumented rats were randomized to breathe room air (control) or 100% oxygen (hyperoxia), and we performed 20-h polysomnography beginning at Zeitgeber time 4 (ZT 4; ZT 0 = lights on, ZT12 = lights off). We examined the effect of strain and inspired gas (twoway analysis of variance) and analyzed circadian and diurnal variability. Measurements and Results: Strain and inspired gas-dependent differences in apnea index (AI; apneas/h) were particularly prominent during the light phase. AI in BN rats (control, 16.9 ± 0.9; hyperoxia, 34.0 ± 5.8) was greater than in ZL rats (control, 8.5 ± 1.0; hyperoxia, 15.4 ± 1.1, [strain effect, P < 0.001; gas effect, P = 0.001]). Hyperoxia reduced respiratory frequency in both strains, and all respiratory pattern variables demonstrated circadian variability. BN rats exposed to hyperoxia demonstrated the largest circadian fluctuation in AI (amplitude = 17.9 ± 3.7 apneas/h [strain effect, P = 0.01; gas effect, P < 0.001; interaction, P = 0.02]; acrophase = 13.9 ± 0.7 h; r2 = 0.8 ± 1.4). Conclusions: Inherited, environmental, and circadian factors all are important elements of underlying sleep related breathing disorder. Our method to examine sleep related breathing disorder phenotypes in rats may have implications for understanding vulnerability for sleep related breathing disorder in humans. Citation: Fink AM; Topchiy I; Ragozzino M; Amodeo DA; Waxman JA; Radulovacki MG; Carley DW. Brown Norway and Zucker Lean rats demonstrate circadian variation in ventilation and sleep apnea. SLEEP 2014

Development of insulin resistance and endothelin-1 levels in the Zucker fatty rat.

PubMed

Berthiaume, Nathalie; Mika, Amanda K; Zinker, Bradley A

2003-07-01

In order to determine the effects of increasing insulin resistance on endothelin-1 (ET-1) levels, Zucker lean and fatty rats were studied at basal and during a complete nutrient meal tolerance test (MTT) at 7, 12, and 15 weeks of age. The fatty rats were mildly hyperglycemic, severely hyperinsulinemic and glucose-intolerant at all ages versus lean animals and this progressed with age within groups, as previously published. Basal ET-1 levels, at 7 weeks, were significantly increased in fatty versus lean rats (3.2+/-0.5 v 2.0+/-0.3 pg/mL, respectively; P<.05); however, we did not observe any significant basal difference at 12 or 15 weeks. At 7 weeks, ET-1 levels between fatty and lean rats were not different during the MTT (15 minutes: 2.9+/-0.4 v 2.7+/-0.7; 120 minutes: 6.5+/-0.8 v 6.6+/-0.5 pg/mL, fatty v lean, respectively). At 12 weeks, though there was no difference in basal levels, fatty rats had higher ET-1 levels during the MTT compared to lean animals (15 minutes: 6.9+/-1.4 v 1.8+/-0.4; 120 minutes: 9.4+/-1.7 v 3.2+/-0.5 pg/mL, respectively; P<.01). At 15 weeks, ET-1 levels during the MTT receded to levels similar to those observed at 7 weeks, which were significantly higher in fatty versus lean rats 15 minutes following the challenge (3.4+/-0.4 v 2.4+/-0.2 pg/mL, respectively; P<.05). In conclusion, ET-1 levels in the Zucker fatty rat: (1) were increased in the early stages of the progression of insulin resistance at 7 weeks, but were unchanged under basal conditions with age thereafter, and (2) were increased under nutrient challenge conditions with advanced insulin resistance up to 12 weeks, and were still significantly but to a lesser degree increased at 15 weeks of age. The explanation for these results and their relationship to the observed insulin resistance is unclear and will require further investigation.

Serum adipokine profile and fatty acid composition of adipose tissues are affected by conjugated linoleic acid and saturated fat diets in obese Zucker rats.

PubMed

Martins, Susana V; Lopes, Paula A; Alfaia, Cristina M; Rodrigues, Pedro O; Alves, Susana P; Pinto, Rui M A; Castro, Matilde F; Bessa, Rui J B; Prates, José A M

2010-03-01

Conjugated linoleic acid (CLA) has been reported as having body fat lowering properties and the ability to modulate the inflammatory system in several models. In the present study, the effects of CLA added to saturated fat diets, from vegetable and animal origins, on the serum adipokine profile of obese Zucker rats were assessed. In addition, the fatty acid composition of epididymal and retroperitoneal adipose tissues was determined and a principal component analysis (PCA) was used to assess possible relationships between fatty acids and serum metabolites. Atherogenic diets (2 % cholesterol) were formulated with palm oil and ovine fat and supplemented or not with 1 % of a mixture (1:1) of cis-9, trans-11 and trans-10, cis-12-CLA isomers. CLA-fed animals exhibited lower daily feed intake, final body and liver weights, and hepatic lipids content. Total and LDL-cholesterol levels were increased in CLA-supplemented groups. CLA also promoted higher adiponectin and lower plasminogen activator inhibitor-1 (PAI-1) serum concentrations. In contrast to palm oil diets, ovine fat increased insulin resistance and serum levels of leptin, TNF-alpha and IL-1beta. Epididymal and retroperitoneal adipose tissues had similar deposition of individual fatty acids. The PCA analysis showed that the trans-10, cis-12-CLA isomer was highly associated with adiponectin and PAI-1 levels. Summing up, CLA added to vegetable saturated enriched diets, relative to those from animal origin, seems to improve the serum profile of adipokines and inflammatory markers in obese Zucker rats due to a more favourable fatty acid composition.

Hydroxypropyl methylcellulose, a viscous soluble fiber, reduces insulin resistance and decreases fatty liver in Zucker Diabetic Fatty rats.

PubMed

Brockman, David A; Chen, Xiaoli; Gallaher, Daniel D

2012-11-12

Diets producing a high glycemic response result in exaggerated insulin secretion which induces hepatic lipogenesis, contributing to development of insulin resistance and fatty liver. Viscous dietary fibers blunt the postprandial rise in blood glucose, however their effect on type 2 diabetes and obesity are not entirely known. This study examined the effect of chronic consumption of the viscous, non-fermentable dietary fiber, hydroxypropyl methylcellulose (HPMC), on glucose control, insulin resistance and liver lipids in an obese diabetic rat model. Three groups of Zucker Diabetic Fatty (ZDF) rats were fed diets containing either 5% non-viscous cellulose (control), low viscosity HPMC (LV-HPMC) or high viscosity HPMC (HV- HPMC) for six weeks. Zucker lean littermates consuming cellulose served as a negative control. Markers of glucose control, including oral glucose tolerance test, glycated hemoglobin and urinary glucose, were measured as well as adiposity and the accumulation of liver lipids. The HPMC diets increased the viscosity of the small intestinal contents and reduced the postprandial rise in blood glucose. The food efficiency ratio was greater with HPMC feeding compared to the obese control and urinary excretion of glucose and ketone bodies was reduced. The two HPMC groups had lower glycated hemoglobin and kidney weights and a reduced area under the curve during a glucose tolerance test, indicating improved glucose control. Epididymal fat pad weight as percent of body weight was reduced in the HV-HPMC group compared to the obese control group. The HV-HPMC group also had lower concentrations of liver lipid and cholesterol and reduced liver weight. However, HV-HPMC feeding did not affect hepatic gene expression of SREBP-1c or FAS. Muscle concentration of acylcarnitines, a lipid intermediate in fatty acid β-oxidation, was not different between the HPMC groups and obese control, suggesting no change in muscle fatty acid oxidation by HPMC. Consumption of the

Effect of obese and lean Zucker rat sera on human and rat prostate cancer cells: implications in obesity-related prostate tumor biology.

PubMed

Lamarre, Neil S; Ruggieri, Michael R; Braverman, Alan S; Gerstein, Matthew I; Mydlo, Jack H

2007-01-01

Several reports have demonstrated the effects of obesity on prostate cancer. Also several reports have linked expression of vascular endothelial cell growth factor (VEGF) and basic fibroblast growth factor (FGF-2) to prostate cancer aggressiveness. The objective of this study was to determine whether a difference exists between lean and obese Zucker rat sera on proliferation prostate cancer cell lines, as well as to examine the differences in FGF-2 and VEGF concentrations. Ten-week-old female obese and lean Zucker rat sera were subjected to charcoal stripping and tested for the proliferation of human LNCaP and rat AT3B-1 prostate cancer cells. An acetonitrile extract of the charcoal used to strip the sera was also tested for mitogenicity. VEGF and FGF-2 concentrations were determined by enzyme-linked immunosorbent assay. Both unstripped and charcoal-stripped obese rat sera had a greater mitogenic effect than did the lean sera on the LNCaP cell line. Charcoal stripping of both obese and lean sera reduced the mitogenic effect on the AT3B-1 cell line. The acetonitrile extract of the charcoal used to strip the sera was unable to recover this proliferative effect. The concentration of VEGF was greater in the obese serum than in the lean serum, and charcoal stripping reduced the concentrations of both FGF-2 and VEGF. The finding of greater VEGF in obese rat sera, as well as greater mitogenic responses on human prostate cancer cells in vitro, suggests this as one of the many possible mechanisms involved in obesity-related prostate cancer biology.

Joint Feedback Analysis Modeling of Nonesterified Fatty Acids in Obese Zucker Rats and Normal Sprague–Dawley Rats after Different Routes of Administration of Nicotinic Acid

PubMed Central

Tapani, Sofia; Almquist, Joachim; Leander, Jacob; Ahlström, Christine; Peletier, Lambertus A; Jirstrand, Mats; Gabrielsson, Johan

2014-01-01

Data were pooled from several studies on nicotinic acid (NiAc) intervention of fatty acid turnover in normal Sprague–Dawley and obese Zucker rats in order to perform a joint PKPD of data from more than 100 normal Sprague–Dawley and obese Zucker rats, exposed to several administration routes and rates. To describe the difference in pharmacodynamic parameters between obese and normal rats, we modified a previously published nonlinear mixed effects model describing tolerance and oscillatory rebound effects of NiAc on nonesterified fatty acids plasma concentrations. An important conclusion is that planning of experiments and dose scheduling cannot rely on pilot studies on normal animals alone. The obese rats have a less-pronounced concentration–response relationship and need higher doses to exhibit desired response. The relative level of fatty acid rebound after cessation of NiAc administration was also quantified in the two rat populations. Building joint normal-disease models with scaling parameter(s) to characterize the “degree of disease” can be a useful tool when designing informative experiments on diseased animals, particularly in the preclinical screen. Data were analyzed using nonlinear mixed effects modeling, for the optimization, we used an improved method for calculating the gradient than the usually adopted finite difference approximation. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:2571–2584, 2014 PMID:24986056

Chronic hyperinsulinemia contributes to insulin resistance under dietary restriction in association with altered lipid metabolism in Zucker diabetic fatty rats.

PubMed

Morita, Ippei; Tanimoto, Keiichi; Akiyama, Nobuteru; Naya, Noriyuki; Fujieda, Kumiko; Iwasaki, Takanori; Yukioka, Hideo

2017-04-01

Hyperinsulinemia is widely thought to be a compensatory response to insulin resistance, whereas its potentially causal role in the progression of insulin resistance remains to be established. Here, we aimed to examine whether hyperinsulinemia could affect the progression of insulin resistance in Zucker fatty diabetic (ZDF) rats. Male ZDF rats at 8 wk of age were fed a diet ad libitum (AL) or dietary restriction (DR) of either 15 or 30% from AL feeding over 6 wk. Insulin sensitivity was determined by hyperinsulinemic euglycemic clamp. ZDF rats in the AL group progressively developed hyperglycemia and hyperinsulinemia by 10 wk of age, and then plasma insulin rapidly declined to nearly normal levels by 12 wk of age. Compared with AL group, DR groups showed delayed onset of hyperglycemia and persistent hyperinsulinemia, leading to weight gain and raised plasma triglycerides and free fatty acids by 14 wk of age. Notably, insulin sensitivity was significantly reduced in the DR group rather than the AL group and inversely correlated with plasma levels of insulin and triglyceride but not glucose. Moreover, enhanced lipid deposition and upregulation of genes involved in lipogenesis were detected in liver, skeletal muscle, and adipose tissues of the DR group rather than the AL group. Alternatively, continuous hyperinsulinemia induced by insulin pellet implantation produced a decrease in insulin sensitivity in ZDF rats. These results suggest that chronic hyperinsulinemia may lead to the progression of insulin resistance under DR conditions in association with altered lipid metabolism in peripheral tissues in ZDF rats. Copyright © 2017 the American Physiological Society.

Moderate red-wine consumption partially prevents body weight gain in rats fed a hyperlipidic diet.

PubMed

Vadillo, Montserrat; Bargalló, Montserrat Vadillo; Ardévol, Anna; Grau, Anna Ardévol; Fernández-Larrea, Juan; Fernández-Larrea, Juan de Dios; Pujadas, Gerard; Anguiano, Gerard Pujadas; Bladé, Cinta; Segarra, Maria Cinta Bladé; Salvadó, Maria Josepa; Rovira, Maria Josepa Salvadó; Arola, Lluís; Ferré, Lluia Arola; Blay, Mayte; Olivé, Mayte Blay

2006-02-01

Red wine is a beverage that can exert a broad spectrum of health-promoting actions both in humans and laboratory animal models if consumed moderately. However, information about its effect on body weight is scarce. We have evaluated the effect of moderate red wine consumption on body weight and energy intake in male Zucker lean rats fed a hypercaloric diet for 8 weeks. For this purpose, we used three 5-animal groups: a high-fat diet group (HFD), a high-fat-diet red-wine-drinking group (HFRWD), and a standard diet group (SD). After 8 weeks, the HFRWD group had a lower body weight gain (175.66 +/- 2.78% vs 188.22 +/- 4.83%; P<.05) and lower energy intake (269.45 +/- 4.02 KJ/animal.day vs day vs 300.81 +/- 4.52 KJ/animal.day; P<.05) and had less fat mass at epididymal location respect to the whole body weight (0.014 +/- 0.001 vs 0.017 +/- 0.001; P<.05) than the HFD group. However, the red wine didn't modified the fed efficiency 0.012 +/- 0.001 g/KJ for HFRWD group versus 0.013 +/- 0.001 g/KJ for the HFD one (P=.080). These findings, though preliminary, show that moderate red wine intake can prevent the increase of body weight by modulating energy intake in a rat diet-induced model of obesity.

Age-related decrease in sensitivity to glucagon and dibutyryl cyclic AMP inhibition of fatty acid synthesis in hepatocytes isolated from obese female Zucker rats.

PubMed

McCune, S A; Durant, P J; Harris, R A

1984-02-01

Hepatocytes were isolated from 3 and 5 month old female genetically obese Zucker rats and their lean littermate controls. An age-dependent loss in sensitivity of fatty acid synthesis to inhibition by both glucagon and dibutyryl cyclic AMP was observed with hepatocytes from the obese rats. Hepatocytes from lean animals were much more sensitive to these agents, regardless of age. Low concentrations of glucagon and dibutyryl cyclic AMP actually produced some stimulation of fatty acid synthesis with hepatocytes prepared from the older obese rats. 5-Tetradecyloxy-2-furoic acid, a compound which inhibits fatty acid synthesis, was a very effective inhibitor of fatty acid synthesis by hepatocytes isolated from all rats used in the study. An inhibition of lactate plus pyruvate accumulation and a strong stimulation of glycogenolysis occurred in response to both glucagon and dibutyryl cyclic AMP with hepatocytes from both age groups of lean and obese rats. The results suggest that with aging of the obese female Zucker rat some step of hepatic fatty acid synthesis becomes progressively less sensitive to inhibition by glucagon and dibutyryl cyclic AMP. This may play an important role in maintenance of obesity in these animals.

Estrogen has opposing effects on vascular reactivity in obese, insulin-resistant male Zucker rats

NASA Technical Reports Server (NTRS)

Brooks-Asplund, Esther M.; Shoukas, Artin A.; Kim, Soon-Yul; Burke, Sean A.; Berkowitz, Dan E.

2002-01-01

We hypothesized that estradiol treatment would improve vascular dysfunction commonly associated with obesity, hyperlipidemia, and insulin resistance. A sham operation or 17beta-estradiol pellet implantation was performed in male lean and obese Zucker rats. Maximal vasoconstriction (VC) to phenylephrine (PE) and potassium chloride was exaggerated in control obese rats compared with lean rats, but estradiol significantly attenuated VC in the obese rats. Estradiol reduced the PE EC50 in all groups. This effect was cyclooxygenase independent, because preincubation with indomethacin reduced VC response to PE similarly in a subset of control and estrogen-treated lean rats. Endothelium-independent vasodilation (VD) to sodium nitroprusside was similar among groups, but endothelium-dependent VD to ACh was significantly impaired in obese compared with lean rats. Estradiol improved VD in lean and obese rats by decreasing EC50 but impaired function by decreasing maximal VD. The shift in EC50 corresponded to an upregulation in nitric oxide synthase III protein expression in the aorta of the estrogen-treated obese rats. In summary, estrogen treatment improves vascular function in male insulin-resistant, obese rats, partially via an upregulation of nitric oxide synthase III protein expression. These effects are counteracted by adverse factors, such as hyperlipidemia and, potentially, a release of an endothelium-derived contractile agent.

trans-trans Conjugated linoleic acid enriched soybean oil reduces fatty liver and lowers serum cholesterol in obese zucker rats.

PubMed

Gilbert, William; Gadang, Vidya; Proctor, Andrew; Jain, Vishal; Devareddy, Latha

2011-10-01

Conjugated linoleic acid (CLA) is a collection of octadecadienoic fatty acids that have been shown to possess numerous health benefits. The CLA used in our study was produced by the photoisomerization of soybean oil and consists of about 20% CLA; this CLA consists of 75% trans-trans (a mixture of t8,t10; t9,t11; t10,t12) isomers. This method could be readily used to increase the CLA content of all soybean oil used as a food ingredient. The objective of this study was to determine the effects of trans-trans CLA-rich soy oil, fed as a dietary supplement, on body composition, dyslipidemia, hepatic steatosis, and markers of glucose control and liver function of obese fa/fa Zucker rats. The trans-trans CLA-rich soy oil lowered the serum cholesterol and low density lipoprotein-cholesterol levels by 41 and 50%, respectively, when compared to obese controls. Trans-trans CLA-rich soy oil supplementation also lowered the liver lipid content significantly (P < 0.05) with a concomitant decrease in the liver weight in the obese rats. In addition, glycated hemoglobin values were improved in the group receiving CLA-enriched soybean oil in comparison to the obese control. PPAR-γ expression in white adipose tissue was unchanged. In conclusion, trans-trans CLA-rich soy oil was effective in lowering total liver lipids and serum cholesterol.

Metabolic syndrome impairs reactivity and wall mechanics of cerebral resistance arteries in obese Zucker rats.

PubMed

Brooks, Steven D; DeVallance, Evan; d'Audiffret, Alexandre C; Frisbee, Stephanie J; Tabone, Lawrence E; Shrader, Carl D; Frisbee, Jefferson C; Chantler, Paul D

2015-12-01

The metabolic syndrome (MetS) is highly prevalent in the North American population and is associated with increased risk for development of cerebrovascular disease. This study determined the structural and functional changes in the middle cerebral arteries (MCA) during the progression of MetS and the effects of chronic pharmacological interventions on mitigating vascular alterations in obese Zucker rats (OZR), a translationally relevant model of MetS. The reactivity and wall mechanics of ex vivo pressurized MCA from lean Zucker rats (LZR) and OZR were determined at 7-8, 12-13, and 16-17 wk of age under control conditions and following chronic treatment with pharmacological agents targeting specific systemic pathologies. With increasing age, control OZR demonstrated reduced nitric oxide bioavailability, impaired dilator (acetylcholine) reactivity, elevated myogenic properties, structural narrowing, and wall stiffening compared with LZR. Antihypertensive therapy (e.g., captopril or hydralazine) starting at 7-8 wk of age blunted the progression of arterial stiffening compared with OZR controls, while treatments that reduced inflammation and oxidative stress (e.g., atorvastatin, rosiglitazone, and captopril) improved NO bioavailability and vascular reactivity compared with OZR controls and had mixed effects on structural remodeling. These data identify specific functional and structural cerebral adaptations that limit cerebrovascular blood flow in MetS patients, contributing to increased risk of cognitive decline, cerebral hypoperfusion, and ischemic stroke; however, these pathological adaptations could potentially be blunted if treated early in the progression of MetS. Copyright © 2015 the American Physiological Society.

Effect of Roux-en-Y gastric bypass and diet-induced weight loss on diabetic kidney disease in the Zucker diabetic fatty rat.

PubMed

Neff, Karl J; Elliott, Jessie A; Corteville, Caroline; Abegg, Kathrin; Boza, Camilo; Lutz, Thomas A; Docherty, Neil G; le Roux, Carel W

2017-01-01

Reductions in urinary protein excretion after Roux-en-Y gastric bypass (RYGB) surgery in patients with diabetic kidney disease have been reported in multiple studies. To determine the weight loss dependence of the effect of RYGB on urinary protein excretion by comparing renal outcomes in Zucker diabetic fatty rats undergoing either gastric bypass surgery or a sham operation with or without weight matching. University laboratories. Zucker diabetic fatty rats underwent surgery at 18 weeks of age. A subgroup of sham operated rats were weight matched to RYGB operated rats by restricting food intake. Urinary protein excretion was assessed at baseline and at postoperative weeks 4 and 12. Renal histology and macrophage-associated inflammation were assessed at postoperative week 12. Progressive urinary protein excretion was attenuated by both RYGB and diet-induced weight loss, albeit to a lesser extent by the latter. Both weight loss interventions produced equivalent reductions in glomerulomegaly, glomerulosclerosis, and evidence of renal macrophage infiltration. Weight loss per se improves renal structure and attenuates renal inflammatory responses in an experimental animal model of diabetic kidney disease. Better glycemic control post-RYGB may in part explain the greater reductions in urinary protein excretion after gastric bypass surgery. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Cardiac lesions in rats fed rapeseed oils.

PubMed Central

Charlton, K M; Corner, A H; Davey, K; Kramer, J K; Mahadevan, S; Sauer, F D

1975-01-01

Fully refined rapeseed oils containing different amounts of erucic acid (1.6%, 4.3% and 22.3%) were fed, at 20% by weight of diet, to weanling male and female Sprague-Dawley rats for periods up to 112 days. Transient myocardial lipidosis characterized by accumulation of fat droplets in myocardial fibers was marked in male and female rats fed oxidized and unoxidized rapeseed oil containing 22.3% erucic acid, moderate with rapeseed oil containing 4.3% erucic acid and very slight in rats fed rapeseed oil containing 1.6% erucic acid. Peak intensity of myocardial lipidosis occurred at three to seven days and regressed thereafter. Focal myocardial necrosis and fibrosis occurred in male rats fed rapeseed oils containing different levels of erucic acid for 112 days. The incidence of myocardial necrosis and fibrosis was markedly lower in female rats, and the incidence of these lesions in either sex was not affected by the state of oxidation of these oils. In a second experiment, male rats were fed diets containing crude, partially refined or fully refined rapeseed oils. There was no correlation between the number of foci of myocardial necrosis and fibrosis and the state of refinement of the oils, but there were generally fewer lesions in rats fed those oils having the lowest levels of erucic acid. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. 9. Fig. 10. PMID:1170010

Beta cell compensation for insulin resistance in Zucker fatty rats: increased lipolysis and fatty acid signalling.

PubMed

Nolan, C J; Leahy, J L; Delghingaro-Augusto, V; Moibi, J; Soni, K; Peyot, M-L; Fortier, M; Guay, C; Lamontagne, J; Barbeau, A; Przybytkowski, E; Joly, E; Masiello, P; Wang, S; Mitchell, G A; Prentki, M

2006-09-01

The aim of this study was to determine the role of fatty acid signalling in islet beta cell compensation for insulin resistance in the Zucker fatty fa/fa (ZF) rat, a genetic model of severe obesity, hyperlipidaemia and insulin resistance that does not develop diabetes. NEFA augmentation of insulin secretion and fatty acid metabolism were studied in isolated islets from ZF and Zucker lean (ZL) control rats. Exogenous palmitate markedly potentiated glucose-stimulated insulin secretion (GSIS) in ZF islets, allowing robust secretion at physiological glucose levels (5-8 mmol/l). Exogenous palmitate also synergised with glucagon-like peptide-1 and the cyclic AMP-raising agent forskolin to enhance GSIS in ZF islets only. In assessing islet fatty acid metabolism, we found increased glucose-responsive palmitate esterification and lipolysis processes in ZF islets, suggestive of enhanced triglyceride-fatty acid cycling. Interruption of glucose-stimulated lipolysis by the lipase inhibitor Orlistat (tetrahydrolipstatin) blunted palmitate-augmented GSIS in ZF islets. Fatty acid oxidation was also higher at intermediate glucose levels in ZF islets and steatotic triglyceride accumulation was absent. The results highlight the potential importance of NEFA and glucoincretin enhancement of insulin secretion in beta cell compensation for insulin resistance. We propose that coordinated glucose-responsive fatty acid esterification and lipolysis processes, suggestive of triglyceride-fatty acid cycling, play a role in the coupling mechanisms of glucose-induced insulin secretion as well as in beta cell compensation and the hypersecretion of insulin in obesity.

Mild and Short-Term Caloric Restriction Prevents Obesity-Induced Cardiomyopathy in Young Zucker Rats without Changing in Metabolites and Fatty Acids Cardiac Profile

PubMed Central

Ruiz-Hurtado, Gema; García-Prieto, Concha F.; Pulido-Olmo, Helena; Velasco-Martín, Juan P.; Villa-Valverde, Palmira; Fernández-Valle, María E.; Boscá, Lisardo; Fernández-Velasco, María; Regadera, Javier; Somoza, Beatriz; Fernández-Alfonso, María S.

2017-01-01

Caloric restriction (CR) ameliorates cardiac dysfunction associated with obesity. However, most of the studies have been performed under severe CR (30–65% caloric intake decrease) for several months or even years in aged animals. Here, we investigated whether mild (20% food intake reduction) and short-term (2-weeks) CR prevented the obese cardiomyopathy phenotype and improved the metabolic profile of young (14 weeks of age) genetically obese Zucker fa/fa rats. Heart weight (HW) and HW/tibia length ratio was significantly lower in fa/fa rats after 2 weeks of CR than in counterparts fed ad libitum. Invasive pressure measurements showed that systolic blood pressure, maximal rate of positive left ventricle (LV) pressure, LV systolic pressure and LV end-diastolic pressure were all significantly higher in obese fa/fa rats than in lean counterparts, which were prevented by CR. Magnetic resonance imaging revealed that the increase in LV end-systolic volume, stroke volume and LV wall thickness observed in fa/fa rats was significantly lower in animals on CR diet. Histological analysis also revealed that CR blocked the significant increase in cardiomyocyte diameter in obese fa/fa rats. High resolution magic angle spinning magnetic resonance spectroscopy analysis of the LV revealed a global decrease in metabolites such as taurine, creatine and phosphocreatine, glutamate, glutamine and glutathione, in obese fa/fa rats, whereas lactate concentration was increased. By contrast, fatty acid concentrations in LV tissue were significantly elevated in obese fa/fa rats. CR failed to restore the LV metabolomic profile of obese fa/fa rats. In conclusion, mild and short-term CR prevented an obesity-induced cardiomyopathy phenotype in young obese fa/fa rats independently of the cardiac metabolic profile. PMID:28203206

Carnitine supplementation to obese Zucker rats prevents obesity-induced type II to type I muscle fiber transition and favors an oxidative phenotype of skeletal muscle

PubMed Central

2013-01-01

Background In the present study, we tested the hypothesis that carnitine supplementation counteracts obesity-induced muscle fiber transition from type I to type II. Methods 24 obese Zucker rats were randomly divided into two groups of 12 rats each (obese control, obese carnitine) and 12 lean Zucker rats were selected for lean control group. A control diet was given to both control groups and a carnitine supplemented diet (3 g/kg diet) was given to obese carnitine group for 4 wk. Components of the muscle fiber transformation in skeletal muscle were examined. Results The plasma level of carnitine were lower in the obese control group compared to the lean control group and higher in the obese carnitine group than in the other groups (P < 0.05). Plasma concentrations of triglycerides and non-esterified fatty acids were increased in obese animals compared to lean animals and the obese carnitine group had lower level compared to the obese control group (P < 0.05). The obese carnitine group had an increased number of type I muscle fibers and higher mRNA levels of type I fiber-specific myosin heavy chain, regulators of muscle fiber transition and of genes involved in carnitine uptake, fatty acid transport, β-oxidation, angiogenesis, tricarboxylic acid cycle and thermo genesis in M. rectus femoris compared to the other groups (P < 0.05). Conclusion The results demonstrate that carnitine supplementation to obese Zucker a rat counteracts the obesity-induced muscle fiber transition and restores the muscle oxidative metabolic phenotype. Carnitine supplementation is supposed to be beneficial for the treatment of elevated levels of plasma lipids during obesity or diabetes. PMID:23842456

Alterations in Glutathione Redox Metabolism, Oxidative Stress, and Mitochondrial Function in the Left Ventricle of Elderly Zucker Diabetic Fatty Rat Heart

PubMed Central

Raza, Haider; John, Annie; Howarth, Frank C.

2012-01-01

The Zucker diabetic fatty (ZDF) rat is a genetic model in which the homozygous (FA/FA) male animals develop obesity and type 2 diabetes. Morbidity and mortality from cardiovascular complications, due to increased oxidative stress and inflammatory signals, are the hallmarks of type 2 diabetes. The precise molecular mechanism of contractile dysfunction and disease progression remains to be clarified. Therefore, we have investigated molecular and metabolic targets in male ZDF (30–34 weeks old) rat heart compared to age matched Zucker lean (ZL) controls. Hyperglycemia was confirmed by a 4-fold elevation in non-fasting blood glucose (478.43 ± 29.22 mg/dL in ZDF vs. 108.22 ± 2.52 mg/dL in ZL rats). An increase in reactive oxygen species production, lipid peroxidation and oxidative protein carbonylation was observed in ZDF rats. A significant increase in CYP4502E1 activity accompanied by increased protein expression was also observed in diabetic rat heart. Increased expression of other oxidative stress marker proteins, HO-1 and iNOS was also observed. GSH concentration and activities of GSH-dependent enzymes, glutathione S-transferase and GSH reductase, were, however, significantly increased in ZDF heart tissue suggesting a compensatory defense mechanism. The activities of mitochondrial respiratory enzymes, Complex I and Complex IV were significantly reduced in the heart ventricle of ZDF rats in comparison to ZL rats. Western blot analysis has also suggested a decreased expression of IκB-α and phosphorylated-JNK in diabetic heart tissue. Our results have suggested that mitochondrial dysfunction and increased oxidative stress in ZDF rats might be associated, at least in part, with altered NF-κB/JNK dependent redox cell signaling. These results might have implications in the elucidation of the mechanism of disease progression and designing strategies for diabetes prevention. PMID:23203193

Supplemental fructose attenuates postprandial glycemia in Zucker fatty fa/fa rats.

PubMed

Wolf, Bryan W; Humphrey, Phillip M; Hadley, Craig W; Maharry, Kati S; Garleb, Keith A; Firkins, Jeffrey L

2002-06-01

Experiments were conducted to evaluate the effects of supplemental fructose on postprandial glycemia. After overnight food deprivation, Zucker fatty fa/fa rats were given a meal glucose tolerance test. Plasma glucose response was determined for 180 min postprandially. At a dose of 0.16 g/kg body, fructose reduced (P < 0.05) the incremental area under the curve (AUC) by 34% when supplemented to a glucose challenge and by 32% when supplemented to a maltodextrin (a rapidly digested starch) challenge. Similarly, sucrose reduced (P = 0.0575) the incremental AUC for plasma glucose when rats were challenged with maltodextrin. Second-meal glycemic response was not affected by fructose supplementation to the first meal, and fructose supplementation to the second meal reduced (P < 0.05) postprandial glycemia when fructose had been supplemented to the first meal. In a dose-response study (0.1, 0.2, and 0.5 g/kg body), supplemental fructose reduced (P < 0.01) the peak rise in plasma glucose (linear and quadratic effects). In the final experiment, a low dose of fructose (0.075 g/kg body) reduced (P < 0.05) the incremental AUC by 18%. These data support the hypothesis that small amounts of oral fructose or sucrose may be useful in lowering the postprandial blood glucose response.

Nebivolol ameliorated kidney damage in Zucker diabetic fatty rats by regulation of oxidative stress/NO pathway: comparison with captopril.

PubMed

Wang, Yan; An, Wenjing; Zhang, Fei; Niu, Mengzhen; Liu, Yu; Shi, Ruizan

2018-06-23

The aim was to evaluate the effects and mechanisms of nebivolol on renal damage in Zucker diabetic fatty (ZDF) rats, in comparison with those of atenolol and captopril. Animals were divided into: control lean Zucker rats, ZDF rats, ZDF rats orally treated with nebivolol (10 mg/kg), atenolol (100 mg/kg) or captopril (40 mg/kg) for 6 months. Systolic blood pressure (SBP), blood glucose, kidney structure and function, plasma and kidney levels of nitric oxide (NO) and asymmetric dimethylarginine (ADMA), and oxidant status were evaluated. Kidney expressions of AMP-activated protein kinase (AMPK), NADPH oxidase (NOX) isoforms 2 and 4 and subunit p22 phox , nitric oxide synthase (NOS) isoforms, eNOS uncoupling, protein arginine N-methyltransferase (PRMT) 1, and dimethylarginine dimethylaminohydrolase (DDAH) 1 and 2 were tested. All drugs induced a similar control of SBP. Nebivolol did not affect the increased plasma glucose. Unlike atenolol, nebivolol prevented the decrease in plasma insulin, and, like captopril, it reduced plasma lipid contents. Nebivolol ameliorated, to a greater extent than captopril, damages to renal structure and function, which were associated with an improvement in interlobular artery dysfunction. Nebivolol elevated kidney phosphorylation of AMPK, attenuated NOX4 and p22 phox expression and oxidative stress marker levels. Nebivolol increased plasma and renal NO, enhanced expressions of eNOS, p-eNOS and nNOS, and suppressed eNOS uncoupling and iNOS expression. High ADMA in plasma and kidney were decreased by nebivolol through increasing DDAH2 and decreasing PRMT1. Long-term treatment of nebivolol ameliorated diabetic nephropathy, at least in part, via regulation of renal oxidative stress/NO pathway. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

COX-2 is involved in vascular oxidative stress and endothelial dysfunction of renal interlobar arteries from obese Zucker rats.

PubMed

Muñoz, Mercedes; Sánchez, Ana; Pilar Martínez, María; Benedito, Sara; López-Oliva, Maria-Elvira; García-Sacristán, Albino; Hernández, Medardo; Prieto, Dolores

2015-07-01

Obesity is related to vascular dysfunction through inflammation and oxidative stress and it has been identified as a risk factor for chronic renal disease. In the present study, we assessed the specific relationships among reactive oxygen species (ROS), cyclooxygenase 2 (COX-2), and endothelial dysfunction in renal interlobar arteries from a genetic model of obesity/insulin resistance, the obese Zucker rats (OZR). Relaxations to acetylcholine (ACh) were significantly reduced in renal arteries from OZR compared to their counterpart, the lean Zucker rat (LZR), suggesting endothelial dysfunction. Blockade of COX with indomethacin and with the selective blocker of COX-2 restored the relaxations to ACh in obese rats. Selective blockade of the TXA2/PGH2 (TP) receptor enhanced ACh relaxations only in OZR, while inhibition of the prostacyclin (PGI2) receptor (IP) enhanced basal tone and inhibited ACh vasodilator responses only in LZR. Basal production of superoxide was increased in arteries of OZR and involved NADPH and xanthine oxidase activation and NOS uncoupling. Under conditions of NOS blockade, ACh induced vasoconstriction and increased ROS generation that were augmented in arteries from OZR and blunted by COX-2 inhibition and by the ROS scavenger tempol. Hydrogen peroxide (H2O2) evoked both endothelium- and vascular smooth muscle (VSM)-dependent contractions, as well as ROS generation that was reduced by COX-2 inhibition. In addition, COX-2 expression was enhanced in both VSM and endothelium of renal arteries from OZR. These results suggest that increased COX-2-dependent vasoconstriction contributes to renal endothelial dysfunction through enhanced (ROS) generation in obesity. COX-2 activity is in turn upregulated by ROS. Copyright © 2015 Elsevier Inc. All rights reserved.

Glucomannan- and glucomannan plus spirulina-enriched pork affect liver fatty acid profile, LDL receptor expression and antioxidant status in Zucker fa/fa rats fed atherogenic diets

PubMed Central

González-Torres, Laura; Matos, Cátia; Vázquez-Velasco, Miguel; Santos-López, Jorge A.; Sánchez-Martínez, Iria; García–Fernández, Camino; Bastida, Sara; Benedí, Juana; Sánchez-Muniz, Francisco J.

2017-01-01

ABSTRACT We evaluated the effects of glucomannan or glucomannan plus spirulina-restructured pork (RP) on liver fatty acid profile, desaturase/elongase enzyme activities and oxidative status of Zucker fa/fa rats for seven weeks. Control (C), glucomannan (G) and glucomannan/spirulina (GS)-RP; HC (cholesterol-enriched control), HG and HGS (cholesterol-enriched glucomannan and glucomannan/spirulina-RP) experimental diets were tested. Increased metabolic syndrome markers were found in C, G and GS rats. Cholesterol feeding increased liver size, fat, and cholesterol and reduced antioxidant enzyme levels and expressions. Cholesterolemia was lower in HG and HGS than in HC. GS vs. G showed higher stearic but lower oleic levels. SFA and PUFA decreased while MUFA increased by cholesterol feeding. The arachidonic/linoleic and docosahexaenoic/alpha-linolenic ratios were lower in HC, HG, and HGS vs. C, G, and GS, respectively, suggesting a delta-6-elongase-desaturase system inhibition. Moreover, cholesterol feeding, mainly in HGS, decreased low-density-lipoprotein receptor expression and the delta-5-desaturase activity and increased the delta-9-desaturase activity. In conclusion, the liver production of highly unsaturated fatty acids was limited to decrease their oxidation in presence of hypercholesterolaemia. Glucomannan or glucomannan/spirulina-RP has added new attributes to their functional properties in meat, partially arresting the negative effects induced by high-fat-high-cholesterol feeding on the liver fatty acid and antioxidant statuses. PMID:28325998

Naringin ameliorates endothelial dysfunction in fructose-fed rats.

PubMed

Malakul, Wachirawadee; Pengnet, Sirinat; Kumchoom, Chanon; Tunsophon, Sakara

2018-03-01

High fructose consumption is associated with metabolic disorders including hyperglycemia and dyslipidemia, in addition to endothelial dysfunction. Naringin, a flavonoid present in citrus fruit, has been reported to exhibit lipid lowering, antioxidant, and cardiovascular protective properties. Therefore, the present study investigated the effect of naringin on fructose-induced endothelial dysfunction in rats and its underlying mechanisms. Male Sprague-Dawley rats were given 10% fructose in drinking water for 12 weeks, whereas control rats were fed drinking water alone. Naringin (100 mg/kg) was orally administered to fructose fed rats during the last 4 weeks of the study. Following 12 weeks, blood samples were collected for measurement of blood glucose, serum lipid profile and total nitrate/nitrite (NOx). Vascular function was assessed by isometric tension recording. Aortic expression of endothelial nitric oxide synthase (eNOS), phosphorylated eNOS (p-eNOS), and nitrotyrosine were evaluated by western blot analysis. Fructose feeding induced increased levels of blood glucose, total cholesterol, triglyceride, and low density lipoprotein. In rat aortae, fructose reduced acethycholine-induced vasorelaxation, without affecting sodium nitroprusside-induced vasorelaxation. Treatment of fructose-fed rats with naringin restored fructose-induced metabolic alterations and endothelial dysfunction. Fructose-fed rats also exhibited decreased serum NOx level, reduced eNOS and p-eNOS protein expression, and enhanced nitrotyrosine expression in aortae. These alterations were improved by naringin treatment. The results of the present study suggested that naringin treatment preserves endothelium-dependent relaxation in aortae from fructose fed rats. This effect is primarily mediated through an enhanced NO bioavailability via increased eNOS activity and decreased NO inactivated to peroxynitrite in aortae.

Changes in alanine turnover rate due to nutritional and genetic obesity in the rat.

PubMed

Yebras, M; Salvadó, J; Arola, L; Remesar, X; Segués, T

1994-08-01

The changes in alanine turnover were determined in Zucker rats, which were either genetically obese (fa/fa) or rendered obese by dietary treatment (cafeteria fed). The whole body rate of alanine turnover was higher in genetically obese rats than in rats in which obesity was induced by diet (cafeteria). This is possibly due to variations in the rate of the amino acid incorporation into proteins, since the rate of whole body alanine degradation is the same for both groups. Thus, the different pattern followed by alanine turnover rate in these types of obese animals reflects the differences in the nitrogen economy of these animals, pointing to a higher alanine utilization in the genetically obese animals and a conservative management of alanine in the cafeteria-fed animals.

Effects of baked and raw salmon fillet on lipids and n-3 PUFAs in serum and tissues in Zucker fa/fa rats​​​​​​​​​​​​​​​​​​​​.

PubMed

Vikøren, Linn A; Drotningsvik, Aslaug; Bergseth, Marthe T; Mjøs, Svein A; Mola, Nazanin; Leh, Sabine; Mellgren, Gunnar; Gudbrandsen, Oddrun A

2017-01-01

Knowledge of the health impact of consuming heat-treated versus raw fish fillet is limited. To investigate effects of baked or raw salmon fillet intake on lipids and n-3 PUFAs in serum and tissues, obese Zucker fa/fa rats were fed diets containing 25% of protein from baked or raw salmon fillet and 75% of protein from casein, or casein as the sole protein source (control group) for four weeks. Salmon diets had similar composition of amino and fatty acids. Growth and energy intake were similar in all groups. Amounts of lipids and n-3 PUFAs in serum, liver and skeletal muscle were similar between rats fed baked or raw salmon fillet. When compared to the control group, rats fed baked salmon had lower serum total and LDL cholesterol and higher serum triacylglycerol levels. Both raw and baked salmon groups had lower HDL cholesterol level when compared to control rats. In conclusion, baking as a preparation method does not alter protein and fat qualities of salmon fillets, and intake of baked and raw salmon fillets gave similar effects on lipids and n-3 PUFAs in serum and tissues from rats.

Effects of baked and raw salmon fillet on lipids and n-3 PUFAs in serum and tissues in Zucker fa/fa rats​​​​​​​​​​​​​​​​​​​​

PubMed Central

Vikøren, Linn A.; Drotningsvik, Aslaug; Bergseth, Marthe T.; Mjøs, Svein A.; Mola, Nazanin; Leh, Sabine; Mellgren, Gunnar; Gudbrandsen, Oddrun A.

2017-01-01

ABSTRACT Knowledge of the health impact of consuming heat-treated versus raw fish fillet is limited. To investigate effects of baked or raw salmon fillet intake on lipids and n-3 PUFAs in serum and tissues, obese Zucker fa/fa rats were fed diets containing 25% of protein from baked or raw salmon fillet and 75% of protein from casein, or casein as the sole protein source (control group) for four weeks. Salmon diets had similar composition of amino and fatty acids. Growth and energy intake were similar in all groups. Amounts of lipids and n-3 PUFAs in serum, liver and skeletal muscle were similar between rats fed baked or raw salmon fillet. When compared to the control group, rats fed baked salmon had lower serum total and LDL cholesterol and higher serum triacylglycerol levels. Both raw and baked salmon groups had lower HDL cholesterol level when compared to control rats. In conclusion, baking as a preparation method does not alter protein and fat qualities of salmon fillets, and intake of baked and raw salmon fillets gave similar effects on lipids and n-3 PUFAs in serum and tissues from rats. PMID:28659746

Effects of the Soluble Fiber Complex PolyGlycopleX® on Glucose Homeostasis and Body Weight in Young Zucker Diabetic Rats

PubMed Central

Grover, Gary James; Koetzner, Lee; Wicks, Joan; Gahler, Roland J.; Lyon, Michael R.; Reimer, Raylene A.; Wood, Simon

2011-01-01

Dietary fiber can reduce insulin resistance, body weight, and hyperlipidemia depending on fiber type, water solubility, and viscosity. PolyGlycopleX® (PGX®) is a natural, novel water soluble, non-starch polysaccharide complex that with water forms a highly viscous gel compared to other naturally occurring dietary fiber. We determined the effect of dietary PGX® vs. cellulose and inulin on the early development of insulin resistance, body weight, hyperlipidemia, and glycemia-induced tissue damage in young Zucker diabetic rats (ZDFs) in fasted and non-fasted states. ZDFs (5 weeks old) were fed a diet containing 5% (wgt/wgt) cellulose, inulin, or PGX® for 8 weeks. Body weight, lipids, insulin, and glucose levels were determined throughout the study and homeostasis model assessment (HOMA) was used to measure insulin sensitivity throughout the study in fasted animals. At study termination, insulin sensitivity (oral glucose tolerance test, OGTT) and kidney, liver, and pancreatic histopathology were determined. Body weight and food intake were significantly reduced by PGX® vs. inulin and cellulose. Serum insulin in fasted and non-fasted states was significantly reduced by PGX® as was non-fasted blood glucose. Insulin resistance, measured as a HOMA score, was significantly reduced by PGX® in weeks 5 through 8 as well as terminal OGTT scores in fed and fasted states. Serum total cholesterol was also significantly reduced by PGX®. PGX® significantly reduced histological kidney and hepatic damage in addition to reduced hepatic steatosis and cholestasis. A greater mass of pancreatic β-cells was found in the PGX® group. PGX® therefore may be a useful dietary additive in the control of the development of the early development of the metabolic syndrome. PMID:21922008

Thyroid hormone modulates food intake and glycemia via ghrelin secretion in Zucker fatty rats.

PubMed

Patel, K; Joharapurkar, A; Dhanesha, N; Patel, V; Kshirsagar, S; Raval, P; Raval, S; Jain, M R

2014-10-01

Hyperthyroidism is known to increase food intake and central administration of thyroid hormone shows acute orexigenic effects in rodents. We investigated whether T3 influences appetite and glucose homeostasis by modulating circulating ghrelin, an important orexigenic hormone, in Zucker fatty rats. The acute anorectic effects of T3 and ghrelin mimetic MK-0677 were studied in rats trained for fasting induced food intake. The serum concentration of T3, ghrelin, glucose, triglycerides, and liver glycogen were estimated. The involvement of sympathetic nervous system was evaluated by conducting similar experiments in vagotomized rats. T3 increased food intake and glucose in rats over 4 h, with increase in serum T3 and decrease in liver glycogen. T3 treatment was associated with increase in serum ghrelin. An additive effect on appetite and glucose was observed when T3 (oral) was administered with central (intracerebroventricular) administration of a ghrelin mimetic, MK-0677. Ghrelin antagonist, compound 8a, antagonized the hyperglycemic and hyperphagic effects of T3. In vagotomized rats, T3 did not show increase in appetite as well as glucose. Serum ghrelin levels were unchanged in these animals after T3 treatment. However, T3 showed increase in serum triglyceride levels indicating its peripheral lipolytic effect, in vagotomized as well as sham treated animals. To conclude, acute orexigenic and hyperglycemic effects of T3 are associated with ghrelin secretion and activity. This effect seems to be mediated via vagus nerves, and is independent of glucoregulatory hormones. © Georg Thieme Verlag KG Stuttgart · New York.

Impaired Ca2+ handling in penile arteries from prediabetic Zucker rats: involvement of Rho kinase.

PubMed

Villalba, Nuria; Contreras, Cristina; Hernández, Medardo; García-Sacristán, Albino; Prieto, Dolores

2011-06-01

Diabetes is associated with an increased vascular tone usually involved in the pathogenesis of diabetic cardiovascular complications such as hypertension, stroke, coronary artery disease, or erectile dysfunction (ED). Enhanced contractility of penile erectile tissue has been associated with augmented activity of the RhoA/Rho kinase (RhoK) pathway in models of diabetes-associated ED. The present study assessed whether abnormal vasoconstriction in penile arteries from prediabetic obese Zucker rats (OZRs) is due to changes in the intracellular Ca(2+) concentration ([Ca(2+)](i)) and/or in myofilament Ca(2+) sensitivity. Penile arteries from OZRs and lean Zucker rats (LZRs) were mounted on microvascular myographs for simultaneous measurements of [Ca(2+)](i) and tension. The relationships between [Ca(2+)](i) and contraction for the α(1)-adrenergic vasoconstrictor phenylephrine (PE) were left shifted and steeper in OZRs compared with LZRs, although the magnitude of the contraction was similar in both groups. In contrast, the vasoconstriction induced by the thromboxane A(2) receptor agonist U-46619 was augmented in arteries from OZRs, and this increase was associated with an increase in both the sensitivity and maximum responses to Ca(2+). The RhoK inhibitor Y-27632 (10 μM) reduced the vasoconstriction induced by PE to a greater extent in OZRs than in LZRs, without altering Ca(2+). Y-27632 inhibited with a greater potency the contraction elicited by high KCl in arteries from OZRs compared with LZRs without changing [Ca(2+)](i). RhoK-II expression was augmented in arteries from OZRs. These results suggest receptor-specific changes in the Ca(2+) handling of penile arteries under conditions of metabolic syndrome. Whereas augmented vasoconstriction upon activation of the thromboxane A(2) receptor is coupled to enhanced Ca(2+) entry, a RhoK-mediated enhancement of myofilament Ca(2+) sensitivity is coupled with the α(1)-adrenergic vasoconstriction in penile arteries from OZRs.

Implications of obesity for tendon structure, ultrastructure and biochemistry: a study on Zucker rats.

PubMed

Biancalana, Adriano; Velloso, Lício Augusto; Taboga, Sebastião Roberto; Gomes, Laurecir

2012-02-01

The extracellular matrix consists of collagen, proteoglycans and non-collagen proteins. The incidence of obesity and associated diseases is currently increasing in developed countries. Obesity is considered to be a disease of modern times, and genes predisposing to the disease have been identified in humans and animals. The objective of the present study was to compare the morphological and biochemical aspects of the deep digital flexor tendon of lean (Fa/Fa or Fa/fa) and genetically obese (fa/fa) Zucker rats. Ultrastructural analysis showed the presence of lipid droplets in both groups, whereas disorganized collagen fibril bundles were observed in obese animals. Lean animals presented a larger amount of non-collagen proteins and glycosaminoglycans than obese rats. We propose that the overweight and lesser physical activity in obese animals may have provoked the alterations in the composition and organization of extracellular matrix components but a genetic mechanism cannot be excluded. These alterations might be related to organizational and structural modifications in the collagen bundles that influence the mechanical properties of tendons and the progression to a pathological state. Copyright © 2011 Elsevier Ltd. All rights reserved.

Energy intake of rats fed a cafeteria diet.

PubMed

Prats, E; Monfar, M; Castellà, J; Iglesias, R; Alemany, M

1989-02-01

The proportion of lipid, carbohydrate and protein energy self-selected by male and female rats from a cafeteria diet has been studied for a 48-day period (36-day in female rats). The diet consisted in 12 different items and was offered daily, in excess and under otherwise standard conditions, to rats--caged in groups of three--from weaning to adulthood. Groups of control animals were studied in parallel and compared with the cafeteria groups. Cafeteria diet fed groups of rats ingested more energy and lowered their metabolic efficiency with age. Male rats ate more than females and increased their body weight even after female practically stopped growing. There was a wide variation in the aliments consumed each day by the cafeteria-fed rats. However, the proportion of lipid, protein and carbohydrate the rats ate remained constant. Male rats ingested more lipid than females. Carbohydrate consumption was constant in control and cafeteria fed groups of rats independently of sex. Protein consumption was higher in cafeteria rats than in controls, but the differences were not so important as with liquid. Fiber content of the cafeteria diet was lower than that of the control diet. The cafeteria diet selected by the rats was, thus, hypercaloric and hyperlipidic, with practically the same amount of carbohydrate than the control diet, slightly hyperproteic and, nevertheless, remarkably constant in its composition with respect to time. Cafeteria rats had a higher water intake than controls. All these trends were maintained despite the observed changes in the animals' tastes and their differential consumption of the ailments of the diet.

Copper status in weanling rats fed low levels of inorganic tin

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

Rader, J.I.; Hight, S.C.

1991-03-15

The metabolism of Cu and Fe is adversely affected by ingestion of tin (Sn). In the present study, weanling male rats were fed 33 ug Sn/g in purified Cu-adequate or Cu-deficient diets for 14 or 28 days. Diets were based upon diet AIN-76A and contained 55% glucose and 15% starch. Ceruloplasmin was undetectable in serum of rats fed diets 2, 3 and 4 for 14 or 28 days. Superoxide dismutase (SOD) and Cu in liver decreased when 33 ug Sn/g was included in +Cu diets. Wt. gain, relative heart wt., SOD, and Cu and Fe in liver were sensitive indicesmore » of copper depletion in rats fed {minus}Cu diets. Cu status in rats fed {minus}Cu diets for 14 or 28 days was adversely affected by inclusion of Sn as indicated by changes in hemoglobin (HGB) and relative heart wt. Ingestion of low levels of inorganic tin causes Cu depletion in rats fed +Cu diets and accelerated the appearance of signs of copper deficiency in those fed {minus}Cu diets.« less

In Vivo Cannabidiol Treatment Improves Endothelium-Dependent Vasorelaxation in Mesenteric Arteries of Zucker Diabetic Fatty Rats

PubMed Central

Wheal, Amanda J.; Jadoon, Khalid; Randall, Michael D.; O’Sullivan, Saoirse E.

2017-01-01

Background and purpose: We have shown that in vitro treatment with cannabidiol (CBD, 2 h) enhances endothelial function in arteries from Zucker diabetic fatty (ZDF) rats, partly due to a cyclooxygenase (COX)-mediated mechanism. The aim of the present study was to determine whether treatment with CBD in vivo would also enhance endothelial function. Experimental approach: Male ZDF rats, or ZDF Lean rats, were treated for 7 days (daily i.p. injection) with either 10mg/kg CBD or vehicle (n = 6 per group). Sections of mesenteric resistance arteries, femoral arteries and thoracic aortae were mounted on a wire myograph, and cumulative concentration-response curves to endothelium-dependent (acetylcholine, ACh, 1 nM–100 μM) or endothelium-independent (sodium nitroprusside, SNP, 1 nM–100 μM) agents were constructed. Multiplex analysis was used to measure serum metabolic and cardiovascular biomarkers. Key results: Vasorelaxation to ACh was significantly enhanced in mesenteric arteries from CBD-treated ZDF rats, but not ZDF Lean rats. The enhanced vasorelaxation in ZDF mesenteric arteries was no longer observed after COX inhibition using indomethacin or nitric oxide (NO) inhibition using L-NAME. Increased levels of serum c-peptide, insulin and intracellular adhesion molecule-1 observed in the ZDF compared to ZDF Lean rats were no longer significant after 7 days CBD treatment. Conclusion and implications: Short-term in vivo treatment with CBD improves ex vivo endothelium-dependent vasorelaxation in mesenteric arteries from ZDF rats due to COX- or NO-mediated mechanisms, and leads to improvements in serum biomarkers. PMID:28572770

Triglyceride kinetics in fasted and fed E. coli septic rats

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

Lanza-Jacoby, S.; Tabares, A.

1990-02-26

The mechanism for the development of hypertriglyceridemia during gram-negative sepsis was studies by examining the liver production and clearance of very-low-density lipoprotein (VLDL) triglyceride (TG). To assess the liver output and peripheral clearance the kinetics of VLDL-TG were determined by a constant intravenous infusion of (2-{sup 3}H) glycerol-labeled VLDL in fasted control, fasted E. coli-treated, fed control, and fed E.coli-treated rats. Lewis inbred rats, 275-300 g, were made septic with 8 {times} 10{sup 7} live E.coli colonies per 100 g body weight. Twenty-four hours following E.coli injection serum TG of fasted E.coli-treated rats was elevated by 170% which was attributedmore » to a 67% decrease in the clearance rate of VLDL-TG in fasted E.coli-treated rats compared with their fasted controls. The secretion of VLDL-TG declined by 31% in the livers of the fasted E.coli-treated rats which was accompanied by a 2-fold increase in the composition of liver TG. In a second series of experiments control and E.coli-treated rats were fed intragastrically (IG) a balanced solution containing glucose plus fat as the sources of nonprotein calories. Serum TG were 26% lower in the fed E.coli-treated rats because the clearance rate increased by 86%. The secretion of TG in the fed septic rats increased by 40% but this difference was not significant. In the septic rat the ability to clear triglycerides from the plasma depends upon the nutritional state.« less

Effects of the Soluble Fiber Complex PolyGlycopleX on Glucose Homeostasis and Body Weight in Young Zucker Diabetic Rats.

PubMed

Grover, Gary James; Koetzner, Lee; Wicks, Joan; Gahler, Roland J; Lyon, Michael R; Reimer, Raylene A; Wood, Simon

2011-01-01

Dietary fiber can reduce insulin resistance, body weight, and hyperlipidemia depending on fiber type, water solubility, and viscosity. PolyGlycopleX(®) (PGX(®)) is a natural, novel water soluble, non-starch polysaccharide complex that with water forms a highly viscous gel compared to other naturally occurring dietary fiber. We determined the effect of dietary PGX(®) vs. cellulose and inulin on the early development of insulin resistance, body weight, hyperlipidemia, and glycemia-induced tissue damage in young Zucker diabetic rats (ZDFs) in fasted and non-fasted states. ZDFs (5 weeks old) were fed a diet containing 5% (wgt/wgt) cellulose, inulin, or PGX(®) for 8 weeks. Body weight, lipids, insulin, and glucose levels were determined throughout the study and homeostasis model assessment (HOMA) was used to measure insulin sensitivity throughout the study in fasted animals. At study termination, insulin sensitivity (oral glucose tolerance test, OGTT) and kidney, liver, and pancreatic histopathology were determined. Body weight and food intake were significantly reduced by PGX(®) vs. inulin and cellulose. Serum insulin in fasted and non-fasted states was significantly reduced by PGX(®) as was non-fasted blood glucose. Insulin resistance, measured as a HOMA score, was significantly reduced by PGX(®) in weeks 5 through 8 as well as terminal OGTT scores in fed and fasted states. Serum total cholesterol was also significantly reduced by PGX(®). PGX(®) significantly reduced histological kidney and hepatic damage in addition to reduced hepatic steatosis and cholestasis. A greater mass of pancreatic β-cells was found in the PGX(®) group. PGX(®) therefore may be a useful dietary additive in the control of the development of the early development of the metabolic syndrome.

Long Term Osmotic Mini Pump Treatment with Alpha-MSH Improves Myocardial Function in Zucker Diabetic Fatty Rats.

PubMed

Szokol, Miklos; Priksz, Daniel; Bombicz, Mariann; Varga, Balazs; Kovacs, Arpad; Fulop, Gabor Aron; Csipo, Tamas; Posa, Aniko; Toth, Attila; Papp, Zoltan; Szilvassy, Zoltan; Juhasz, Bela

2017-10-12

The present investigation evaluates the cardiovascular effects of the anorexigenic mediator alpha-melanocyte stimulating hormone (MSH), in a rat model of type 2 diabetes. Osmotic mini pumps delivering MSH or vehicle, for 6 weeks, were surgically implanted in Zucker Diabetic Fatty (ZDF) rats. Serum parameters, blood pressure, and weight gain were monitored along with oral glucose tolerance (OGTT). Echocardiography was conducted and, following sacrifice, the effects of treatment on ischemia/reperfusion cardiac injury were assessed using the isolated working heart method. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity was measured to evaluate levels of oxidative stress, and force measurements were performed on isolated cardiomyocytes to determine calcium sensitivity, active tension and myofilament co-operation. Vascular status was also evaluated on isolated arterioles using a contractile force measurement setup. The echocardiographic parameters ejection fraction (EF), fractional shortening (FS), isovolumetric relaxation time (IVRT), mitral annular plane systolic excursion (MAPSE), and Tei-index were significantly better in the MSH-treated group compared to ZDF controls. Isolated working heart aortic and coronary flow was increased in treated rats, and higher Hill coefficient indicated better myofilament co-operation in the MSH-treated group. We conclude that MSH improves global heart functions in ZDF rats, but these effects are not related to the vascular status.

Complementary Cholesterol-Lowering Response of a Phytosterol/α-Lipoic Acid Combination in Obese Zucker Rats

PubMed Central

Rideout, Todd C.; Carrier, Bradley; Wen, Shin; Raslawsky, Amy; Browne, Richard W.; Harding, Scott V.

2015-01-01

To investigate the cholesterol-lowering effectiveness of a phytosterol/α-lipoic acid (PS/αLA) therapy, thirty-two male Zucker rats were randomly assigned to 1 of 4 diets for 30 days: (i) high fat diet (HF, 40% energy from fat); (ii) HF diet supplemented with 3% phytosterols; (iii) HF diet supplemented with 0.25% αLA; or (iv) HF diet supplemented with PS (3%) and αLA (0.25%, PS/αLA). Compared with the HF diet, combination PS/αLA proved more effective in reducing non-HDL cholesterol (−55%) than either the PS (−24%) or the αLA (−25%) therapies alone. PS supplementation did not affect LDL particle number, however, αLA supplementation reduced LDL particle number when supplemented alone (−47%) or in combination with PS (−54%). Compared with the HF-fed animals, evidence of increased HDL-particle number was evident in all treatment groups to a similar extent (21–22%). PS-mediated interruption of intestinal cholesterol absorption was evident by increased fecal cholesterol loss (52%) and compensatory increase in HMG-CoA reductase mRNA (1.6 fold of HF), however, αLA supplementation did not affect fecal cholesterol loss. Hepatic mRNA and protein expression patterns suggested that αLA modulated multiple aspects of cholesterol homeostasis including reduced synthesis (HMG-CoA reductase mRNA, 0.7 fold of HF), reduced bile acid synthesis (CYP7a1 expression, 0.17 of HF), and increased cholesterol clearance (reduced PCSK9 mRNA, 0.5 fold of HF; increased LDLr protein, 2 fold of HF). Taken together, this data suggests that PS and αLA work through unique and complementary mechanisms to provide a superior and more comprehensive cholesterol lowering response than either therapy alone. PMID:25664679

Inhibition of Gastric Lipase as a Mechanism for Body Weight and Plasma Lipids Reduction in Zucker Rats Fed a Rosemary Extract Rich in Carnosic Acid

PubMed Central

Romo Vaquero, María; Yáñez-Gascón, María-Josefa; García Villalba, Rocío; Larrosa, Mar; Fromentin, Emilie; Ibarra, Alvin; Roller, Marc; Tomás-Barberán, Francisco; Espín de Gea, Juan Carlos; García-Conesa, María-Teresa

2012-01-01

Background Rosemary (Rosmarinus officinalis L.) extracts (REs) exhibit hepatoprotective, anti-obesity and anti-inflammatory properties and are widely used in the food industry. REs are rich in carnosic acid (CA) and carnosol which may be responsible for some of the biological activities of REs. The aim of this study was to investigate whether inhibition of lipase activity in the gut may be a mechanism by which a RE enriched in CA (40%) modulates body weight and lipids levels in a rat model of metabolic disorders and obesity. Methods and Principal Findings RE was administered for 64 days to lean (fa/+) and obese (fa/fa) female Zucker rats and body weight, food intake, feces weight and blood biochemical parameters were monitored throughout the study. Lipase activity (hydrolysis of p-nitrophenylbutyrate) was measured in the gastrointestinal tract at the end of the study and the contents of CA, carnosol and methyl carnosate were also determined. Sub-chronic administration of RE moderately reduced body weight gain in both lean and obese animals but did not affect food intake. Serum triglycerides, cholesterol and insulin levels were also markedly decreased in the lean animals supplemented with RE. Importantly, lipase activity was significantly inhibited in the stomach of the RE-supplemented animals where the highest content of intact CA and carnosol was detected. Conclusions Our results confirm that long-term administration of RE enriched in CA moderates weight gain and improves the plasma lipids profile, primarily in the lean animals. Our data also suggest that these effects may be caused, at least in part, by a significant inhibition of gastric lipase and subsequent reduction in fat absorption. PMID:22745826

Effects of habitual exercise on the eHsp72-induced release of inflammatory cytokines by macrophages from obese Zucker rats.

PubMed

Garcia, J J; Martin-Cordero, L; Hinchado, M D; Bote, M E; Ortega, E

2013-06-01

Regular exercise is a good non-pharmacological treatment of metabolic syndrome in that it improves obesity, diabetes, and inflammation. The 72 kDa extracellular heat shock protein (eHsp72) is released during exercise, thus stimulating the inflammatory responses. The aim of the present work was to evaluate the effect of regular exercise on the eHsp72-induced release of IL-1β, IL-6, and TNFα by macrophages from genetically obese Zucker rats (fa/fa) (ObZ), using lean Zucker (LZ) rats (Fa/fa) to provide reference values. ObZ presented a higher plasma concentration of eHsp72 than LZ, and exercise increased that concentration. In response to eHsp72, the macrophages from ObZ released less IL-1β and TNFα, but more IL-6, than macrophages from LZ. While eHsp72 stimulated the release of IL-1β, TNFα, and IL-6 in the macrophages from healthy LZ (with respect to the constitutive release), it inhibited the release of IL-1β and IL-6 in macrophages from ObZ. The habitual exercise improved the release of inflammatory cytokines by macrophages from ObZ in response to eHsp72 (it increased IL-1β and TNFα, and decreased IL-6), tending to values closer to those determined in healthy LZ. A deregulated macrophage inflammatory and stress response induced by eHsp72 underlies MS, and this is improved by habitual exercise. © Georg Thieme Verlag KG Stuttgart · New York.

Exaggerated response to mild stress in rats fed high-fat diet.

PubMed

Legendre, Ariadne; Harris, Ruth B S

2006-11-01

It has been suggested that high-fat (HF) diet exaggerates the stress-induced release of glucocorticoids due to activation of the hypothalamic-pituitary-adrenal (HPA) axis. In an initial experiment, in which rats were fed HF diet for 4 days, we found that HF-fed controls stopped gaining weight, indicating that they were hyperresponsive to the mild stress of tail bleeding but responded the same as low-fat (LF)-fed rats to the more severe stress of restraint. A second experiment confirmed these results when rats fed a HF diet for 4 days showed an exaggerated corticosterone release in response to an intraperitoneal injection of saline and movement to a novel cage, compared with LF-fed rats. Experiment 3 tested the same parameters as experiment 2 but interchanged the diets. This allowed us to differentiate between the effects of the dietary fat and the novelty of the diet. Additionally, this experiment determined whether hyperresponsiveness to mild stress in HF-fed rats was sustained during a prolonged exposure to diet. The results confirmed that a HF diet, not novelty, exaggerated the endocrine stress response after 9 days on the diet but that the effect was no longer present after 23 days on the diet. The hyperresponsiveness of the HPA axis in HF-fed rats is similar to that observed in animals that have been exposed to a significant chronic or acute stress, suggesting that the HF diet may initially be perceived as a stressor.

A High-Protein Diet Reduces Weight Gain, Decreases Food Intake, Decreases Liver Fat Deposition, and Improves Markers of Muscle Metabolism in Obese Zucker Rats

PubMed Central

French, William W.; Dridi, Sami; Shouse, Stephanie A.; Wu, Hexirui; Hawley, Aubree; Lee, Sun-Ok; Gu, Xuan; Baum, Jamie I.

2017-01-01

A primary factor in controlling and preventing obesity is through dietary manipulation. Diets higher in protein have been shown to improve body composition and metabolic health during weight loss. The objective of this study was to examine the effects of a high-protein diet versus a moderate-protein diet on muscle, liver and fat metabolism and glucose regulation using the obese Zucker rat. Twelve-week old, male, Zucker (fa/fa) and lean control (Fa/fa) rats were randomly assigned to either a high-protein (40% energy) or moderate-protein (20% energy) diet for 12 weeks, with a total of four groups: lean 20% protein (L20; n = 8), lean 40% protein (L40; n = 10), obese 20% protein (O20; n = 8), and obese 40% protein (O40; n = 10). At the end of 12 weeks, animals were fasted and euthanized. There was no difference in food intake between L20 and L40. O40 rats gained less weight and had lower food intake (p < 0.05) compared to O20. O40 rats had lower liver weight (p < 0.05) compared to O20. However, O40 rats had higher orexin (p < 0.05) levels compared to L20, L40 and O20. Rats in the L40 and O40 groups had less liver and muscle lipid deposition compared to L20 and L40 diet rats, respectively. O40 had decreased skeletal muscle mechanistic target of rapamycin complex 1 (mTORC1) phosphorylation and peroxisome proliferator-activated receptor gamma (PPARγ) mRNA expression compared to O20 (p < 0.05), with no difference in 5′ AMP-activated protein kinase (AMPK), eukaryotic translation initiation factor 4E binding protein 1 (4EBP1), protein kinase B (Akt) or p70 ribosomal S6 kinase (p70S6K) phosphorylation. The data suggest that high-protein diets have the potential to reduce weight gain and alter metabolism, possibly through regulation of an mTORC1-dependent pathway in skeletal muscle. PMID:28594375

A High-Protein Diet Reduces Weight Gain, Decreases Food Intake, Decreases Liver Fat Deposition, and Improves Markers of Muscle Metabolism in Obese Zucker Rats.

PubMed

French, William W; Dridi, Sami; Shouse, Stephanie A; Wu, Hexirui; Hawley, Aubree; Lee, Sun-Ok; Gu, Xuan; Baum, Jamie I

2017-06-08

A primary factor in controlling and preventing obesity is through dietary manipulation. Diets higher in protein have been shown to improve body composition and metabolic health during weight loss. The objective of this study was to examine the effects of a high-protein diet versus a moderate-protein diet on muscle, liver and fat metabolism and glucose regulation using the obese Zucker rat. Twelve-week old, male, Zucker (fa/fa) and lean control (Fa/fa) rats were randomly assigned to either a high-protein (40% energy) or moderate-protein (20% energy) diet for 12 weeks, with a total of four groups: lean 20% protein (L20; n = 8), lean 40% protein (L40; n = 10), obese 20% protein (O20; n = 8), and obese 40% protein (O40; n = 10). At the end of 12 weeks, animals were fasted and euthanized. There was no difference in food intake between L20 and L40. O40 rats gained less weight and had lower food intake ( p < 0.05) compared to O20. O40 rats had lower liver weight ( p < 0.05) compared to O20. However, O40 rats had higher orexin ( p < 0.05) levels compared to L20, L40 and O20. Rats in the L40 and O40 groups had less liver and muscle lipid deposition compared to L20 and L40 diet rats, respectively. O40 had decreased skeletal muscle mechanistic target of rapamycin complex 1 (mTORC1) phosphorylation and peroxisome proliferator-activated receptor gamma (PPARγ) mRNA expression compared to O20 ( p < 0.05), with no difference in 5' AMP-activated protein kinase (AMPK), eukaryotic translation initiation factor 4E binding protein 1 (4EBP1), protein kinase B (Akt) or p70 ribosomal S6 kinase (p70S6K) phosphorylation. The data suggest that high-protein diets have the potential to reduce weight gain and alter metabolism, possibly through regulation of an mTORC1-dependent pathway in skeletal muscle.

Mangiferin protects against adverse skeletal muscle changes and enhances muscle oxidative capacity in obese rats

PubMed Central

Acevedo, Luz M.; Raya, Ana I.; Martínez-Moreno, Julio M.

2017-01-01

Obesity-related skeletal muscle changes include muscle atrophy, slow-to-fast fiber-type transformation, and impaired mitochondrial oxidative capacity. These changes relate with increased risk of insulin resistance. Mangiferin, the major component of the plant Mangifera indica, is a well-known anti-inflammatory, anti-diabetic, and antihyperlipidemic agent. This study tested the hypothesis that mangiferin treatment counteracts obesity-induced fiber atrophy and slow-to-fast fiber transition, and favors an oxidative phenotype in skeletal muscle of obese rats. Obese Zucker rats were fed gelatin pellets with (15 mg/kg BW/day) or without (placebo group) mangiferin for 8 weeks. Lean Zucker rats received the same gelatin pellets without mangiferin and served as non-obese and non-diabetic controls. Lesser diameter, fiber composition, and histochemical succinic dehydrogenase activity (an oxidative marker) of myosin-based fiber-types were assessed in soleus and tibialis cranialis muscles. A multivariate discriminant analysis encompassing all fiber-type features indicated that obese rats treated with mangiferin displayed skeletal muscle phenotypes significantly different compared with both lean and obese control rats. Mangiferin significantly decreased inflammatory cytokines, preserved skeletal muscle mass, fiber cross-sectional size, and fiber-type composition, and enhanced muscle fiber oxidative capacity. These data demonstrate that mangiferin attenuated adverse skeletal muscle changes in obese rats. PMID:28253314

Mangiferin protects against adverse skeletal muscle changes and enhances muscle oxidative capacity in obese rats.

PubMed

Acevedo, Luz M; Raya, Ana I; Martínez-Moreno, Julio M; Aguilera-Tejero, Escolástico; Rivero, José-Luis L

2017-01-01

Obesity-related skeletal muscle changes include muscle atrophy, slow-to-fast fiber-type transformation, and impaired mitochondrial oxidative capacity. These changes relate with increased risk of insulin resistance. Mangiferin, the major component of the plant Mangifera indica, is a well-known anti-inflammatory, anti-diabetic, and antihyperlipidemic agent. This study tested the hypothesis that mangiferin treatment counteracts obesity-induced fiber atrophy and slow-to-fast fiber transition, and favors an oxidative phenotype in skeletal muscle of obese rats. Obese Zucker rats were fed gelatin pellets with (15 mg/kg BW/day) or without (placebo group) mangiferin for 8 weeks. Lean Zucker rats received the same gelatin pellets without mangiferin and served as non-obese and non-diabetic controls. Lesser diameter, fiber composition, and histochemical succinic dehydrogenase activity (an oxidative marker) of myosin-based fiber-types were assessed in soleus and tibialis cranialis muscles. A multivariate discriminant analysis encompassing all fiber-type features indicated that obese rats treated with mangiferin displayed skeletal muscle phenotypes significantly different compared with both lean and obese control rats. Mangiferin significantly decreased inflammatory cytokines, preserved skeletal muscle mass, fiber cross-sectional size, and fiber-type composition, and enhanced muscle fiber oxidative capacity. These data demonstrate that mangiferin attenuated adverse skeletal muscle changes in obese rats.

Soy protein isolate modified metabolic phenotype and hepatic Wnt signaling in obese Zucker rats.

PubMed

Cain, J; Banz, W J; Butteiger, D; Davis, J E

2011-10-01

We have previously shown that soy protein isolate (SPI) with intact phytoestrogen content prevented obesity-related dysfunction. Recent data have suggested that soy ingredients may act as regulators of adipogenic programming in adipose tissue (AT) and liver. Thus, the current study was undertaken to determine whether the beneficial effects of SPI are linked to changes in adipogenic regulators, such as the Wnt signaling cascade. For this, lean (LZR) and obese Zucker (OZR) rats were provided isocaloric and isonitrogenous diets containing SPI, sodium caseinate, or dairy whey protein for 17 weeks. At termination, SPI increased body weight and total adiposity in rodents, which corresponded with an increase in both adipocyte size and number. Furthermore, markers of inflammation, hypercholesterolemia, and hepatic steatosis were all reduced in OZR rats provided SPI. Transcript abundance of several canonical and noncanonical Wnt signaling intermediates in liver, but not AT, was distinctly modified by SPI. Collectively, these data confirm the protective SPI attenuated obesity-related metabolic dysfunction conceivably through regulation of adipogenic programming, as evident by changes in AT morphology and hepatic Wnt signaling. Collectively, this study confirmed the potential utilization of soy protein and its bioactive ingredients for prevention and treatment of obesity-related comorbidities. © Georg Thieme Verlag KG Stuttgart · New York.

A cafeteria diet triggers intestinal inflammation and oxidative stress in obese rats.

PubMed

Gil-Cardoso, K; Ginés, I; Pinent, M; Ardévol, A; Terra, X; Blay, M

2017-01-01

The gastrointestinal alterations associated with the consumption of an obesogenic diet, such as inflammation, permeability impairment and oxidative stress, have been poorly explored in both diet-induced obesity (DIO) and genetic obesity. The aim of the present study was to examine the impact of an obesogenic diet on the gut health status of DIO rats in comparison with the Zucker (fa/fa) rat leptin receptor-deficient model of genetic obesity over time. For this purpose, female Wistar rats (n 48) were administered a standard or a cafeteria diet (CAF diet) for 12, 14·5 or 17 weeks and were compared with fa/fa Zucker rats fed a standard diet for 10 weeks. Morphometric variables, plasma biochemical parameters, myeloperoxidase (MPO) activity and reactive oxygen species (ROS) levels in the ileum were assessed, as well as the expressions of proinflammatory genes (TNF-α and inducible nitric oxide synthase (iNOS)) and intestinal permeability genes (zonula occludens-1, claudin-1 and occludin). Both the nutritional model and the genetic obesity model showed increased body weight and metabolic alterations at the final time point. An increase in intestinal ROS production and MPO activity was observed in the gastrointestinal tracts of rats fed a CAF diet but not in the genetic obesity model. TNF-α was overexpressed in the ileum of both CAF diet and fa/fa groups, and ileal inflammation was associated with the degree of obesity and metabolic alterations. Interestingly, the 17-week CAF group and the fa/fa rats exhibited alterations in the expressions of permeability genes. Relevantly, in the hyperlipidic refined sugar diet model of obesity, the responses to chronic energy overload led to time-dependent increases in gut inflammation and oxidative stress.

Gene expression of insulin signal-transduction pathway intermediates is lower in rats fed a beef tallow diet than in rats fed a safflower oil diet.

PubMed

Kim, Y B; Nakajima, R; Matsuo, T; Inoue, T; Sekine, T; Komuro, M; Tamura, T; Tokuyama, K; Suzuki, M

1996-09-01

To elucidate the effects of dietary fatty acid composition on the insulin signaling pathway, we measured the gene expression of the earliest steps in the insulin action pathway in skeletal muscle of rats fed a safflower oil diet or a beef tallow diet. Rats were meal-fed an isoenergetic diet based on either safflower oil or beef tallow for 8 weeks. Both diets provided 45%, 35%, and 20% of energy as fat, carbohydrate, and protein, respectively. Insulin resistance, assessed from the diurnal rhythm of plasma glucose and insulin and the oral glucose tolerance test (OGTT), developed in rats fed a beef tallow diet. Body fat content was greater in rats fed a beef tallow diet versus a safflower oil diet. The level of insulin receptor mRNA, relative expression of the insulin receptor mRNA isoforms, and receptor protein were not affected by the composition of dietary fatty acids. The abundance of insulin receptor substrate-1 (IRS-1) and phosphatidylinositol (PI) 3-kinase mRNA and protein was significantly lower in rats fed a beef tallow diet versus a safflower oil diet. We conclude that long-term feeding of a high-fat diet with saturated fatty acids induces decrease in IRS-1 and PI 3-kinase mRNA and protein levels, causing insulin resistance in skeletal muscle.

ZiBuPiYin recipe improves cognitive decline by regulating gut microbiota in Zucker diabetic fatty rats

PubMed Central

Wang, Wang; Xiang, Hong; Xu, Huiying; Liang, Lina; Sui, Hua; Zhan, Libin; Lu, Xiaoguang

2017-01-01

Numerous researches supported that microbiota can influence behavior and modulate cognitive function through “microbiota-gut-brain” axis. Our previous study has demonstrated that ZiBuPiYin recipe (ZBPYR) possesses excellent pharmacological effects against diabetes-associated cognitive decline. To elucidate the role of ZBPYR in regulating the balance of gut microbiota to improve psychological-stress-induced diabetes-associated cognitive decline (PSDACD), we compared blood glucose, behavioral and cognitive functions and diversity of the bacterial community among experimental groups. The Zucker diabetic fatty (ZDF) rats with PSDACD exhibited behavioral and cognitive anomalies showing as increased anxiety- and depression-like behaviors and decreased learning and memory abilities. High-throughput sequencing of the bacterial 16S rRNA gene revealed that Roseburia and Coprococcus were decreased in ZDF rats with PSDACD compared with control group. Notably, these changes were reversed by ZBPYR treatment. Our findings indicate that ZBPYR might prevent PSDACD by maintaining the compositions of gut microbiota, which could be developed as a new therapy for T2D with PSDACD. PMID:28099913

ZiBuPiYin recipe improves cognitive decline by regulating gut microbiota in Zucker diabetic fatty rats.

PubMed

Gu, Chunyan; Zhou, Wen; Wang, Wang; Xiang, Hong; Xu, Huiying; Liang, Lina; Sui, Hua; Zhan, Libin; Lu, Xiaoguang

2017-04-25

Numerous researches supported that microbiota can influence behavior and modulate cognitive function through "microbiota-gut-brain" axis. Our previous study has demonstrated that ZiBuPiYin recipe (ZBPYR) possesses excellent pharmacological effects against diabetes-associated cognitive decline. To elucidate the role of ZBPYR in regulating the balance of gut microbiota to improve psychological-stress-induced diabetes-associated cognitive decline (PSDACD), we compared blood glucose, behavioral and cognitive functions and diversity of the bacterial community among experimental groups. The Zucker diabetic fatty (ZDF) rats with PSDACD exhibited behavioral and cognitive anomalies showing as increased anxiety- and depression-like behaviors and decreased learning and memory abilities. High-throughput sequencing of the bacterial 16S rRNA gene revealed that Roseburia and Coprococcus were decreased in ZDF rats with PSDACD compared with control group. Notably, these changes were reversed by ZBPYR treatment. Our findings indicate that ZBPYR might prevent PSDACD by maintaining the compositions of gut microbiota, which could be developed as a new therapy for T2D with PSDACD.

Effect of combination treatment of S–amlodipine with peroxisome proliferator-activated receptor agonists on metabolic and cardiovascular parameters in Zucker fa/fa rats

PubMed Central

2014-01-01

Background Type 2 diabetes is a complex metabolic disorder characterized by hyperglycemia, impaired glucose tolerance and insulin resistance associated with dyslipidemia and hypertension. The available drugs are not sufficiently efficacious in reducing cardiovascular risk and restoring normal glucose metabolism associated with type 2 diabetes as a mono- or a combination therapy. The present study examined the combined effects of an antihypertensive (S-Amlodipine) and an insulin-sensitizing agent, peroxisome proliferator-activated receptor (PPAR) agonists (Pioglitazone and Ragaglitazar), on cardiovascular risk factors in aged diabetic and insulin-resistant Zucker fa/fa rats. Methods Following combination treatment for 14 days, blood pressure (BP), serum glucose, total cholesterol and triglycerides were measured. Aortic ring study was conducted to determine the effect of combination treatments on phenylephrine-induced vasoconstriction and acetylcholine (Ach)-induced vasorelaxation. Results In combination, S-Amlodipine and Pioglitazone significantly reduced blood glucose (115.1 ± 6.6 vs. 81.7 ± 4.2), BP (184.4 ± 5.0 vs. 155.1 ± 5.0), serum triglycerides (362.5 ± 47.5 vs. 211.1 ± 23.7) and glucose intolerance when compared with vehicle treated Zucker fa/fa rats. Similar results were observed with the combination of S-Amlodipine and Ragaglitazar (Triglycerides, 362.5 ± 47.5 vs. 252.34 ± 27.86; BP, 184.4 ± 5.0 vs. 159.0 ± 8.0) except for serum glucose. ACh-induced vasorelaxation in aortic rings was also superior with both of the combinations compared to individual treatment. Furthermore, there was less body weight gain and food intake with S-Amlodipine and Pioglitazone combination in Zucker fa/fa rats. S-Amlodipine itself caused significant reduction in glucose (115.1 ± 6.6 vs. 89.7 ± 2.7) and BP (184.4 ± 5.0 vs. 156.1 ± 4.0) with improvement in insulin sensitivity observed through oral glucose

Oral Administration of Interferon Tau Enhances Oxidation of Energy Substrates and Reduces Adiposity in Zucker Diabetic Fatty Rats

PubMed Central

Tekwe, Carmen D.; Lei, Jian; Yao, Kang; Rezaei, Reza; Li, Xilong; Dahanayaka, Sudath; Carroll, Raymond J.; Meininger, Cynthia J.; Bazer, Fuller W.; Wu, Guoyao

2013-01-01

Male Zucker diabetic fatty (ZDF) rats were used to study effects of oral administration of interferon tau (IFNT) in reducing obesity. Eighteen ZDF rats (28 days of age) were assigned randomly to receive 0, 4 or 8 μg IFNT/kg body weight (BW) per day (n=6/group) for 8 weeks. Water consumption was measured every two days. Food intake and BW were recorded weekly. Energy expenditure in 4-, 6-, 8-, and 10-week-old rats was determined using indirect calorimetry. Starting at 7 weeks of age, urinary glucose and ketone bodies were tested daily. Rates of glucose and oleate oxidation in liver, brown adipose tissue, and abdominal adipose tissue, leucine catabolism in skeletal muscle, and lipolysis in white and brown adipose tissues were greater for rats treated with 8 μg IFNT/kg BW/day in comparison with control rats. Treatment with 8 μg IFNT/kg BW/day increased heat production, reduced BW gain and adiposity, ameliorated fatty liver syndrome, delayed the onset of diabetes, and decreased concentrations of glucose, free fatty acids, triacylglycerol, cholesterol, and branched-chain amino acids in plasma, compared to control rats. Oral administration of 8 μg IFNT/kg BW/day ameliorated oxidative stress in skeletal muscle, liver and adipose tissue, as indicated by decreased ratios of oxidized glutathione to reduced glutathione and increased concentrations of the antioxidant tetrahydrobiopterin. These results indicate that IFNT stimulates oxidation of energy substrates and reduces obesity in ZDF rats and may have broad important implications for preventing and treating obesity-related diseases in mammals. PMID:23804503

Brain electrophysiology in Sprague-Dawley rats fed low copper diets

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

Penland, J.G.; Sawler, B.G.; Klevay, L.M.

1986-03-01

Electrical activity of the brain was assessed in 38 unanesthetized male rats fed a Cu deficient diet for c.100 days after weaning. Rats were supplemented with drinking solutions containing 0, 0.75, or 2 ..mu..g Cu/ml and 10 ..mu..g Zn/ml (as sulfate and acetate, respectively). Three weeks prior to recording, dural ball electrodes were placed bilaterally 1 mm anterior to the lambda and 4 mm lateral to the midline, with a midline reference 2 mm anterior to the bregma. Cu deficiency was verified by atomic absorption spectroscopy of plasma Cu (p < .0001). The electroencephalogram revealed dietary effects on both logmore » power and arcsin percent-total power in each of four frequency bands (1-3, 4-7, 8-12, 13-18 Hz). Low dietary Cu resulted in less log power and percent-total power in the lowest frequencies, and log power evidenced lateralized effects in the higher frequencies. Rats fed the diet most deficient in Cu had lower left and higher right hemisphere power than did rats fed the more adequate Cu diets. Percent-total power was higher in the mid-range frequencies in both hemispheres for rats fed the Cu deficient diets, compared to rats supplemented with the largest amount of Cu. The findings confirm a previous experiment (unpublished) and suggest that dietary Cu influences the electrical activity of the brain in a select (i.e., frequency and location specific) rather than undifferentiated manner.« less

Engineering brown fat into skeletal muscle using ultrasound-targeted microbubble destruction gene delivery in obese Zucker rats: Proof of concept design.

PubMed

Bastarrachea, Raul A; Chen, Jiaxi; Kent, Jack W; Nava-Gonzalez, Edna J; Rodriguez-Ayala, Ernesto; Daadi, Marcel M; Jorge, Barbara; Laviada-Molina, Hugo; Comuzzie, Anthony G; Chen, Shuyuan; Grayburn, Paul A

2017-09-01

Ultrasound-targeted microbubble destruction (UTMD) is a novel means of tissue-specific gene delivery. This approach systemically infuses transgenes precoupled to gas-filled lipid microbubbles that are burst within the microvasculature of target tissues via an ultrasound signal resulting in release of DNA and transfection of neighboring cells within the tissue. Previous work has shown that adenovirus containing cDNA of UCP-1, injected into the epididymal fat pads in mice, induced localized fat depletion, improving glucose tolerance, and decreasing food intake in obese diabetic mice. Our group recently demonstrated that gene therapy by UTMD achieved beta cell regeneration in streptozotocin (STZ)-treated mice and baboons. We hypothesized that gene therapy with BMP7/PRDM16/PPARGC1A in skeletal muscle (SKM) of obese Zucker diabetic fatty (fa/fa) rats using UTMD technology would produce a brown adipose tissue (BAT) phenotype with UCP-1 overexpression. This study was designed as a proof of concept (POC) project. Obese Zucker rats were administered plasmid cDNA contructs encoding a gene cocktail with BMP7/PRDM16/PPARGC1A incorporated within microbubbles and intravenously delivered into their left thigh. Controls received UTMD with plasmids driving a DsRed reporter gene. An ultrasound transducer was directed to the thigh to disrupt the microbubbles within the microcirculation. Blood samples were drawn at baseline, and after treatment to measure glucose, insulin, and free fatty acids levels. SKM was harvested for immunohistochemistry (IHC). Our IHC results showed a reliable pattern of effective UTMD-based gene delivery in enhancing SKM overexpression of the UCP-1 gene. This clearly indicates that our plasmid DNA construct encoding the gene combination of PRDM16, PPARGC1A, and BMP7 reprogrammed adult SKM tissue into brown adipose cells in vivo. Our pilot established POC showing that the administration of the gene cocktail to SKM in this rat model of genetic obesity using UTMD

Dietary taurine alters ascorbic acid metabolism in rats fed diets containing polychlorinated biphenyls.

PubMed

Mochizuki, H; Oda, H; Yokogoshi, H

2000-04-01

The effect of dietary taurine on ascorbic acid metabolism and hepatic drug-metabolizing enzymes was investigated in rats fed diets containing polychlorinated biphenyls (PCB) to determine whether taurine has an adaptive and protective function in xenobiotic-treated animals. Young male Wistar rats (60 g) were fed diets containing 0 or 0.2 g/kg diet PCB with or without 30 g/kg diet of taurine for 14 d. The rats fed the PCB-containing diets had greater liver weight, higher ascorbic acid concentrations in the liver and spleen and greater hepatic cytochrome P-450 contents than control rats that were not treated with PCB (P < 0.01). In PCB-fed rats, urinary ascorbic acid excretion was enhanced, and serum cholesterol concentration (especially HDL-cholesterol) was significantly elevated compared with those in control rats. Dietary taurine significantly potentiated the increases in the urinary excretion of ascorbic acid and the rise in the levels of cytochrome P-450 which were caused by PCB treatment. On the other hand, the supplementation of taurine to control diet did not alter these variables. Taurine may enhance the hepatic drug-metabolizing systems, leading to the stimulation of the ascorbic acid metabolism in rats fed diets containing PCB.

Treadmill exercise prevents diabetes-induced increases in lipid peroxidation and decreases in Cu,Zn-superoxide dismutase levels in the hippocampus of Zucker diabetic fatty rats.

PubMed

Kim, Jong Whi; Chae, Junghyun; Nam, Sung Min; Kim, Yo Na; Yoo, Dae Young; Choi, Jung Hoon; Jung, Hyo Young; Song, Wook; Hwang, In Koo; Seong, Je Kyung; Yoon, Yeo Sung

2015-01-01

In the present study, we investigated the effects of treadmill exercise on lipid peroxidation and Cu,Zn-superoxide dismutase (SOD1) levels in the hippocampus of Zucker diabetic fatty (ZDF) rats and lean control rats (ZLC) during the onset of diabetes. At 7 weeks of age, ZLC and ZDF rats were either placed on a stationary treadmill or made to run for 1 h/day for 5 consecutive days at 16~22 m/min for 5 weeks. At 12 weeks of age, the ZDF rats had significantly higher blood glucose levels and body weight than the ZLC rats. In addition, malondialdehyde (MDA) levels in the hippocampus of the ZDF rats were significantly higher than those of the ZLC rats whereas SOD1 levels in the hippocampus of the ZDF rats were moderately decreased. Notably, treadmill exercise prevented the increase of blood glucose levels in ZDF rats. In addition, treadmill exercise significantly ameliorated changes in MDA and SOD1 levels in the hippocampus although SOD activity was not altered. These findings suggest that diabetes increases lipid peroxidation and decreases SOD1 levels, and treadmill exercise can mitigate diabetes-induced oxidative damage in the hippocampus.

Rats fed only during the light period are resistant to stress-induced weight loss.

PubMed

Harris, Ruth B S; Zhou, Jun; Mitchell, Tiffany; Hebert, Sadie; Ryan, Donna H

2002-08-01

Repeated restraint stress (3 h/day for 3 days) causes a chronic down-regulation of body weight in rats. This study determined whether weight loss was influenced by the time of day that rats had access to food or that stress was applied. Groups of male Sprague-Dawley rats were fed a 40% kcal fat diet with food given ad libitum, only during the light phase or only during the dark phase. After 2 weeks of adaptation, rats within each feeding treatment were divided into four groups. One was exposed to repeated restraint at the start of the light phase, another was restrained at the start of the dark phase and the remaining groups were nonstressed controls for restrained rats. Body weight was significantly reduced in ad libitum- and dark-fed restrained rats, compared with nonstressed controls, from Day 2 of restraint, regardless of the time of day that they were stressed. There was no significant effect of restraint on weight change of light-fed rats. Food intake was inhibited by stress in ad libitum- and dark-fed rats, but it was not changed in light-fed rats. Serum corticosterone was increased by restraint in all rats irrespective of feeding schedule. This study demonstrates that stress-induced weight loss only occurs when rats have food available during their normal feeding period (dark phase) and is not determined by increased corticosterone release.

Effects of exposure to dietary chromium on tissue mineral contents in rats fed diets with fiber.

PubMed

Prescha, Anna; Krzysik, Monika; Zabłocka-Słowińska, Katarzyna; Grajeta, Halina

2014-06-01

This study evaluated the effects of diets with fiber (cellulose and/or pectin) supplemented with chromium(III) on homeostasis of selected minerals in femurs, thigh muscles, livers, and kidneys of rats. For 6 weeks, male rats were fed experimental diets: a fiber-free diet (FF), a diet containing 5% cellulose (CEL), 5% pectin (PEC), or 2.5% cellulose and 2.5% pectin (CEL+PEC). These diets had 2.53 or 0.164 mg Cr/kg diet. The tissue levels of Ca, Mg, Zn, Fe, and Cr were determined by using atomic absorption spectrometry. Supplementing diets with Cr resulted in significantly higher Cr levels in the femurs of rats fed the CEL diet and significantly higher Cr and Fe levels in the rats fed the CEL+PEC diet compared to the rats fed FF diet. Muscle Ca content was significantly lower in the rats fed the CEL+PEC+Cr diet compared to the rats fed FF+Cr diet. The rats consuming the PEC+Cr diet had the highest liver Cr content. The highest kidney Zn content was observed in the rats fed diets containing Cr and one type of fiber. These results indicate that diets containing chromium at elevated dose and fiber have a significant effect on the mineral balance in rat tissues.

Basis of aggravated hepatic lipid metabolism by chronic stress in high-fat diet-fed rat.

PubMed

Han, Ying; Lin, Min; Wang, Xiaobin; Guo, Keke; Wang, Shanshan; Sun, Mengfei; Wang, Jiao; Han, Xiaoyu; Fu, Ting; Hu, Yang; Fu, Jihua

2015-03-01

Our previous study has demonstrated that long-term stress, known as chronic stress (CS), can aggravate nonalcoholic fatty liver disease in high-fat diet (HFD)-fed rat. In this study, we tried to figure out which lipid metabolic pathways were impacted by CS in the HFD-fed rat. Male Sprague-Dawley rats (6 weeks of age, n = 8 per group) were fed with either standard diet or HFD with or without CS exposure for 8 weeks. Hepatic lipidosis, biochemical, hormonal, and lipid profile markers in serum and liver, and enzymes involved in de novo lipogenesis (DNL) of fatty acids (FAs) and cholesterol, β-oxidation, FAs uptake, triglycerides synthesis, and very low-density lipoprotein (VLDL) assembly in the liver were detected. CS exposure reduced hepatic lipidosis but further elevated hepatic VLDL content with aggravated dyslipidemia in the HFD-fed rats. There was a synergism between CS and HFD on VLDL production and dyslipidemia. PCR and western blot assays showed that CS exposure significantly promoted hepatic VLDL assembly in rats, especially in the HFD-fed rats, while it had little impact on DNL, β-oxidation, FAs uptake, and triglycerides synthesis in the HFD-fed rats. This phenomenon was in accordance with elevated serum glucocorticoid level. The critical influence of CS exposure on hepatic lipid metabolism in the HFD-fed rats is VLDL assembly which might be regulated by glucocorticoid.

/sup 54/Mn absorption and excretion in rats fed soy protein and casein diets

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

Lee, D.Y.; Johnson, P.E.

1989-02-01

Rats were fed diets containing either soy protein or casein and different levels of manganese, methionine, phytic acid, or arginine for 7 days and then fed test meals labeled with 2 microCi of 54Mn after an overnight fast. Retention of 54Mn in each rat was measured every other day for 21 days using a whole-body counter. Liver manganese was higher (P less than 0.0001) in soy protein-fed rats (8.8 micrograms/g) than in casein-fed rats (5.2 micrograms/g); manganese superoxide dismutase activity also was higher in soy protein-fed rats than in casein-fed rats (P less than 0.01). There was a significant interactionmore » between manganese and protein which affected manganese absorption and biologic half-life of 54Mn. In a second experiment, rats fed soy protein-test meals retained more 54Mn (P less than 0.001) than casein-fed rats. Liver manganese (8.3 micrograms/g) in the soy protein group was also higher than that (5.7 micrograms/g) in the casein group (P less than 0.0001), but manganese superoxide dismutase activity was unaffected by protein. Supplementation with methionine increased 54Mn retention from both soy and casein diets (P less than 0.06); activity of manganese superoxide dismutase increased (P less than 0.05) but liver manganese did not change. The addition of arginine to casein diets had little effect on manganese bioavailability. Phytic acid affected neither manganese absorption nor biologic half-life in two experiments, but it depressed liver manganese in one experiment. These results suggest that neither arginine nor phytic acid was the component in soy protein which made manganese more available from soy protein diets than casein diets.« less

Antioxidant status and mineral contents in tissues of rutin and baicalin fed rats.

PubMed

Gao, Zhonghong; Xu, Huibi; Chen, Xiaojun; Chen, Hao

2003-08-08

The versatile benefit effects of flavonoids lead some nutritionists to believe that they are micronutrients. However, excess intake of flavonoids may cause side effects. In this paper, the effects produced by a higher intake of rutin and baicalin on antioxidant status as well as trace minerals such as iron, copper and zinc in rat tissues were studied. When rats were fed a rutin or baicalin containing diet (1%) for 20 days, the body weight gain was lower than that of the control group. Both rutin and baicalin caused significant a decrease of catalase activity and a moderate increase of total superoxide dismutase activity in the liver. The total antioxidant status of flavonoid fed rats was increased in the liver but decreased in the serum. In comparison to the control group, the lipid peroxidation level in the liver of the rutin fed group was significantly decreased; however, there was no statistical significance in the liver of the baicalin fed group and the brain of both flavonoids groups. The liver homogenates of both flavonoid fed rats significantly inhibited alkyl radical-induced lipid peroxidation. The iron contents in the liver of flavonoid fed rats were significantly decreased; rutin also caused zinc and copper decrease in the liver. These results indicated that high flavonoid intake can improve rat antioxidant systems in the liver; while it can also cause a trace mineral decrease and, in turn, reduce the activities of some metal-containing enzymes and may cause harmful effects on health.

Beneficial effects of coconut water feeding on lipid metabolism in cholesterol-fed rats.

PubMed

Sandhya, V G; Rajamohan, T

2006-01-01

The purpose of this study was to determine the effect of coconut water feeding in cholesterol-fed rats. Male albino rats were fed tender coconut water and mature coconut water at a dose level of 4 mL/100 g of body weight. Cholesterol feeding caused a marked increase in total cholesterol, very low-density lipoprotein (VLDL) + low-density lipoprotein (LDL) cholesterol, and triglycerides in serum. Administration of coconut water counteracts the increase in total cholesterol, VLDL + LDL cholesterol, and triglycerides, while high-density lipoprotein cholesterol was higher. Lipid levels in the tissues viz. liver, heart, kidney, and aorta were markedly decreased in cholesterol-fed rats supplemented with coconut water. Feeding coconut water resulted in increased activities of 3-hydroxy-3-methylglutaryl-CoA reductase in liver, lipoprotein lipase in heart and adipose tissue, and plasma lecithin:cholesterol acyl transferase, while lipogenic enzymes showed decreased activities. An increased rate of cholesterol conversion to bile acid and an increased excretion of bile acids and neutral sterols were observed in rats fed coconut water. Histopathological studies of liver and aorta revealed much less fatty accumulation in these tissues in cholesterol-fed rats supplemented with coconut water. Feeding coconut water resulted in increased plasma L-arginine content, urinary nitrite level, and nitric oxide synthase activity. These results indicate that both tender and mature coconut water has beneficial effects on serum and tissue lipid parameters in rats fed cholesterol-containing diet.

HEPATIC FATTY ACID PROFILE OF RATS FED A TRIHEPTANOIN-BASED KETOGENIC DIET.

PubMed

Vieira de Melo, Ingrid Sofia; Da Rocha Ataide, Terezinha; Lima de Oliveira, Suzana; Bezerra Bueno, Nassib; Duarte de Freitas, Johnnatan; Goulart Sant'Ana, Antônio Euzébio

2015-07-01

the aim of this study was to evaluate the influence of consumption of a ketogenic diet supplemented with triheptanoin, a medium-chain anaplerotic triacylglycerol, on the liver fatty acid profile of Wistar rats. three groups of male Wistar rats (n = 10) were submitted to an AIN-93 control diet, a triheptanoin- based ketogenic diet, or a soybean oil-based ketogenic diet for 60 days. Excised livers were subjected to lipid extraction and methylation to obtain fatty acids methyl esters, which were subjected to gas chromatography- mass spectrometry. compared to the rats fed the control diet, those fed ketogenic diets showed a significant reduction in the concentrations of 9-hexadecenoic and 9-octadecenoic acids, whereas those fed triheptanoin showed increased levels of octadecanoic acid. changes in the liver fatty acid profiles of the rats fed a triheptanoin-based or a soybean oil-based ketogenic diet did not seem to be related to the dietary fat source, but rather to the characteristics of the ketogenic diets themselves. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Thioredoxin-mimetic peptide CB3 lowers MAPKinase activity in the Zucker rat brain☆

PubMed Central

Cohen-Kutner, Moshe; Khomsky, Lena; Trus, Michael; Ben-Yehuda, Hila; Lenhard, James M.; Liang, Yin; Martin, Tonya; Atlas, Daphne

2014-01-01

Diabetes is a high risk factor for dementia. High glucose may be a risk factor for dementia even among persons without diabetes, and in transgenic animals it has been shown to cause a potentiation of indices that are pre-symptomatic of Alzheimer's disease. To further elucidate the underlying mechanisms linking inflammatory events elicited in the brain during oxidative stress and diabetes, we monitored the activation of mitogen-activated kinsase (MAPKs), c-jun NH2-terminal kinase (JNK), p38 MAP kinases (p38MAPK), and extracellular activating kinsae1/2 (ERK1/2) and the anti-inflammatory effects of the thioredoxin mimetic (TxM) peptides, Ac-Cys-Pro-Cys-amide (CB3) and Ac-Cys-Gly-Pro-Cys-amide (CB4) in the brain of male leptin-receptor-deficient Zucker diabetic fatty (ZDF) rats and human neuroblastoma SH-SY5Y cells. Daily i.p. injection of CB3 to ZDF rats inhibited the phosphorylation of JNK and p38MAPK, and prevented the expression of thioredoxin-interacting-protein (TXNIP/TBP-2) in ZDF rat brain. Although plasma glucose/insulin remained high, CB3 also increased the phosphorylation of AMP-ribose activating kinase (AMPK) and inhibited p70S6K kinase in the brain. Both CB3 and CB4 reversed apoptosis induced by inhibiting thioredoxin reductase as monitored by decreasing caspase 3 cleavage and PARP dissociation in SH-SY5Y cells. The decrease in JNK and p38MAPK activity in the absence of a change in plasma glucose implies a decrease in oxidative or neuroinflammatory stress in the ZDF rat brain. CB3 not only attenuated MAPK phosphorylation and activated AMPK in the brain, but it also diminished apoptotic markers, most likely acting via the MAPK–AMPK–mTOR pathway. These results were correlated with CB3 and CB4 inhibiting inflammation progression and protection from oxidative stress induced apoptosis in human neuronal cells. We suggest that by attenuating neuro-inflammatory processes in the brain Trx1 mimetic peptides could become beneficial for preventing neurological

Maternal antioxidant supplementation prevents adiposity in the offspring of Western diet-fed rats.

PubMed

Sen, Sarbattama; Simmons, Rebecca A

2010-12-01

Obesity in pregnancy significantly increases the risk of the offspring developing obesity after birth. The aims of this study were to test the hypothesis that maternal obesity increases oxidative stress during fetal development, and to determine whether administration of an antioxidant supplement to pregnant Western diet-fed rats would prevent the development of adiposity in the offspring. Female Sprague Dawley rats were started on the designated diet at 4 weeks of age. Four groups of animals were studied: control chow (control); control + antioxidants (control+Aox); Western diet (Western); and Western diet + antioxidants (Western+Aox). The rats were mated at 12 to 14 weeks of age, and all pups were weaned onto control diet. Offspring from dams fed the Western diet had significantly increased adiposity as early as 2 weeks of age as well as impaired glucose tolerance compared with offspring of dams fed a control diet. Inflammation and oxidative stress were increased in preimplantation embryos, fetuses, and newborns of Western diet-fed rats. Gene expression of proadipogenic and lipogenic genes was altered in fat tissue of rats at 2 weeks and 2 months of age. The addition of an antioxidant supplement decreased adiposity and normalized glucose tolerance. CONCLUSIONS; Inflammation and oxidative stress appear to play a key role in the development of increased adiposity in the offspring of Western diet-fed pregnant dams. Restoration of the antioxidant balance during pregnancy in the Western diet-fed dam is associated with decreased adiposity in offspring.

Acute effect of the dual angiotensin-converting enzyme and neutral endopeptidase 24-11 inhibitor mixanpril on insulin sensitivity in obese Zucker rat

PubMed Central

Arbin, V; Claperon, N; Fournié-Zaluski, M -C; Roques, B P; Peyroux, J

2001-01-01

The aim of this study was to determine whether acute dual angiotensin-converting enzyme (ACE)/neutral endopeptidase 24-11 (NEP) inhibition could improve whole body insulin-mediated glucose disposal (IMGD) more than ACE inhibition alone and whether this effect was mediated by the kinin-nitric oxide (NO) pathway activation.We therefore compared in anaesthetized obese (fa/fa) Zucker rats (ZOs) the effects of captopril (2 mg kg−1, i.v.+2 mg kg−1 h−1), retrothiorphan (25 mg kg−1, i.v. +25 mg  kg−1 h−1), a selective NEP inhibitor, and mixanpril (25 mg kg−1, i.v.+25 mg kg−1 h−1), a dual ACE/NEP inhibitor, on IMGD using hyperinsulinaemic euglycaemic clamp technique. The role of the kinin-NO pathway in the effects of mixanpril was tested using a bradykinin B2 receptor antagonist (Hoe-140, 300 μg kg−1) and a NO-synthase inhibitor (Nω-nitro-L-arginine methyl ester, L-NAME, 10 mg kg−1 i.v. +10 mg kg−1 h−1) as pretreatments.Insulin sensitivity index (ISI) was lower in ZO controls than in lean littermates. Increases in ISI were observed in captopril- and retrothiorphan-treated ZOs. In mixanpril-treated ZOs, ISI was further increased, compared to captopril- and retrothiorphan-treated ZOs.In ZOs, Hoe-140 and L-NAME alone did not significantly alter and slightly reduced the ISI respectively. Hoe-140 and L-NAME markedly inhibited the ISI improvement induced by mixanpril.These results show that in obese insulin-resistant Zucker rats, under acute conditions, NEP or ACE inhibition can improve IMGD and that dual ACE/NEP inhibition improves IMGD more effectively than does either single inhibition. This effect is linked to an increased activation of the kinin-NO pathway. PMID:11399666

Enhancement of in vivo antioxidant ability in the brain of rats fed tannin.

PubMed

Nakajima, Akira; Ueda, Yuto; Matsuda, Emiko; Sameshima, Hiroshi; Ikenoue, Tsuyomu

2013-07-01

The effect of the oral administration of mimosa tannin (MMT) on the rat intra-hippocampal antioxidant ability was examined. Wistar rats at the age of 6 weeks were reared for 8 weeks with the rodent diet (RD) consisting of 0.1 g/kg of MMT (RD-MMT). The antioxidant ability of rat brain was evaluated from the decay of a brain-blood-barrier permeable stable nitroxide, 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (PCAM) measured by the microdialysis-electron spin resonance system under a freely moving state. The decay rate of PCAM in the brain of rats fed RD-MMT was significantly larger than that of rats fed control rodent diet, which indicates the increase of the antioxidant ability in the brain of rats fed RD-MMT. In vitro study showed that MMT did not reduce PCAM directly but enhanced the reduction of PCAM by ascorbic acid. These results indicate that MMT is a potent antioxidant in vitro and in vivo.

Changes in cardiac energy metabolic pathways in overweighed rats fed a high-fat diet.

PubMed

Modrego, Javier; de las Heras, Natalia; Zamorano-León, Jose J; Mateos-Cáceres, Petra J; Martín-Fernández, Beatriz; Valero-Muñoz, Maria; Lahera, Vicente; López-Farré, Antonio J

2013-03-01

Heart produces ATP through long-chain fatty acids beta oxidation. To analyze whether in ventricular myocardium, high-fat diet may modify the expression of proteins associated with energy metabolism before myocardial function was affected. Wistar Kyoto rats were divided into two groups: (a) rats fed standard diet (control; n = 6) and (b) rats fed high-fat diet (HFD; n = 6). Proteins from left ventricles were analyzed by two-dimensional electrophoresis, mass spectrometry and Western blotting. Rats fed with HFD showed higher body weight, insulin, glucose, leptin and total cholesterol plasma levels as compared with those fed with standard diet. However, myocardial functional parameters were not different between them. The protein expression of 3-ketoacyl-CoA thiolase, acyl-CoA hydrolase mitochondrial precursor and enoyl-CoA hydratase, three long-chain fatty acid β-oxidation-related enzymes, and carnitine-O-palmitoyltransferase I was significantly higher in left ventricles from HFD rats. Protein expression of triosephosphate isomerase was higher in left ventricles from HFD rats than in those from control. Two α/β-enolase isotypes and glyceraldehyde-3-phosphate isomerase were significantly increased in HFD rats as compared with control. Pyruvate and lactate contents were similar in HFD and control groups. Expression of proteins associated with Krebs cycle and mitochondrial oxidative phosphorylation was higher in HFD rats. Expression of proteins involved in left ventricle metabolic energy was enhanced before myocardial functionality was affected in rats fed with HFD. These findings may probably indicate higher cardiac energy requirement due to weight increase by HFD.

Salacia oblonga root improves postprandial hyperlipidemia and hepatic steatosis in Zucker diabetic fatty rats: Activation of PPAR-{alpha}

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

Hsun-Wei Huang, Tom; Peng Gang; Qian Li, George

Salacia oblonga (SO) root is an Ayurvedic medicine with anti-diabetic and anti-obese properties. Peroxisome proliferator-activated receptor (PPAR)-{alpha}, a nuclear receptor, plays an important role in maintaining the homeostasis of lipid metabolism. Here, we demonstrate that chronic oral administration of the water extract from the root of SO to Zucker diabetic fatty (ZDF) rats, a genetic model of type 2 diabetes and obesity, lowered plasma triglyceride and total cholesterol (TC) levels, increased plasma high-density lipoprotein levels and reduced the liver contents of triglyceride, non-esterified fatty acids (NEFA) and the ratio of fatty droplets to total tissue. By contrast, the extract hadmore » no effect on plasma triglyceride and TC levels in fasted ZDF rats. After olive oil administration to ZDF the extract also inhibited the increase in plasma triglyceride levels. These results suggest that SO extract improves postprandial hyperlipidemia and hepatic steatosis in ZDF rats. Additionally, SO treatment enhanced hepatic expression of PPAR-{alpha} mRNA and protein, and carnitine palmitoyltransferase-1 and acyl-CoA oxidase mRNAs in ZDF rats. In vitro, SO extract and its main component mangiferin activated PPAR-{alpha} luciferase activity in human embryonic kidney 293 cells and lipoprotein lipase mRNA expression and enzyme activity in THP-1 differentiated macrophages; these effects were completely suppressed by a selective PPAR-{alpha} antagonist MK-886. The findings from both in vivo and in vitro suggest that SO extract functions as a PPAR-{alpha} activator, providing a potential mechanism for improvement of postprandial hyperlipidemia and hepatic steatosis in diabetes and obesity.« less

In Zucker Diabetic Fatty rats, subclinical diabetic neuropathy increases in vivo lidocaine block duration but not in vitro neurotoxicity

PubMed Central

Lirk, Philipp; Flatz, Magdalena; Haller, Ingrid; Hausott, Barbara; Blumenthal, Stephan; Stevens, Markus F.; Suzuki, Suzuko; Klimaschewski, Lars; Gerner, Peter

2012-01-01

Background and Objectives Application of local anesthetics may lead to nerve damage. Increasing evidence suggests that risk of neurotoxicity is higher in patients with diabetic peripheral neuropathy. Additionally, block duration may be prolonged in neuropathy. We sought to investigate neurotoxicity in vitro and block duration in vivo in a genetic animal model of diabetes mellitus type II. Methods In the first experiments, neurons harvested from control Zucker Diabetic Fatty (ZDF) rats were exposed to acute (24 hours) or chronic (72 hours) hyperglycemia, followed by incubation with lidocaine 40 mM (approximately 1%). In a second experiment, neurons harvested from control ZDF rats, or diabetic ZDF rats, were incubated with lidocaine, with or without SB203580, an inhibitor of the p38 Mitogen-Activated Protein Kinase. Finally, we performed sciatic nerve block (lidocaine 2%, 0.2 mL) in control or diabetic ZDF rats, and measured motor and nociceptive block duration. Results In vitro, neither acute nor chronic hyperglycemia altered neurotoxic properties of lidocaine. In vitro, incubation of neurons with lidocaine resulted in a slightly decreased survival ratio when neurons were harvested from diabetic (57 ± 19) as compared to control (64 ± 9 %) rats. The addition of SB203580 partly reversed this enhanced neurotoxic effect and raised survival to 71 ± 12 in diabetic and 66 ± 9 % in control rats, respectively. In vivo, even though no difference was detected at baseline testing, motor block was significantly prolonged in diabetic as compared to control rats (137 ± 16 min versus 86 ± 17 min). Conclusions In vitro, local anesthetic neurotoxicity was more pronounced on neurons from diabetic animals, but the survival difference was small. In vivo, subclinical neuropathy leads to substantial prolongation of block duration. We conclude that early diabetic neuropathy increases block duration, while the observed increase in toxicity was small. PMID:23011115

Fed, but not Fasted, Adrenalectomized Rats Survive the Stress of Hemorrhage and Hypovolemia

NASA Technical Reports Server (NTRS)

Darlington, Daniel N.; Neves, Robert B.; Ha, Taryn; Chew, Gordon; Dallman, Mary F.

1990-01-01

We have recently shown that conscious adrenalectomized rats exhibit nearly normal recovery of arterial blood pressure during the 5 h after hemorrhage. In those experiments, it appeared that a previous reduction in food intake might have compromised the recovery of blood pressure and increased mortality. These experiments were designed to test in conscious sham-adrenalectomized (control) and adrenalectomized rats prepared with indwelling arterial and venous cannulae: 1. The effects of a 20- to 24-h fast (compared to rats fed ab libitum) on the mobilization of plasma substrates and recovery of arterial blood pressure after a 15 ml/kg - 5 min hemorrhage, and 2. Vascular responsivity to pressor agents in fed or fasted groups before or 2 h after hemorrhage. In all rats hemorrhage resulted in decreased arterial pressure and heart rate. Arterial pressure recovered to near normal in both fed and fasted control groups and in the led adrenalectomized rats, and all of these rats survived for 24 h after stress. By contrast, in the fasted adrenalectomized rats, arterial pressure recovered only during the first 1.5 - 2 h and then failed, resulting in 100% mortality by 3-5 h. Compared to the other three groups, in which substrate levels either increased or remained fairly stable, plasma glucose and beta-hydoxybutyrate concentrations fell steadily, from 1.5-2 h after hemorrhage until death occurred in the fasted adrenalectomized rats. Basal ACTH concentrations were elevated cormpared to control values in both adrenalectomized groups (fed and fasted). Hemorrhage caused increases in plasma ACTH in all groups; the magnitude of the responses did not differ among the groups. The dilution of Evans' blue dve after hemorrhage (used as an index of fluid movement into the vascular space) was not different in contol and adrenalectomized rats (either fed or fasted). There were no differences in pressor responses to phenylephrine, vasopressin, or angiotensin-II between the fed and fasted

Hypolipidemic effect of fruit fibers in rats fed with high dietary fat.

PubMed

Esmael, O A; Sonbul, S N; Kumosani, T A; Moselhy, S S

2015-03-01

The hypolipidemic effect of 10% fruit fibers in rats fed with high-fat diet (HFD) was evaluated. This study was conducted on a total of 50 male Albino rats divided into 10 equal groups fed with different types of dietary fruits. The feeding period lasted for 24 weeks. Fasting blood samples were collected and sera separated and subjected to lipid profile assay and atherogenic index. In addition, total antioxidant activity of different fruits was determined. The results obtained showed that pomegranate had higher content of antioxidants followed by apple, strawberry and guava compared with other fruits. Rats fed with 20% coconut oil showed a highly significant elevation in the levels of serum total cholesterol, low-density lipoprotein cholesterol and atherogenic factor while the level of high-density lipoprotein cholesterol was significantly decreased when compared with control rats. Histological examination revealed that there was a large lipid and cholesterol deposition in the livers of rats fed with HFD. The potential in lowering the levels of plasma total cholesterol and triglyceride is in the following order: pomegranate > apple > strawberry > guava > papaya > mandarin and orange. Accumulation of hepatic lipid droplets was diminished when compared with the HFD group. Also, antiatherogenic is better than the untreated groups. Accordingly these hypolipidemic effects may be due to high-fiber content and antioxidant activity of these fruits. © The Author(s) 2012.

S-phenylpiracetam, a selective DAT inhibitor, reduces body weight gain without influencing locomotor activity.

PubMed

Zvejniece, Liga; Svalbe, Baiba; Vavers, Edijs; Makrecka-Kuka, Marina; Makarova, Elina; Liepins, Vilnis; Kalvinsh, Ivars; Liepinsh, Edgars; Dambrova, Maija

2017-09-01

S-phenylpiracetam is an optical isomer of phenotropil, which is a clinically used nootropic drug that improves physical condition and cognition. Recently, it was shown that S-phenylpiracetam is a selective dopamine transporter (DAT) inhibitor that does not influence norepinephrine (NE) or serotonin (5-HT) receptors. The aim of the present study was to study the effects of S-phenylpiracetam treatment on body weight gain, blood glucose and leptin levels, and locomotor activity. Western diet (WD)-fed mice and obese Zucker rats were treated daily with peroral administration of S-phenylpiracetam for 8 and 12weeks, respectively. Weight gain and plasma metabolites reflecting glucose metabolism were measured. Locomotor activity was detected in an open-field test. S-phenylpiracetam treatment significantly decreased body weight gain and fat mass increase in the obese Zucker rats and in the WD-fed mice. In addition, S-phenylpiracetam reduced the plasma glucose and leptin concentration and lowered hyperglycemia in a glucose tolerance test in both the mice and the rats. S-phenylpiracetam did not influence locomotor activity in the obese Zucker rats or in the WD-fed mice. The results demonstrate that S-phenylpiracetam reduces body weight gain and improves adaptation to hyperglycemia without stimulating locomotor activity. Our findings suggest that selective DAT inhibitors, such as S-phenylpiracetam, could be potentially useful for treating obesity in patients with metabolic syndrome with fewer adverse health consequences compared to other anorectic agents. Copyright © 2017. Published by Elsevier Inc.

Matrix Metalloproteinase-9 Expression Is Enhanced in Renal Parietal Epithelial Cells of Zucker Diabetic Fatty Rats and Is Induced by Albumin in In Vitro Primary Parietal Cell Culture

PubMed Central

Zhang, Yuanyuan; George, Jasmine; Li, Yun; Olufade, Rebecca; Zhao, Xueying

2015-01-01

As a subfamily of matrix metalloproteinases (MMPs), gelatinases including MMP-2 and MMP-9 play an important role in remodeling and homeostasis of the extracellular matrix. However, conflicting results have been reported regarding their expression level and activity in the diabetic kidney. This study investigated whether and how MMP-9 expression and activity were changed in glomerular epithelial cells upon albumin overload. In situ zymography, immunostaining and Western blot for renal MMP gelatinolytic activity and MMP-9 protein expression were performed in Zucker lean and Zucker diabetic rats. Confocal microscopy revealed a focal increase in gelatinase activity and MMP-9 protein in the glomeruli of diabetic rats. Increased glomerular MMP-9 staining was mainly observed in hyperplastic parietal epithelial cells (PECs) expressing claudin-1 in the diabetic kidneys. Interestingly, increased parietal MMP-9 was often accompanied by decreased staining for podocyte markers (nephrin and podocalyxin) in the sclerotic area of affected glomeruli in diabetic rats. Additionally, urinary excretion of podocyte marker proteins was significantly increased in association with the levels of MMP-9 and albumin in the urine of diabetic animals. To evaluate the direct effect of albumin on expression and activity of MMP-9, primary cultured rat glomerular PECs were incubated with rat serum albumin (0.25 - 1 mg/ml) for 24 - 48 hrs. MMP-9 mRNA levels were significantly increased following albumin treatment. Meanwhile, albumin administration resulted in a dose-dependent increase in MMP-9 protein and activity in culture supernatants of PECs. Moreover, albumin activated p44/42 mitogen-activated protein kinase (MAPK) in PECs. Inhibition of p44/42 MAPK suppressed albumin-induced MMP-9 secretion from glomerular PECs. Taken together, we have demonstrated that an up-regulation of MMP-9 in activated parietal epithelium is associated with a loss of adjacent podocytes in progressive diabetic nephropathy

Grape skin improves antioxidant capacity in rats fed a high fat diet

PubMed Central

Lee, Su-Jin; Choi, Soo-Kyong

2009-01-01

This study was conducted to investigate the effect of dietary grape skin on lipid peroxidation and antioxidant defense system in rats fed high fat diet. The Sprague-Dawley rats were fed either control (5% fat) diet or high fat (25% fat) diet which was based on AIN-93 diet for 2 weeks, and then they were grouped as control group (C), control + 5% grape skin group (CS), high-fat group (HF), high fat + 5% grape skin group (HFS) with 10 rats each and fed corresponding diets for 4 weeks. The hepatic thiobarbituric acid reacting substances (TBARS) were increased in high fat group as compared with control group, but reduced by grape skin. The serum total antioxidant status, and activities of hepatic catalase and superoxide dismutase, xanthine oxidase and glucose-6-phosphatase were increased by supplementation of grape skin. Glutathione peroxidase activity was significantly higher in CS group than in C group. Grape skin feeding tended to increase the concentration of total glutathione, especially in control group. The ratio of reduced glutathione to oxidized glutathione was lower in high fat groups than in control groups. The ratio was increased by dietary supplementation of grape skin in control group. These results suggest that dietary supplementation of grape skin would be effective on protection of oxidative damage by lipid peroxidation through improvement of antioxidant defense system in rats fed high fat diet as well as rats with low fat diet. PMID:20098580

Decreased insulin secretion in pregnant rats fed a low protein diet.

PubMed

Gao, Haijun; Ho, Eric; Balakrishnan, Meena; Yechoor, Vijay; Yallampalli, Chandra

2017-10-01

Low protein (LP) diet during pregnancy leads to reduced plasma insulin levels in rodents, but the underlying mechanisms remain unclear. Glucose is the primary insulin secretagogue, and enhanced glucose-stimulated insulin secretion (GSIS) in beta cells contributes to compensation for insulin resistance and maintenance of glucose homeostasis during pregnancy. In this study, we hypothesized that plasma insulin levels in pregnant rats fed LP diet are reduced due to disrupted GSIS of pancreatic islets. We first confirmed reduced plasma insulin levels, then investigated in vivo insulin secretion by glucose tolerance test and ex vivo GSIS of pancreatic islets in the presence of glucose at different doses, and KCl, glibenclamide, and L-arginine. Main findings include (1) plasma insulin levels were unaltered on day 10, but significantly reduced on days 14-22 of pregnancy in rats fed LP diet compared to those of control (CT) rats; (2) insulin sensitivity was unchanged, but glucose intolerance was more severe in pregnant rats fed LP diet; (3) GSIS in pancreatic islets was lower in LP rats compared to CT rats in the presence of glucose, KCl, and glibenclamide, and the response to L-arginine was abolished in LP rats; and (4) the total insulin content in pancreatic islets and expression of Ins2 were reduced in LP rats, but expression of Gcg was unaltered. These studies demonstrate that decreased GSIS in beta cells of LP rats contributes to reduced plasma insulin levels, which may lead to placental and fetal growth restriction and programs hypertension and other metabolic diseases in offspring. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Excess Folic Acid Increases Lipid Storage, Weight Gain, and Adipose Tissue Inflammation in High Fat Diet-Fed Rats.

PubMed

Kelly, Karen B; Kennelly, John P; Ordonez, Marta; Nelson, Randal; Leonard, Kelly; Stabler, Sally; Gomez-Muñoz, Antonio; Field, Catherine J; Jacobs, René L

2016-09-23

Folic acid intake has increased to high levels in many countries, raising concerns about possible adverse effects, including disturbances to energy and lipid metabolism. Our aim was to investigate the effects of excess folic acid (EFA) intake compared to adequate folic acid (AFA) intake on metabolic health in a rodent model. We conducted these investigations in the setting of either a 15% energy low fat (LF) diet or 60% energy high fat (HF) diet. There was no difference in weight gain, fat mass, or glucose tolerance in EFA-fed rats compared to AFA-fed rats when they were fed a LF diet. However, rats fed EFA in combination with a HF diet had significantly greater weight gain and fat mass compared to rats fed AFA (p < 0.05). Gene expression analysis showed increased mRNA levels of peroxisome proliferator-activated receptor γ (PPARγ) and some of its target genes in adipose tissue of high fat-excess folic acid (HF-EFA) fed rats. Inflammation was increased in HF-EFA fed rats, associated with impaired glucose tolerance compared to high fat-adequate folic acid (HF-AFA) fed rats (p < 0.05). In addition, folic acid induced PPARγ expression and triglyceride accumulation in 3T3-L1 cells. Our results suggest that excess folic acid may exacerbate weight gain, fat accumulation, and inflammation caused by consumption of a HF diet.

Excess Folic Acid Increases Lipid Storage, Weight Gain, and Adipose Tissue Inflammation in High Fat Diet-Fed Rats

PubMed Central

Kelly, Karen B.; Kennelly, John P.; Ordonez, Marta; Nelson, Randal; Leonard, Kelly; Stabler, Sally; Gomez-Muñoz, Antonio; Field, Catherine J.; Jacobs, René L.

2016-01-01

Folic acid intake has increased to high levels in many countries, raising concerns about possible adverse effects, including disturbances to energy and lipid metabolism. Our aim was to investigate the effects of excess folic acid (EFA) intake compared to adequate folic acid (AFA) intake on metabolic health in a rodent model. We conducted these investigations in the setting of either a 15% energy low fat (LF) diet or 60% energy high fat (HF) diet. There was no difference in weight gain, fat mass, or glucose tolerance in EFA-fed rats compared to AFA-fed rats when they were fed a LF diet. However, rats fed EFA in combination with a HF diet had significantly greater weight gain and fat mass compared to rats fed AFA (p < 0.05). Gene expression analysis showed increased mRNA levels of peroxisome proliferator-activated receptor γ (PPARγ) and some of its target genes in adipose tissue of high fat-excess folic acid (HF-EFA) fed rats. Inflammation was increased in HF-EFA fed rats, associated with impaired glucose tolerance compared to high fat-adequate folic acid (HF-AFA) fed rats (p < 0.05). In addition, folic acid induced PPARγ expression and triglyceride accumulation in 3T3-L1 cells. Our results suggest that excess folic acid may exacerbate weight gain, fat accumulation, and inflammation caused by consumption of a HF diet. PMID:27669293

Effects of glutamine administration on inflammatory responses in chronic ethanol-fed rats.

PubMed

Peng, Hsiang-Chi; Chen, Ya-Ling; Chen, Jiun-Rong; Yang, Sien-Sing; Huang, Kuan-Hsun; Wu, Yi-Chin; Lin, Yun-Ho; Yang, Suh-Ching

2011-03-01

The purpose of this study was to investigate the effects of glutamine supplementation on inflammatory responses in chronic ethanol-fed rats. Male Wistar rats weighing about 160 g were divided into five groups. Two groups were fed a normal liquid diet and three groups were fed a glutamine-containing liquid diet. After 1 week, one of the normal liquid diet groups was fed an ethanol-containing liquid diet (CE), and the other group served as the control (CC) group. At the same time, one of the glutamine-containing liquid diet groups was continually fed the same diet (GCG), but the other two groups were fed ethanol-containing diet supplemented with glutamine (GEG) or without glutamine (GE). The following items were analyzed: (1) liver function, (2) cytokine contents, and (3) hepatic oxidative stress. The activities of aspartate transaminase (AST) and alanine transaminase (ALT) and levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1β in the CE group had significantly increased. In addition, hepatic cytochrome P450 2E1 (CYP2E1) expression had significantly increased in the CE, GE and GEG groups. However, the activities of AST and ALT and levels of TNF-α and IL-1β in the GE group were significantly lower than those of the CE group. The results suggest that the plasma inflammatory responses of rats fed an ethanol-containing liquid diet for 7 weeks significantly increased. However, pretreatment with glutamine improved the plasma inflammatory responses induced by ethanol. Copyright © 2011 Elsevier Inc. All rights reserved.

Amygdalin metabolism and effect on reproduction of rats fed apricot kernels.

PubMed

Miller, K W; Anderson, J L; Stoewsand, G S

1981-01-01

Diets containing 10% ground apricot kernels were fed to young and breeding male and female Sprague-Dawley rats. The kernels werE obtained from 35 specific apricot cultivars and divided into groups containing low amygdalin (less than 50 mg cyanide per 100 g), moderate amygdalin (100-200 mg cyanide per 100 g), or high amygdalin (more than 200 mg cyanide per 100 g). Growth of young male rats was greatest in the low- or moderate-amygdalin group which may indicate only that they were more sensitive to the bitter taste of the kernels with high amygdalin contents. In female rats, but not males, liver rhodanese activity and thiocyanate (SCN) blood levels were increased with the high-amygdalin diet, but both male and females efficiently excreted thiocyanate, indicating efficient detoxication and clearance of cyanide hydrolyzed from the dietary amygdalin. No changes in blood chemistry were observed. Although parturition and 3-d survival indices were poor in pups from dams fed a basal semisynthetic diet, offspring of breeding rats fed the high-amygdalin diet for 18 wk had lower 3-d survival indices, lactation indices, and weaning weights than those in the low-amygdalin group. This may indicate that the cyanide present in the milk may not be efficiently detoxified to SCN and excreted by neonates.

Modifications of hepatic drug metabolizing enzyme activities in rats fed baobab seed oil containing cyclopropenoid fatty acids.

PubMed

Andrianaivo-Rafehivola, A A; Siess, M H; Gaydou, E M

1995-05-01

The effects on drug metabolizing enzymes of cyclopropenoid fatty acids present in baobab seed oil were evaluated in rats fed either a diet with baobab seed oil (1.27% cyclopropenoid fatty acids in the diet) or a diet with heated baobab seed oil (0.046% cyclopropenoid fatty acids in the diet). Comparison was made with rats fed a mixture of oils that contained no cyclopropenoid fatty acid. Rats fed baobab oil showed retarded growth. In comparison with the other groups, the relative liver weights were markedly increased whereas cytochrome P-450 content and NADPH cytochrome c reductase and NADH cytochrome c reductase activities were decreased. In rats fed the heated baobab oil the relative liver weight was decreased and the cytochrome P-450 level and reductase activities were increased relative to levels in rats fed the unheated oil. Ethoxycoumarin deethylase, ethoxyresorufin deethylase and pentoxyresorufin depentylase activities, expressed on the basis of cytochrome P-450, were greater in the group fed unheated baobab seed oil. Cytosolic glutathione transferase activity was markedly decreased in rats fed fresh baobab seed oil and heating the oil, which reduced the content of cyclopropenoid fatty acids, led to a considerable increase of this activity. UDP-glucuronyl transferase activities were not modified by the type of oil included in the diet. It is possible that the mechanisms of action of cyclopropenoid fatty acids are related to alterations of membrane lipid composition or microsomal proteins.

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

Cardiac Hypertrophy and Brain Natriuretic Peptide Levels in an Ovariectomized Rat Model Fed a High-Fat Diet

PubMed Central

Goncalves, Gleisy Kelly; de Oliveira, Thiago Henrique Caldeira; de Oliveira Belo, Najara

2017-01-01

Background Heart failure in women increases around the time of menopause when high-fat diets may result in obesity. The heart produces brain natriuretic peptide (BNP), also known as B-type natriuretic peptide. This aims of this study were to assess cardiac hypertrophy and BNP levels in ovariectomized rats fed a high-fat diet. Material/Methods Forty-eight female Wistar rats were divided into four groups: sham-operated rats fed a control diet (SC) (n=12); ovariectomized rats fed a control diet (OC) (n=12); sham-operated rats fed a high-fat diet (SF) (n=12); and ovariectomized rats fed a high-fat diet (OF) (n=12). Body weight and blood pressure were measured weekly for 24 weeks. Rats were then euthanized, and plasma samples and heart tissue were studied for gene expression, hydroxyproline levels, and histological examination. Results A high-fat diet and ovariectomy (group OF) increased the weight body and the systolic blood pressure after three months and five months, respectively. Cardiomyocyte hypertrophy was associated with increased expression of ventricular BNP, decreased natriuretic peptide receptor (NPR)-A and increased levels of hydroxyproline and transforming growth factor (TGF)-β. The plasma levels of BNP and estradiol were inversely correlated; expression of estrogen receptor (ER)β and ERα were reduced. Conclusions The findings of this study showed that, in the ovariectomized rats fed a high-fat diet, the BNP-NPR-A receptor complex was involved in cardiac remodeling. BNP may be a marker of cardiac hypertrophy in this animal model. PMID:29249795

Fructo-oligosaccharides reduce energy intake but do not affect adiposity in rats fed a low-fat diet but increase energy intake and reduce fat mass in rats fed a high-fat diet.

PubMed

Hadri, Zouheyr; Rasoamanana, Rojo; Fromentin, Gilles; Azzout-Marniche, Dalila; Even, Patrick C; Gaudichon, Claire; Darcel, Nicolas; Bouras, Abdelkader Dilmi; Tomé, Daniel; Chaumontet, Catherine

2017-12-01

The ingestion of low or high lipid diets enriched with fructo-oligosaccharide (FOS) affects energy homeostasis. Ingesting protein diets also induces a depression of energy intake and decreases body weight. The goal of this study was to investigate the ability of FOS, combined or not with a high level of protein (P), to affect energy intake and body composition when included in diets containing different levels of lipids (L). We performed two studies of similar design over a period of 5weeks. During the first experiment (exp1), after a 3-week period of adaptation to a normal protein-low fat diet, the rats received one of the following four diets for 5weeks (6 rats per group): (i) normal protein (14% P/E (Energy) low fat (10% L/E) diet, (ii) normal protein, low fat diet supplemented with 10% FOS, (iii) high protein (55%P/E) low fat diet, and (iv) high protein, low fat diet supplemented with 10% FOS. In a second experiment (exp2) after the 3-week period of adaptation to a normal protein-high fat diet, the rats received one of the following 4 diets for 5weeks (6 rats per group): (i) normal protein, high fat diet (35% of fat), (ii) normal protein, high fat diet supplemented with 10% FOS, (iii) high protein high fat diet and (iv) high protein high fat diet supplemented with 10% FOS. In low-fat fed rats, FOS did not affect lean body mass (LBM) and fat mass but the protein level reduced fat mass and tended to reduce adiposity. In high-fat fed rats, FOS did not affect LBM but reduced fat mass and adiposity. No additive or antagonistic effects between FOS and the protein level were observed. FOS reduced energy intake in low-fat fed rats, did not affect energy intake in normal-protein high-fat fed rats but surprisingly, and significantly, increased energy intake in high-protein high-fat fed rats. The results thus showed that FOS added to a high-fat diet reduced body fat and body adiposity. Published by Elsevier Inc.

Antioxidant potential of fungal metabolite nigerloxin during eye lens abnormalities in galactose-fed rats.

PubMed

Suresha, Bharathinagar S; Srinivasan, Krishnapura

2013-10-01

The role of osmotic and oxidative stress has been strongly implicated in the pathogenesis of cataract. Nigerloxin, a fungal metabolite, has been shown to possess aldose reductase inhibition and improved antioxidant defense system in lens of diabetic rats. In the present study, the beneficial influence of nigerloxin was investigated in galactose-induced cataract in experimental animals. Cataract was induced in Wistar rats by feeding 30% galactose in diet. Groups of galactose-fed rats were orally administered with nigerloxin (25 and 100 mg/kg body weight/day) for 24 days. Lens aldose reductase activity was increased significantly in galactose-fed animals. Lens lipid peroxides and advanced glycation end products were also significantly increased. Antioxidant molecule - reduced glutathione, total thiols and activities of antioxidant enzymes superoxide dismutase and glutathione peroxidase were decreased in the lens of galactose-fed animals. Oral administration of nigerloxin once a day for 24 days at a dose of 100 mg/kg body weight, significantly decreased lens lipid peroxides and advanced glycation end products in galactose-fed rats. Lens aldose reductase activity was reduced and lens antioxidant molecules and antioxidant enzyme activities were elevated significantly by nigerloxin administration. The results suggest that alteration in polyol pathway and antioxidant defense system were countered by nigerloxin in the lens of galactose-fed animals, suggesting the potential of nigerloxin in ameliorating the development of galactose-induced cataract in experimental animals.

Defects in oxygen supply to skeletal muscle of prediabetic ZDF rats

PubMed Central

Goldman, Daniel; Hanson, Madelyn; Stephenson, Alan H.; Milkovich, Stephanie; Benlamri, Amina; Ellsworth, Mary L.; Sprague, Randy S.

2010-01-01

In humans, prediabetes is characterized by marked increases in plasma insulin and near normal blood glucose levels as well as microvascular dysfunction of unknown origin. Using the extensor digitorum longus muscle of 7-wk inbred male Zucker diabetic fatty rats fed a high-fat diet as a model of prediabetes, we tested the hypothesis that hyperinsulinemia contributes to impaired O2 delivery in skeletal muscle. Using in vivo video microscopy, we determined that the total O2 supply to capillaries in the extensor digitorum longus muscle of prediabetic rats was reduced to 64% of controls with a lower O2 supply rate per capillary and higher O2 extraction resulting in a decreased O2 saturation at the venous end of the capillary network. These findings suggest a lower average tissue Po2 in prediabetic animals. In addition, we determined that insulin, at concentrations measured in humans and Zucker diabetic fatty rats with prediabetes, inhibited the O2-dependent release of ATP from rat red blood cells (RBCs). This inability to release ATP could contribute to the impaired O2 delivery observed in rats with prediabetes, especially in light of the finding that the endothelium-dependent relaxation of resistance arteries from these animals is not different from controls and is not altered by insulin. Computational modeling confirmed a significant 8.3-mmHg decrease in average tissue Po2 as well as an increase in the heterogeneity of tissue Po2, implicating a failure of a regulatory system for O2 supply. The finding that insulin attenuates the O2-dependent release of ATP from RBCs suggests that this defect in RBC physiology could contribute to a failure in the regulation of O2 supply to meet the demand in skeletal muscle in prediabetes. PMID:20207810

Dahl salt-sensitive rats develop hypovitaminosis D and hyperparathyroidism when fed a standard diet

NASA Technical Reports Server (NTRS)

Thierry-Palmer, Myrtle; Cephas, Stacy; Sayavongsa, Phouyong; Doherty, Akins; Arnaud, Sara B.

2005-01-01

The Dahl salt-sensitive rat (S), a model for salt-sensitive hypertension, excretes protein-bound 25-hydroxyvitamin D (25-OHD) into urine when fed a low salt diet. Urinary 25-OHD increases during high salt intake. We tested the hypothesis that continuous loss of 25-OHD into urine would result in low plasma 25-OHD concentration in mature S rats raised on a standard diet. Dahl S and salt-resistant (R) male rats were raised to maturity (12-month-old) on a commercial rat diet (1% salt) and switched to 0.3% (low) or 2% (high) salt diets 3 weeks before euthanasia. Urine (24 h) was collected at the end of the dietary treatments. Urinary 25-OHD and urinary 25-OHD binding activity of S rats were three times that of R rats, resulting in lower plasma 25-OHD and 24,25-dihydroxyvitamin D concentrations in S rats than in R rats (P < 0.001). Plasma parathyroid hormone concentrations of S rats were twice that of R rats. S rats fed 2% salt had higher plasma 1,25-dihydroxyvitamin D concentrations than those fed 0.3% salt (P = 0.002). S rats excreted more calcium into urine than R rats (P < 0.001) and did not exhibit the expected calciuric response to salt. Proteinuria of the S rats was three times that of the R rats, suggesting kidney damage in the S rats. Low plasma 25-OHD and 24,25-dihydroxyvitamin D and high plasma 1,25-dihydroxyvitamin D and PTH concentrations seen in the mature S rats have also been reported for elderly patients with low-renin (salt-induced) hypertension. An implication of this study is that low vitamin D status may occur with age in salt-sensitive individuals, even when salt intake is normal.

Mixed compared with single-source proteins in high-protein diets affect kidney structure and function differentially in obese fa/fa Zucker rats.

PubMed

Devassy, Jessay G; Wojcik, Jennifer L; Ibrahim, Naser H M; Zahradka, Peter; Taylor, Carla G; Aukema, Harold M

2017-02-01

Questions remain regarding the potential negative effects of dietary high protein (HP) on kidney health, particularly in the context of obesity in which the risk for renal disease is already increased. To examine whether some of the variability in HP effects on kidney health may be due to source of protein, obese fa/fa Zucker rats were given HP (35% of energy from protein) diets containing either casein, soy protein, or a mixed source of animal and plant proteins for 12 weeks. Control lean and obese rats were given diets containing casein at normal protein (15% of energy from protein) levels. Body weight and blood pressure were measured, and markers of renal structural changes, damage, and function were assessed. Obesity alone resulted in mild renal changes, as evidenced by higher kidney weights, proteinuria, and glomerular volumes. In obese rats, increasing the protein level using the single, but not mixed, protein sources resulted in higher renal fibrosis compared with the lean rats. The mixed-protein HP group also had lower levels of serum monocyte chemoattractant protein-1, even though this diet further increased kidney and glomerular size. Soy and mixed-protein HP diets also resulted in a small number of damaged glomeruli, while soy compared with mixed-protein HP diet delayed the increase in blood pressure over time. Since obesity itself confers added risk of renal disease, an HP diet from mixed-protein sources that enables weight loss but has fewer risks to renal health may be advantageous.

Rats socially-reared and full fed learned an autoshaping task, showing less levels of fear-like behaviour than fasted or singly-reared rats.

PubMed

Molina-Hernández, Miguel; Téllez-Alcántara, N Patricia

2004-07-01

During the learning of instrumental tasks, rats are usually fasted to increase reinforced learning. However, fasting produces several undesirable side effects. The aim of this study was to test the hypothesis that control rats, i.e. full-fed and group-reared rats, will learn an autoshaping task to the same level as fasted or singly-reared rats. The interaction between fasting and single-rearing of rats was also tested. Results showed that control rats and fasted rats acquired the autoshaping task similarly, independently of rearing condition or gender. However, fasted or singly-reared rats produced fear-like behaviour, since male rats group-reared and fasted (85% body/wt, P <0.05), male rats singly-reared (full fed, P <0.05; 12 h fasted, P <0.05; 85% body/wt, P <0.05), female rats group-reared (12 h fasted, P <0.05; 85% body/wt, P <0.05) and female rats singly reared (full fed, P <0.05; 12 h fasted, P <0.05; 85% body/wt, P <0.05) displayed reduced amounts of time exploring the open arms of the elevated plus-maze. In conclusion, control rats learned the autoshaping task to the same level as fasted or singly-reared rats. However, fasting or single-rearing produced fear-like behaviour. Thus, the training of control rats in autoshaping tasks may be an option that improves animal welfare.

Veratric acid ameliorates hyperlipidemia and oxidative stress in Wistar rats fed an atherogenic diet.

PubMed

Raja, Boobalan; Saravanakumar, Murugesan; Sathya, Gopal

2012-07-01

An investigation was made to reveal the protective effects of veratric acid (VA), a phenolic acid against atherogenic diet-induced hyperlipidemic rats. Male albino Wistar rats were fed with atherogenic diet (4% cholesterol, 1% cholic acid, and 0.5% 2-thiouracil) daily for 30 days and treated with VA (40 mg/kg body weight) daily for a period of 30 days. Rats fed with atherogenic diet showed significant (P < 0.05) elevation in the level of plasma lipids, systolic and diastolic blood pressure, oxidative stress markers (thiobarbituric acid reactive substances, lipid peroxides) and significant (P < 0.05) reduction in the activities of enzymatic (superoxide dismutase, catalase, glutathione peroxidase) and non-enzymatic (vitamin C, vitamin E, and reduced glutathione) antioxidants in erythrocytes, plasma, and tissues (liver, kidney, and aorta). Oral administration of VA (40 mg/kg body weight) for 30 days to atherogenic diet fed rats markedly attenuates systolic, diastolic blood pressure and lipid peroxidation products. Further, VA treatment significantly improved enzymatic and non-enzymatic antioxidants levels and showed beneficial effects on lipid profile in atherogenic diet rats. All the above alterations were supported by histopathological observations. These results indicate that oral administration of VA ameliorates atherogenic diet-induced hyperlipidemia in rats by its free radical scavenging; improving the antioxidants and lipid lowering properties.

Insulin-sensitizing effect of rosiglitazone (BRL-49653) by regulation of glucose transporters in muscle and fat of Zucker rats.

PubMed

Kramer, D; Shapiro, R; Adler, A; Bush, E; Rondinone, C M

2001-11-01

Thiazolidinediones (TZDs), a class of antidiabetic agents, are specific agonists of peroxisome proliferator activator receptor (PPARgamma). However, their mechanisms of action, and the in vivo target tissues that mediate insulin sensitization are not well understood. The aim of this study was to investigate the role of glucose transporters (GLUT-1 and GLUT-4) in the TZD insulin-sensitizer action. The effects of rosiglitazone treatment were studied using Zucker (fa/fa) rats after 7 days of oral dosing (3.6 mg/kg/d). Rosiglitazone lowered (approximate 80%) basal plasma insulin levels in obese rats and substantially corrected (approximately 50%) insulin resistance based upon results from hyperinsulinemic euglycemic clamp studies. GLUT-4 protein levels were reduced (approximately 75%) in adipose tissue of obese rats and treatment with rosiglitazone normalized them. Interestingly, GLUT-1 protein content was increased in adipose tissue ( thick approximate 150%) and skeletal muscle (approximately 50%) of obese rats and treatment with rosiglitazone increased it even more by 5.5-fold in fat and by 2.5-fold in muscle. Consistent with these results, basal (GLUT-1-mediated) transport rate of 3-O-methyl-D-glucose into isolated epitrochlearis muscle was elevated in response to rosiglitazone. Incubation of fully differentiated 3T3-L1 adipocytes with the drug for 7 days increased the levels of GLUT-1 protein, but did not affect GLUT-4 levels. In conclusion, rosiglitazone may improve insulin resistance in vivo by normalizing GLUT-4 protein content in adipose tissue and increasing GLUT-1 in skeletal muscle and fat. While the drug has a direct effect on GLUT-1 protein expression in vitro without a direct effect on GLUT-4 suggests that direct and indirect effects of rosiglitazone on glucose transporters may have an important role in improving insulin resistance in vivo. Copyright 2001 by W.B. Saunders Company

Chromium dinicocysteinate supplementation can lower blood glucose, CRP, MCP-1, ICAM-1, creatinine, apparently mediated by elevated blood vitamin C and adiponectin and inhibition of NFkappaB, Akt, and Glut-2 in livers of zucker diabetic fatty rats.

PubMed

Jain, Sushil K; Croad, Jennifer L; Velusamy, Thirunavukkarasu; Rains, Justin L; Bull, Rebeca

2010-09-01

Chromium and cysteine supplementation can improve glucose metabolism in animal studies. This study examined the hypothesis that a cysteinate complex of chromium is significantly beneficial than either of them in lowering blood glucose and vascular inflammation markers in Zucker diabetic fatty (ZDF) rats. Starting at the age of 6 wk, ZDF rats were supplemented orally (daily gavages for 8 more weeks) with saline-placebo (D) or chromium (400 microg Cr/Kg body weight) as chromium dinicocysteinate (CDNC), chromium dinicotinate (CDN) or chromium picolinate (CP) or equimolar L-cysteine (LC, img/Kg body weight), and fed Purina 5008 diet for 8 wk. ZDF rats of 6 wk age before any supplementations and onset of diabetes were considered as baseline. D rats showed elevated levels of fasting blood glucose, HbA(1), CRP, MCP-1, ICAM-1 and oxidative stress (lipid peroxidation) and lower adiponectin and vitamin C, when compared with baseline rats. In comparison to D group, CDNC group had significantly lower blood glucose, HbA(1), CRP, MCP-1, ICAM-1 and lipid peroxidation and increased vitamin C and adiponectin levels. CDN, CP or LC showed significantly less or no effect on these biomarkers. Only CDNC lowered blood creatinine levels in comparison to D. While CDN and CP had no effect, activation of NFkappaB, Akt and glucose transporter-2 levels were decreased, insulin receptor substrate 1 (IRS-1) activation increased in livers of CDNC-rats. CDNC effect on glycemia, NFkappaB, Akt and IRS-1 in liver was significantly greater compared with LC. Blood chromium levels did not differ between Cr-groups. Exogenous vitamin C supplementation significantly inhibited MCP-1 secretion in U937 monocytes cultured in high-glucose-medium. CDNC is a potent hypoglycemic compound with anti-inflammatory activity apparently mediated by elevated blood vitamin C and adiponectin and inhibition of NFkappaB, Akt, and Glut-2 and increased IRS-1 activation in livers of type 2 diabetic rats.

High temperature-ultra performance liquid chromatography-mass spectrometry for the metabonomic analysis of Zucker rat urine.

PubMed

Gika, Helen G; Theodoridis, Georgios; Extance, Jon; Edge, Anthony M; Wilson, Ian D

2008-08-15

The applicability and potential of using elevated temperatures and sub 2-microm porous particles in chromatography for metabonomics/metabolomics was investigated using, for the first time, solvent temperatures higher than the boiling point of water (up to 180 degrees C) and thermal gradients to reduce the use of organic solvents. Ultra performance liquid chromatography, combined with mass spectrometry, was investigated for the global metabolite profiling of the plasma and urine of normal and Zucker (fa/fa) obese rats (a well established disease animal model). "Isobaric" high temperature chromatography, where the temperature and flow rate follow a gradient program, was developed and evaluated against a conventional organic solvent gradient. LC-MS data were first examined by established chromatographic criteria in order to evaluate the chromatographic performance and next were treated by special peak picking algorithms to allow the application of multivariate statistics. These studies showed that, for urine (but not plasma), chromatography at elevated temperatures provided better results than conventional reversed-phase LC with higher peak capacity and better peak asymmetry. From a systems biology point of view, better group clustering and separation was obtained with a larger number of variables of high importance when using high temperature-ultra performance liquid chromatography (HT-UPLC) compared to conventional solvent gradients.

Vascular filtration function in galactose-fed versus diabetic rats: The role of polyol pathway activity

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

Pugliese, G.; Tilton, R.G.; Speedy, A.

1990-07-01

These studies were undertaken to assess the effects of increased galactose (v increased glucose) metabolism via the polyol pathway on vascular filtration function in the kidneys, eyes, nerves, and aorta. Quantitative radiolabeled tracer techniques were used to assess glomerular filtration rate (GFR) and regional tissue vascular clearance of plasma 131I-bovine serum albumin (BSA) in five groups of male Sprague-Dawley rats: nondiabetic controls, streptozotocin-diabetic rats, nondiabetic rats fed a 50% galactose diet, diabetic rats treated with sorbinil (an aldose reductase inhibitor), and galactose-fed rats treated with sorbinil. Sorbinil was added to the diet to provide a daily dose of approximately .2more » mmol/kg body weight. After 2 months of diabetes or galactose ingestion, albumin clearance was increased twofold to fourfold in the eye (anterior uvea, choroid, and retina), sciatic nerve, aorta, and kidney; GFR was increased approximately twofold and urinary excretion of endogenous albumin and IgG were increased approximately 10-fold. Sorbinil treatment markedly reduced or completely prevented all of these changes in galactose-fed, as well as in diabetic rats. These observations support the hypothesis that increased metabolism of glucose via the sorbitol pathway is of central importance in mediating virtually all of the early changes in vascular filtration function associated with diabetes in the kidney, as well as in the eyes, nerves, and aorta. On the other hand, renal hypertrophy in diabetic rats and polyuria, hyperphagia, and impaired weight gain in galactose-fed and in diabetic rats were unaffected by sorbinil and therefore are unlikely to be mediated by increased polyol metabolism.« less

Study of antidiarrheal and hematology profile of laboratory rat fed with yogurt containing local probiotic and purple sweet potato extract

NASA Astrophysics Data System (ADS)

Tari, A. I. N.; Handayani, C. B.; Hartati, S.

2018-03-01

The aim of this study was to evaluate the effectiveness of local probiotic in yogurt with purple sweet potato extract supplementation on the hematological parameters of albino rats (Spraque dawley). The study was conducted using a Completely Randomized Design with 30 rats divided into 6 groups. In group K-, rats were fed with distilled water from day 1 to 21. In group YTP, Rats were fed with yogurt without probiotics from day 1 to 21. YDP group was rats were fed with probiotic yogurt from day 1 to 21. In group YTP+E, rats were fed with yogurt without probiotic from day 1 to 7, interspersed with exposure to enteropathogenic Escherichia coli (EPEC) on day 8 to 14. In group YDP+E, rats were fed with probiotic yogurt from day 1 to 7, interspersed by EPEC on day 8 to 24. In group K +, rats were fed with water from day 1 to 7, then fed with EPEC on day 8 to 14, after which water was given back on day 15 to 21. The result showed that probiotic yogurt treatment with supplement of purple sweet potato extract had a significant effect (P<0,05) on feces water content, number of erythrocyte, leucocyte, and hemoglobin. The treatment of YDP had water content in feces 48.422% and the number of erythrocyte, leucocytes, and hemoglobin were 8.578 106/μl, 14.152 106/μl and 13.98 g/dL respectively.

Rats fed fructose-enriched diets have characteristics of nonalcoholic hepatic steatosis.

PubMed

Kawasaki, Takahiro; Igarashi, Kanji; Koeda, Tatsuki; Sugimoto, Keiichiro; Nakagawa, Kazuya; Hayashi, Shuichi; Yamaji, Ryoichi; Inui, Hiroshi; Fukusato, Toshio; Yamanouchi, Toshikazu

2009-11-01

Nonalcoholic steatohepatitis (NASH) and nonalcoholic fatty liver disease are increasing in adults and are likely to be increasing in children. Both conditions are hepatic manifestations of metabolic syndrome. Experimental animals fed fructose-enriched diets are widely recognized as good models for metabolic syndrome. However, few reports have described the hepatic pathology of these experimental animals. In this study, 5-wk-old Wistar specific pathogen-free rats, which are a normal strain, were fed experimental diets for 5 wk. We then evaluated the degree of steatohepatitis. The 5 diet groups were as follows: cornstarch (70% wt:wt) [control (C)], high-fructose (70%) (HFr), high-sucrose (70%) (HS), high-fat (15%) (HF), and high-fat (15%) high-fructose (50%) (HFHFr) diets. The macrovesicular steatosis grade, liver:body weight ratio, and hepatic triglyceride concentration were significantly higher in the HFr group than in the other 4 groups. However, the HFr group had a significantly lower ratio of epididymal white fat:body weight than the other 4 groups and had a lower final body weight than the HF and HFHFr groups. The HF group had a greater final body weight than the C, HFr, and HS groups, but no macrovesicular steatosis was observed. The HFr group had a significantly higher grade of lobular inflammation than the other 4 groups. The distribution of lobular inflammation was predominant over portal inflammation, which is consistent with human NASH. In conclusion, rats fed fructose-enriched diets are a better model for NASH than rats fed fat-enriched diets.

Antidiabetic Effect of Fresh Nopal (Opuntia ficus-indica) in Low-Dose Streptozotocin-Induced Diabetic Rats Fed a High-Fat Diet

PubMed Central

Hwang, Seung Hwan; Kang, Il-Jun

2017-01-01

The objective of the present study was to evaluate α-glucosidase inhibitory and antidiabetic effects of Nopal water extract (NPWE) and Nopal dry power (NADP) in low-dose streptozotocin- (STZ-) induced diabetic rats fed a high-fat diet (HFD). The type 2 diabetic rat model was induced by HFD and low-dose STZ. The rats were divided into four groups as follows: (1) nondiabetic rats fed a regular diet (RD-Control); (2) low-dose STZ-induced diabetic rats fed HFD (HF-STZ-Control); (3) low-dose STZ-induced diabetic rats fed HFD and supplemented with NPWE (100 mg/kg body weight, HF-STZ-NPWE); and (4) low-dose STZ-induced diabetic rats fed HFD and supplemented with comparison medication (rosiglitazone, 10 mg/kg, body weight, HF-STZ-Rosiglitazone). In results, NPWE and NADP had IC50 values of 67.33 and 86.68 μg/mL, both of which exhibit inhibitory activities but lower than that of acarbose (38.05 μg/mL) while NPWE group significantly decreased blood glucose levels compared to control and NPDP group on glucose tolerance in the high-fat diet fed rats model (P < 0.05). Also, the blood glucose levels of HR-STZ-NPWE group were significantly lower (P < 0.05) than HR-STZ-Control group on low-dose STZ-induced diabetic rats fed HFD. Based on these findings, we suggested that NPWE could be considered for the prevention and/or treatment of blood glucose and a potential use as a dietary supplement. PMID:28303158

Antidiabetic Effect of Fresh Nopal (Opuntia ficus-indica) in Low-Dose Streptozotocin-Induced Diabetic Rats Fed a High-Fat Diet.

PubMed

Hwang, Seung Hwan; Kang, Il-Jun; Lim, Soon Sung

2017-01-01

The objective of the present study was to evaluate α -glucosidase inhibitory and antidiabetic effects of Nopal water extract (NPWE) and Nopal dry power (NADP) in low-dose streptozotocin- (STZ-) induced diabetic rats fed a high-fat diet (HFD). The type 2 diabetic rat model was induced by HFD and low-dose STZ. The rats were divided into four groups as follows: (1) nondiabetic rats fed a regular diet (RD-Control); (2) low-dose STZ-induced diabetic rats fed HFD (HF-STZ-Control); (3) low-dose STZ-induced diabetic rats fed HFD and supplemented with NPWE (100 mg/kg body weight, HF-STZ-NPWE); and (4) low-dose STZ-induced diabetic rats fed HFD and supplemented with comparison medication (rosiglitazone, 10 mg/kg, body weight, HF-STZ-Rosiglitazone). In results, NPWE and NADP had IC 50 values of 67.33 and 86.68  μ g/mL, both of which exhibit inhibitory activities but lower than that of acarbose (38.05  μ g/mL) while NPWE group significantly decreased blood glucose levels compared to control and NPDP group on glucose tolerance in the high-fat diet fed rats model ( P < 0.05). Also, the blood glucose levels of HR-STZ-NPWE group were significantly lower ( P < 0.05) than HR-STZ-Control group on low-dose STZ-induced diabetic rats fed HFD. Based on these findings, we suggested that NPWE could be considered for the prevention and/or treatment of blood glucose and a potential use as a dietary supplement.

Methionine deficiency in rats fed soy protein induces hypercholesterolemia and potentiates lipoprotein susceptibility to peroxidation.

PubMed

Moundras, C; Rémésy, C; Levrat, M A; Demigné, C

1995-09-01

A number of studies have provided evidence that plant proteins, especially soy protein, have a cholesterol-lowering effect as compared with casein. However, dietary supply of sulfur amino acids may be deficient when soy protein is present in the diet at a suboptimal level, which could affect lipid metabolism. Accordingly, in rats fed 13% protein diets, soy protein feeding resulted in a cholesterol-increasing effect (+18%), which could be counteracted by methionine supplementation (0.4%). In contrast, soy protein was effective in decreasing plasma triglyceride, as compared with levels in rats fed casein; this triglyceride-lowering effect was entirely abolished by methionine supplementation. The hypercholesterolemic effect of soy protein was characterized by a higher cholesterol content in low-density lipoprotein (LDL) and high-density lipoprotein 1 (HDL1) fractions, together with a marked induction of hepatic hydroxymethyl glutaryl coenzyme A (HMG CoA) reductase activity and to a lesser extent cholesterol 7 alpha-hydroxylase. There was practically no induction of these enzymes, as compared with levels in rats fed casein diets, when the soy protein diet was supplemented with methionine. Very-low-density lipoprotein (VLDL) plus LDL susceptibility to peroxidation was higher in rats fed soy protein than in casein-fed rats, which could reflect in part the lack of sulfur amino acid availability, since methionine supplementation led to a partial recovery of lipoprotein resistance to peroxidation. These findings suggest that amino acid imbalance could be atherogenic by increasing circulating cholesterol and leading to a higher lipoprotein susceptibility to peroxidation.

Cardiac β-adrenergic responsiveness of obese Zucker rats: The role of AMPK.

PubMed

Bussey, Carol T; Thaung, Hp Aye; Hughes, Gillian; Bahn, Andrew; Lamberts, Regis R

2018-06-05

What is the central question of the study? What is the main finding and its importance? 1. Is the reduced signalling of AMPK, a key regulator of energy homeostasis in the heart, responsible for the reduced β-adrenergic responsiveness of the heart in obesity? 2. Inhibition of AMPK in isolated hearts prevented the reduced cardiac β-adrenergic responsiveness of obese rats, which was accompanied by reduced phosphorylation of AMPK, a proxy of AMPK activity. This suggests a direct functional link between β-adrenergic responsiveness and AMPK signalling in the heart, and that AMPK might be an important target to restore the β-adrenergic responsiveness in the heart in obesity. The obesity epidemic impacts heavily on cardiovascular health, in part due to changes in cardiac metabolism. AMP-activated protein kinase (AMPK) is a key regulator of energy homeostasis in the heart, and is regulated by β-adrenoceptors (AR) under normal conditions. In obesity, chronic sympathetic overactivation leads to impaired cardiac β-AR responsiveness, although it is unclear whether AMPK signalling, downstream of β-AR, contributes to this dysfunction. Therefore, we aimed to determine whether reduced AMPK signalling is responsible for the reduced β-AR responsiveness in obesity. In isolated hearts of lean and obese Zucker rats, we tested β-AR responsiveness to β 1 -AR agonist isoproterenol (ISO, 1 × 10 -10 - 5 × 10 -8  M) in the absence and presence of the AMPK inhibitor compound C (CC, 10 μM). β 1 -AR expression and AMPK phosphorylation were assessed by Western blot. β-Adrenergic responsiveness was reduced in the hearts of obese rats (LogEC50 of ISO-developed pressure dose-response curves: lean -8.53 ± 0.13 vs. obese -8.35 ± 0.10 10 x M; p < 0.05 lean vs. obese, n = 6 per group). This difference was not apparent after AMPK inhibition (LogEC50 of ISO-developed pressure curves: lean CC -8.19 ± 0.12 vs. obese CC 8.17 ± 0.13 10 x M, p > 0.05, n = 6 per group

Aerobic interval exercise improves parameters of nonalcoholic fatty liver disease (NAFLD) and other alterations of metabolic syndrome in obese Zucker rats.

PubMed

Kapravelou, Garyfallia; Martínez, Rosario; Andrade, Ana M; Nebot, Elena; Camiletti-Moirón, Daniel; Aparicio, Virginia A; Lopez-Jurado, Maria; Aranda, Pilar; Arrebola, Francisco; Fernandez-Segura, Eduardo; Bermano, Giovanna; Goua, Marie; Galisteo, Milagros; Porres, Jesus M

2015-12-01

Metabolic syndrome (MS) is a group of metabolic alterations that increase the susceptibility to cardiovascular disease and type 2 diabetes. Nonalcoholic fatty liver disease has been described as the liver manifestation of MS. We aimed to test the beneficial effects of an aerobic interval training (AIT) protocol on different biochemical, microscopic, and functional liver alterations related to the MS in the experimental model of obese Zucker rat. Two groups of lean and obese animals (6 weeks old) followed a protocol of AIT (4 min at 65%-80% of maximal oxygen uptake, followed by 3 min at 50%-65% of maximal oxygen uptake for 45-60 min, 5 days/week, 8 weeks of experimental period), whereas 2 control groups remained sedentary. Obese rats had higher food intake and body weight (P < 0.0001) and suffered significant alterations in plasma lipid profile, area under the curve after oral glucose overload (P < 0.0001), liver histology and functionality, and antioxidant status. The AIT protocol reduced the severity of alterations related to glucose and lipid metabolism and increased the liver protein expression of PPARγ, as well as the gene expression of glutathione peroxidase 4 (P < 0.001). The training protocol also showed significant effects on the activity of hepatic antioxidant enzymes, although this action was greatly influenced by rat phenotype. The present data suggest that AIT protocol is a feasible strategy to improve some of the plasma and liver alterations featured by the MS.

Melatonin counteracts changes in hypothalamic gene expression of signals regulating feeding behavior in high-fat fed rats.

PubMed

Ríos-Lugo, María J; Jiménez-Ortega, Vanesa; Cano-Barquilla, Pilar; Mateos, Pilar Fernández; Spinedi, Eduardo J; Cardinali, Daniel P; Esquifino, Ana I

2015-03-01

Previous studies indicate that the administration of melatonin caused body weight and abdominal visceral fat reductions in rodent models of hyperadiposity. The objective of the present study performed in high-fat fed rats was to evaluate the activity of melatonin on gene expression of some medial basal hypothalamus (MBH) signals involved in feeding behavior regulation, including neuropeptide Y (NPY), proopiomelanocortin (POMC), prolactin-releasing peptide (PrRP), leptin- and insulin-receptors (R) and insulin-R substrate (IRS)-1 and -2. Blood levels of leptin and adiponectin were also measured. Adult Wistar male rats were divided into four groups (n=16 per group): (i) control diet (3% fat); (ii) high-fat (35%) diet; (iii) high-fat diet+melatonin; (iv) control diet+melatonin. Rats had free access to high-fat or control chow and one of the following drinking solutions: (a) tap water; (b) 25 μg/mL of melatonin. After 10 weeks, the high-fat fed rats showed augmented MBH mRNA levels of NPY, leptin-R, PrRP, insulin-R, IRS-1 and IRS-2. The concomitant administration of melatonin counteracted this increase. Feeding of rats with a high-fat diet augmented expression of the MBH POMC gene through an effect insensitive to melatonin treatment. The augmented levels of circulating leptin and adiponectin seen in high-fat fed rats were counteracted by melatonin as was the augmented body weight: melatonin significantly attenuated a body weight increase in high-fat fed rats without affecting chow or water consumption. Melatonin augmented plasma leptin and adiponectin in control rats. The results indicate that an effect on gene expression of feeding behavior signals at the central nervous system (CNS) may complement a peripheral rise of the energy expenditure produced by melatonin to decrease body weight in high-fat fed rats.

Phytase supplementation increases bone mineral density, lean body mass and voluntary physical activity in rats fed a low-zinc diet.

PubMed

Scrimgeour, Angus G; Marchitelli, Louis J; Whicker, Jered S; Song, Yang; Ho, Emily; Young, Andrew J

2010-07-01

Phytic acid forms insoluble complexes with nutritionally essential minerals, including zinc (Zn). Animal studies show that addition of microbial phytase (P) to low-Zn diets improves Zn status and bone strength. The present study determined the effects of phytase supplementation on bone mineral density (BMD), body composition and voluntary running activity of male rats fed a high phytic acid, low-Zn diet. In a factorial design, rats were assigned to ZnLO (5 mg/kg diet), ZnLO+P (ZnLO diet with 1500 U phytase/kg) or ZnAD (30 mg/kg diet) groups and were divided into voluntary exercise (EX) or sedentary (SED) groups, for 9 weeks. SED rats were significantly heavier from the second week, and no catch-up growth occurred in EX rats. Feed intakes were not different between groups throughout the study. ZnLO animals had decreased food efficiency ratios compared to both phytase-supplemented (ZnLO+P) and Zn-adequate (ZnAD) animals (P<.01 compared to ZnLO). The ZnLO+P and ZnAD rats ran 56-75 km more total distance than ZnLO rats (P<.05), with the ZnLO+P rats running more kilometers per week than the ZnLO rats by Week 6. In vivo DEXA analyses indicate that rats fed phytase-supplemented diets had higher lean body mass (LBM) than those fed ZnLO diets; and that rats fed the Zn-adequate diets had the highest LBM. Body fat (%) was significantly lower in EX rats and was both Zn- and phytase insensitive. Rats fed phytase-supplemented diets had higher bone mineral content (BMC), bone area (BA) and BMD than rats fed ZnLO diets; and in rats fed ZnAD diets these indices were the highest. The dietary effects on BMC, BA and BMD were independent of activity level. We conclude that consuming supplemental dietary phytase or dietary Zn additively enhances Zn status to increase BMD, LBM and voluntary physical activity in rats fed a low-Zn diet. While the findings confirm that bone health is vulnerable to disruption by moderate Zn deficiency in rats, this new data suggests that if dietary Zn is

Regular exercise prevents the development of hyperglucocorticoidemia via adaptations in the brain and adrenal glands in male Zucker diabetic fatty rats.

PubMed

Campbell, Jonathan E; Király, Michael A; Atkinson, Daniel J; D'souza, Anna M; Vranic, Mladen; Riddell, Michael C

2010-07-01

We determined the effects of voluntary wheel running on the hypothalamic-pituitary-adrenal (HPA) axis, and the peripheral determinants of glucocorticoids action, in male Zucker diabetic fatty (ZDF) rats. Six-week-old euglycemic ZDF rats were divided into Basal, Sedentary, and Exercise groups (n = 8-9 per group). Basal animals were immediately killed, whereas Sedentary and Exercising rats were monitored for 10 wk. Basal (i.e., approximately 0900 AM in the resting state) glucocorticoid levels increased 2.3-fold by week 3 in Sedentary rats where they remained elevated for the duration of the study. After an initial elevation in basal glucocorticoid levels at week 1, Exercise rats maintained low glucocorticoid levels from week 3 through week 10. Hyperglycemia was evident in Sedentary animals by week 7, whereas Exercising animals maintained euglycemia throughout. At the time of death, the Sedentary group had approximately 40% lower glucocorticoid receptor (GR) content in the hippocampus, compared with the Basal and Exercise groups (P < 0.05), suggesting that the former group had impaired negative feedback regulation of the HPA axis. Both Sedentary and Exercise groups had elevated ACTH compared with Basal rats, indicating that central drive of the axis was similar between groups. However, Sedentary, but not Exercise, animals had elevated adrenal ACTH receptor and steroidogenic acute regulatory protein content compared with the Basal animals, suggesting that regular exercise protects against elevations in glucocorticoids by a downregulation of adrenal sensitivity to ACTH. GR and 11beta-hydroxysteroid dehydrogenase type 1 content in skeletal muscle and liver were similar between groups, however, GR content in adipose tissue was elevated in the Sedentary groups compared with the Basal and Exercise (P < 0.05) groups. Thus, the gradual elevations in glucocorticoid levels associated with the development of insulin resistance in male ZDF rats can be prevented with regular

Isoflavone and Protein Constituents of Lactic Acid-Fermented Soy Milk Combine to Prevent Dyslipidemia in Rats Fed a High Cholesterol Diet

PubMed Central

Kobayashi, Maki; Egusa, Shintaro; Fukuda, Mitsuru

2014-01-01

A high cholesterol diet induces dyslipidemia. This study investigated whether isoflavone aglycones in lactic acid-fermented soy milk (LFS) improve lipid metabolism in rats fed a high cholesterol diet. Male Sprague-Dawley rats aged seven weeks were fed an AIN-93G diet, a 1% cholesterol diet (a high cholesterol diet), a high-cholesterol diet containing 4% isoflavone extract of LFS (LFS extract diet), a high-cholesterol diet containing 19.4% ethanol-washed LFS (ethanol-washed LFS diet, isoflavone-poor diet), or a high cholesterol diet containing 23.2% intact LFS (intact LFS diet) for five weeks. The plasma total cholesterol (TC) level was increased in the rats fed the LFS extract diet compared with those fed the high cholesterol diet. The TC level was decreased by the intact LFS and ethanol-washed LFS diets. The cholesterol-lowering effect was stronger in the rats fed the intact LFS diet than those fed the ethanol-washed LFS diet. The plasma triglyceride (TG) level was unchanged in the rats fed the LFS extract diet, but it decreased in rats fed the intact LFS and ethanol-washed LFS diets. Although, compared with the high cholesterol diet, the LFS extract and ethanol-washed LFS diets did not reduce hepatic cholesterol and TG, both levels were remarkably lowered by the intact LFS diet. These results suggest that the improvement in lipid metabolism of rats fed a high-cholesterol diet containing LFS isoflavone aglycones is not due to an independent effect but due to a cooperative effect with soy protein. PMID:25514389

The soluble fiber complex PolyGlycopleX lowers serum triglycerides and reduces hepatic steatosis in high-sucrose-fed rats.

PubMed

Reimer, Raylene A; Grover, Gary J; Koetzner, Lee; Gahler, Roland J; Lyon, Michael R; Wood, Simon

2011-04-01

Viscous soluble fibers have been shown to reduce risk factors associated with type 2 diabetes and cardiovascular disease. The novel functional fiber, PolyGlycopleX (PGX) (InovoBiologic Inc, Calgary, Alberta, Canada) displays greater viscosity than other currently identified soluble fibers. The objective of this study was to determine if PGX lowers serum and hepatic triglycerides (TGs) in a high-sucrose-fed rat model. In this rodent model, feeding a high-sucrose diet consistently increases serum TGs. We hypothesized that consumption of PGX would attenuate hypertriglyceridemia and reduce hepatic steatosis compared with cellulose in rats fed a high-sucrose background diet. Male Sprague-Dawley rats were fed diets containing 65% sucrose and supplemented with either 5% cellulose (control) or 5% PGX (wt/wt) for 43 weeks. At study termination, serum insulin and TGs, hepatic steatosis, and hepatocellular injury were assessed. Body weight increased over time in both groups, but weight gain was attenuated in rats fed PGX vs cellulose in weeks 2 through 22 (P < .05). Serum TGs did not differ from baseline for the first half of the study but consistently increased in the cellulose group thereafter. PolyGlycopleX significantly reduced serum TG to near-baseline levels. At study termination, rats fed PGX had significantly lower hepatic steatosis scores (measured by Sudan black staining) compared with rats fed cellulose. Hepatocellular injury scores did not differ between the groups. In conclusion, PGX reduced serum TG and lipid accumulation in the liver of sucrose-fed rats. Further examination of its potential as a fiber supplement aimed at lessening the burden of hepatic steatosis is warranted. Copyright © 2011 Elsevier Inc. All rights reserved.

Effect of potato on acid-base and mineral homeostasis in rats fed a high-sodium chloride diet.

PubMed

Narcy, Agnès; Robert, Laetitia; Mazur, Andrzej; Demigné, Christian; Rémésy, Christian

2006-05-01

Excessive dietary NaCl in association with a paucity of plant foods, major sources of K alkaline salts, is a common feature in Western eating habits which may lead to acid-base disorders and to Ca and Mg wasting. In this context, to evaluate the effects of potato, rich in potassium citrate, on acid-base homeostasis and mineral retention, Wistar rats were fed wheat starch (WS) or cooked potato (CP) diets with a low (0.5 %) or a high (2 %) NaCl content during 3 weeks. The replacement of WS by CP in the diets resulted in a significant urinary alkalinisation (pH from 5.5 to 7.3) parallel to a rise in citrate and K excretion. Urinary Ca and Mg elimination represented respectively 17 and 62 % of the daily absorbed mineral in rats fed the high-salt WS diet compared with 5 and 28 % in rats fed the high-salt CP diet. The total SCFA concentration in the caecum was 3-fold higher in rats fed the CP diets compared with rats fed the WS diets, and it led to a significant rise in Ca and Mg intestinal absorption (Ca from 39 to 56 %; Mg from 37 to 60 %). The present model of low-grade metabolic acidosis indicates that CP may be effective in alkalinising urine, enhancing citrate excretion and ameliorating Ca and Mg balance.

Vagus nerve contributes to metabolic syndrome in high-fat diet-fed young and adult rats.

PubMed

Barella, Luiz F; Miranda, Rosiane A; Franco, Claudinéia C S; Alves, Vander S; Malta, Ananda; Ribeiro, Tatiane A S; Gravena, Clarice; Mathias, Paulo C F; de Oliveira, Júlio C

2015-01-01

What is the central question of this study? Different nerve contributes periods of life are known for their differential sensitivity to interventions, and increased parasympathetic activity affects the development and maintenance of obesity. Thus, we evaluated the involvement of the vagus nerve by performing a vagotomy in young or adult rats that were offered an obesogenic high-fat diet. What is the main finding and its importance? Although the accumulation of adipose tissue decreased in both younger and older groups, the younger rats showed a greater response to the effects of vagotomy in general. In addition to the important role of the parasympathetic activity, we suggest that the vagus nerve contributes to the condition of obesity. Obesity has become a global problem, and this condition develops primarily because of an imbalance between energy intake and expenditure. The high complexity involved in the regulation of energy metabolism results from several factors besides endocrine factors. It has been suggested that obesity could be caused by an imbalance in the autonomous nervous system, which could lead to a condition of high parasympathetic activity in counterpart to low sympathetic tonus. High-fat (HF) diets have been used to induce obesity in experimental animals, and their use in animals leads to insulin resistance, hyperinsulinaemia and high parasympathetic activity, among other disorders. The aim of this work was to evaluate the effects of a vagotomy performed at the initiation of a HF diet at two different stages of life, weaning and adulthood. The vagotomy reduced parasympathetic activity (-32 and -51% in normal fat-fed rats and -43 and -55% in HF diet-fed rats; P < 0.05) and fat depots (-17 and -33%, only in HF diet-fed rats; P < 0.05). High-fat diet-fed rats exhibited fasting hyperinsulinaemia (fivefold higher in young rats and threefold higher in older rats; P < 0.05); however, vagotomy corrected it in younger rats only, and a similar effect was

Impaired Expression of Neuronal Nitric Oxide Synthase in the Gracile Nucleus Is Involved in Neuropathic Changes in Zucker Diabetic Fatty Rats with and without 2,5-Hexanedione Intoxication

PubMed Central

Ma, Sheng-Xing; Peterson, Richard G.; Magee, Edward M.; Lee, Paul; Lee, Wai-Nang Paul; Li, Xi-Yan

2015-01-01

These studies examined the influence of 2,5-hexanedione (2,5-HD) intoxication on expression of neuronal nitric oxide synthase (nNOS) in the brainstem nuclei in Zucker Diabetic Fatty (ZDF) vs. lean control (LC) rats. Functional neuropathic changes were also investigated following axonal damage and impaired axonal transport induced by the treatment. Animals were intoxicated by i.p. injection of 2,5-HD plus unilateral administration of 2,5-HD over the sciatic nerve. The mechanical thresholds and withdrawal latencies to heat and cold stimuli on the foot were measured at baseline and after intoxication. The medulla sections were examined by nNOS immunohistochemistry and NADPH-diaphorase histochemistry at the end of the treatments. The mechanical thresholds and withdrawal latencies were significantly decreased while nNOS immunostained neurons and NADPH-diaphorase positive cells were selectively reduced in the gracile nucleus at baseline in ZDF vs. LC rats. NADPH-diaphorase reactivity and nNOS positive neurons were increased in the ipsilateral gracile nucleus in LC rats following 2,5-HD intoxication, but its up-regulation was attenuated in ZDF rats. These results suggest that diabetic and chemical intoxication-induced nNOS expression is selectively reduced in the gracile nucleus in ZDF rats. Impaired axonal damage-induced nNOS expression in the gracile nucleus is involved in neuropathic pathophysiology in type II diabetic rats. PMID:26519861

Docosapentaenoic acid and docosahexaenoic acid are positively associated with insulin sensitivity in rats fed high-fat and high-fructose diets.

PubMed

Huang, Jiung-Pang; Cheng, Mei-Ling; Hung, Cheng-Yu; Wang, Chao-Hung; Hsieh, Po-Shiuan; Shiao, Ming-Shi; Chen, Jan-Kan; Li, Dai-Er; Hung, Li-Man

2017-10-01

The aim of the present study was to compare insulin resistance and metabolic changes using a global lipidomic approach. Rats were fed a high-fat diet (HFD) or a high-fructose diet (HFrD) for 12 weeks to induce insulin resistance (IR) syndrome. After 12 weeks feeding, physiological and biochemical parameters were examined. Insulin sensitivity and plasma metabolites were evaluated using a euglycemic-hyperinsulinemic clamp and mass spectrometry, respectively. Pearson's correlation coefficient was used to investigate the strength of correlations. Rats on both diets developed IR syndrome, characterized by hypertension, hyperlipidemia, hyperinsulinemia, impaired fasting glucose, and IR. Compared with HFrD-fed rats, non-esterified fatty acids were lower and body weight and plasma insulin levels were markedly higher in HFD-fed rats. Adiposity and plasma leptin levels were increased in both groups. However, the size of adipocytes was greater in HFD- than HFrD-fed rats. Notably, the lipidomic heat map revealed metabolites exhibiting greater differences in HFD- and HFrD-fed rats compared with controls. Plasma adrenic acid levels were higher in HFD- than HFrD-fed rats. Nevertheless, linoleic and arachidonic acid levels decreased in HFrD-fed rats compared with controls. Plasma concentrations of docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) were significantly reduced after feeding of both diets, particularly the HFrD. There was a strong positive correlation between these two fatty acids and the insulin sensitivity index. The systemic lipidomic analysis indicated that a reduction in DHA and DPA was strongly correlated with IR in rats under long-term overnutrition. These results provide a potential therapeutic target for IR and metabolic syndrome. © 2016 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.

Dietary salt restriction improves cardiac and adipose tissue pathology independently of obesity in a rat model of metabolic syndrome.

PubMed

Hattori, Takuya; Murase, Tamayo; Takatsu, Miwa; Nagasawa, Kai; Matsuura, Natsumi; Watanabe, Shogo; Murohara, Toyoaki; Nagata, Kohzo

2014-12-02

Metabolic syndrome (MetS) enhances salt sensitivity of blood pressure and is an important risk factor for cardiovascular disease. The effects of dietary salt restriction on cardiac pathology associated with metabolic syndrome remain unclear. We investigated whether dietary salt restriction might ameliorate cardiac injury in DahlS.Z-Lepr(fa)/Lepr(fa) (DS/obese) rats, which are derived from a cross between Dahl salt-sensitive and Zucker rats and represent a model of metabolic syndrome. DS/obese rats were fed a normal-salt (0.36% NaCl in chow) or low-salt (0.0466% NaCl in chow) diet from 9 weeks of age and were compared with similarly treated homozygous lean littermates (DahlS.Z-Lepr(+)/Lepr(+), or DS/lean rats). DS/obese rats fed the normal-salt diet progressively developed hypertension and showed left ventricular hypertrophy, fibrosis, and diastolic dysfunction at 15 weeks. Dietary salt restriction attenuated all of these changes in DS/obese rats. The levels of cardiac oxidative stress and inflammation and the expression of cardiac renin-angiotensin-aldosterone system genes were increased in DS/obese rats fed the normal-salt diet, and dietary salt restriction downregulated these parameters in both DS/obese and DS/lean rats. In addition, dietary salt restriction attenuated the increase in visceral adipose tissue inflammation and the decrease in insulin signaling apparent in DS/obese rats without reducing body weight or visceral adipocyte size. Dietary salt restriction did not alter fasting serum glucose levels but it markedly decreased the fasting serum insulin concentration in DS/obese rats. Dietary salt restriction not only prevents hypertension and cardiac injury but also ameliorates insulin resistance, without reducing obesity, in this model of metabolic syndrome. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Upregulation of aldolase B and overproduction of methylglyoxal in vascular tissues from rats with metabolic syndrome.

PubMed

Liu, Jianghai; Wang, Rui; Desai, Kaushik; Wu, Lingyun

2011-12-01

Methylglyoxal (MG) overproduction has been reported in metabolic syndrome with hyperglycaemia (diabetes) or without hyperglycaemia (hypertension), and the underlying mechanism was investigated. Contributions of different pathways or enzymes to MG formation were evaluated in aorta or cultured vascular smooth muscle cells (VSMCs). In all four animal models of metabolic syndrome, i.e. chronically fructose-fed hypertensive Sprague-Dawley rats, spontaneously hypertensive rats, obese non-diabetic Zucker rats, and diabetic Zucker rats, serum and aortic MG and fructose levels were increased, and the expression of GLUT5 (transporting fructose) and aldolase B (converting fructose to MG) in aorta were up-regulated. Aortic expressions of aldolase A, semicarbazide-sensitive amine oxidase (SSAO), and cytochrome P450 2E1 (CYP 2E1), accounting for MG formation during glycolysis, protein, and lipid metabolism, respectively, was unchanged/reduced. Fructose (25 mM) treatment of VSMCs up-regulated the expression of GLUT5 and aldolase B and accelerated MG formation. Insulin (100 nM) increased GLUT5 expression and augmented fructose-increased cellular fructose accumulation and MG formation. Glucose (25 mM) treatment activated the polyol pathway and enhanced fructose formation, leading to aldolase B upregulation and MG overproduction. Inhibition of the polyol pathway reduced the glucose-increased aldolase B expression and MG generation. The excess formation of MG in under these conditions was eliminated by knock-down of aldolase B, but not by knock-down of aldolase A or inhibition of SSAO or CYP 2E1. Upregulation of aldolase B by accumulated fructose is a common mechanism for MG overproduction in VSMCs and aorta in different models of metabolic syndrome.

Ciprofibrate, clofibric acid and respective glycinate derivatives. Effects of a four-week treatment on male lean and obese Zucker rats.

PubMed

Lupp, Amelie; Karge, Elke; Deufel, Thomas; Oelschlägers, Herbert; Fleck, Christian

2008-01-01

Fibrates are widely prescribed in hyperlpidemic patients to prevent atherosclerosis. Their therapeutic use, however, can be associated with adverse effects like gastrointestinal disorders, myalgia, myositis and hepatotoxicity. In rodents large doses can even cause hepatocellular carcinoma. Additionally, interactions with the biotransformation of other compounds at the cytochrome P450 (CYP) system have been observed. Thus, the discovery of new substances or derivatives with less side effects is of great interest. In the present study the influence of a four-week daily oral administration of 2 mg/kg body weight ciprofibrate (CAS 52214-84-3) or of 100 mg/kg body weight clofibric acid (CAS 882-09-7) was compared to that of the respective doses of their newly synthesized glycine conjugates in adult male lean and obese Zucker rats. Although obese rats displayed distinctly higher serum lipid concentrations, after fibrate treatment values were significantly lowered in lean animals only. Livers of obese rats were significantly enlarged, histologically showing a fine-droplet like fatty degeneration and an increase in glycogen content, but no signs of inflammation. After fibrate administration histologically a hypertrophy, an eosinophilia, a reduced glycogen content and also hepatocyteapoptosis were observed. Livers of obese rats displayed higher CYP1A1 andCYP2E1 expression, but lower immunostaining for CYP2B1 and CYP3A2. No differences between the two groups of rats were seen with respect to CYP4A1 expression. Due to fibrate treatment especially CYP2E1 and CYP4A1, but also CYP1A1, 2B1 and 3A2 were induced. Resulting CYP mediated monooxygenase activities were also elevated in most cases. In general, effects of clofibric acid and clofibric acid glycinate (CAS 4896-55-3) were less distinct than those of ciprofibrate and its glycinate (CAS 640772-36-7). With no parameterinvestigated major differences were seen between the parent fibrates and their glycine conjugates. Thus, the

Protein and energy metabolism of young male Wistar rats fed conjugated linoleic acid as structured triacylglycerol.

PubMed

Jørgensen, Henry; Hansen, Christina Hørup; Mu, Huiling; Jakobsen, Kirsten

2010-08-01

Twelve 4-week-old male Wistar rats weighing 100 g were fed diets semi-ad libitum for 22 d containing either 1.5% conjugated linoleic acid (CLA-diet) or high oleic sunflower oil (Control-diet). The CLA was structured triacylglycerol with predominantly cis-9, trans-11 and trans-10, cis-12 fatty acid isomers in the inner position and oleic acid in the other positions of the glycerol molecule. The rats were kept individually in metabolic cages. From days 8-16 energy, nitrogen (N) and carbon (C) balances as well as gas exchange measurements in open-air circuit respiration chambers were performed. CLA had no significant influence on feed intake, daily gain in weight or feed conversion efficiency, but the digestibility of nutrients and energy was significantly reduced (except for fat). CLA did not affect N-balance, but reduced the level of daily retained fat (RQ-method: 0.107 vs. 0.417 g/d, p < 0.01) and consequently energy retention in fat. This was explained by increased heat production (HP, RQ-method: 224.6 vs. 214.6 kJ/d, p < 0.001) caused by a higher fat oxidation (28.9% vs. 22.3%, p < 0.001) at the expense of oxidation of carbohydrates (65.6% vs. 71.4%, p < 0.001), while there was no significant effect on the oxidation of protein (5.5% vs. 6.3%). Consequently, the non-protein respiratory quotient (RQnp) was lower in the rats fed the CLA-diet than in the rats fed the Control-diet (0.907 vs. 0.928, p < 0.001). Plasma total lipids of the CLA-fed rats had higher concentrations of the cis-9, trans-11 than the trans-10, cis-12 CLA-isomer. This study shows that young male Wistar rats respond to CLA fed as structured triacylglycerol.

Sardine protein diet increases plasma glucagon-like peptide-1 levels and prevents tissue oxidative stress in rats fed a high-fructose diet.

PubMed

Madani, Zohra; Sener, Abdullah; Malaisse, Willy J; Dalila, Ait Yahia

2015-11-01

The current study investigated whether sardine protein mitigates the adverse effects of fructose on plasma glucagon‑like peptide-1 (GLP-1) and oxidative stress in rats. Rats were fed casein (C) or sardine protein (S) with or without high‑fructose (HF) for 2 months. Plasma glucose, insulin, GLP‑1, lipid and protein oxidation and antioxidant enzymes were assayed. HF rats developed obesity, hyperglycemia, hyperinsulinemia, insulin resistance and oxidative stress despite reduced energy and food intakes. High plasma creatinine and uric acid levels, in addition to albuminuria were observed in the HF groups. The S‑HF diet reduced plasma glucose, insulin, creatinine, uric acid and homeostasis model assessment‑insulin resistance index levels, however increased GLP‑1 levels compared with the C‑HF diet. Hydroperoxides were reduced in the liver, kidney, heart and muscle of S‑HF fed rats compared with C‑HF fed rats. A reduction in liver, kidney and heart carbonyls was observed in S‑HF fed rats compared with C‑HF fed rats. Reduced levels of nitric oxide (NO) were detected in the liver, kidney and heart of the S‑HF fed rats compared with C‑HF fed rats. The S diet compared with the C diet reduced levels of liver hydroperoxides, heart carbonyls and kidney NO. The S‑HF diet compared with the C‑HF diet increased the levels of liver and kidney superoxide dismutase, liver and muscle catalase, liver, heart and muscle glutathione peroxidase and liver ascorbic acid. The S diet prevented and reversed insulin resistance and oxidative stress, and may have benefits in patients with metabolic syndrome.

Polyphenol-Rich Bilberry Ameliorates Total Cholesterol and LDL-Cholesterol when Implemented in the Diet of Zucker Diabetic Fatty Rats

PubMed Central

Brader, Lea; Overgaard, Ann; Christensen, Lars P.; Jeppesen, Per B.; Hermansen, Kjeld

2013-01-01

BACKGROUND: Bilberries and blackcurrants are nutrient sources rich in bioactive components, including dietary fibers, polyphenols, and anthocyanins, which possess potent cardiovascular protective properties. Few studies investigating the cardio-protective effects of natural components have focused on whole bilberries or blackcurrants. OBJECTIVE: The aim of this trial was to investigate whether a diet enriched with bilberries or blackcurrants has beneficial effects on glucose metabolism, lipid profile, blood pressure, and expression of genes related to glucose and lipid metabolism. METHODS: Male Zucker Diabetic Fatty (ZDF) rats (n = 48) were randomly assigned to either a control, bilberry-enriched, blackcurrant-enriched, or fiber-enriched diet for 8 weeks ad libitum. Real-time quantitative PCR analysis was performed on liver, adipose, and muscle tissue. Berry polyphenol content was determined by HPLC and LC-MS analysis. RESULTS: Bilberry enrichment reduced total (-21%, p = 0.0132) and LDL-cholesterol (-60%, p = 0.0229) levels, but increased HDL-cholesterol to a lesser extent than in controls. This may partly be due to the altered hepatic liver X receptor-α expression (-24%, p < 0.001). Neither bilberries nor blackcurrants influenced glucose metabolism or blood pressure. Nevertheless, transcriptional analysis implied a better conservation of hepatic and adipocyte insulin sensitivity by bilberry enrichment. Anthocyanins constituted 91% and 87% of total polyphenol content in bilberries and blackcurrants, respectively. However, total anthocyanin content (3441 mg/100 g) was 4-fold higher in bilberries than in blackcurrants (871 mg/100 g). CONCLUSIONS: Bilberry consumption ameliorated total and LDL-cholesterol levels, but not HDL-cholesterol levels in ZDF rats. Neither bilberry nor blackcurrant enrichment delayed the development of diabetes or hypertension. Thus, in rats, bilberries may be valuable as a dietary preventive agent against hypercholesterolemia, probably by

Effects of NS lactobacillus strains on lipid metabolism of rats fed a high-cholesterol diet

PubMed Central

2013-01-01

Background Elevated serum cholesterol level is generally considered to be a risk factor for the development of cardiovascular diseases which seriously threaten human health. The cholesterol-lowering effects of lactic acid bacteria have recently become an area of great interest and controversy for many researchers. In this study, we investigated the effects of two NS lactobacillus strains, Lactobacillus plantarum NS5 and Lactobacillus delbrueckii subsp. bulgaricus NS12, on lipid metabolism of rats fed a high cholesterol diet. Methods Thirty-two SD rats were assigned to four groups and fed either a normal or a high-cholesterol diet. The NS lactobacillus treated groups received the high-cholesterol diet supplemented with Lactobacillus plantarum NS5 or Lactobacillus delbrueckii subsp. bulgaricus NS12 in drinking water. The rats were sacrificed after a 6-week feeding period. Body weights, visceral organ and fat weights, serum and liver cholesterol and lipid levels, intestinal microbiota and liver mRNA expression levels related to cholesterol metabolism were analyzed. Liver lipid deposition and adipocyte size were evaluated histologically. Results Compared with rats fed a high cholesterol diet, serum total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B and free fatty acids levels were decreased and apolipoprotein A-I level was increased in NS5 or NS12 strain treated rats, and with no significant change in high-density lipoprotein cholesterol level. Liver cholesterol and triglyceride levels were also significantly decreased in NS lactobacillus strains treated groups. Meanwhile, the NS lactobacillus strains obviously alleviated hepatic injuries, decreased liver lipid deposition and reduced adipocyte size of high cholesterol diet fed rats. NS lactobacillus strains restored the changes in intestinal microbiota compositions, such as the increase in Bacteroides and the decrease in Clostridium. NS lactobacillus strains also regulated the mRNA expression

Hepatic DNA adduct dosimetry in rats fed tamoxifen: a comparison of methods.

PubMed

Schild, Laura J; Phillips, David H; Osborne, Martin R; Hewer, Alan; Beland, Frederick A; Churchwell, Mona I; Brown, Karen; Gaskell, Margaret; Wright, Elizabeth; Poirier, Miriam C

2005-03-01

Liver homogenates from rats fed tamoxifen (TAM) in the diet were shared among four different laboratories. TAM-DNA adducts were assayed by high pressure liquid chromatography-electrospray tandem mass spectrometry (HPLC-ES-MS/MS), TAM-DNA chemiluminescence immunoassay (TAM-DNA CIA), and (32)P-postlabeling with either thin layer ((32)P-P-TLC) or liquid chromatography ((32)P-P-HPLC) separation. In the first study, rats were fed a diet containing 500 p.p.m. TAM for 2 months, and the values for measurements of the (E)-alpha-(deoxyguanosin-N(2)-yl)-tamoxifen (dG-N(2)-TAM) adduct in replicate rat livers varied by 3.5-fold when quantified using 'in house' TAM-DNA standards, or other approaches where appropriate. In the second study, rats were fed 0, 50, 250 or 500 p.p.m. TAM for 2 months, and TAM-DNA values were quantified using both 'in house' approaches as well as a newly synthesized [N-methyl-(3)H]TAM-DNA standard that was shared among all the participating groups. In the second study, the total TAM-DNA adduct values varied by 2-fold, while values for the dG-N(2)-TAM varied by 2.5-fold. Ratios of dG-N(2)-TAM:(E)-alpha-(deoxyguanosin-N(2)-yl)-N-desmethyltamoxifen (dG-N(2)-N-desmethyl-TAM) in the second study were approximately 1:1 over the range of doses examined. The study demonstrated a remarkably good agreement for TAM-DNA adduct measurements among the diverse methods employed.

Genetic Relatedness of WNIN and WNIN/Ob with Major Rat Strains in Biomedical Research.

PubMed

Battula, Kiran Kumar; Nappanveettil, Giridharan; Nakanishi, Satoshi; Kuramoto, Takashi; Friedman, Jeffry M; Kalashikam, Rajender Rao

2015-06-01

WNIN (Wistar/NIN) is an inbred rat strain maintained at National Institute of Nutrition (NIN) for more than 90 years, and WNIN/Ob is an obese mutant originated from it. To determine their genetic relatedness with major rat strains in biomedical research, they were genotyped at various marker loci. The recently identified markers for albino and hooded mutations which clustered all the known albino rats into a single lineage also included WNIN and WNIN/Ob rats. Genotyping using microsatellite DNA markers and phylogenetic analysis with 49 different rat strains suggested that WNIN shares a common ancestor with many Wistar originated strains. Fst estimates and Fischer's exact test suggest that WNIN rats differed significantly from all other strains tested. WNIN/Ob though shows hyper-leptinemia, like Zucker fatty rat, did not share the Zucker fatty rat mutation. The above analyses suggest WNIN as a highly differentiated rat strain and WNIN/Ob a novel obese mutant evolved from it.

Antioxidative and antihypertensive effects of Welsh onion on rats fed with a high-fat high-sucrose diet.

PubMed

Yamamoto, Yukiko; Aoyama, Sakiko; Hamaguchi, Noriko; Rhi, Gyou-Sei

2005-07-01

The effects of Welsh onion on the development of hypertension and autoxidation were studied in 6-week-old male Sprague-Dawley rats. The rats were fed with a control diet or a high-fat high-sucrose (HFS) diet with or without 5% Welsh onion (green-leafy type or white-sheath type) for 4 weeks. The systolic blood pressure was elevated and the thiobarbituric acid reactive substances (TBARS) in plasma were increased in the rats fed with the HFS diet without Welsh onion. The rats fed with the HFS diet containing Welsh onion, especially the green-leafy type, had lower blood pressure. They also had a higher level of nitric oxide (NO) metabolites in both the urine and plasma, lower activity of NADH/NADPH oxidase in the aorta, and suppressed angiotensin II production. The effect of white Welsh onion on decreasing the blood pressure was not significant, although the effects on increasing NO metabolites in the urine and decreasing NADH oxidase activity in the aorta were significant. The TBARS value in the plasma was lowered in the rats fed with either green or white Welsh onion, but the in vitro radical scavenging and ferric reducing antioxidative activities were much higher with green Welsh onion than with the white type. These results suggest that the green-leafy Welsh onion, but not the white type, reduced superoxide generation by suppressing the angiotensine II production and then the NADH/NADPH oxidase activity, increasing the NO availability in the aorta, and consequently lowering the blood pressure in the rats fed with the HFS diet. The radical scavenging and reducing antioxidative activities of green Welsh onion may also be effective in decreasing superoxide.

Immune functions in the Fisher rat fed beluga whale (Delphinapterus leucas) blubber from the contaminated St. Lawrence estuary

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

Lapierre, P.; Guise, S. De; Muir, D.C.G.

1999-02-01

In order to assess the immunotoxic potential of food naturally contaminated with PCBs and other organohalogens, Fisher rats were fed a diet in which the lipids originated from the blubber of either a highly polluted St. Lawrence beluga or a relatively uncontaminated Arctic beluga. After a period of 2 months, different immune functions were evaluated, including lymphoblastic transformation, natural killer cell activity, plaque-forming cells, phagocytosis, oxidative burst, and immunophenotyping. For all assays, rats fed at St. Lawrence beluga blubber diet or a mixture of Arctic and St. Lawrence beluga blubber diet were not different from control rats fed a dietmore » containing Arctic beluga blubber. These results are inconsistent with the well-known immunosuppressive effects of organochlorines in numerous species and with the lesions suggestive of organochlorine-related immunosuppression that are observed in St. Lawrence belugas. The lack of observable immunotoxic effects in rats fed contaminated beluga blubber might be explained by antagonistic effects in the organohalogen mixture, by a response specific to the rat, by a strain-related lack of sensitivity to organochlorines, or by insufficient dose due to the shortness of the exposure period or the route of exposure.« less

Yogurt protects against growth retardation in weanling rats fed diets high in phytic acid

PubMed Central

Gaetke, Lisa M.; McClain, Craig J.; Toleman, C. Jean; Stuart, Mary A.

2010-01-01

The purpose of this study was to determine the affects of adding yogurt to animal diets which were high in phytic acid (PA) and adequate in zinc (38 μg Zn/g). The PA:Zn molar ratio was 60:1. Zinc status was determined by documenting growth and measuring the zinc concentration in bone (tibia) and plasma. For 25 days, 6 groups (n=6) of Sprague-Dawley weanling rats were fed one of the following AIN-76 diets. Half of the diets contained PA. Four of the diets contained yogurt with either active or heat-treated (inactive) cultures added at 25% of the diet. Diets: (without PA) 1) AIN, 2) AIN with active yogurt, 3) AIN and inactive yogurt; and (with PA) 4) AIN with PA, 5) AIN with PA plus active yogurt, and 6) AIN with PA plus inactive yogurt. Body weight, weight gain, and zinc concentration in bone and plasma were measured, and feed efficiency ratio (FER) was calculated. Rats fed diets with PA and yogurt had normal growth compared to the control group. Growth retardation was evident in the group fed the diet with PA and no yogurt. This group had significantly lower body weight compared to all other groups (p<0.05). Rats fed diets with PA, with or without yogurt, had significantly lower zinc concentration in bone and plasma (p<0.05). Adding yogurt to diets high in PA resulted in normal growth in weanling rats, however, zinc concentration in bone and plasma was still sub-optimal. PMID:19269152

A grape polyphenol extract modulates muscle membrane fatty acid composition and lipid metabolism in high-fat--high-sucrose diet-fed rats.

PubMed

Aoun, Manar; Michel, Francoise; Fouret, Gilles; Schlernitzauer, Audrey; Ollendorff, Vincent; Wrutniak-Cabello, Chantal; Cristol, Jean-Paul; Carbonneau, Marie-Annette; Coudray, Charles; Feillet-Coudray, Christine

2011-08-01

Accumulation of muscle TAG content and modification of muscle phospholipid fatty acid pattern may have an impact on lipid metabolism, increasing the risk of developing diabetes. Some polyphenols have been reported to modulate lipid metabolism, in particular those issued from red grapes. The present study was designed to determine whether a grape polyphenol extract (PPE) modulates skeletal muscle TAG content and phospholipid fatty acid composition in high-fat-high-sucrose (HFHS) diet-fed rats. Muscle plasmalemmal and mitochondrial fatty acid transporters, GLUT4 and lipid metabolism pathways were also explored. The PPE decreased muscle TAG content in HFHS/PPE diet-fed rats compared with HFHS diet-fed rats and induced higher proportions of n-3 PUFA in phospholipids. The PPE significantly up-regulated GLUT4 mRNA expression. Gene and protein expression of muscle fatty acid transporter cluster of differentiation 36 (CD36) was increased in HFHS diet-fed rats but returned to control values in HFHS/PPE diet-fed rats. Carnitine palmitoyltransferase 1 protein expression was decreased with the PPE. Mitochondrial β-hydroxyacyl CoA dehydrogenase was increased in HFHS diet-fed rats and returned to control values with PPE supplementation. Lipogenesis, mitochondrial biogenesis and mitochondrial activity were not affected by the PPE. In conclusion, the PPE modulated membrane phospholipid fatty acid composition and decreased muscle TAG content in HFHS diet-fed rats. The PPE lowered CD36 gene and protein expression, probably decreasing fatty acid transport and lipid accumulation within skeletal muscle, and increased muscle GLUT4 expression. These effects of the PPE are in favour of a better insulin sensibility.

High dose lycopene supplementation increases hepatic cytochrome P4502E1 protein and inflammation in alcohol-fed rats.

PubMed

Veeramachaneni, Sudipta; Ausman, Lynne M; Choi, Sang Woon; Russell, Robert M; Wang, Xiang-Dong

2008-07-01

Recent in vitro evidence suggests that the antioxidant lycopene can prevent alcohol-induced oxidative stress and inflammation. However, knowledge of possible interactions in vivo between escalating doses of lycopene and chronic alcohol ingestion are lacking. In this study, we investigated potential interactions between alcohol ingestion and lycopene supplementation and their effect on hepatic lycopene concentration, cytochrome P4502E1 (CYP2E1) induction, and inflammation. Fischer 344 rats (6 groups, n = 10 per group) were fed either a liquid ethanol Lieber-DeCarli diet or a control diet (isocaloric maltodextrin substituted for ethanol) with or without lycopene supplementation at 2 doses (1.1 or 3.3 mg x kg body weight(-1) x d(-1)) for 11 wk. Plasma and hepatic concentrations of lycopene isomers were assessed by HPLC analysis. We examined expressions of hepatic CYP2E1 and tumor necrosis factor-alpha (TNFalpha) and the incidence of hepatic inflammatory foci. Both plasma and hepatic lycopene concentrations were greater in alcohol-fed rats than in control rats supplemented with identical doses of lycopene. In contrast, alcohol-fed rats had a lower percentage of lycopene cis isomers in the plasma and the liver compared with control rats fed the same dose of lycopene. Notably, lycopene supplementation at the higher dose significantly induced hepatic CYP2E1 protein, TNFalpha mRNA, and the incidence of inflammatory foci in the alcohol-fed rats but not in the control rats. These data indicate an interaction between chronic alcohol ingestion and lycopene supplementation and suggest a need for caution among individuals consuming high amounts of both alcohol and lycopene.

Serum lipids, hepatic glycerolipid metabolism and peroxisomal fatty acid oxidation in rats fed omega-3 and omega-6 fatty acids.

PubMed Central

Rustan, A C; Christiansen, E N; Drevon, C A

1992-01-01

Rats were fed, for 3 weeks, high-fat (20% w/w) diets containing sunflower-seed oil, linseed oil or fish oil. Chow-fed rats were used as a low-fat reference. The high-fat diets markedly reduced non-fasting-rat serum triacylglycerol as compared with the low-fat reference, and the highest reduction (85%) was observed with the fish-oil group, which was significantly lower than that of the other high-fat diets. The serum concentration of phospholipids was significantly reduced (30%) only in the fish-oil-fed animals, whereas serum non-esterified fatty acids were reduced 40-50% by both the fish-oil- and linseed-oil-fed groups. The liver content of triacylglycerol showed a 1.7-fold increase with the fish-oil diet and 2-2.5-fold with the other dietary groups when compared with rats fed a low-fat diet, whereas the hepatic content of phospholipids was unchanged. Peroxisomal fatty acid oxidation (acyl-CoA oxidase) was 2-fold increased for the rats fed fish oil; however this was not significantly higher when comparison was made with rats fed the linseed-oil diet. There was no difference in phosphatidate hydrolysis (microsomal and cytosolic fractions) among animals fed the various diets. Acyl-CoA:diacylglycerol acyltransferase activity was increased by all high-fat diets, but the fish-oil-diet-fed group showed a significantly lower enzyme activity than did rats fed the other high-fat diets. A linear correlation between acyl-CoA:diacylglycerol acyltransferase activity and liver triacylglycerol was observed, and the microsomal enzyme activity was decreased 40-50% by incubation in the presence of eicosapentaenoyl-CoA. CoA derivatives of arachidonic, linolenic and linoleic acid had no inhibitory effect when compared with the control. These results indicate that dietary fish oil may have greater triacylglycerol-lowering effect than other polyunsaturated diets, owing to decreased triacylglycerol synthesis caused by inhibition of acyl-CoA:diacylglycerol acyltransferase. In addition

Virgin coconut oil maintains redox status and improves glycemic conditions in high fructose fed rats.

PubMed

Narayanankutty, Arunaksharan; Mukesh, Reshma K; Ayoob, Shabna K; Ramavarma, Smitha K; Suseela, Indu M; Manalil, Jeksy J; Kuzhivelil, Balu T; Raghavamenon, Achuthan C

2016-01-01

Virgin Coconut Oil (VCO), extracted from fresh coconut kernel possess similar fatty acid composition to that of Copra Oil (CO), a product of dried kernel. Although CO forms the predominant dietary constituent in south India, VCO is being promoted for healthy life due to its constituent antioxidant molecules. High fructose containing CO is an established model for insulin resistance and steatohepatitis in rodents. In this study, replacement of CO with VCO in high fructose diet markedly improved the glucose metabolism and dyslipidemia. The animals fed VCO diet had only 17 % increase in blood glucose level compared to CO fed animals (46 %). Increased level of GSH and antioxidant enzyme activities in VCO fed rats indicate improved hepatic redox status. Reduced lipid peroxidation and carbonyl adducts in VCO fed rats well corroborate with the histopathological findings that hepatic damage and steatosis were comparatively reduced than the CO fed animals. These results suggest that VCO could be an efficient nutraceutical in preventing the development of diet induced insulin resistance and associated complications possibly through its antioxidant efficacy.

Arctium lappa ameliorates endothelial dysfunction in rats fed with high fat/cholesterol diets.

PubMed

Lee, Yun Jung; Choi, Deok Ho; Cho, Guk Hyun; Kim, Jin Sook; Kang, Dae Gill; Lee, Ho Sub

2012-08-06

Arctium lappa L. (Asteraceae), burdock, is a medicinal plant that is popularly used for treating hypertension, gout, hepatitis, and other inflammatory disorders. This study was performed to test the effect of ethanol extract of Arctium lappa L. (EAL) seeds on vascular reactivity and inflammatory factors in rats fed a high fat/cholesterol diet (HFCD). EAL-I (100 mg·kg-1/day), EAL-II (200 mg·kg-1/day), and fluvastatin (3 mg·kg-1/day) groups initially received HFCD alone for 8 weeks, with EAL supplementation provided during the final 6 weeks. Treatment with low or high doses of EAL markedly attenuated plasma levels of triglycerides and augmented plasma levels of high-density lipoprotein (HDL) in HFCD-fed rats. Chronic treatment with EAL markedly reduced impairments of acetylcholine (ACh)-induced relaxation of aortic rings. Furthermore, chronic treatment with EAL significantly lowered systolic blood pressure (SBP) and maintained smooth and flexible intimal endothelial layers in HFCD-fed rats. Chronic treatment with EAL suppressed upregulation of intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, and E-selectin in the aorta. Chronic treatment with EAL also suppressed increases in matrix metalloproteinase (MMP)-2 expression. These results suggested that EAL can inhibit HFCD-induced vascular inflammation in the rat model. The present study provides evidence that EAL ameliorates HFCD-induced vascular dysfunction through protection of vascular relaxation and suppression of vascular inflammation.

Arctium lappa ameliorates endothelial dysfunction in rats fed with high fat/cholesterol diets

PubMed Central

2012-01-01

Background Arctium lappa L. (Asteraceae), burdock, is a medicinal plant that is popularly used for treating hypertension, gout, hepatitis, and other inflammatory disorders. This study was performed to test the effect of ethanol extract of Arctium lappa L. (EAL) seeds on vascular reactivity and inflammatory factors in rats fed a high fat/cholesterol diet (HFCD). Method EAL-I (100 mg·kg−1/day), EAL-II (200 mg·kg−1/day), and fluvastatin (3 mg·kg−1/day) groups initially received HFCD alone for 8 weeks, with EAL supplementation provided during the final 6 weeks. Results Treatment with low or high doses of EAL markedly attenuated plasma levels of triglycerides and augmented plasma levels of high-density lipoprotein (HDL) in HFCD-fed rats. Chronic treatment with EAL markedly reduced impairments of acetylcholine (ACh)-induced relaxation of aortic rings. Furthermore, chronic treatment with EAL significantly lowered systolic blood pressure (SBP) and maintained smooth and flexible intimal endothelial layers in HFCD-fed rats. Chronic treatment with EAL suppressed upregulation of intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, and E-selectin in the aorta. Chronic treatment with EAL also suppressed increases in matrix metalloproteinase (MMP)-2 expression. These results suggested that EAL can inhibit HFCD-induced vascular inflammation in the rat model. Conclusion The present study provides evidence that EAL ameliorates HFCD-induced vascular dysfunction through protection of vascular relaxation and suppression of vascular inflammation. PMID:22866890

Haloperidol and Rimonabant Increase Delay Discounting in Rats Fed High-Fat and Standard-Chow Diets

PubMed Central

Boomhower, Steven R.; Rasmussen, Erin B.

2016-01-01

The dopamine and endocannabinoid neurotransmitter systems have been implicated in delay discounting, a measure of impulsive choice, and obesity. The current study was designed to determine the extent to which haloperidol and rimonabant affected delay discounting in rats fed standard-chow and high-fat diets. Sprague-Dawley rats were allowed to free-feed under a high-fat diet (4.73 kcal/g) or a standard-chow diet (3.0 kcal/g) for three months. Then, operant sessions began in which rats (n = 9 standard chow; n = 10 high-fat) chose between one sucrose pellet delivered immediately vs. three sucrose pellets after a series of delays. In another condition, carrot-flavored pellets replaced sucrose pellets. After behavior stabilized, acute injections of rimonabant (0.3-10 mg/kg) and haloperidol (0.003-0.1 mg/kg) were administered i.p. before some choice sessions in both pellet conditions. Haloperidol and rimonabant increased discounting in both groups of rats by decreasing percent choice for the larger reinforcer and area-under-the-curve (AUC) values. Rats in the high-fat diet condition demonstrated increased sensitivity to haloperidol compared to chow-fed controls: haloperidol increased discounting in both dietary groups in the sucrose condition,, but only in the high-fat-fed rats in the carrot-pellet condition. These findings indicate that blocking D2 and CB1 receptors results in increased delay discounting, and that a high-fat diet may alter sensitivity to dopaminergic compounds using the delay-discounting task. PMID:25000488

Rimonabant's reductive effects on high densities of food reinforcement, but not palatability, in lean and obese Zucker rats.

PubMed

Buckley, Jessica L; Rasmussen, Erin B

2014-05-01

Cannabinoid antagonists purportedly have greater effects in reducing the intake of highly palatable food compared to less palatable food. However, this assertion is based on free-feeding studies in which the amount of palatable food eaten under baseline conditions is often confounded with other variables, such as unequal access to both food options and differences in qualitative features of the foods. We attempted to reduce these confounds by using a model of choice that programmed the delivery rates of sucrose and carrot-flavored pellets. Lever pressing of ten lean (Fa/Fa or Fa/fa) and ten obese (fa/fa) Zucker rats was placed under three conditions in which programmed ratios for food pellets on two levers were 5:1, 1:1, and 1:5. In phase 1, responses on the two levers produced one type of pellet (sucrose or carrot); in phase 2, responses on one lever produced sucrose pellets and on the other lever produced carrot pellets. After responses stabilized under each food ratio, acute doses of rimonabant (0, 3, and 10 mg/kg) were administered before experimental sessions. The number of reinforcers and responses earned per session under each ratio and from each lever was compared. Rimonabant reduced reinforcers in 1:5 and 5:1 food ratios in phase 1, and across all ratios in phase 2. Rimonabant reduced sucrose and carrot-flavored pellet consumption similarly; rimonabant did not affect bias toward sucrose, but increased sensitivity to amount differences in lean rats. This suggests that relative amount of food, not palatability, may be an important behavioral mechanism in the effects of rimonabant.

Ibipinabant attenuates β-cell loss in male Zucker diabetic fatty rats independently of its effects on body weight.

PubMed

Rohrbach, K; Thomas, M A; Glick, S; Fung, E N; Wang, V; Watson, L; Gregory, P; Antel, J; Pelleymounter, M A

2012-06-01

To test the antidiabetic efficacy of ibipinabant, this new cannabinoid receptor 1 (CB1) antagonist was compared with food-restriction-induced weight loss, rosiglitazone (4 mg/kg) and rimonabant (3 and 10 mg/kg), using parameters of glycaemic control in male Zucker diabetic fatty (ZDF) rats. Body weight, food and water intake, fasted and non-fasted glucose and insulin, glucose tolerance and glycosylated haemoglobin (HbA1c) were all assessed over the course of the 9-week study. Pancreatic insulin content and islet area were also evaluated. At the end of the study, vehicle-treated ZDF rats were severely hyperglycaemic and showed signs of β-cell decline, including dramatic reductions in unfasted insulin levels. Ibipinanbant (10 mg/kg) reduced the following relative to vehicle controls: fasting glucose (-61%), glucose excursion area under the curve (AUC) in an oral glucose tolerance test (OGTT, -44%) and HbA1c (-50%). Furthermore, non-fasting insulin, islet area and islet insulin content were all increased (71, 40 and 76%, respectively) relative to vehicle controls by the end of the study. All of these effects were similar to those of rimonabant and rosiglitazone, where ibipinabant was slightly more effective than rimonabant at the lowest dose and somewhat less effective than rosiglitazone at all doses. These antidiabetic effects appear independent of weight loss because none of the parameters above were consistently improved by the comparable weight loss induced by food restriction. Ibipinabant may have weight loss-independent antidiabetic effects and may have the potential to attenuate β-cell loss in a model of progressive β-cell dysfunction. © 2012 Blackwell Publishing Ltd.

Characterization of the Prediabetic State in a Novel Rat Model of Type 2 Diabetes, the ZFDM Rat.

PubMed

Gheni, Ghupurjan; Yokoi, Norihide; Beppu, Masayuki; Yamaguchi, Takuro; Hidaka, Shihomi; Kawabata, Ayako; Hoshino, Yoshikazu; Hoshino, Masayuki; Seino, Susumu

2015-01-01

We recently established a novel animal model of obese type 2 diabetes (T2D), the Zucker fatty diabetes mellitus (ZFDM) rat strain harboring the fatty mutation (fa) in the leptin receptor gene. Here we performed a phenotypic characterization of the strain, focusing mainly on the prediabetic state. At 6-8 weeks of age, fa/fa male rats exhibited mild glucose intolerance and severe insulin resistance. Although basal insulin secretion was remarkably high in the isolated pancreatic islets, the responses to both glucose stimulation and the incretin GLP-1 were retained. At 10-12 weeks of age, fa/fa male rats exhibited marked glucose intolerance as well as severe insulin resistance similar to that at the earlier age. In the pancreatic islets, the insulin secretory response to glucose stimulation was maintained but the response to the incretin was diminished. In nondiabetic Zucker fatty (ZF) rats, the insulin secretory responses to both glucose stimulation and the incretin in the pancreatic islets were similar to those of ZFDM rats. As islet architecture was destroyed with age in ZFDM rats, a combination of severe insulin resistance, diminished insulin secretory response to incretin, and intrinsic fragility of the islets may cause the development of T2D in this strain.

Cinnamon Polyphenol Extract Inhibits Hyperlipidemia and Inflammation by Modulation of Transcription Factors in High-Fat Diet-Fed Rats.

PubMed

Tuzcu, Zeynep; Orhan, Cemal; Sahin, Nurhan; Juturu, Vijaya; Sahin, Kazim

2017-01-01

We evaluated the effects of cinnamon polyphenol extract on hepatic transcription factors expressions including SREBP-1c and LXR- α in rats fed high fat diet (HFD). Twenty-eight Wistar rats were allocated into four groups: (i) normal control: animals fed with normal chow; (ii) cinnamon: animals supplemented with cinnamon polyphenol; (iii) HFD: animals fed a high-fat diet; and (iv) HFD + cinnamon: animals fed a high-fat diet and treated with cinnamon polyphenol. Obesity was linked to hyperglycemia, hyperlipidemia, and oxidative stress as imitated by elevated serum glucose, lipid profile, and serum and liver malondialdehyde (MDA) concentrations. Cinnamon polyphenol decreased body weight, visceral fat, liver weight and serum glucose and insulin concentrations, liver antioxidant enzymes, and lipid profile ( P < 0.05) and reduced serum and liver MDA concentration compared to HFD rats ( P < 0.05). Cinnamon polyphenol also suppressed the hepatic SREBP-1c, LXR- α , ACLY, FAS, and NF- κ B p65 expressions and enhanced the PPAR- α , IRS-1, Nrf2, and HO-1 expressions in the HFD rat livers ( P < 0.05). In conclusion, cinnamon polyphenol reduces the hyperlipidemia, inflammation, and oxidative stress through activating transcription factors and antioxidative defense signaling pathway in HFD rat liver.

Cinnamon Polyphenol Extract Inhibits Hyperlipidemia and Inflammation by Modulation of Transcription Factors in High-Fat Diet-Fed Rats

PubMed Central

Tuzcu, Zeynep; Orhan, Cemal; Sahin, Nurhan; Juturu, Vijaya

2017-01-01

We evaluated the effects of cinnamon polyphenol extract on hepatic transcription factors expressions including SREBP-1c and LXR-α in rats fed high fat diet (HFD). Twenty-eight Wistar rats were allocated into four groups: (i) normal control: animals fed with normal chow; (ii) cinnamon: animals supplemented with cinnamon polyphenol; (iii) HFD: animals fed a high-fat diet; and (iv) HFD + cinnamon: animals fed a high-fat diet and treated with cinnamon polyphenol. Obesity was linked to hyperglycemia, hyperlipidemia, and oxidative stress as imitated by elevated serum glucose, lipid profile, and serum and liver malondialdehyde (MDA) concentrations. Cinnamon polyphenol decreased body weight, visceral fat, liver weight and serum glucose and insulin concentrations, liver antioxidant enzymes, and lipid profile (P < 0.05) and reduced serum and liver MDA concentration compared to HFD rats (P < 0.05). Cinnamon polyphenol also suppressed the hepatic SREBP-1c, LXR-α, ACLY, FAS, and NF-κB p65 expressions and enhanced the PPAR-α, IRS-1, Nrf2, and HO-1 expressions in the HFD rat livers (P < 0.05). In conclusion, cinnamon polyphenol reduces the hyperlipidemia, inflammation, and oxidative stress through activating transcription factors and antioxidative defense signaling pathway in HFD rat liver. PMID:28396714

Forskolin- and dihydroalprenolol (DHA) binding sites and adenylate cyclase activity in heart of rats fed diets containing different oils

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

Alam, S.Q.; Ren, Y.F.; Alam, B.S.

1987-05-01

The purpose of the present investigation was to determine if dietary lipids can induce changes in the adenylate cyclase system in rat heart. Three groups of male young Sprague-Dawley rats were fed for 6 weeks diets containing 10% corn oil (I), 8% coconut oil + 2% corn oil (II) or 10% menhaden oil (III). Adenylate cyclase activity (basal, fluoride-, isoproterenol-, and forskolin-stimulated) was higher in heart homogenates of rats in group III than in the other two groups. Concentration of the (/sup 3/H)-forskolin binding sites in the cardiac membranes were significantly higher in rats fed menhaden oil. The values (pmol/mgmore » protein) were 4.8 +/- 0.2 (I), 4.5 +/- 0.7 (II) and 8.4 +/- 0.5 (III). There was no significant difference in the affinity of the forskolin binding sites among the 3 dietary groups. When measured at different concentrations of forskolin, the adenylate cyclase activity in cardiac membranes of rats fed menhaden oil was higher than in the other 2 groups. Concentrations of the (/sup 3/H)DHA binding sites were slightly higher but their affinity was lower in cardiac membranes of rats fed menhaden oil. The results suggest that diets containing fish oil increase the concentration of the forskolin binding sites and may also affect the characteristics of the ..beta..-adrenergic receptor in rat heart.« less

Influence of fenofibrate treatment on triacylglycerides, diacylglycerides and fatty acids in fructose fed rats.

PubMed

Kopf, Thomas; Schaefer, Hans-Ludwig; Troetzmueller, Martin; Koefeler, Harald; Broenstrup, Mark; Konovalova, Tatiana; Schmitz, Gerd

2014-01-01

Fenofibrate (FF) lowers plasma triglycerides via PPARα activation. Here, we analyzed lipidomic changes upon FF treatment of fructose fed rats. Three groups with 6 animals each were defined as control, fructose-fed and fructose-fed/FF treated. Male Wistar Unilever Rats were subjected to 10% fructose-feeding for 20 days. On day 14, fenofibrate treatment (100 mg/kg p.o.) was initiated and maintained for 7 days. Lipid species in serum were analyzed using mass spectrometry (ESI-MS/MS; LC-FT-MS, GC-MS) on days 0, 14 and 20 in all three groups. In addition, lipid levels in liver and intestine were determined. Short-chain TAGs increased in serum and liver upon fructose-feeding, while almost all TAG-species decreased under FF treatment. Long-chain unsaturated DAG-levels (36:1, 36:2, 36:4, 38:3, 38:4, 38:5) increased upon FF treatment in rat liver and decreased in rat serum. FAs, especially short-chain FAs (12:0, 14:0, 16:0) increased during fructose-challenge. VLDL secretion increased upon fructose-feeding and together with FA-levels decreased to control levels during FF treatment. Fructose challenge of de novo fatty acid synthesis through fatty acid synthase (FAS) may enhance the release of FAs ≤ 16:0 chain length, a process reversed by FF-mediated PPARα-activation.

Effects of estradiol, estrogen receptor subtype-selective agonists and genistein on glucose metabolism in leptin resistant female Zucker diabetic fatty (ZDF) rats.

PubMed

Weigt, Carmen; Hertrampf, Torsten; Flenker, Ulrich; Hülsemann, Frank; Kurnaz, Pinar; Fritzemeier, Karl Heinrich; Diel, Patrick

2015-11-01

The leptin resistant Zucker diabetic fatty (ZDF) rats are hyperphagic and become obese, but whereas the males develop type 2 diabetes mellitus (T2DM), the females remain euglycaemic. As estrogen deficiency is known to increase the risk of developing T2DM, we evaluated the role of ER subtypes alpha and beta in the development of glucose tolerance in leptin resistant ovariectomized (OVX) ZDF rats. At least six rats per group were treated with either vehicle (OVX), 17β-estradiol (E2), ER subtype-selective agonists (Alpha and Beta), or genistein (Gen) for 17 weeks. At the end of the treatment period a glucose tolerance assay was performed and the metabolic flux of (13)C-glucose for the E2 group was investigated. OVX ZDF rats treated with E2, Alpha, Beta, and Gen tolerated the glucose significantly better than untreated controls. E2 treatment increased absorbance/flux of (13)C-glucose to metabolic relevant tissues such liver, adipose tissue, gastrocnemius, and soleus muscle. Moreover, whereas Alpha treatment markedly increased mRNA expression of GLUT4 in gastrocnemius muscle, Beta treatment resulted in the largest fiber sizes of the soleus muscle. Treatment with Gen increased both the mRNA expression of GLUT 4 and the fiber sizes in the skeletal muscle. In addition, E2 and Alpha treatment decreased food intake and body weight gain. In summary, estrogen-improved glucose absorption is mediated via different molecular mechanisms: while activation of ER alpha seems to stimulate muscular GLUT4 functionality, activation of ER beta results in a hypertrophy of muscle fibers. In addition, selective activation of ER alpha decreased food intake and body weight gain. Our data further indicate that ER subtype-selective agonists and genistein improve systemic glucose tolerance also in the absence of a functional leptin signaling pathway. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dietary Whole Egg Consumption Attenuates Body Weight Gain and Is More Effective than Supplemental Cholecalciferol in Maintaining Vitamin D Balance in Type 2 Diabetic Rats.

PubMed

Saande, Cassondra J; Jones, Samantha K; Hahn, Kaylee E; Reed, Carter H; Rowling, Matthew J; Schalinske, Kevin L

2017-09-01

Background: Type 2 diabetes (T2D) is characterized by vitamin D insufficiency owing to excessive urinary loss of 25-hydroxycholecalciferol [25(OH)D]. We previously reported that a diet containing dried whole egg, a rich source of vitamin D, was effective at maintaining circulating 25(OH)D concentrations in rats with T2D. Furthermore, whole egg consumption reduced body weight gain in rats with T2D. Objective: This study was conducted to compare whole egg consumption with supplemental cholecalciferol with respect to vitamin D balance, weight gain, and body composition in rats with T2D. Methods: Male Zucker diabetic fatty (ZDF) rats ( n = 24) and their lean controls ( n = 24) were obtained at 5 wk of age and randomly assigned to 3 treatment groups: a casein-based diet (CAS), a dried whole egg-based diet (WE), or a casein-based diet containing supplemental cholecalciferol (CAS+D) at the same amount of cholecalciferol provided by WE (37.6 μg/kg diet). Rats were fed their respective diets for 8 wk. Weight gain and food intake were measured daily, circulating 25(OH)D concentrations were measured by ELISA, and body composition was analyzed by dual X-ray absorptiometry. Results: Weight gain and percentage of body fat were reduced by ∼20% and 11%, respectively, in ZDF rats fed WE compared with ZDF rats fed CAS or CAS+D. ZDF rats fed CAS had 21% lower serum 25(OH)D concentrations than lean rats fed CAS. In ZDF rats, WE consumption increased serum 25(OH)D concentrations 130% compared with CAS, whereas consumption of CAS+D increased serum 25(OH)D concentrations 35% compared with CAS. Conclusions: Our data suggest that dietary consumption of whole eggs is more effective than supplemental cholecalciferol in maintaining circulating 25(OH)D concentrations in rats with T2D. Moreover, whole egg consumption attenuated weight gain and reduced percentage of body fat in ZDF rats. These data may support new dietary recommendations targeting the prevention of vitamin D insufficiency in

The Combined Intervention with Germinated Vigna radiata and Aerobic Interval Training Protocol Is an Effective Strategy for the Treatment of Non-Alcoholic Fatty Liver Disease (NAFLD) and Other Alterations Related to the Metabolic Syndrome in Zucker Rats.

PubMed

Kapravelou, Garyfallia; Martínez, Rosario; Nebot, Elena; López-Jurado, María; Aranda, Pilar; Arrebola, Francisco; Cantarero, Samuel; Galisteo, Milagros; Porres, Jesus M

2017-07-19

Metabolic syndrome (MetS) is a group of related metabolic alterations that increase the risk of developing non-alcoholic fatty liver disease (NAFLD). Several lifestyle interventions based on dietary treatment with functional ingredients and physical activity are being studied as alternative or reinforcement treatments to the pharmacological ones actually in use. In the present experiment, the combined treatment with mung bean ( Vigna radiata ), a widely used legume with promising nutritional and health benefits that was included in the experimental diet as raw or 4 day-germinated seed flour, and aerobic interval training protocol (65-85% VO₂ max) has been tested in lean and obese Zucker rats following a 2 × 2 × 2 (2 phenotypes, 2 dietary interventions, 2 lifestyles) factorial ANOVA (Analysis of Variance) statistical analysis. Germination of V. radiata over a period of four days originated a significant protein hydrolysis leading to the appearance of low molecular weight peptides. The combination of 4 day-germinated V. radiata and aerobic interval training was more efficient compared to raw V. radiata at improving the aerobic capacity and physical performance, hepatic histology and functionality, and plasma lipid parameters as well as reverting the insulin resistance characteristic of the obese Zucker rat model. In conclusion, the joint intervention with legume sprouts and aerobic interval training protocol is an efficient treatment to improve the alterations of glucose and lipid metabolism as well as hepatic histology and functionality related to the development of NAFLD and the MetS.

Comparative evaluation of the hypolipidemic effects of coconut water and lovastatin in rats fed fat-cholesterol enriched diet.

PubMed

Sandhya, V G; Rajamohan, T

2008-12-01

The coconut water presents a series of nutritional and therapeutic properties, being a natural, acid and sterile solution, which contains several biologically active components, l-arginine, ascorbic acid, minerals such as calcium, magnesium and potassium, which have beneficial effects on lipid levels. Recent studies in our laboratory showed that both tender and mature coconut water feeding significantly (P<0.05) reduced hyperlipidemia in cholesterol fed rats [Sandhya, V.G., Rajamohan, T., 2006. Beneficial effects of coconut water feeding on lipid metabolism in cholesterol fed rats. J. Med. Food 9, 400-407]. The current study evaluated the hypolipidemic effect of coconut water (4ml/100g body weight) with a lipid lowering drug, lovastatin (0.1/100g diet) in rats fed fat-cholesterol enriched diet ad libitum for 45 days. Coconut water or lovastatin supplementation lowered the levels of serum total cholesterol, VLDL+LDL cholesterol, triglycerides and increased HDL cholesterol in experimental rats (P<0.05). Coconut water feeding decreased activities of hepatic lipogenic enzymes and increased HMG CoA reductase and lipoprotein lipase activity (P<0.05). Incorporation of radioactive acetate into free and ester cholesterol in the liver were higher in coconut water treated rats. Coconut water supplementation increased hepatic bile acid and fecal bile acids and neutral sterols (P<0.05). Coconut water has lipid lowering effect similar to the drug lovastatin in rats fed fat-cholesterol enriched diet.

Watermelon consumption improves inflammation and antioxidant capacity in rats fed an atherogenic diet.

PubMed

Hong, Mee Young; Hartig, Nicole; Kaufman, Katy; Hooshmand, Shirin; Figueroa, Arturo; Kern, Mark

2015-03-01

Cardiovascular disease (CVD) is the leading cause of death in the United States. Watermelon, rich in antioxidants and other bioactive components, may be a viable method to improve CVD risk factors through reduced oxidative stress. The purpose of the study was to determine the effects of watermelon powder consumption on lipid profiles, antioxidant capacity, and inflammation in dextran sodium sulfate (DSS)-treated rats fed an atherogenic diet. We hypothesized that watermelon would increase antioxidant capacity and reduce blood lipids and inflammation through modulation of related gene expression. Forty male-weanling (21 days old) Sprague-Dawley rats were divided into 4 groups (10 per group, total N = 40) in a 2 diets (control or 0.33% watermelon) × 2 treatments (with or without DSS) factorial design using an atherogenic diet. Watermelon-fed groups exhibited significantly lower serum triglycerides, total cholesterol, and low-density lipoprotein cholesterol (P< .05). C-reactive protein levels were significantly lower in watermelon-fed rats than the control (P= .001). In addition, oxidative stress as measured by thiobarbituric acid reactive substances was significantly lower in watermelon groups (P= .001). Total antioxidant capacity, superoxide dismutase, and catalase activities were greater in watermelon groups (P< .05). Aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and lactate dehydrogenase were significantly lower in DSS-treated rats when watermelon was consumed (P< .05). Fatty acid synthase, 3-hydroxy-3methyl-glutaryl-CoA reductase, sterol regulatory element-binding protein 1, sterol regulatory element-binding protein 2, and cyclooxygenase-2 gene expression was significantly downregulated in the watermelon group without DSS (P< .05). These findings indicate that watermelon improves risk factors for CVD in rats through better lipid profiles, lower inflammation, and greater antioxidant capacity by altering gene expression for lipid

Raspberry Ketone Protects Rats Fed High-Fat Diets Against Nonalcoholic Steatohepatitis

PubMed Central

Wang, Lili; Zhang, Fengqing

2012-01-01

Abstract The protective effect of raspberry ketone against nonalcoholic steatohepatitis (NASH) was tested by using a high-fat diet-induced NASH model, and its mechanism was explored. Forty Sprague–Dawley rats with a 1:1 male to female ratio were randomly divided into five groups: the normal control (NC) group (n=8) fed normal diet for 8 weeks, the model control (MC) group (n=8) fed high-fat diet (82% standard diet, 8.3% yolk powder, 9.0% lard, 0.5% cholesterol, and 0.2% sodium taurocholate), and the raspberry ketone low-dose (0.5%) (RKL) group (n=8), the raspberry ketone middle-dose (1%) (RKM) group (n=8), and the raspberry ketone high-dose (2%) (RKH) group (n=8) fed high-fat diet for 4 weeks. After 8 weeks of experiment, all the rats were sacrificed, and blood lipid parameters (total cholesterol [TC], triglycerides [TG], high-density lipoprotein cholesterol [HDL-C], and low-density lipoprotein cholesterol [LDL-C]), liver function parameters (serum alanine aminotransferase [ALT], aspartate aminotransferase [AST], and alkaline phosphatase [ALP]), leptin (LEP), free fatty acid (FFA), tumor necrosis factor α (TNF-α), blood glucose (GLU), and insulin (INS) with calculated INS resistance index (IRI) and INS-sensitive index (ISI) were measured in rats. Therefore, we determined the peroxisome proliferator-activated receptor (PPAR)-α activity in liver homogenate and the levels of low-density lipoprotein receptor (LDLR), high-sensitivity C-reactive protein (hs-CRP), adiponection (APN), superoxide dismutase, and malondialdehyde (MDA). The liver tissues of rats in each group were imaged by electron microscopy with hematoxylin–eosin as the staining agent. The levels of TG, TC, LDL-C, ALT, AST, ALP, GLU, INS, IRI, FFA, LEP, TNF-α, MDA, and hs-CRP of MC rats were significantly increased (P<.05, P<.01). Therefore, the levels of HDL-C, ISI, PPAR-α, LDLR, and APN were significantly decreased (P<.05, P<.01). Compared with the MC group, each parameter in the RKL, RKM, and

Raspberry ketone protects rats fed high-fat diets against nonalcoholic steatohepatitis.

PubMed

Wang, Lili; Meng, Xianjun; Zhang, Fengqing

2012-05-01

The protective effect of raspberry ketone against nonalcoholic steatohepatitis (NASH) was tested by using a high-fat diet-induced NASH model, and its mechanism was explored. Forty Sprague-Dawley rats with a 1:1 male to female ratio were randomly divided into five groups: the normal control (NC) group (n=8) fed normal diet for 8 weeks, the model control (MC) group (n=8) fed high-fat diet (82% standard diet, 8.3% yolk powder, 9.0% lard, 0.5% cholesterol, and 0.2% sodium taurocholate), and the raspberry ketone low-dose (0.5%) (RKL) group (n=8), the raspberry ketone middle-dose (1%) (RKM) group (n=8), and the raspberry ketone high-dose (2%) (RKH) group (n=8) fed high-fat diet for 4 weeks. After 8 weeks of experiment, all the rats were sacrificed, and blood lipid parameters (total cholesterol [TC], triglycerides [TG], high-density lipoprotein cholesterol [HDL-C], and low-density lipoprotein cholesterol [LDL-C]), liver function parameters (serum alanine aminotransferase [ALT], aspartate aminotransferase [AST], and alkaline phosphatase [ALP]), leptin (LEP), free fatty acid (FFA), tumor necrosis factor α (TNF-α), blood glucose (GLU), and insulin (INS) with calculated INS resistance index (IRI) and INS-sensitive index (ISI) were measured in rats. Therefore, we determined the peroxisome proliferator-activated receptor (PPAR)-α activity in liver homogenate and the levels of low-density lipoprotein receptor (LDLR), high-sensitivity C-reactive protein (hs-CRP), adiponection (APN), superoxide dismutase, and malondialdehyde (MDA). The liver tissues of rats in each group were imaged by electron microscopy with hematoxylin-eosin as the staining agent. The levels of TG, TC, LDL-C, ALT, AST, ALP, GLU, INS, IRI, FFA, LEP, TNF-α, MDA, and hs-CRP of MC rats were significantly increased (P<.05, P<.01). Therefore, the levels of HDL-C, ISI, PPAR-α, LDLR, and APN were significantly decreased (P<.05, P<.01). Compared with the MC group, each parameter in the RKL, RKM, and RKH groups was

Betaine alleviates hepatic lipid accumulation via enhancing hepatic lipid export and fatty acid oxidation in rats fed with a high-fat diet.

PubMed

Xu, Li; Huang, Danping; Hu, Qiaolin; Wu, Jing; Wang, Yizhen; Feng, Jie

2015-06-28

To assess the effects of betaine on hepatic lipid accumulation and investigate the underlying mechanism, thirty-two male Sprague-Dawley rats weighing 100 (sd 2·50) g were divided into four groups, and started on one of four treatments: basal diet, basal diet with betaine administration, high-fat diet and high-fat diet with betaine administration. The results showed that no significant difference of body weight was found among experimental groups. Compared with high-fat diet-fed rats, a betaine supplementation decreased (P< 0·05) hepatic TAG accumulation induced by high-fat diet, which was also supported by hepatic histology results. Additionally, hepatic betaine-homocysteine methyltransferase concentration [corrected] as well as its mRNA abundance and lecithin level were found increased (P< 0·05) by betaine supplementation in both basal diet-fed rats and high-fat diet-fed rats. Betaine administration in high-fat diet-fed rats exhibited a higher (P< 0·05) concentration [corrected] of hepatic carnitine palmitoyltransferase 1 (CPT1) compared with high-fat diet-fed rats. High-fat diet inhibited (P< 0·05) the gene expression of hepatic PPARα and CPT1. However, betaine administration in high-fat diet-fed rats elevated (P< 0·05) the gene expression of PPARα and CPT1. Moreover, concentration, gene and protein expressions of hepatic fibroblast growth factor 21 (FGF21) were increased (P< 0·05) in response to betaine administration in high-fat diet group; meanwhile the gene expression of hepatic AMP-activated protein kinase was increased (P< 0·05) as well. The results suggest that betaine administration enhanced hepatic lipid export and fatty acid oxidation in high-fat diet-fed rats, thus effectively alleviating fat accumulation in the liver.

[Effects of refined konjac meal on lipid metabolism and blood viscosity of rats fed by high fat forage].

PubMed

Wang, Zhongxia; Yang, Lili; Liu, Hong; Tan, Xiutao

2002-04-01

Male SD rats are fed by high fat diet supplemented with refined konjac meal for 6 weeks and the effect of refined konjac meal on the serum lipid peroxides (LPO) and blood viscosity are observed. The results showed that the refined konjac meal can obviously decrease serum cholesterol, triglyceride and serum LPO of rats in comparison with those of rats fed only by high fat forage, and can elevate, at the same time, the high density lipoprotein-cholesterol and high density lipoprotein-cholesterol/triglyceride value. It is also shown that the refined konjac meal can decrease the blood viscosity, but has no effect on forage intake and weight gain of rats.

Inhibition of angiotensin-1-converting enzyme activity by two varieties of ginger (Zingiber officinale) in rats fed a high cholesterol diet.

PubMed

Akinyemi, Ayodele Jacob; Ademiluyi, Adedayo Oluwaseun; Oboh, Ganiyu

2014-03-01

Angiotensin-1-converting enzyme (ACE) inhibitors are widely used in the treatment of cardiovascular diseases. This study sought to investigate the inhibitory effect of two varieties of ginger (Zingiber officinale) commonly consumed in Nigeria on ACE activity in rats fed a high cholesterol diet. The inhibition of ACE activity of two varieties of ginger (Z. officinale) was investigated in a high cholesterol (2%) diet fed to rats for 3 days. Feeding high cholesterol diets to rats caused a significant (P<.05) increase in the ACE activity. However, there was a significant (P<.05) inhibition of ACE activity as a result of supplementation with the ginger varieties. Rats that were fed 4% white ginger had the greatest inhibitory effect as compared with a control diet. Furthermore, there was a significant (P<.05) increase in the plasma lipid profile with a concomitant increase in malondialdehyde (MDA) content in rat liver and heart tissues. However, supplementing the diet with red and white ginger (either 2% or 4%) caused a significant (P<.05) decrease in the plasma total cholesterol, triglyceride, very low density lipoprotein-cholesterol, and low-density lipoprotein-cholesterol levels, and in MDA content in the tissues. Conversely, supplementation caused a significant (P<.05) increase in plasma high-density lipoprotein-cholesterol level when compared with the control diet. Nevertheless, rats fed 4% red ginger had the greatest reduction as compared with control diet. In conclusion, both ginger varieties exhibited anti-hypercholesterolemic properties in a high cholesterol diet fed to rats. This activity of the gingers may be attributed to its ACE inhibitory activity. However, white ginger inhibited ACE better in a high cholesterol diet fed to rats than red ginger. Therefore, both gingers could serve as good functional foods/nutraceuticals in the management/treatment of hypertension and other cardiovascular diseases.

Jinlida reduces insulin resistance and ameliorates liver oxidative stress in high-fat fed rats.

PubMed

Liu, Yixuan; Song, An; Zang, Shasha; Wang, Chao; Song, Guangyao; Li, Xiaoling; Zhu, Yajun; Yu, Xian; Li, Ling; Wang, Yun; Duan, Liyuan

2015-03-13

Jinlida (JLD) is a compound preparation formulated on the basis of traditional Chinese medicine and is officially approved for the treatment of type 2 diabetes (T2DM) in China. We aimed to elucidate the mechanism of JLD treatment, in comparison to metformin treatment, on ameliorating insulin sensitivity in insulin resistant rats and to reveal its anti-oxidant properties. Rats were fed with standard or high-fat diet for 6 weeks. After 6 weeks, the high-fat fed rats were subdivided into five groups and orally fed with JLD or metformin for 8 weeks. Fasting blood glucose (FBG), fasting blood insulin, blood lipid and antioxidant enzymes were measured. Intraperitoneal glucose tolerance test (IPGTT) and hyperinsulinemic euglycemic clamp technique were carried out to measure insulin sensitivity. Gene expression of the major signaling pathway molecules that regulate glucose uptake, including insulin receptor (INSR), insulin receptor substrate-1 (IRS-1), phosphoinositide-3-kinase (PI3K), protein kinase beta (AKT), and glucose transporter type 2 (GLUT2), were assessed by quantitative RT-PCR. The totle and phosphorylation expression of IRS-1, AKT, JNK and p38MAPK were determined by Western blot. Treatment with JLD effectively ameliorated the high-fat induced hyperglycemia, hyperinsulinemia and hyperlipidemia. Similar to metformin, the high insulin resistance in high-fat fed rats was significantly decreased by JLD treatment. JLD displayed anti-oxidant effects, coupled with up-regulation of the insulin signaling pathway. The attenuation of hepatic oxidative stress by JLD treatment was associated with reduced phosphorylation protein levels of JNK and p38MAPK. Treatment with JLD could moderate glucose and lipid metabolism as well as reduce hepatic oxidative stress, most likely through the JNK and p38MAPK pathways. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Intake of phytic acid and myo-inositol lowers hepatic lipogenic gene expression and modulates gut microbiota in rats fed a high-sucrose diet.

PubMed

Okazaki, Yukako; Sekita, Ayaka; Katayama, Tetsuyuki

2018-05-01

Dietary phytic acid (PA) was recently reported by our group to suppress hepatic lipogenic gene expression and modulate gut microbiota in rats fed a high-sucrose (HSC) diet. The present study aimed to investigate whether the modulatory effects of PA depend on the dietary carbohydrate source and are attributed to the myo-inositol (MI) ring of PA. Male Sprague-Dawley rats were fed an HSC or a high-starch (HSR) diet with or without 1.02% sodium PA for 12 days. Subsequently, the rats were fed the HSC diet, the HSC diet containing 1.02% sodium PA or an HSC diet containing 0.2% MI for 12 days. The HSC diet significantly increased the hepatic triglyceride (TG) concentration as well as the activity and expression of hepatic lipogenic enzymes compared with the HSR diet. The increases were generally suppressed by dietary PA with a concomitant increase in the fecal and cecal ratios of Lactobacillus spp. In rats fed the HSR diet, PA intake did not substantially affect the factors associated with hepatic lipid metabolism or gut microbiota composition. The effects of MI intake were similar to that of PA intake on hepatic lipogenesis and gut microbiota in rats fed the HSC diet. These results suggest that dietary PA downregulates hepatic lipogenic gene expression and modulates gut microbiota composition in rats fed an HSC diet but not in rats fed an HSR diet. The MI ring of PA may be responsible for the effects of PA intake on hepatic lipogenic gene expression and gut microbiota.

Euterpe edulis effects on cardiac and renal tissues of Wistar rats fed with cafeteria diet.

PubMed

De Barrios Freitas, Rodrigo; Melato, Fernanda Araujo; Oliveira, Jerusa Maria de; Bastos, Daniel Silva Sena; Cardoso, Raisa Mirella; Leite, João Paulo Viana; Lima, Luciana Moreira

2017-02-01

This study's objective was to evaluate the antioxidant and toxic effects of E. edulison cardiac and renal tissues of Wistar rats fed with cafeteria diet. Catalase (CAT), glutathione-S-transferase (GST), superoxide dismutase (SOD) and malondialdehyde (MDA) were measured in cardiac muscle and renal tissue of 60 animals, which were randomly assigned for 10 equal groups. Half of the rats were fed with cafeteria diet and the other half with commercial chow, combined or not to E. edulislyophilized extract, E. edulis deffated lyophilized extract or E. edulisoil. Data were evaluated using ANOVA, followed by the Student-Newman-Keuls test. Data showed a significant increase of CAT activity in cardiac tissue of animals from the groups fed with cafeteria diet associated to E. edulis lyophilized extract at 5%, E. edulis lyophilized extract at 10% and E. edulis deffated lyophilized extract at 10%. In addition, the same result was found in animals from the groups fed with commercial chow and commercial chow combined with E. edulislyophilized extract at 10% in comparison to the group fed exclusively with cafeteria diet. GST and SOD enzyme activity showed significant increase in the heart tissue of animals nourished with commercial chow when compared to the groups fed with cafeteria diet. On the other hand, there were no significant differences enzymatic levels in renal tissues. The oil and the extract of E. edulishad an important role promoting an increase of antioxidant enzymes levels in cardiac muscle, which prevent the oxidative damage resulting from the cafeteria diet in Wistar rats. There were no evidenced signs of lipid peroxidation in renal or in cardiac tissue of the animals studied, indicating that the E. edulisuse did not promote any increase in malondialdehyde cytotoxic products formation. This show that both E. edulis oil and extracts evaluated in this study were well tolerated in the studied doses.

Muscle and liver protein synthesis in growing rats fed diets containing raw legumes as the main source of protein

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

Goena, M.; Santidrian, S.; Cuevillas, F.

1986-03-01

Although legumes are widely used as protein sources, their effects on protein metabolism remain quite unexplored. The authors have measured the rates of gastrocnemius muscle and liver protein synthesis in growing rats fed ad libitum over periods of 12 days on diets containing raw field bean (Vicia faba L.), raw kidney bean (Phaseolus vulgaris L.), and raw bitter vetch (Vicia ervilia L.) as the major sources of protein. Diets were isocaloric and contained about 12% protein. Protein synthesis was evaluated by the constant-intravenous-infusion method, using L-//sup 14/C/-tyrosine, as well as by the determination of the RNA-activity (g of newly synthesizedmore » protein/day/g RNA). Results showed that, as compared to well-fed control animals, those fed the raw legume diets exhibited a marked reduction in the rate of growth with no changes in the amount of food intake (per 100 g b.wt.). These changes were accompanied by a significant reduction in the rate of muscle protein synthesis in all legume-treated rats, being this reduction greater in the animals fed the Ph. vulgaris and V. ervilia diets. Liver protein synthesis was slightly higher in the rats fed the V. faba and V. ervilia diets, and smaller in the Ph. vulgaris-fed rats. It is suggested that both sulfur amino acid deficiency and the presence of different anti-nutritive factors in raw legumes may account for these effects.« less

(/sup 3/H)forskolin- and (/sup 3/H)dihydroalprenolol-binding sites and adenylate cyclase activity in heart of rats fed diets containing different oils

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

Alam, S.Q.; Ren, Y.F.; Alam, B.S.

1988-03-01

The characteristics of the cardiac adenylate cyclase system were studied in rats fed diets containing fish oil (menhaden oil) and other oils. Adenylate cyclase activity generally was higher in cardiac homogenates and membranes of rats fed diet containing 10% menhaden oil than in the other oils. The increase in enzyme activity, especially in forskolin-stimulated activity, was associated with an increase in the concentration of the (/sup 3/H) forskolin-binding sites in cardiac membranes of rats fed menhaden oil. The beta-adrenergic receptor concentration was not significantly altered although the affinity for (/sup 3/H)dihydroalprenolol-binding was lower in membranes of rats fed menhaden oilmore » than those fed the other oils. omega-3 fatty acids from menhaden oil were incorporated into the cardiac membrane phospholipids. The results suggest that the observed increase in myocardial adenylate cyclase activity of rats fed menhaden oil may be due to an increase in the number of the catalytic subunits of the enzyme or due to a greater availability of the forskolin-binding sites.« less

Restoration of euglycemia after duodenal bypass surgery is reliant on central and peripheral inputs in Zucker fa/fa rats.

PubMed

Jiao, Jian; Bae, Eun Ju; Bandyopadhyay, Gautam; Oliver, Jason; Marathe, Chaitra; Chen, Michael; Hsu, Jer-Yuan; Chen, Yu; Tian, Hui; Olefsky, Jerrold M; Saberi, Maziyar

2013-04-01

Gastrointestinal bypass surgeries that result in rerouting and subsequent exclusion of nutrients from the duodenum appear to rapidly alleviate hyperglycemia and hyperinsulinemia independent of weight loss. While the mechanism(s) responsible for normalization of glucose homeostasis remains to be fully elucidated, this rapid normalization coupled with the well-known effects of vagal inputs into glucose homeostasis suggests a neurohormonally mediated mechanism. Our results show that duodenal bypass surgery on obese, insulin-resistant Zucker fa/fa rats restored insulin sensitivity in both liver and peripheral tissues independent of body weight. Restoration of normoglycemia was attributable to an enhancement in key insulin-signaling molecules, including insulin receptor substrate-2, and substrate metabolism through a multifaceted mechanism involving activation of AMP-activated protein kinase and downregulation of key regulatory genes involved in both lipid and glucose metabolism. Importantly, while central nervous system-derived vagal nerves were not essential for restoration of insulin sensitivity, rapid normalization in hepatic gluconeogenic capacity and basal hepatic glucose production required intact vagal innervation. Lastly, duodenal bypass surgery selectively altered the tissue concentration of intestinally derived glucoregulatory hormone peptides in a segment-specific manner. The present data highlight and support the significance of vagal inputs and intestinal hormone peptides toward normalization of glucose and lipid homeostasis after duodenal bypass surgery.

Rimonabant’s Reductive Effects on High Densities of Food Reinforcement, but not Palatability, in Lean and Obese Zucker Rats

PubMed Central

Buckley, Jessica Lynn; Rasmussen, Erin B.

2014-01-01

Rationale Cannabinoid antagonists purportedly have greater effects in reducing the intake of highly palatable food compared to less palatable food. However, this assertion is based on free-feeding studies in which the amount of palatable food eaten under baseline conditions is often confounded with other variables, such as unequal access to both food options and differences in qualitative features of the foods. Objective We attempted to reduce these confounds by using a model of choice that programmed the delivery rates of sucrose and carrot-flavored pellets. Methods Lever-pressing of ten lean (Fa/Fa or Fa/fa) and ten obese (fa/fa) Zucker rats was placed under three conditions in which programmed ratios for food pellets on two levers were 5:1, 1:1, and 1:5. In Phase 1, responses on the two levers produced one type of pellet (sucrose or carrot); in Phase 2, responses on one lever produced sucrose pellets and on the other lever produced carrot pellets. After responses stabilized under each food ratio, acute doses of rimonabant (0, 3, and 10 mg/kg) were administered before experimental sessions. The number of reinforcers and responses earned per session under each ratio and from each lever was compared. Results and Conclusions Rimonabant reduced reinforcers in 1:5 and 5:1 food ratios in Phase 1, and across all ratios in Phase 2. Rimonabant reduced sucrose and carrot-flavored pellet consumption similarly; rimonabant did not affect bias toward sucrose, but increased sensitivity to amount differences in lean rats. This suggests that relative amount of food, not palatability, may be an important behavioral mechanism in the effects of rimonabant. PMID:24398820

Effects of Shiitake Intake on Serum Lipids in Rats Fed Different High-Oil or High-Fat Diets.

PubMed

Asada, Norihiko; Kairiku, Rumi; Tobo, Mika; Ono, Akifumi

2018-04-27

Shiitake (Lentinula edodes) extract, eritadenine, has been shown to reduce cholesterol levels, and its hypocholesterolemic actions are involved in the metabolism of methionine. However, the mechanisms by which eritadenine affects cholesterol metabolism in animals fed a high-fat diet containing different sources of lipids have not yet been elucidated in detail. This study was conducted to investigate the effects of shiitake supplementation on serum lipid concentrations in rats fed a diet including a high amount of a plant oil (HO [high oil] and HOS [high oil with shiitake] groups), animal fat (HF [high fat] and HFS [high fat with shiitake] groups), or MCT- (medium-chain triglyceride-) rich plant oil (HM [high MCT] and HMS [high MCT with shiitake] groups). Rats in the HOS, HFS, and HMS groups were fed shiitake. When rats were fed a diet containing shiitake, serum triglyceride, cholesterol levels, and LCAT (lecithin-cholesterol acyltransferase) activities were lower in rats given MCT-rich plant oil than in those that consumed lard. The lipid type in the diet with shiitake also affected serum cholesterol levels and LCAT activities. The diet containing MCT-rich plant oil showed the greatest rates of decrease in all serum lipid profiles and LCAT activities. These results suggest that shiitake and MCT-rich plant oil work together to reduce lipid profiles and LCAT activity in serum.

Tissue-specific selection of stable reference genes for real-time PCR normalization in an obese rat model.

PubMed

Cabiati, Manuela; Raucci, Serena; Caselli, Chiara; Guzzardi, Maria Angela; D'Amico, Andrea; Prescimone, Tommaso; Giannessi, Daniela; Del Ry, Silvia

2012-06-01

Obesity is a complex pathology with interacting and confounding causes due to the environment, hormonal signaling patterns, and genetic predisposition. At present, the Zucker rat is an eligible genetic model for research on obesity and metabolic syndrome, allowing scrutiny of gene expression profiles. Real-time PCR is the benchmark method for measuring mRNA expressions, but the accuracy and reproducibility of its data greatly depend on appropriate normalization strategies. In the Zucker rat model, no specific reference genes have been identified in myocardium, kidney, and lung, the main organs involved in this syndrome. The aim of this study was to select among ten candidates (Actb, Gapdh, Polr2a, Ywhag, Rpl13a, Sdha, Ppia, Tbp, Hprt1 and Tfrc) a set of reference genes that can be used for the normalization of mRNA expression data obtained by real-time PCR in obese and lean Zucker rats both at fasting and during acute hyperglycemia. The most stable genes in the heart were Sdha, Tbp, and Hprt1; in kidney, Tbp, Actb, and Gapdh were chosen, while Actb, Ywhag, and Sdha were selected as the most stably expressed set for pulmonary tissue. The normalization strategy was used to analyze mRNA expression of tumor necrosis factor α, the main inflammatory mediator in obesity, whose variations were more significant when normalized with the appropriately selected reference genes. The findings obtained in this study underline the importance of having three stably expressed reference gene sets for use in the cardiac, renal, and pulmonary tissues of an experimental model of obese and hyperglycemic Zucker rats.

Increased methylglyoxal formation with upregulation of renin angiotensin system in fructose fed Sprague Dawley rats.

PubMed

Dhar, Indu; Dhar, Arti; Wu, Lingyun; Desai, Kaushik M

2013-01-01

The current epidemic of obesity and type 2 diabetes is attributed to a high carbohydrate diet, containing mainly high fructose corn syrup and sucrose. More than two thirds of diabetic patients have hypertension. Methylglyoxal is a highly reactive dicarbonyl generated during glucose and fructose metabolism, and a major precursor of advanced glycation end products (AGEs). Plasma methylglyoxal levels are increased in hypertensive rats and diabetic patients. Our aim was to examine the levels of methylglyoxal, mediators of the renin angiotensin system and blood pressure in male Sprague-Dawley rats treated with a high fructose diet (60% of total calories) for 4 months. The thoracic aorta and kidney were used for molecular studies, along with cultured vascular smooth muscle cells (VSMCs). HPLC, Western blotting and Q-PCR were used to measure methylglyoxal and reduced glutathione (GSH), proteins and mRNA, respectively. Fructose treated rats developed a significant increase in blood pressure. Methylglyoxal level and protein and mRNA for angiotensin II, AT1 receptor, adrenergic α1D receptor and renin were significantly increased, whereas GSH levels were decreased, in the aorta and/or kidney of fructose fed rats. The protein expression of the receptor for AGEs (RAGE) and NF-κB were also significantly increased in the aorta of fructose fed rats. MG treated VSMCs showed increased protein for angiotensin II, AT1 receptor, and α1D receptor. The effects of methylglyoxal were attenuated by metformin, a methylglyoxal scavenger and AGEs inhibitor. In conclusion, we report a strong association between elevated levels of methylglyoxal, RAGE, NF-κB, mediators of the renin angiotensin system and blood pressure in high fructose diet fed rats.

Innate immune reactivity of the liver in rats fed a choline-deficient L-amino-acid-defined diet.

PubMed

Kawaratani, Hideto; Tsujimoto, Tatsuhiro; Kitazawa, Toshiyuki; Kitade, Mitsuteru; Yoshiji, Hitoshi; Uemura, Masahito; Fukui, Hiroshi

2008-11-21

To investigate the innate immune reactivity of tumor necrosis factor-alpha (TNF-alpha), Toll-like receptor 4 (TLR4), and CD14 in the liver of non-alcoholic steatohepatitis (NASH) model rats. Male F344 rats were fed a choline-deficient L-amino-acid-defined (CDAA) diet. The rats were killed after 4 or 8 wk of the diet, and their livers were removed for immunohistochemical investigation and RNA extraction. The liver specimens were immunostained for TNF-alpha, TLR4, and CD14. The gene expressions of TNF-alpha, TLR4, and CD14 were determined by reverse-transcriptase polymerase chain reaction (RT-PCR). Kupffer cells were isolated from the liver by Percoll gradient centrifugation, and were then cultured to measure TNF-alpha production. The serum and liver levels of TNF-alpha in the CDAA-fed rats increased significantly as compared with the control group, as did the immunohistochemical values and gene expressions of TNF-alpha, TLR4, and CD14 with the progression of steatohepatitis. TNF-alpha production from the isolated Kupffer cells of the CDAA-fed rats was elevated by lipopolysaccharide stimulation. The expressions of TNF-alpha, TLR4, and CD14 increased in the NASH model, suggesting that TLR4 and CD14-mediated endotoxin liver damage may also occur in NASH.

Altered nitrogen balance and decreased urea excretion in male rats fed cafeteria diet are related to arginine availability.

PubMed

Sabater, David; Agnelli, Silvia; Arriarán, Sofía; Fernández-López, José-Antonio; Romero, María del Mar; Alemany, Marià; Remesar, Xavier

2014-01-01

Hyperlipidic diets limit glucose oxidation and favor amino acid preservation, hampering the elimination of excess dietary nitrogen and the catabolic utilization of amino acids. We analyzed whether reduced urea excretion was a consequence of higher NO x ; (nitrite, nitrate, and other derivatives) availability caused by increased nitric oxide production in metabolic syndrome. Rats fed a cafeteria diet for 30 days had a higher intake and accumulation of amino acid nitrogen and lower urea excretion. There were no differences in plasma nitrate or nitrite. NO(x) and creatinine excretion accounted for only a small part of total nitrogen excretion. Rats fed a cafeteria diet had higher plasma levels of glutamine, serine, threonine, glycine, and ornithine when compared with controls, whereas arginine was lower. Liver carbamoyl-phosphate synthetase I activity was higher in cafeteria diet-fed rats, but arginase I was lower. The high carbamoyl-phosphate synthetase activity and ornithine levels suggest activation of the urea cycle in cafeteria diet-fed rats, but low arginine levels point to a block in the urea cycle between ornithine and arginine, thereby preventing the elimination of excess nitrogen as urea. The ultimate consequence of this paradoxical block in the urea cycle seems to be the limitation of arginine production and/or availability.

Altered Nitrogen Balance and Decreased Urea Excretion in Male Rats Fed Cafeteria Diet Are Related to Arginine Availability

PubMed Central

Sabater, David; Arriarán, Sofía; Fernández-López, José-Antonio; Romero, María del Mar; Remesar, Xavier

2014-01-01

Hyperlipidic diets limit glucose oxidation and favor amino acid preservation, hampering the elimination of excess dietary nitrogen and the catabolic utilization of amino acids. We analyzed whether reduced urea excretion was a consequence of higher NOx; (nitrite, nitrate, and other derivatives) availability caused by increased nitric oxide production in metabolic syndrome. Rats fed a cafeteria diet for 30 days had a higher intake and accumulation of amino acid nitrogen and lower urea excretion. There were no differences in plasma nitrate or nitrite. NOx and creatinine excretion accounted for only a small part of total nitrogen excretion. Rats fed a cafeteria diet had higher plasma levels of glutamine, serine, threonine, glycine, and ornithine when compared with controls, whereas arginine was lower. Liver carbamoyl-phosphate synthetase I activity was higher in cafeteria diet-fed rats, but arginase I was lower. The high carbamoyl-phosphate synthetase activity and ornithine levels suggest activation of the urea cycle in cafeteria diet-fed rats, but low arginine levels point to a block in the urea cycle between ornithine and arginine, thereby preventing the elimination of excess nitrogen as urea. The ultimate consequence of this paradoxical block in the urea cycle seems to be the limitation of arginine production and/or availability. PMID:24707502

Genetic predisposition to obesity affects behavioural traits including food reward and anxiety-like behaviour in rats.

PubMed

Vogel, Heike; Kraemer, Maria; Rabasa, Cristina; Askevik, Kaisa; Adan, Roger A H; Dickson, Suzanne L

2017-06-15

Here we sought to define behavioural traits linked to anxiety, reward, and exploration in different strains of rats commonly used in obesity research. We hypothesized that genetic variance may contribute not only to their metabolic phenotype (that is well documented) but also to the expression of these behavioural traits. Rat strains that differ in their susceptibility to develop an obese phenotype (Sprague-Dawley, Obese Prone, Obese Resistant, and Zucker rats) were exposed to a number of behavioural tests starting at the age of 8 weeks. We found a similar phenotype in the obesity susceptible models, Obese Prone and Zucker rats, with a lower locomotor activity, exploratory activity, and higher level of anxiety-like behaviour in comparison to the leaner Obese Resistant strain. We did not find evidence that rat strains with a genetic predisposition to obesity differed in their ability to experience reward from chocolate (in a condition place preference task). However, Zucker rats show higher motivated behaviour for sucrose compared to Obese Resistant rats when the effort required to obtain palatable food is relatively low. Together our data demonstrate that rat strains that differ in their genetic predisposition to develop obesity also differ in their performance in behavioural tests linked to anxiety, exploration, and reward and that these differences are independent of body weight. We conclude that genetic variations which determine body weight and the aforementioned behaviours co-exist but that future studies are required to identify whether (and which) common genes are involved. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Renin inhibition improves metabolic syndrome, and reduces angiotensin II levels and oxidative stress in visceral fat tissues in fructose-fed rats

PubMed Central

Chen, Jin-Shuen

2017-01-01

Renin–angiotensin system in visceral fat plays a crucial role in the pathogenesis of metabolic syndrome in fructose-fed rats. However, the effects of renin inhibition on visceral adiposity in metabolic syndrome are not fully investigated. We investigated the effects of renin inhibition on visceral adiposity in fructose-fed rats. Male Wistar–Kyoto rats were divided into 4 groups for 8-week experiments: Group Con (standard chow diet), Group Fru (high-fructose diet; 60% fructose), Group FruA (high-fructose diet and concurrent aliskiren treatment; 100 mg/kg body weight [BW] per day), and Group FruB (high-fructose diet and subsequent, i.e. 4 weeks after initiating high-fructose feeding, aliskiren treatment; 100 mg/kg BW per day). The high-fructose diet induced metabolic syndrome, increased visceral fat weights and adipocyte sizes, and augmented angiotensin II (Ang II), NADPH oxidase (NOX) isoforms expressions, oxidative stress, and dysregulated production of adipocytokines from visceral adipose tissues. Concurrent and subsequent aliskiren administration ameliorated metabolic syndrome, dysregulated adipocytokines, and visceral adiposity in high fructose-fed hypertensive rats, and was associated with reducing Ang II levels, NOX isoforms expressions and oxidative stress in visceral fat tissues. Therefore, this study demonstrates renin inhibition could improve metabolic syndrome, and reduce Ang II levels and oxidative stress in visceral fat tissue in fructose-fed rats, and suggests that visceral adipose Ang II plays a crucial role in the pathogenesis of metabolic syndrome in fructose-fed rats. PMID:28700686

Renin inhibition improves metabolic syndrome, and reduces angiotensin II levels and oxidative stress in visceral fat tissues in fructose-fed rats.

PubMed

Chou, Chu-Lin; Lin, Heng; Chen, Jin-Shuen; Fang, Te-Chao

2017-01-01

Renin-angiotensin system in visceral fat plays a crucial role in the pathogenesis of metabolic syndrome in fructose-fed rats. However, the effects of renin inhibition on visceral adiposity in metabolic syndrome are not fully investigated. We investigated the effects of renin inhibition on visceral adiposity in fructose-fed rats. Male Wistar-Kyoto rats were divided into 4 groups for 8-week experiments: Group Con (standard chow diet), Group Fru (high-fructose diet; 60% fructose), Group FruA (high-fructose diet and concurrent aliskiren treatment; 100 mg/kg body weight [BW] per day), and Group FruB (high-fructose diet and subsequent, i.e. 4 weeks after initiating high-fructose feeding, aliskiren treatment; 100 mg/kg BW per day). The high-fructose diet induced metabolic syndrome, increased visceral fat weights and adipocyte sizes, and augmented angiotensin II (Ang II), NADPH oxidase (NOX) isoforms expressions, oxidative stress, and dysregulated production of adipocytokines from visceral adipose tissues. Concurrent and subsequent aliskiren administration ameliorated metabolic syndrome, dysregulated adipocytokines, and visceral adiposity in high fructose-fed hypertensive rats, and was associated with reducing Ang II levels, NOX isoforms expressions and oxidative stress in visceral fat tissues. Therefore, this study demonstrates renin inhibition could improve metabolic syndrome, and reduce Ang II levels and oxidative stress in visceral fat tissue in fructose-fed rats, and suggests that visceral adipose Ang II plays a crucial role in the pathogenesis of metabolic syndrome in fructose-fed rats.

Effects of potato fiber and potato-resistant starch on biomarkers of colonic health in rats fed diets containing red meat.

PubMed

Paturi, Gunaranjan; Nyanhanda, Tafadzwa; Butts, Christine A; Herath, Thanuja D; Monro, John A; Ansell, Juliet

2012-10-01

The effects of red meat consumption with and without fermentable carbohydrates on indices of large bowel health in rats were examined. Sprague-Dawley rats were fed cellulose, potato fiber, or potato-resistant starch diets containing 12% casein for 2 wk, then similar diets containing 25% cooked beef for 6 wk. After week 8, cecal and colonic microbiota composition, fermentation end-products, colon structure, and colonocyte DNA damage were analyzed. Rats fed potato fiber had lower Bacteroides-Prevotella-Porphyromonas group compared to other diet groups. Colonic Bifidobacterium spp. and/or Lactobacillus spp. were higher in potato fiber and potato-resistant starch diets than in the cellulose diet. Beneficial changes were observed in short-chain fatty acid concentrations (acetic, butyric, and propionic acids) in rats fed potato fiber compared with rats fed cellulose. Phenol and p-cresol concentrations were lower in the cecum and colon of rats fed potato fiber. An increase in goblet cells per crypt and longer crypts were found in the colon of rats fed potato fiber and potato-resistant starch diets. Fermentable carbohydrates had no effect on colonic DNA damage. Dietary combinations of red meat with potato fiber or potato-resistant starch have distinctive effects in the large bowel. Future studies are essential to examine the efficacy of different types of nondigestible carbohydrates in maintaining colonic health during long-term consumption of high-protein diets. Improved understanding of interactions between the food consumed and gut microbiota provides knowledge needed to make healthier food choices for large bowel health. The impact of red meat on large bowel health may be ameliorated by consuming with fermentable dietary fiber, a colonic energy source that produces less harmful by-products than the microbial breakdown of colonic protein for energy. Developing functional red meat products with fermentable dietary fiber could be one way to promote a healthy and balanced

Obese ZDF rats fermented resistant starch with effects on gut microbiota but no reduction in abdominal fat.

PubMed

Goldsmith, Felicia; Guice, Justin; Page, Ryan; Welsh, David A; Taylor, Christopher M; Blanchard, Eugene E; Luo, Meng; Raggio, Anne M; Stout, Rhett W; Carvajal-Aldaz, Diana; Gaither, Amanda; Pelkman, Christine; Ye, Jianping; Martin, Roy J; Geaghan, James; Durham, Holiday A; Coulon, Diana; Keenan, Michael J

2017-01-01

To determine if whole-grain (WG) flour with resistant starch (RS) will produce greater fermentation than isolated RS in obese Zucker Diabetic Fatty (ZDF) rats, and whether greater fermentation results in different microbiota, reduced abdominal fat, and increased insulin sensitivity. This study utilized four groups fed diets made with either isolated digestible control starch, WG control flour (6.9% RS), isolated RS-rich corn starch (25% RS), or WG corn flour (25% RS). ZDF rats fermented RS and RS-rich WG flour to greatest extent among groups. High-RS groups had increased serum glucagon-like peptide 1 (GLP-1) active. Feeding isolated RS showed greater Bacteroidetes to Firmicutes phyla among groups, and rats consuming low RS diets possessed more bacteria in Lactobacillus genus. However, no differences in abdominal fat were observed, but rats with isolated RS had greatest insulin sensitivity among groups. Data demonstrated ZDF rats (i) possess a microbiota that fermented RS, and (ii) WG high-RS fermented better than purified RS. However, fermentation and microbiota changes did not translate into reduced abdominal fat. The defective leptin receptor may limit ZDF rats from responding to increased GLP-1 and different microbiota for reducing abdominal fat, but did not prevent improved insulin sensitivity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Refeeding meal-fed rats increases lipoprotein lipase activity and deposition of dietary [14C]lipid in white adipose tissue and decreases oxidation to 14CO2. The role of undernutrition.

PubMed Central

Cruz, M L; Williamson, D H

1992-01-01

Meal-fed (3 h) rats had a decreased food intake, body weight and carcass fat compared with rats fed ad libitum. On refeeding a chow meal containing [1-14C]triolein, the production of 14CO2 was lower (45%) and the accumulation of carcass [14C]lipid higher (37%) in the meal-fed rats. There was higher lipoprotein lipase activity and greater accumulation of [14C]lipid in the epididymal and subcutaneous adipose-tissue depots of the meal-fed rats. In contrast, heparin-releasable lipoprotein lipase was not increased in perfused hearts of meal-fed rats on refeeding. Return of meal-fed rats to feeding ad libitum reversed these changes before the restoration of body weight or carcass fat. Evidence is presented that decreased dietary intake rather than meal pattern is an important determinant of the alterations in adipose lipid metabolism in the meal-fed rat in response to a meal. PMID:1497615

Protein source in a high-protein diet modulates reductions in insulin resistance and hepatic steatosis in fa/fa Zucker rats.

PubMed

Wojcik, Jennifer L; Devassy, Jessay G; Wu, Yinghong; Zahradka, Peter; Taylor, Carla G; Aukema, Harold M

2016-01-01

High-protein diets are being promoted to reduce insulin resistance and hepatic steatosis in metabolic syndrome. Therefore, the effect of protein source in high-protein diets on reducing insulin resistance and hepatic steatosis was examined. Fa/fa Zucker rats were provided normal-protein (15% of energy) casein, high-protein (35% of energy) casein, high-protein soy, or high-protein mixed diets with animal and plant proteins. The high-protein mixed diet reduced area under the curve for insulin during glucose tolerance testing, fasting serum insulin and free fatty acid concentrations, homeostatic model assessment index, insulin to glucose ratio, and pancreatic islet cell area. The high-protein mixed and the high-protein soy diets reduced hepatic lipid concentrations, liver to body weight ratio, and hepatic steatosis rating. These improvements were observed despite no differences in body weight, feed intake, or adiposity among high-protein diet groups. The high-protein casein diet had minimal benefits. A high-protein mixed diet was the most effective for modulating reductions in insulin resistance and hepatic steatosis independent of weight loss, indicating that the source of protein within a high-protein diet is critical for the management of these metabolic syndrome parameters. © 2015 The Obesity Society.

Mass spectrometric profiling of lipids in intestinal tissue from rats fed cereals processed for medical conditions.

PubMed

Dowlatshahi Pour, Masoumeh; Jennische, Eva; Lange, Stefan; Ewing, Andrew G; Malmberg, Per

2016-06-11

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used for lipid profiling of intestine tissue sections from rats fed specially processed cereals and rats fed ordinary feed as a control. This cereal is known to increase the activity of antisecretory factor in plasma and the exact mechanism for the activation process at the cellular level is unclear. ToF-SIMS has been used to track food induced changes in lipid content in intestinal tissue sections to gain insight into the possible mechanisms involved. Data from 20 intestine sections belonging to four different rats from each group of control and specially processed cereals-fed rats were obtained using the stage scan macroraster with a lateral resolution of 5 μm. Data were subsequently subjected to orthogonal partial least squares discriminant analysis. The data clearly show that changes of certain lipids are induced by the specially processed cereal feed. Scores plots show a well-defined separation between the two groups. The corresponding loading plots reveal that the groups separate mainly due to changes of vitamin E, phosphocholine, and phosphosphingolipid fragments, and that for the c18:2 fatty acid. The observed changes in lipids might give insight into the working mechanisms of antisecretory factor in the body, and this has been successfully used to understand the working mechanism of specially processed cereal-induced antisecretory factor activation in intestine.

THE EFFECT OF PROPRANOLOL ON GENE EXPRESSION DURING THE BLOOD ALCOHOL CYCLE OF RATS FED ETHANOL INTRAGASTRICALLY

PubMed Central

Li, Jun; Bardag-Gorce, F; Joan, Oliva; French, BA; Dedes, J; French, SW

2010-01-01

Propranolol, a beta adrenergic blocker prevents the blood alcohol (BAL) cycle in rats fed ethanol intragastrically at a constant rate by preventing the cyclic changes in the metabolic rate caused by fluctuating levels of norepinephrine released into the blood. The change in the rate of metabolism changes the rate of alcohol elimination in the blood which causes the BAL to cycle. Microarray analysis of the livers from the rats fed ethanol and propranolol showed similar changes in clusters of functionally related gene expressions. The controls and the trough of the cycle differed dramatically from the cluster pattern seen in the rats at the peaks of the blood alcohol cycle. The changes in gene expression induced by ethanol were similar when propranolol was fed without ethanol especially with the changes in the kinases and phosphatases, Toll-like receptor signaling and cytokine-cytokine receptor interaction were also changed. The changes in gene expression caused by ethanol and propranolol feeding are alike probably because both drugs induce β adrenergic receptor desensitization. PMID:19925788

Mechanism of the anticataract effect of liposomal magnesium taurate in galactose-fed rats

PubMed Central

Iezhitsa, Igor; Saad, Sarah Diyana Bt; Zakaria, Fatin Kamilah Bt; Agarwal, Puneet; Krasilnikova, Anna; Rahman, Thuhairah Hasrah Abdul; Rozali, Khairul Nizam Bin; Spasov, Alexander; Ozerov, Alexander; Alyautdin, Renad; Ismail, Nafeeza Mohd

2016-01-01

Purpose Increased lenticular oxidative stress and altered calcium/magnesium (Ca/Mg) homeostasis underlie cataractogenesis. We developed a liposomal formulation of magnesium taurate (MgT) and studied its effects on Ca/Mg homeostasis and lenticular oxidative and nitrosative stress in galactose-fed rats. Methods The galactose-fed rats were topically treated with liposomal MgT (LMgT), liposomal taurine (LTau), or corresponding vehicles twice daily for 28 days with weekly anterior segment imaging. At the end of the experimental period, the lenses were removed and subjected to analysis for oxidative and nitrosative stress, Ca and Mg levels, ATP content, Ca2+-ATPase, Na+,K+-ATPase, and calpain II activities. Results The LTau and LMgT groups showed significantly lower opacity index values at all time points compared to the corresponding vehicle groups (p<0.001). However, the opacity index in the LMgT group was lower than that in the LTau group (p<0.05). Significantly reduced oxidative and nitrosative stress was observed in the LTau and LMgT groups. The lens Ca/Mg ratio in LMgT group was decreased by 1.15 times compared to that in the LVh group. Calpain II activity in the LMgT group was decreased by 13% compared to the LVh group. The ATP level and Na+,K+-ATPase and Ca2+-ATPase activities were significantly increased in the LMgT group compared to the LVh group (p<0.05). Conclusions Topical liposomal MgT delays cataractogenesis in galactose-fed rats by maintaining the lens mineral homeostasis and reducing lenticular oxidative and nitrosative stress. PMID:27440992

The effects of Mucuna pruriens on the renal oxidative stress and transcription factors in high-fructose-fed rats.

PubMed

Ulu, Ramazan; Gozel, Nevzat; Tuzcu, Mehmet; Orhan, Cemal; Yiğit, İrem Pembegül; Dogukan, Ayhan; Telceken, Hafize; Üçer, Özlem; Kemeç, Zeki; Kaman, Dilara; Juturu, Vijaya; Sahin, Kazim

2018-05-31

In the present study, we evaluated the effects of M. pruriens administration on metabolic parameters, oxidative stress and kidney nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling pathways in high-fructose fed rats. Male rats (n = 28) were divided into 4 groups as control, M. pruriens, fructose, and M. pruriens plus fructose. All rats were fed a standard diet supplemented or no supplemented with M. pruriens (200 mg/kg/d by gavage). Fructose was given in drinking water for 8 weeks. High fructose consumption led to an increase in the serum level of glucose, triglyceride, urea and renal malondialdehyde (MDA) levels. Although M. pruriens treatment reduced triglyceride and MDA levels, it did not affect other parameters. M. pruriens supplementation significantly decreased the expression of NF-ҡB and decreased expression of Nrf2 and HO-1 proteins in the kidney. This study showed that the adverse effects of high fructose were alleviated by M. pruriens supplementation via modulation of the expression of kidney nuclear transcription factors in rats fed high fructose diet. Copyright © 2018 Elsevier Ltd. All rights reserved.

BETAINE FEEDING PREVENTS THE BLOOD ALCOHOL CYCLE IN RATS FED ALCOHOL CONTINUOUSLY FOR 1 MONTH USING THE RAT INTRAGASTRIC TUBE FEEDING MODEL

PubMed Central

Li, J; Li, XM; Caudill, M; Malysheva, O; Bardag-Gorce, F; Oliva, J; French, BA; Gorce, E; Morgan, K; Kathirvel, E; Morgan, T; French, SW

2011-01-01

Background Blood alcohol levels (BAL) cycle up and down over a 7–8 day period when ethanol is fed continuously for one month in the intragastric tube feeding rat model (ITFRM) of alcoholic liver disease. The cycling phenomenon is due to an alternating increase and decrease in the metabolic rate. Recently, we found that S-adenosyl-methionine (SAMe) fed with alcohol prevented the BAL cycle. Method Using the ITFRM we fed rats betaine (2 g/kg/day) with ethanol for 1 month and recorded the daily 24 h urine ethanol level (UAL) to measure the BAL cycle. UAL is equivalent to BAL because of the constant ethanol infusion. Liver histology, steatosis and BAL were measured terminally after 1 month of treatment. Microarray analysis was done on the mRNA extracted from the liver to determine the effects of betaine and alcohol on changes in gene expression. Results Betaine fed with ethanol completely prevented the BAL cycle similar to SAMe. Betaine also significantly reduced the BAL compared to ethanol fed rats without betaine. This was also observed when SAMe was fed with ethanol. The mechanism involved in both cases is that SAMe is required for the conversion of epinephrine from norepinephrine by phenylethanolamine methyltransferase (PNMT). Epinephrine is 5 to 10 fold more potent than norepinephrine in increasing the metabolic rate. The increase in the metabolic rate generates NAD, permitting ADH to increase the oxidation of alcohol. NAD is the rate limiting factor in oxidation of alcohol by alcohol dehydrogenase (ADH). This explains how SAMe and betaine prevented the cycle. Microarray analysis showed that betaine feeding prevented the up regulation of a large number of genes including TLR2/4, Il-1b, Jax3, Sirt3, Fas, Ifngr1, Tgfgr2, Tnfrsf21, Lbp and Stat 3 which could explain how betaine prevented fatty liver. Conclusion Betaine feeding lowers the BAL and prevents the BAL cycle by increasing the metabolic rate. This increases the rate of ethanol elimination by generating NAD

Effects of obesity on IL-33/ST2 system in heart, adipose tissue and liver: study in the experimental model of Zucker rats.

PubMed

Ragusa, Rosetta; Cabiati, Manuela; Guzzardi, Maria Angela; D'Amico, Andrea; Giannessi, Daniela; Del Ry, Silvia; Caselli, Chiara

2017-04-01

Suppression of tumorigenicity 2 (ST2) mediates the effect of Interleukin-33 (IL-33). Few data are reported on the relationship between IL-33/ST2 and obesity. We aimed to investigate effects of obesity on IL-33/ST2 system in heart, adipose tissue and liver in a rodent model of obesity. The relationship of cardiac expression of IL-33/ST2 system with natriuretic peptides (NPs) system and inflammatory mediators was also studied. mRNA expression of IL-33/ST2 system was evaluated in cardiac, adipose and hepatic biopsies from obese Zucker rats (O) and controls (CO). Expression levels of sST2 was significantly lower in O rats compared with CO (p<0.05) in all tissues. Besides, the mRNA levels of IL-33 decreased significant in fat of O respect to CO, while, expression levels of ST2L was significantly higher in liver of CO than in O. A strong relationship of IL-33/ST2 with NPs and classical inflammatory mediators was observed in cardiac tissue. Expression of sST2 in cardiac, adipose and liver tissue decreased in O compared with controls, suggesting an involvement for IL-33/ST2 system in molecular mechanisms of obesity. The strong relationships with NP systems and inflammatory mediators could suggest an involvement for IL-33/ST2 in molecular pathways leading to cardiac dysfunction and inflammation associated with obesity. Copyright © 2017 Elsevier Inc. All rights reserved.

Metabolomics Study of Type 2 Diabetes Mellitus and the AntiDiabetic Effect of Berberine in Zucker Diabetic Fatty Rats Using Uplc-ESI-Hdms.

PubMed

Dong, Yu; Chen, Yi-Tao; Yang, Yuan-Xiao; Zhou, Xiao-Jie; Dai, Shi-Jie; Tong, Jun-Feng; Shou, Dan; Li, Changyu

2016-05-01

The present study aimed to evaluate the pathogenesis of type 2 diabetes mellitus (T2DM) and the anti-diabetic effect of berberine in Zucker diabetic fatty (ZDF) rats. A urinary metabolomics analysis was performed with ultra-performance liquid chromatography/electrospray ionization synapt high-definition mass spectrometry. Pattern recognition approaches were integrated to discover differentiating metabolites. We identified 29 ions (13 in negative mode and 16 in positive mode) as 'differentiating metabolites' with this metabolomic approach. A functional pathway analysis revealed that the alterations were mainly associated with glyoxylate and dicarboxylate metabolism, pentose and glucuronate interconversions and sphingolipid metabolism. These results indicated that the dysfunctions of glycometabolism and lipometabolism are involved in the pathological process of T2DM. Berberine could decrease the serum levels of glycosylated hemoglobin, total cholesterol and triglyceride and increase the secretion of insulin. The urinary metabolomics analysis showed that berberine could reduce the concentrations of citric acid, tetrahydrocortisol, ribothymidine and sphinganine to a near-normal state. These results suggested that the anti-diabetic effect of berberine occurred mainly via its regulation of glycometabolism and lipometabolism and activation of adenosine 5'-monophosphate-activated protein kinase. Our work not only provides a better understanding of the anti-diabetic effect of berberine in ZDF rats but also supplies a useful database for further study in humans and for investigating the pharmacological actions of drugs. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Exercise counteracts fatty liver disease in rats fed on fructose-rich diet

PubMed Central

2010-01-01

Background This study aimed to analyze the effects of exercise at the aerobic/anaerobic transition on the markers of non-alcoholic fatty liver disease (NAFLD), insulin sensitivity and the blood chemistry of rats kept on a fructose-rich diet. Methods We separated 48 Wistar rats into two groups according to diet: a control group (balanced diet AIN-93 G) and a fructose-rich diet group (60% fructose). The animals were tested for maximal lactate-steady state (MLSS) in order to identify the aerobic/anaerobic metabolic transition during swimming exercises at 28 and 90 days of age. One third of the animals of each group were submitted to swimming training at an intensity equivalent to the individual MLSS for 1 hours/day, 5 days/week from 28 to 120 days (early protocol). Another third were submitted to the training from 90 to 120 days (late protocol), and the others remained sedentary. The main assays performed included an insulin tolerance test (ITT) and tests of serum alanine aminotransferase [ALT] and aspartate aminotransferase [AST] activities, serum triglyceride concentrations [TG] and liver total lipid concentrations. Results The fructose-fed rats showed decreased insulin sensitivity, and the late-exercise training protocol counteracted this alteration. There was no difference between the groups in levels of serum ALT, whereas AST and liver lipids increased in the fructose-fed sedentary group when compared with the other groups. Serum triglycerides concentrations were higher in the fructose-fed trained groups when compared with the corresponding control group. Conclusions The late-training protocol was effective in restoring insulin sensitivity to acceptable standards. Considering the markers here evaluated, both training protocols were successful in preventing the emergence of non-alcoholic fatty liver status disease. PMID:20946638

Increased hepatic beta-oxidation of docosahexaenoic acid, elongation of eicosapentaenoic acid, and acylation of lysophosphatidate in rats fed a docosahexaenoic acid-enriched diet.

PubMed

Kanazawa, A; Shirota, Y; Fujimoto, K

1997-07-01

Rats were fed a diet supplemented with corn oil (n-3 deficient), soy oil, or a mixture containing 8% 22:6n-3 ethyl ester for 6 wk. The hepatic capacities for the beta-oxidation and synthesis of 22:6n-3, in addition to the acylation of lysophosphatidate, were tested in vitro. In rats that were fed a 22:6n-3-enriched diet, both the beta-oxidation of 22:6n-3 and elongation of 20:5n-3 were enhanced compared to those in rats fed the other diets. Acylation of lysophosphatidate was also enhanced in rats fed a 22:6n-3-enriched diet, while the rate of dephosphorylation of phosphatidate was not changed. The amount of 22:6n-3 in the liver was much less than that consumed in a docosahexaenoic acid-enriched diet. These results suggest that a significant amount of dietary 22:6n-3 was degraded via beta-oxidation, and that a portion of the retroconverted 20:5n-3 was recycled for the synthesis of 22:6n-3. The recycling of 20:5n-3 might contribute to the low level of 22:6n-3 in rats fed an n-3-deficient diet.

Results of a 90-day safety assurance study with rats fed grain from corn borer-protected corn.

PubMed

Hammond, B G; Dudek, R; Lemen, J K; Nemeth, M A

2006-07-01

The results of a 90-day rat feeding study with grain from MON 810 corn (YieldGard Cornborer -- YieldGard Cornborer is a registered trademark of Monsanto Technology, LLC) that is protected against feeding damage from corn and stalk boring lepidopteran insects are presented. Corn borer protection was accomplished through the introduction of cry1Ab coding sequences into the corn genome for in planta production of a bioactive form of Cry1Ab protein. Grain from MON 810 and its near-isogenic control was separately formulated into rodent diets at levels of 11% and 33% (w/w) by Purina Mills, Inc. (PMI). All diets were nutritionally balanced and conformed to PMI specifications for Certified LabDiet (PMI Certified LabDiet 5002 is a registered trademark of Purina Mills, Inc.) 5002. There were a total of 400 rats in the study divided into 10 groups of 20 rats/sex/group. The responses of rats fed diets containing MON 810 were compared to those of rats fed grain from conventional corn varieties. Overall health, body weight, food consumption, clinical pathology parameters (hematology, blood chemistry, urinalysis), organ weights, and gross and microscopic appearance of tissues were comparable between groups fed diets containing MON 810 and conventional corn varieties. This study complements extensive agronomic, compositional and farm animal feeding studies with MON 810 grain, confirming that it is as safe and nutritious as grain from existing commercial corn varieties.

Protective effect of kombucha on rats fed a hypercholesterolemic diet is mediated by its antioxidant activity.

PubMed

Bellassoued, Khaled; Ghrab, Ferdaws; Makni-Ayadi, Fatma; Van Pelt, Jos; Elfeki, Abdelfattah; Ammar, Emna

2015-01-01

Kombucha (KT) is claimed to have various beneficial effects on human health, but there is very little scientific evidence available in the literature. The present study investigates the effects of Camellia sinensis (GT) Linn. (Theaceae) and KT, two natural drinks, on cholesterol and antioxidant status using a hypercholesterolemia rat model. The present study compared the free-radical scavenging abilities and polyphenol levels of GT and KT. Wistar rats fed cholesterol-rich diets were given KT or GT (5 mL/kg body weight per day, po) for 16 weeks, then fasted overnight and sacrificed. The plasma lipid levels, thiobarbituric acid reactive substances (TBARS) and aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamyl transpeptidase (GGT) serum levels, antioxidant activities of superoxide dismutase (SOD) and catalase (CAT), and creatinine and urea rats were examined. KT had a phenolic compound of 955 ± 0.75 mg GAE/g) followed, by GT (788.92 ± 0.02 mg GAE/g). The free radical scavenging activity of KT was higher than GT. Compared with GT, KT induced lowered serum levels of TC, TG, VLDL-C, and LDL-C by 26, 27, 28, and 36%, respectively, and increased the serum level of high-density lipoprotein cholesterol (HDL-C). KT induced a 55% decrease of TBARS level in liver and 44% in kidney, compared with those of rats fed a cholesterol-rich diet alone. Moreover, CAT and SOD activities were reduced by 29 and 33%, respectively, in liver and 31 and 35%, respectively, in kidney, after oral administration of KT, compared with those of HCD-fed rats. The findings revealed that KT administration induced attractive curative effects on hypercholesterolemic, particularly in terms of liver-kidney functions in rats. Its effect on humans needs to be studied further.

Cytochrome P450 2E1 inhibition prevents hepatic carcinogenesis induced by diethylnitrosamine in alcohol-fed rats

USDA-ARS?s Scientific Manuscript database

Chronic alcohol ingestion increases hepatic cytochrome P450 2E1 (CYP2E1), which is associated with hepatocarcinogenesis. We investigated whether treatment with chlormethiazole (CMZ), a CYP2E1 inhibitor, protects against alcohol-associated hepatic carcinogenesis in rats. Rats were fed either an ethan...

No long-term feeding toxicities on the health status in rats fed with cloned Korean native beef cattle (Hanwoo) meat.

PubMed

Lee, Nam-Jin; Yang, Byoung-Chul; Im, Gi-Sun; Lee, Sung-Soo; Seong, Hwan-Hoo; Park, Jin-Ki; Chang, Won-Kyong; Kang, Jong-Koo; Hwang, Seongsoo

2013-08-01

This study was designed to undertake a risk assessment to identify the health status of rats fed with somatic cell nuclear transfer (SCNT)-cloned Korean native beef cattle (Hanwoo) meat for 26 weeks. The rats were randomly divided into 5 groups, each consisting of 12 male (142.6 ± 5.23 g) and 12 female (113.7 ± 6.31 g) rats each. The animals were fed commercial pellets (control), pellets containing 5% (N-5) and 10% (N-10) of normal cattle meat, and diets containing 5% (C-5) and 10% (C-10) of cloned cattle meat. The mortality; clinical signs; body weight; food consumption; urinary, hematology, blood biochemistry, and histopathological analyses; and absolute and relative organ weights were analyzed and compared. During the 26-week test period, health status-related factors of the rats fed on cloned Hanwoo meat were found to have no test substance-related toxicities. The only difference was the increased uterus weight in female C-10 rats as compared to their counterparts counterparts (p < .05). On the basis of these health status results, it can be postulated that no food consumption risks might arise from the long-term feeding of cloned cattle meat in rats.

Blockade of renal medullary bradykinin B2 receptors increases tubular sodium reabsorption in rats fed a normal-salt diet

PubMed Central

Sivritas, Sema-Hayriye; Ploth, David W.; Fitzgibbon, Wayne R.

2008-01-01

The present study was performed to test the hypothesis that under normal physiological conditions and/or during augmentation of kinin levels, intrarenal kinins act on medullary bradykinin B2 (BKB2) receptors to acutely increase papillary blood flow (PBF) and therefore Na+ excretion. We determined the effect of acute inner medullary interstitial (IMI) BKB2 receptor blockade on renal hemodynamics and excretory function in rats fed either a normal (0.23%)- or a low (0.08%)-NaCl diet. For each NaCl diet, two groups of rats were studied. Baseline renal hemodynamic and excretory function were determined during IMI infusion of 0.9% NaCl into the left kidney. The infusion was then either changed to HOE-140 (100 μg·kg−1·h−1, treated group) or maintained with 0.9% NaCl (time control group), and the parameters were again determined. In rats fed a normal-salt diet, HOE-140 infusion decreased left kidney Na+ excretion (urinary Na+ extraction rate) and fractional Na+ excretion by 40 ± 5% and 40 ± 4%, respectively (P < 0.01), but did not alter glomerular filtration rate, inner medullary blood flow (PBF), or cortical blood flow. In rats fed a low-salt diet, HOE-140 infusion did not alter renal regional hemodynamics or excretory function. We conclude that in rats fed a normal-salt diet, kinins act tonically via medullary BKB2 receptors to increase Na+ excretion independent of changes in inner medullary blood flow. PMID:18632797

In vivo determination of triglyceride (TG) secretion in rats fed different dietary saturated fats using (2- sup 3 H)-glycerol

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

Lai, H.C.; Yang, H.; Lasekan, J.

1990-02-26

Male, Sprague-Dawley rats (154{plus minus}1 g) were fed diets containing 2% corn oil (CO) + 14% butterfat (BF), beef tallow (BT), olive oil (OO) or coconut oil (CN) vs a 16% CO control diet for 5 weeks. Changes in plasma TG specific activity (dpm/mg TG) were determined in individual unanesthetized rats after injection of 100 {mu}Ci (2-{sup 3}H)-glycerol via a carotid cannula. Fractional rate constants were obtained using a 2-compartment model and nonlinear regression analysis. Results demonstrated no difference in the fractional rate constants among dietary groups; but, differences in the rates of hepatic TG secretion were noted. Rats fedmore » BT showed a higher rate of hepatic TG secretion than rats fed CO. Rats fed BF, OO or CN showed somewhat higher rates of hepatic TG secretion than CO. VLDL TG, phospholipid, and apolipoprotein B and E levels were higher with saturated fats vs CO. The data suggest that the higher plasma TG levels noted in response to feeding saturated fats vs corn oil can be explained, in part, by an increased flux of hepatic TG secretion.« less

Methodological evaluation of indirect calorimetry data in lean and obese rats.

PubMed

Rafecas, I; Esteve, M; Fernández-López, J A; Remesar, X; Alemany, M

1993-11-01

1. The applicability of current indirect calorimetry formulae to the study of energy and substrate balances on obese rats has been evaluated. The energy consumption of series of 60-day rats of Wistar, lean and obese Zucker stock were studied by means of direct and indirect calorimetry, and by establishing their energy balance through measurement of food intake and retention. Calorimetric studies encompassed a 24 h period, with gas and heat output measurements every 2 or 5 min, respectively, for direct and indirect calorimetry. 2. The analysis of fat composition (diet, whole rat, and synthesized and oxidized fat) showed only small variations that had only a limited effect on the overall energy equation parameters. 3. A gap in the nitrogen balance, which represents a urinary N excretion lower than the actual protein oxidized, resulted in significant deviations in the estimation of carbohydrate and lipid oxidized when using the equations currently available for indirect calorimetry. 4. Analysis of the amino acid composition of diet and rat protein as well as of the portion actually oxidized, and correcting for the nitrogen gap allowed the establishment of a set of equations that gave better coincidence of the calculated data with the measured substrate balance. 5. The measured heat output of all rats was lower than the estimated values calculated by means of either indirect calorimetry of direct energy balance measurement; the difference corresponded to the energy lost in water evaporation, and was in the range of one-fifth of total energy produced in the three rat stocks. 6. Wistar rats showed a biphasic circadian rhythm of substrate utilization, with alternate lipid synthesis/degradation that reversed that of carbohydrate, concordant with nocturnal feeding habits. Zucker rats did not show this rhythm; obese rats synthesized large amounts of fat during most of the light period, consuming fat at the end of the dark period, which suggests more diurnal feeding habits

Differences in betaine-homocysteine methyltransferase expression, ER stress response and liver injury between alcohol-fed mice and rats

PubMed Central

Shinohara, Masao; Ji, Cheng; Kaplowitz, Neil

2009-01-01

Chronic ethanol infusion resulted in greater serum ALT elevation, lipid accumulation, necroinflammation, and focal hepatic cell death in mice than rats. Mice exhibited a remarkable hyperhomocysteinemia but no increase was seen in rats. Similarly, a high methionine low folate diet (HMLF) induced less steatosis, serum ALT increase, and hyperhomocysteinemia in rats than in mice. Western blot analysis of betaine homocysteine methyltransferase (BHMT) expression showed that rats fed either ethanol or HMLF had significantly increased BHMT expression which did not occur in mice. Nuclear NFκB p65 was increased in mouse in response to alcohol feeding. The human BHMT promoter was repressed by homocysteine in mouse hepatocytes but not rat hepatocytes. BHMT induction was faster and greater in primary rat hepatocytes than mouse hepatocytes in response to exogenous homocysteine exposure. Mice fed ethanol i.g. exhibited an increase in GRP78 and IRE1 which was not seen in the rat and SREBP-1 was increased to a greater extent in mice than rats. Thus, rats are more resistant to ethanol induced steatosis, ER stress and hyperhomocysteinemia and this correlates with induction of BHMT in rats. These findings support the hypothesis that a critical factor in the pathogenesis of alcoholic liver injury is the enhanced ability of rat or impaired ability of mouse to up-regulate BHMT which prevents hyperhomocysteinemia, ER stress and liver injury. PMID:20069651

Biochemical Effects of Aqueous Extract of Persea americana (Mill) on the Myocardium of Left Ventricle of High Salt–Fed Adult Wistar Rats

PubMed Central

Olushola, Ayoola I.; Aderibigbe, Komolafe O.; Stephen, Saka O.; Ayodeji, Odukoya S.

2017-01-01

Background. The cardioprotective effects of Persea americana extract was investigated on biochemical activities of high salt–fed adult Wistar rats in this study. Method. Forty healthy Wistar rats of both sexes weighing 120 to 150 g were randomly assigned into 8 groups of 5 rats each (groups A, B, C, D, E, F, G, and H). Rats in groups A, F, G, and H were fed with standard laboratory pellets, while groups B, C, D, and E were fed on the high-salt diet for 4 weeks. Concomitantly, daily administration of 50, 100, and 150 mg/kg of the P americana extract were given orally to groups C and F, D and G, and E and H, respectively, while rats in groups A and B were administered distilled water. Blood samples were taken by cardiac puncture; concentration of sodium ion, potassium ion, nitric oxide, and activity of lactate dehydrogenase were determined. One-way analysis of variance was used to analyze data, followed by Student-Newman-Keuls (SNK) test for multiple comparison. Results. Results revealed that concentration of potassium ion and nitric oxide was significantly lower (P < .05) in high salt–fed groups. Sodium ion concentration and activity of lactate dehydrogenase were higher in high salt–fed group while P americana prevented biochemical perturbations in other experimental groups. Conclusion. In conclusion, high salt–diet induced biochemical alterations which were significantly protected by oral administration of P americana extract. PMID:29228805

Biochemical Effects of Aqueous Extract of Persea americana (Mill) on the Myocardium of Left Ventricle of High Salt-Fed Adult Wistar Rats.

PubMed

Olushola, Ayoola I; Aderibigbe, Komolafe O; Stephen, Saka O; Ayodeji, Odukoya S

2017-10-01

The cardioprotective effects of Persea americana extract was investigated on biochemical activities of high salt-fed adult Wistar rats in this study. Forty healthy Wistar rats of both sexes weighing 120 to 150 g were randomly assigned into 8 groups of 5 rats each (groups A, B, C, D, E, F, G, and H). Rats in groups A, F, G, and H were fed with standard laboratory pellets, while groups B, C, D, and E were fed on the high-salt diet for 4 weeks. Concomitantly, daily administration of 50, 100, and 150 mg/kg of the P americana extract were given orally to groups C and F, D and G, and E and H, respectively, while rats in groups A and B were administered distilled water. Blood samples were taken by cardiac puncture; concentration of sodium ion, potassium ion, nitric oxide, and activity of lactate dehydrogenase were determined. One-way analysis of variance was used to analyze data, followed by Student-Newman-Keuls (SNK) test for multiple comparison. Results revealed that concentration of potassium ion and nitric oxide was significantly lower ( P < .05) in high salt-fed groups. Sodium ion concentration and activity of lactate dehydrogenase were higher in high salt-fed group while P americana prevented biochemical perturbations in other experimental groups. In conclusion, high salt-diet induced biochemical alterations which were significantly protected by oral administration of P americana extract.

Inhibition of serum cholesterol oxidation by dietary vitamin C and selenium intake in high fat fed rats.

PubMed

Menéndez-Carreño, M; Ansorena, D; Milagro, F I; Campión, J; Martínez, J A; Astiasarán, I

2008-04-01

Cholesterol oxidation products (COPs) have been considered as specific in vivo markers of oxidative stress. In this study, an increased oxidative status was induced in Wistar rats by feeding them a high-fat diet (cafeteria diet). Another group of animals received the same diet supplemented with a combination of two different antioxidants, ascorbic acid (100 mg/kg rat/day) and sodium selenite (200 microg/kg rat/day) and a third group fed on a control diet. Total and individual COPs analysis of the different diets showed no differences among them. At the end of the experimental trial, rats were sacrificed and serum cholesterol, triglycerides and COPs were measured. None of the diets induced changes in rats body weight, total cholesterol and triglycerides levels. Serum total COPs in rats fed on the high-fat diet were 1.01 microg/ml, two times the amount of the control rats (0.47 microg/ml). When dietary antioxidant supplementation was given, serum total COPs concentration (0.44 microg/ml) showed the same levels than those of the rats on control diet. 7beta-hydroxycholesterol, formed non-enzymatically via cholesterol peroxidation in the presence of reactive oxygen species, showed slightly lower values in the antioxidant-supplemented animals compared to the control ones. This study confirms the importance of dietary antioxidants as protective factors against the formation of oxysterols.

Antioxidative activity of microencapsulated gamma-oryzanol on high cholesterol-fed rats.

PubMed

Suh, Mun-Hee; Yoo, Sang-Ho; Chang, Pahn-Shick; Lee, Hyeon Gyu

2005-12-14

The effectiveness of microencapsulated gamma-oryzanol (M-gamma-OZ) was evaluated as an antioxidant in Sprague-Dawley rats. Lard containing 100 ppm of gamma-OZ (HCD III) or 100 ppm of M-gamma-OZ (HCD IV) was heated in an oven for 7 days, and the heat-treated lard as an ingredient in a high cholesterol diet (HCD) formulation was tested for analyzing in vivo cholesterol and lipid profiles. The HCDs containing fresh lard (HCD I) and heat-treated lard (HCD II) were fed to the rats for 4 weeks as control groups A and B, respectively, in this experiment. The liver thiobarbituric acid reactive substances values of group C (fed with HCD III) and group D (with HCD IV) were significantly lower (p < 0.05) than that of negative control, group B. One of the cholesterol oxidation products, 7-ketocholesterol, was not detected from group D, indicating that microencapsulation preserved antioxidative activity effectively. The levels of serum total cholesterol and lipoproteins, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and very low-density lipoprotein were also affected by heat-induced lipid oxidation.The M-gamma-OZ evidently decreased LDL-cholesterol content and increased HDL-cholesterol in blood samples of tested rats. These results suggested that the M-gamma-OZ was not only effective in inhibiting the hypercholesterolemia of serum and liver but also reduced the oxidation degree of lipids and cholesterol. Therefore, this microencapsulation can be a good potential technique to protect the antioxidant activity of gamma-OZ from heat-induced lipid oxidation.

RNA-sequencing data analysis of uterus in ovariectomized rats fed with soy protein isolate,17B-estradiol and casein

USDA-ARS?s Scientific Manuscript database

This data file describes the bioinformatics analysis of uterine RNA-seq data comparing genome wide effects of feeding soy protein isolate compared to casein to ovariectomized female rats age 64 days relative to treatment of casein fed rats with 5 ug/kg/d estradiol and relative to rats treated with e...

Effect of ingestion of soy yogurt on intestinal parameters of rats fed on a beef-based animal diet

PubMed Central

Bedani, Raquel; Pauly-Silveira, Nadiége Dourado; Cano, Veridiana Soares Pereira; Valentini, Sandro Roberto; de Rossi, Graciela Font; Valdez, Elizeu Antonio

2011-01-01

The aim of this study was to investigate whether the ingestion of soy yogurt fermented with Enterococcus faecium CRL 183 would modify the intestinal count of enterococci, fecal pH and ammonia content in rats fed on a diet containing red meat. The rats were placed in 4 groups: for 60 days, group I was given a standard casein-based rodent feed and groups II-IV, the beef-based feed. From day 30, groups III-IV also received the following products: III) soy yogurt; IV) suspension of E. faecium CRL 183. At the start and on days 30 and 60, feces were collected for the determination of pH, ammonia content, count of enterococci and identification of their species. On day 60, rats were sacrificed and their colons also removed for count of enterococci and identification of their species. Rats that ingested soy yogurt showed no significant change (P<0.05) in fecal counts of Enterococcus spp., but, this rat group showed a higher count of E. faecium than rats that ingested suspension of E. faecium CRL 183. The ingestion of soy yogurt and E. faecium culture caused a significant rise (P < 0.05) in fecal pH and ammonia content. Our results suggest that consumption of soy yogurt fermented with E. faecium CRL 183 and L. helveticus subsp. jugurti could change the species of Enterococcus spp. present in the feces and colon of rats fed on a beef-based diet. However, the fermented soy product and the pure culture of E. faecium CRL 183 also induced undesirable effects such as the increase of fecal pH and ammonia content in the feces of rats fed on a beef-based diet. PMID:24031747

Distribution of magnesium in central nervous system tissue, trabecular and cortical bone in rats fed with unbalanced diets of minerals.

PubMed

Yasui, M; Yano, I; Yase, Y; Ota, K

1990-11-01

Recent epidemiological changes in patterns of foci of amyotrophic lateral sclerosis (ALS) in the Western Pacific suggest that environmental factors play a contributory role in the pathogenic process of this disorder. In this experimental study on rats, a similar situation of dietary mineral imbalance was created as is found in the soil and drinking water of these ALS foci with a low content of calcium (Ca) and magnesium (Mg) and a high content of aluminum (Al). In groups of rats fed a low Ca diet, low Ca-Mg diet, and low Ca-Mg plus high Al diet, serum Ca levels were found to be lower than those in a group fed a standard diet. Also, serum Mg levels were lower in the groups fed a low Ca-Mg diet and a low Ca-Mg plus high Al diet than in the groups fed a standard diet and only a low Ca diet. There was no significant difference in Mg content of central nervous system (CNS) tissues of groups fed unbalanced and standard diets, except for a significant decrease in Mg content of the spinal cord of rats fed a low Ca-Mg plus high Al diet. Mg content of the lumbar spine and cortical bone decreased in the unbalanced diet groups compared with that of a group fed a standard diet. These findings suggest that under the disturbed bone mineralization induced by unbalanced mineral diets, Mg may be mobilized from bone to maintain the level necessary for vital activity in soft tissues including CNS tissue.

Evaluation of some selected blood parameters and histopathology of liver and kidney of rats fed protein-substituted mucuna flour and derived protein rich product.

PubMed

Ngatchic, Josiane Therese Metsagang; Sokeng, Selestion Dongmo; Njintang, Nicolas Yanou; Maoundombaye, Theophile; Oben, Julius; Mbofung, Carl Moses F

2013-07-01

This comparative study reports the nutritional and toxicological characteristics of Mucuna pruriens flour and a protein-rich product developed from it. The protein-rich mucuna product (PRMP) was obtained by the three steps procedure: protein solubilization, heat-coagulation and sieving. Three weeks rats (n=6 per group) were fed for 28 days on standard protein-substituted rat feed with mucuna flour or PRMP. The experimental design was a factorial design with three mucuna accessions (Velvet, Black and White) and two treatments (flour and PRMP). The protein content ranged 27.2-31.5 g/100 g for flour and 58.8-61.1% for PRMP. Processing flour into PRMP led to a significant (p<0.05) reduction of tannins (50%), total polyphenols (50%) and trypsin inhibitors (94%). The rats fed PMRP diets witnessed weight gain similar to casein, while those fed mucuna flour lost weight. The levels of total cholesterol, HDL-cholesterol and LDL-cholesterol observed in animals groups fed mucuna flour and PRMP were significantly lower (p<0.05) than the control group. In addition lymphocytes, granulocytes, red blood cells, hemoglobin and hematocrit of rats fed mucuna flour were significantly (p<0.05) lower than values in other rats groups. Kidneys glomerular sclerosis and high creatinine levels were observed in group fed mucuna flour. PRMP then represents a good alternative of using mucuna proteins for human nutrition. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Naringin Improves Diet-Induced Cardiovascular Dysfunction and Obesity in High Carbohydrate, High Fat Diet-Fed Rats

PubMed Central

Alam, Md. Ashraful; Kauter, Kathleen; Brown, Lindsay

2013-01-01

Obesity, insulin resistance, hypertension and fatty liver, together termed metabolic syndrome, are key risk factors for cardiovascular disease. Chronic feeding of a diet high in saturated fats and simple sugars, such as fructose and glucose, induces these changes in rats. Naturally occurring compounds could be a cost-effective intervention to reverse these changes. Flavonoids are ubiquitous secondary plant metabolites; naringin gives the bitter taste to grapefruit. This study has evaluated the effect of naringin on diet-induced obesity and cardiovascular dysfunction in high carbohydrate, high fat-fed rats. These rats developed increased body weight, glucose intolerance, increased plasma lipid concentrations, hypertension, left ventricular hypertrophy and fibrosis, liver inflammation and steatosis with compromised mitochondrial respiratory chain activity. Dietary supplementation with naringin (approximately 100 mg/kg/day) improved glucose intolerance and liver mitochondrial dysfunction, lowered plasma lipid concentrations and improved the structure and function of the heart and liver without decreasing total body weight. Naringin normalised systolic blood pressure and improved vascular dysfunction and ventricular diastolic dysfunction in high carbohydrate, high fat-fed rats. These beneficial effects of naringin may be mediated by reduced inflammatory cell infiltration, reduced oxidative stress, lowered plasma lipid concentrations and improved liver mitochondrial function in rats. PMID:23446977

Calorie restriction attenuates cardiac remodeling and diastolic dysfunction in a rat model of metabolic syndrome.

PubMed

Takatsu, Miwa; Nakashima, Chieko; Takahashi, Keiji; Murase, Tamayo; Hattori, Takuya; Ito, Hiromi; Murohara, Toyoaki; Nagata, Kohzo

2013-11-01

Calorie restriction (CR) can modulate the features of obesity-related metabolic and cardiovascular diseases. We have recently characterized DahlS.Z-Lepr(fa)/Lepr(fa) (DS/obese) rats, derived from a cross between Dahl salt-sensitive and Zucker rats, as a new animal model of metabolic syndrome. DS/obese rats develop hypertension and manifest left ventricular remodeling and diastolic dysfunction, as well as increased cardiac oxidative stress and inflammation. We have now investigated the effects of CR on cardiac pathophysiology in DS/obese rats. DS/obese rats were fed either normal laboratory chow ad libitum or a calorie-restricted diet (65% of the average food intake for ad libitum) from 9 to 13 weeks. Age-matched homozygous lean (DahlS.Z-Lepr(+)/Lepr(+) or DS/lean) littermates served as controls. CR reduced body weight in both DS/obese and DS/lean rats, as well as attenuated the development of hypertension in DS/obese rats without affecting blood pressure in DS/lean rats. CR also reduced body fat content, ameliorated left ventricular hypertrophy, fibrosis, and diastolic dysfunction, and attenuated cardiac oxidative stress and inflammation in DS/obese rats. In addition, it increased serum adiponectin concentration, as well as downregulated the expression of angiotensin-converting enzyme and angiotensin II type 1A receptor genes in the heart of DS/obese rats. Our results thus show that CR attenuated obesity and hypertension, as well as left ventricular remodeling and diastolic dysfunction in DS/obese rats, with these latter effects being associated with reduced cardiac oxidative stress and inflammation.

Normal distribution of body weight gain in male Sprague-Dawley rats fed a high-energy diet.

PubMed

Archer, Zoe A; Rayner, D Vernon; Rozman, Jan; Klingenspor, Martin; Mercer, Julian G

2003-11-01

To investigate the effect of a high-energy (HE) diet on caloric intake, body weight, and related parameters in outbred male Sprague-Dawley (SD) rats. Twenty-eight SD rats were fed either chow (C) for 19 weeks or HE diet for 14 weeks and then C for 5 weeks. Blood hormones and metabolites were assayed, and expression of uncoupling protein-1 and hypothalamic energy-balance-related genes were determined by Northern blotting and in situ hybridization, respectively. HE rats gained body weight more rapidly than C animals with a range of weight gains, but there was no evidence that weight gain was bimodally distributed. Caloric intake was transiently elevated after introduction of the HE diet. Transfer of HE rats back to C resulted in a drop in caloric intake, but a stable body weight. In terminal analysis, two of four dissected adipose tissue depots were heavier in rats that had previously been fed HE diet. Blood leptin, insulin, glucose, and nonesterified fatty acids were not different between the groups. Uncoupling protein-1 mRNA was elevated in interscapular brown adipose tissue from HE rats. There was a trend for agouti-related peptide mRNA in the hypothalamic arcuate nucleus to be higher in HE rats. Contrary to other studies of the SD rat on HE diet, body weight and other measured parameters were normally distributed. There was no segregation into two distinct populations on the basis of susceptibility to diet-induced obesity. This characteristic may be dependent on the breeding colony from which animals were sourced.

Effects of Mucuna pruriens on Free Fatty Acid Levels and Histopathological Changes in the Brains of Rats Fed a High Fructose Diet.

PubMed

Akgun, Bekir; Sarı, Aysel; Ozturk, Sait; Erol, Fatih Serhat; Ozercan, Ibrahim Hanifi; Ulu, Ramazan

2017-01-01

To investigate free fatty acid levels and histopathological changes in the brain of rats fed a high fructose diet (HFrD) and to evaluate the effects of Mucuna pruriens, known to have antidiabetic activity, on these changes. The study comprised 28 mature female Wistar rats. The rats were divided into 4 groups, each included 7 rats. Group 1: control; group 2: fed an HFrD; group 3: fed normal rat chow and M. pruriens; group 4: fed an HFrD and M. pruriens for 6 weeks. At the end of 6 weeks, the rats were decapitated, blood and brain tissues were obtained. Serum glucose and triglyceride levels were measured. Free fatty acid levels were measured in 1 cerebral hemisphere of each rat and histopathological changes in the other. The Mann-Whitney U test was used to compare quantitative continuous data between 2 independent groups, and the Kruskal-Wallis test was used to compare quantitative continuous data between more than 2 independent groups. Arachidonic acid and docosahexaenoic acid levels were significantly higher in group 2 than in group 1 (p < 0.05). Free arachidonic acid and docosahexaenoic acid levels in group 4 were significantly less than in group 2 (p < 0.05). Histopathological examination of group 2 revealed extensive gliosis, neuronal hydropic degeneration, and edema. In group 4, gliosis was much lighter than in group 2, and edema was not observed. Neuronal structures in group 4 were similar to those in group 1. The HFrD increased the levels of free arachidonic acid and docosahexaenoic acid probably due to membrane degradation resulting from possible oxidative stress and inflammation in the brain. The HFrD also caused extensive gliosis, neuronal hydropic degeneration, and edema. Hence, M. pruriens could have therapeutic effects on free fatty acid metabolism and local inflammatory responses in the brains of rats fed an HFrD. © 2017 The Author(s) Published by S. Karger AG, Basel.

Effects of Mucuna pruriens on Free Fatty Acid Levels and Histopathological Changes in the Brains of Rats Fed a High Fructose Diet

PubMed Central

Akgun, Bekir; Sarı, Aysel; Ozturk, Sait; Erol, Fatih Serhat; Ozercan, Ibrahim Hanifi; Ulu, Ramazan

2018-01-01

Objective To investigate free fatty acid levels and histopathological changes in the brain of rats fed a high fructose diet (HFrD) and to evaluate the effects of Mucuna pruriens, known to have antidiabetic activity, on these changes. Materials and Methods The study comprised 28 mature female Wistar rats. The rats were divided into 4 groups, each included 7 rats. Group 1: control; group 2: fed an HFrD; group 3: fed normal rat chow and M. pruriens; group 4: fed an HFrD and M. pruriens for 6 weeks. At the end of 6 weeks, the rats were decapitated, blood and brain tissues were obtained. Serum glucose and triglyceride levels were measured. Free fatty acid levels were measured in 1 cerebral hemisphere of each rat and histopathological changes in the other. The Mann-Whitney U test was used to compare quantitative continuous data between 2 independent groups, and the Kruskal-Wallis test was used to compare quantitative continuous data between more than 2 independent groups. Results Arachidonic acid and docosahexaenoic acid levels were significantly higher in group 2 than in group 1 (p < 0.05). Free arachidonic acid and docosahexaenoic acid levels in group 4 were significantly less than in group 2 (p < 0.05). Histopathological examination of group 2 revealed extensive gliosis, neuronal hydropic degeneration, and edema. In group 4, gliosis was much lighter than in group 2, and edema was not observed. Neuronal structures in group 4 were similar to those in group 1. Conclusions The HFrD increased the levels of free arachidonic acid and docosahexaenoic acid probably due to membrane degradation resulting from possible oxidative stress and inflammation in the brain. The HFrD also caused extensive gliosis, neuronal hydropic degeneration, and edema. Hence, M. pruriens could have therapeutic effects on free fatty acid metabolism and local inflammatory responses in the brains of rats fed an HFrD. PMID:28898884

Peroxisome proliferator-activated receptor subtype-specific regulation of hepatic and peripheral gene expression in the Zucker diabetic fatty rat.

PubMed

Dana, S L; Hoener, P A; Bilakovics, J M; Crombie, D L; Ogilvie, K M; Kauffman, R F; Mukherjee, R; Paterniti, J R

2001-08-01

Fibrates and thiazolidinediones are used clinically to treat hypertriglyceridemia and hyperglycemia, respectively. Fibrates bind to the peroxisome proliferator-activated receptor (PPAR)-alpha, and thiazolidinediones are ligands of PPAR-gamma. These intracellular receptors form heterodimers with retinoid X receptor to modulate gene transcription. To elucidate the target genes regulated by these compounds, we treated Zucker diabetic fatty rats (ZDF) for 15 days with a PPAR-alpha-specific compound, fenofibrate, a PPAR-gamma-specific ligand, rosiglitazone, and a PPAR-alpha/-gamma coagonist, GW2331, and measured the levels of several messenger RNAs (mRNAs) in liver by real-time polymerase chain reaction. All 3 compounds decreased serum glucose and triglyceride levels. Fenofibrate and GW2331 induced expression of acyl-coenzyme A (CoA) oxidase and enoyl-CoA hydratase and reduced apolipoprotein C-III and phosphoenolpyruvate carboxykinase mRNAs. Rosiglitazone modestly increased apolipoprotein C-III mRNA and had no effect on expression of the other 2 genes in the liver but increased the expression of glucose transporter 4 and phosphoenolpyruvate carboxykinase in adipose tissue. We identified a novel target in liver, mitogen-activated phosphokinase phosphatase 1, whose down-regulation by PPAR-alpha agonists may improve insulin sensitivity in that tissue by prolonging insulin responses. The results of these studies suggest that activation of PPAR-alpha as well as PPAR-gamma in therapy for type 2 diabetes will enhance glucose and triglyceride control by combining actions in hepatic and peripheral tissues. Copyright 2001 by W.B. Saunders Company

Functional Comparison for Lipid Metabolism and Intestinal and Fecal Microflora Enzyme Activities between Low Molecular Weight Chitosan and Chitosan Oligosaccharide in High-Fat-Diet-Fed Rats.

PubMed

Chiu, Chen-Yuan; Feng, Shih-An; Liu, Shing-Hwa; Chiang, Meng-Tsan

2017-07-24

The present study investigated and compared the regulatory effects on the lipid-related metabolism and intestinal disaccharidase/fecal bacterial enzyme activities between low molecular weight chitosan and chitosan oligosaccharide in high-fat-diet-fed rats. Diet supplementation of low molecular weight chitosan showed greater efficiency than chitosan oligosaccharide in suppressing the increased weights in body and in liver and adipose tissues of high-fat-diet-fed rats. Supplementation of low molecular weight chitosan also showed a greater improvement than chitosan oligosaccharide in imbalance of plasma, hepatic, and fecal lipid profiles, and intestinal disaccharidase activities in high-fat-diet-fed rats. Moreover, both low molecular weight chitosan and chitosan oligosaccharide significantly decreased the fecal microflora mucinase and β-glucuronidase activities in high-fat-diet-fed rats. These results suggest that low molecular weight chitosan exerts a greater positive improvement than chitosan oligosaccharide in lipid metabolism and intestinal disaccharidase activity in high-fat-diet-induced obese rats.

Repeated electroacupuncture in obese Zucker diabetic fatty rats: adiponectin and leptin in serum and adipose tissue.

PubMed

Peplow, Philip V

2015-04-01

Fasted, male, obese, Zucker, diabetic fatty rats aged 10-16 weeks were anesthetized with 1% halothane in nitrous oxide-oxygen (3:1) on alternate weekdays over 2 weeks. Group 1 (n = 4) did not receive electroacupuncture (controls); Group 2 (n = 4) received electroacupuncture using the Zhongwan and the Guanyuan acupoints; Group 3 (n = 4) received electroacupuncture using the bilateral Zusanli acupoints; Group 4 (n = 6) received neither halothane in nitrous oxide:oxygen nor electroacupuncture. At the end of study, animals were injected with sodium pentobarbitone (60 mg/mL, i.p.), and blood and white adipose tissue were collected. Analysis of variance and Duncan's tests showed that the mean leptin in serum was significantly lower and the adiponectin:leptin ratio was significantly higher in Group 2 than in Group 1 (p < 0.05); for Group 4, the serum leptin was significantly higher than it was for Groups 1-3 (p < 0.05), and the adiponectin:leptin ratio was significantly lower than it was for Group 2 (p < 0.05). Similar changes occurred for the leptin levels in the pelvic adipose tissue. In addition, for Group 2, the mean serum insulin: glucose ratio was significantly higher than it was for Group 1 (p < 0.05); for Group 4 the mean serum insulin and insulin: glucose ratio were significantly higher than they were for Groups 1 and 3 (p < 0.05), but not Group 2 (p > 0.05). No significant differences in the serum or the adipose-tissue measurements between Groups 1 and 3 were observed (p > 0.05). Copyright © 2015. Published by Elsevier B.V.

CONFOCAL LASER SCANNING MICROSCOPY OF APOPTOSIS IN WHOLE MOUSE AND RAT OVARIES

EPA Science Inventory

Confocal Laser Scanning Microscopy of Apoptosis in Whole Mouse and Rat Ovaries. Robert M. Zucker Susan C. Jeffay and Sally D. Perreault Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research ...

Anti-obesity efficacy of nanoemulsion oleoresin capsicum in obese rats fed a high-fat diet

PubMed Central

Kim, Joo-Yeon; Lee, Mak-Soon; Jung, Sunyoon; Joo, Hyunjin; Kim, Chong-Tai; Kim, In-Hwan; Seo, Sangjin; Oh, Soojung; Kim, Yangha

2014-01-01

Purpose This study determined the effects of oleoresin capsicum (OC) and nanoemulsion OC (NOC) on obesity in obese rats fed a high-fat diet. Methods The rats were randomly separated into three groups: a high-fat (HF) diet group, HF + OC diet group, and HF + NOC diet group. All groups were fed the diet and water ad libitum for 14 weeks. Results NOC reduced the body weight and adipose tissue mass, whereas OC did not. OC and NOC reduced mRNA levels of adipogenic genes, including peroxisome proliferator-activated receptor (PPAR)-γ, sterol regulatory element-binding protein-1c, and fatty acid-binding protein in white adipose tissue. The mRNA levels of genes related to β-oxidation or thermogenesis including PPAR-α, palmitoyltransferase-1α, and uncoupling protein-2 were increased by the OC and NOC relative to the HF group. Both OC and NOC clearly stimulated AMP-activated protein kinase (AMPK) activity. In particular, PPAR-α, palmitoyltransferase-1α, uncoupling protein-2 expression, and AMPK activity were significantly increased in the NOC group compared to in the OC group. NOC decreased glycerol-3-phosphate dehydrogenase activity whereas OC did not. Conclusion From these results, NOC could be suggested as a potential anti-obesity agent in obese rats fed a HF diet. The effects of the NOC on obesity were associated with changes of multiple gene expression, activation of AMPK, and inhibition of glycerol-3-phosphate dehydrogenase in white adipose tissue. PMID:24403834

Anti-obesity efficacy of nanoemulsion oleoresin capsicum in obese rats fed a high-fat diet.

PubMed

Kim, Joo-Yeon; Lee, Mak-Soon; Jung, Sunyoon; Joo, Hyunjin; Kim, Chong-Tai; Kim, In-Hwan; Seo, Sangjin; Oh, Soojung; Kim, Yangha

2014-01-01

This study determined the effects of oleoresin capsicum (OC) and nanoemulsion OC (NOC) on obesity in obese rats fed a high-fat diet. THE RATS WERE RANDOMLY SEPARATED INTO THREE GROUPS: a high-fat (HF) diet group, HF + OC diet group, and HF + NOC diet group. All groups were fed the diet and water ad libitum for 14 weeks. NOC reduced the body weight and adipose tissue mass, whereas OC did not. OC and NOC reduced mRNA levels of adipogenic genes, including peroxisome proliferator-activated receptor (PPAR)-γ, sterol regulatory element-binding protein-1c, and fatty acid-binding protein in white adipose tissue. The mRNA levels of genes related to β-oxidation or thermogenesis including PPAR-α, palmitoyltransferase-1α, and uncoupling protein-2 were increased by the OC and NOC relative to the HF group. Both OC and NOC clearly stimulated AMP-activated protein kinase (AMPK) activity. In particular, PPAR-α, palmitoyltransferase-1α, uncoupling protein-2 expression, and AMPK activity were significantly increased in the NOC group compared to in the OC group. NOC decreased glycerol-3-phosphate dehydrogenase activity whereas OC did not. From these results, NOC could be suggested as a potential anti-obesity agent in obese rats fed a HF diet. The effects of the NOC on obesity were associated with changes of multiple gene expression, activation of AMPK, and inhibition of glycerol-3-phosphate dehydrogenase in white adipose tissue.

Glucomannan or Glucomannan Plus Spirulina-Enriched Squid-Surimi Diets Reduce Histological Damage to Liver and Heart in Zucker fa/fa Rats Fed a Cholesterol-Enriched and Non-Cholesterol-Enriched Atherogenic Diet.

PubMed

Vázquez-Velasco, Miguel; González-Torres, Laura; García-Fernández, Rosa A; Méndez, María Teresa; Bastida, Sara; Benedí, Juana; González-Muñoz, María José; Sánchez-Muniz, Francisco J

2017-06-01

Glucomannan-enriched squid surimi improves cholesterolemia and liver antioxidant status. The effect of squid surimi enriched with glucomannan or glucomannan plus spirulina on liver and heart structures and cell damage markers was tested in fa/fa rats fed highly saturated-hyper-energetic diets. Animals were fed 70% AIN-93M rodent diet plus six versions of 30% squid surimi for 7 weeks: control (C), glucomannan (G), and glucomannan plus spirulina (GS). The cholesterol-control (HC), cholesterol-glucomannan (HG), and cholesterol-glucomannan plus spirulina (HGS) groups were given similar diets that were enriched with 2% cholesterol and 0.4% cholic acid. G and GS diets versus C diet significantly inhibited weight gain and lowered plasma alanine aminotransferase and aspartate aminotransferase, liver steatosis, lipogranulomas, and total inflammation and alteration scores. The hypercholesterolemic agent significantly increased the harmful effects of the C diet. Liver weight, the hepatosomatic index, all damage markers, and total histological scoring rose for HC versus C (at least P < .05). The addition of glucomannan (HG vs. HC) improved these biomarkers, and non-additional effects from spirulina were observed except for the total liver alteration score. In conclusion, glucomannan and glucomannan plus spirulina blocked the highly saturated-hyper-energetic diet negative effects both with and without added cholesterol. Results suggest the usefulness of including these functional ingredients in fish products.

Mixed Effects Modeling Using Stochastic Differential Equations: Illustrated by Pharmacokinetic Data of Nicotinic Acid in Obese Zucker Rats.

PubMed

Leander, Jacob; Almquist, Joachim; Ahlström, Christine; Gabrielsson, Johan; Jirstrand, Mats

2015-05-01

Inclusion of stochastic differential equations in mixed effects models provides means to quantify and distinguish three sources of variability in data. In addition to the two commonly encountered sources, measurement error and interindividual variability, we also consider uncertainty in the dynamical model itself. To this end, we extend the ordinary differential equation setting used in nonlinear mixed effects models to include stochastic differential equations. The approximate population likelihood is derived using the first-order conditional estimation with interaction method and extended Kalman filtering. To illustrate the application of the stochastic differential mixed effects model, two pharmacokinetic models are considered. First, we use a stochastic one-compartmental model with first-order input and nonlinear elimination to generate synthetic data in a simulated study. We show that by using the proposed method, the three sources of variability can be successfully separated. If the stochastic part is neglected, the parameter estimates become biased, and the measurement error variance is significantly overestimated. Second, we consider an extension to a stochastic pharmacokinetic model in a preclinical study of nicotinic acid kinetics in obese Zucker rats. The parameter estimates are compared between a deterministic and a stochastic NiAc disposition model, respectively. Discrepancies between model predictions and observations, previously described as measurement noise only, are now separated into a comparatively lower level of measurement noise and a significant uncertainty in model dynamics. These examples demonstrate that stochastic differential mixed effects models are useful tools for identifying incomplete or inaccurate model dynamics and for reducing potential bias in parameter estimates due to such model deficiencies.

Antidiabetic and antihiperlipidemic effect of Andrographis paniculata (Burm. f.) Nees and andrographolide in high-fructose-fat-fed rats

PubMed Central

Nugroho, Agung Endro; Andrie, Mohamad; Warditiani, Ni Kadek; Siswanto, Eka; Pramono, Suwidjiyo; Lukitaningsih, Endang

2012-01-01

Objectives: Andrographis paniculata (Burm. f.) Nees originates from India and grows widely in many areas in Southeast Asian countries. Andrographis paniculata (Burm. f.) Nees has shown an antidiabetic effect in type 1 DM rats. The present study investigates the purified extract of the plant and its active compound andrographolide for antidiabetic and antihyperlipidemic effects in high-fructose-fat-fed rats, a model of type 2 DM rats. Materials and Methods: Hyperglycemia in rats was induced by high-fructose-fat diet containing 36% fructose, 15% lard, and 5% egg yolks in 0.36 g/200 gb.wt. 55 days. The rats were treated with the extract or test compound on the 50th day. Antidiabetic activity was measured by estimating mainly the pre– and postprandial blood glucose levels and other parameters such as cholesterol, LDL, triglyceride, and body weight. Results: The purified extract and andrographolide significantly (P<0.05) decreased the levels of blood glucose, triglyceride, and LDL compared to controls. However, no changes were observed in serum cholesterol and rat body weight. Metformin also showed similar effects on these parameters. Conclusions: Andrographis paniculata (Burm. f.) Nees or its active compound andrographolide showed hypoglycemic and hypolipidemic effects in high-fat-fructose-fed rat. PMID:22701250

Decreased rate of protein synthesis, caspase-3 activity, and ubiquitin-proteasome proteolysis in soleus muscles from growing rats fed a low-protein, high-carbohydrate diet.

PubMed

Batistela, Emanuele; Pereira, Mayara Peron; Siqueira, Juliany Torres; Paula-Gomes, Silvia; Zanon, Neusa Maria; Oliveira, Eduardo Brandt; Navegantes, Luiz Carlos Carvalho; Kettelhut, Isis C; Andrade, Claudia Marlise Balbinotti; Kawashita, Nair Honda; Baviera, Amanda Martins

2014-06-01

The aim of this study was to investigate the changes in the rates of both protein synthesis and breakdown, and the activation of intracellular effectors that control these processes in soleus muscles from growing rats fed a low-protein, high-carbohydrate (LPHC) diet for 15 days. The mass and the protein content, as well as the rate of protein synthesis, were decreased in the soleus from LPHC-fed rats. The availability of amino acids was diminished, since the levels of various essential amino acids were decreased in the plasma of LPHC-fed rats. Overall rate of proteolysis was also decreased, explained by reductions in the mRNA levels of atrogin-1 and MuRF-1, ubiquitin conjugates, proteasome activity, and in the activity of caspase-3. Soleus muscles from LPHC-fed rats showed increased insulin sensitivity, with increased levels of insulin receptor and phosphorylation levels of AKT, which probably explains the inhibition of both the caspase-3 activity and the ubiquitin-proteasome system. The fall of muscle proteolysis seems to represent an adaptive response that contributes to spare proteins in a condition of diminished availability of dietary amino acids. Furthermore, the decreased rate of protein synthesis may be the driving factor to the lower muscle mass gain in growing rats fed the LPHC diet.

Brain glucose content in fetuses of ethanol-fed rats

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

Pullen, G.; Singh, S.P.; Snyder, A.K.

1986-03-01

The authors have previously demonstrated impaired placental glucose transfer and fetal hypoglycemia in association with ethanol ingestion by pregnant rats. The present study examines the relationship between glucose availability and fetal brain growth under the same conditions. Rats (EF) were fed ethanol (30% of caloric intake) in liquid diet throughout gestation. Controls received isocaloric diet without ethanol by pair-feeding (PF) or ad libitum (AF). On the 22nd day of gestation fetuses were obtained by cesarean section. Fetal brains were removed and freeze-clamped. Brain weight was significantly reduced (p < 0.001) by maternal ethanol ingestion (206 +/- 2, 212 +/- 4more » and 194 +/- 2 mg in AF, FP and EF fetuses respectively). Similarly, fetal brain glucose content was lower (p < 0.05) in the EF group (14.3 +/- 0.9 mmoles/g dry weight) than in the PF (18.6 +/- 1.0) or the AF (16.2 +/- 0.9) groups. The protein: DNA ratio, an indicator of cell size, correlated positively (r = 0.371, p < 0.005) with brain glucose content. In conclusion, maternal ethanol ingestion resulted in lower brain weight and reduced brain glucose content. Glucose availability may be a significant factor in the determination of cell size in the fetal rat brain.« less

XAS Studies of Se Speciation in Selenite-Fed Rats

PubMed Central

Weekley, Claire M.; Aitken, Jade B.; Witting, Paul K.; Harris, Hugh H.

2014-01-01

The biological activity of selenium is dependent on its chemical form. Therefore, knowledge of Se chemistry in vivo is required for efficacious use of selenium compounds in disease prevention and treatment. Using X-ray absorption spectroscopy, Se speciation in the kidney, liver, heart, spleen, testis and red blood cells of rats fed control (~0.3 ppm Se) or selenite-supplemented (1 ppm or 5 ppm Se) diets for 3 or 6 weeks, was investigated. X-ray absorption spectroscopy revealed the presence of Se–Se and Se–C species in the kidney and liver, and Se–S species in the kidney, but not the liver. X-ray absorption near edge structure (XANES) spectra showed that there was variation in speciation in the liver and kidneys, but Se speciation was much more uniform in the remaining organs. Using principal component analysis (PCA) to interpret the Se K-edge X-ray absorption spectra, we were able to directly compare the speciation of Se in two different models of selenite metabolism – human lung cancer cells and rat tissues. The effects of Se dose, tissue type and duration of diet on selenium speciation in rat tissues were investigated, and a relationship between the duration of the diet (3 weeks versus 6 weeks) and selenium speciation was observed. PMID:25363824

A novel nutritional supplement containing chromium picolinate, phosphatidylserine, docosahexaenoic acid, and boron activates the antioxidant pathway Nrf2/HO-1 and protects the brain against oxidative stress in high-fat-fed rats.

PubMed

Sahin, Nurhan; Akdemir, Fatih; Orhan, Cemal; Aslan, Abdullah; Agca, Can A; Gencoglu, Hasan; Ulas, Mustafa; Tuzcu, Mehmet; Viyaja, Juturu; Komorowskı, James R; Sahin, Kazim

2012-09-01

A novel nutritional supplement complex (N21 #125) composed of four well-known compounds (chromium picolinate, phosphatidylserine, docosahexaenoic acid, and boron) was designed to improve memory function and maintain brain health. The present study evaluated the complex's potential mechanism of action and its role in reducing oxidative stress in the brain of obese rats fed a high-fat diet (HFD). Male Wistar rats (n = 40, 8-week-old) were divided into four groups. Group I was fed a standard diet; Group II was fed a standard diet and supplemented with N21 } Group III was fed an HFD; and Group IV was fed an HFD and supplemented with N21 #125 for 12 weeks. Rats fed HFD had greater serum C-reactive protein (CRP) and tumor necrosis factor alpha (TNF-α) and brain malondialdehyde (MDA) concentrations than rats fed the control diet. Supplementation of N21 #125 decreased CRP, TNF-α, and MDA concentration in rats fed HFD. The levels of brain nuclear factor-E2-related factor-2 (Nrf2), heme oxygenase, extracellular signal-regulated kinases and protein kinase B were lower in rats fed the control diet than for rats fed the HFD. These parameters were increased by supplementation of N21 #125. The data indicate that N21 #125 protected the brain from oxidative damage and inflammation induced by the HFD. This effect may be through up-regulation of the transcription factor Nrf2 expression.

Protective Effects of Ellagitannin-Rich Strawberry Extracts on Biochemical and Metabolic Disturbances in Rats Fed a Diet High in Fructose.

PubMed

Fotschki, Bartosz; Juśkiewicz, Jerzy; Kołodziejczyk, Krzysztof; Jurgoński, Adam; Kosmala, Monika; Milala, Joanna; Ognik, Katarzyna; Zduńczyk, Zenon

2018-04-04

The present study compares the effects of two dietary strawberry extracts rich in monomeric (ME) or dimeric (DE) ellagitannins (ETs) on gastrointestinal, blood and tissue biomarkers in Wistar rats fed high-fructose diets. Both strawberry extracts beneficially affect the antioxidant status and lipid profile of the liver and serum. The ME extract shows a greater ability to inhibit lipid peroxidation in kidneys, more effectively decreases serum and liver triglycerides, and exerts greater anti-inflammatory effects in blood serum than the DE extract. The DE extract significantly reduces the activity of microbial enzymes in the cecum. These effects might be associated with higher cecum and urine levels of ET metabolites in rats fed with ME than in rats fed with DE. In conclusion, the diet-induced fructose-related disturbances observed in biochemical parameters are regulated by both extracts; nevertheless, the beneficial effects of the ME extract are mostly associated with systemic parameters, while those of the DE extracts are associated with local microbial activity.

Petroselinum crispum extract attenuates hepatic steatosis in rats fed with fructose enriched diet.

PubMed

Nair, V Yuneesha; Balakrishanan, N; Antony Santiago, J Victor

2015-01-01

Non alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and ongoing research efforts are focused on understanding the underlying pathophysiology of hepatic steatosis with the anticipation that these efforts will identify novel therapeutic targets. This study investigated the Petroselinum crispum extract in hepatic steatosis in rats fed with fructose enriched diet. Rats were divided into the 4 groups: Group 1 rats received standard pellet diet with corn starch for the entire experimental period of 8 weeks. Group 2 rats received standard pellet diet and 2 gm/kg body weight crude Parsley leaf ethanol extract for the entire experimental period of 8 weeks. Group 3 rats received modified fructose diet. Group 4 rats received modified fructose diet and 2gm/kg crude Parsley leaf ethanol extract. Hepatic function and structure was evaluated in these rats. Modified fructose diet produced dyslipidemia, hepatic steatosis and infiltration of inflammatory cells in the liver and higher plasma hepatic markers. Petroselinum crispum extract reversed metabolic changes such as abnormal crispum extract attenuated chronic changes in modified fructose diet induced NAFLD (Tab. 2, Fig. 3, Ref. 43).

Fatty acid utilization by young Wistar rats fed a cafeteria diet.

PubMed

Esteve, M; Rafecas, I; Fernández-López, J A; Remesar, X; Alemany, M

1992-12-02

The content and accretion of fatty acids in 30, 45 and 60-day old Wistar rats fed either reference chow or a cafeteria diet has been studied, together with their actual fatty acid intake during that period. Diet had a small overall effect on the pattern of deposition of fatty acids, but the deposition of fat was much higher in cafeteria rats. The fat-rich cafeteria diet allowed the direct incorporation of most fatty acids into lipid storage, whilst chow-feeding activated lipogenesis and the deposition of a shorter chain and more saturated type of fatty acids. During the second month of the rat's life, the elongation pathway as well as delta 9-desaturase became functional, thus helping to shape the pattern of fatty acids actually accrued. The 60-day rats showed a relative impairment in the operation of delta 5-desaturase, since their lipids had a higher C20:4/C20:3 ratio than those of the diet ingested. Cafeteria-diet feeding minimized this effect since the large supply of dietary polyunsaturated fatty acids made the operation of the elongation-desaturase pathways practically unnecessary.

Fructose-fed streptozotocin-injected rat: an alternative model for type 2 diabetes.

PubMed

Wilson, Rachel D; Islam, Md Shahidul

2012-01-01

The main objective of the study was to develop an alternative non-genetic rat model for type 2 diabetes (T2D). Six-week-old male Sprague-Dawley rats (190.56 ± 23.60 g) were randomly divided into six groups, namely: Normal Control (NC), Diabetic Control (DBC), Fructose-10 (FR10), Fructose-20 (FR20), Fructose-30 (FR30) and Fructose-40 (FR40) and were fed a normal rat pellet diet ad libitum for 2 weeks. During this period, the two control groups received normal drinking water whilst the fructose groups received 10, 20, 30 and 40% fructose in drinking water ad libitum, respectively. After two weeks of dietary manipulation, all groups except the NC group received a single injection (i.p.) of streptozotocin (STZ) (40 mg/kg b.w.) dissolved in citrate buffer (pH 4.4). The NC group received only a vehicle buffer injection (i.p.). One week after the STZ injection, animals with non-fasting blood glucose levels > 300 mg/dl were considered as diabetic. Three weeks after the STZ injection, the animals in FR20, FR30 and FR40 groups were eliminated from the study due to the severity of diabetes and the FR10 group was selected for the remainder of the 11 weeks experimental period. The significantly (p < 0.05) higher fluid intake, blood glucose, serum lipids, liver glycogen, liver function enzymes and insulin resistance (HOMA-IR) and significantly (p < 0.05) lower body weight, oral glucose tolerance, number of pancreatic β-cells and pancreatic β-cell functions (HOMA-β) of FR10 group demonstrate that the 10% fructose-fed followed by 40 mg/kg of BWSTZ injected rat can be a new and alternative model for T2D.

Decoy receptor 3 analogous supplement protects steatotic rat liver from ischemia-reperfusion injury.

PubMed

Li, Tzu-Hao; Liu, Chih-Wei; Lee, Pei-Chang; Huang, Chia-Chang; Lee, Kuei-Chuan; Hsieh, Yun-Cheng; Yang, Ying-Ying; Hsieh, Shie-Liang; Lin, Han-Chieh; Tsai, Chang-Youh

2017-07-01

For steatotic livers, pharmacological approaches to minimize the hepatic neutrophil and macrophage infiltration, and cytokine and chemokine release in ischemia-reperfusion (IR) injury are still limited. Tumor necrosis factor (TNF)-α superfamily-stimulated pathogenic cascades and M1 macrophage/Kupffer cells (KC) polarization from Th1 cytokines are important in the pathogenesis of IR liver injury with hepatic steatosis (HS). Conversely, anti-inflammatory M2 macrophages produce Th2 cytokine (interleukin-4), which reciprocally enhances M2 polarization. Toll-like receptor 4-activated KCs can release proinflammatory mediators, skew M1 polarization and escalate liver IR injury. Decoy receptor 3 (DcR 3 ) could be potential agents simultaneously blocking the IR liver injury-related pathogenic changes and extend the survival of steatotic graft. Rats were fed with methionine and choline-deficient high-fat diet (MCD HFD) for 6 weeks to induce HS. Preliminary experiments with HS group and IR group were conducted, and either immunoglobulin G Fc protein or DcR3 analogue was treated for 14 days in all groups to evaluate the severity. In the Zucker rat-focused experiments, various serum and hepatic substances, M1 polarization, and hepatic microcirculation were assessed. We found that serum/hepatic DcR 3 levels were lower in nonalcoholic fatty liver disease patients with HS. DcR 3 a protected Zucker rats with HS from IR liver injury. The beneficial effects of DcR 3 a supplement were mediated by inhibiting hepatic M1 polarization of KCs, decreasing serum/hepatic TNFα, nitric oxide, nitrotyrosine, soluble TNF-like cytokine 1A, Fas ligand, and interferon-γ levels, neutrophil infiltration, and improving hepatic microcirculatory failure among rats with IR-injured steatotic livers. Additionally, downregulated hepatic TNF-like cytokine 1A/Fas-ligand and toll-like receptor 4/nuclear factor-κB signals were found to mediate the DcR 3 a-related protective effects of steatotic livers from

Assessment of insulin resistance in fructose-fed rats with 125I-6-deoxy-6-iodo-D-glucose, a new tracer of glucose transport.

PubMed

Perret, Pascale; Slimani, Lotfi; Briat, Arnaud; Villemain, Danièle; Halimi, Serge; Demongeot, Jacques; Fagret, Daniel; Ghezzi, Catherine

2007-05-01

Insulin resistance, characterised by an insulin-stimulated glucose transport defect, is an important feature of the pre-diabetic state that has been observed in numerous pathological disorders. The purpose of this study was to assess variations in glucose transport in rats using (125)I-6-deoxy-6-iodo-D-glucose (6DIG), a new tracer of glucose transport proposed as an imaging tool to assess insulin resistance in vivo. Two protocols were performed, a hyperinsulinaemic-euglycaemic clamp and a normoinsulinaemic-normoglycaemic protocol, in awake control and insulin-resistant fructose-fed rats. The tracer was injected at steady state, and activity in 11 tissues and the blood was assessed ex vivo at several time points. A multicompartmental mathematical model was developed to obtain fractional transfer coefficients of 6DIG from the blood to the organs. Insulin sensitivity of fructose-fed rats, estimated by the glucose infusion rate, was reduced by 40% compared with control rats. At steady state, 6DIG uptake was significantly stimulated by insulin in insulin-sensitive tissues of control rats (basal versus insulin: diaphragm, p < 0.01; muscle, p<0.05; heart, p<0.001), whereas insulin did not stimulate 6DIG uptake in insulin-resistant fructose-fed rats. Moreover, in these tissues, the fractional transfer coefficients of entrance were significantly increased with insulin in control rats (basal vs insulin: diaphragm, p<0.001; muscle, p<0.001; heart, p<0.01) whereas no significant changes were observed in fructose-fed rats. This study sets the stage for the future use of 6DIG as a non-invasive means for the evaluation of insulin resistance by nuclear imaging.

Assessment of insulin resistance in fructose-fed rats with 125I-6-deoxy-6-iodo-D-glucose, a new tracer of glucose transport

PubMed Central

Perret, Pascale; Slimani, Lotfi; Briat, Arnaud; Villemain, Danièle; Halimi, Serge; Demongeot, Jacques; Fagret, Daniel; Ghezzi, Catherine

2007-01-01

Purpose Insulin resistance, characterised by an insulin-stimulated glucose transport defect, is an important feature of the pre-diabetic state and it has been observed in numerous pathological disorders. The purpose of this study was to assess variations in glucose transport in rats with 125I-6-Deoxy-6-Iodo-D-glucose (6DIG), a new tracer of glucose transport proposed as an imaging tool to assess insulin resistance in vivo. Methods Two protocols were performed, a hyperinsulinaemic-euglycaemic clamp and a normoinsulinaemic normoglycaemic protocol, in awake control and insulin-resistant fructose-fed rats. The tracer was injected at steady state, and activity in 11 tissues and the blood were assessed ex vivo at several time points. A multicompartmental mathematical model was developed to obtain fractional transfer coefficients of 6DIG from the blood to the organs. Results Insulin sensitivity of fructose-fed rats, estimated by the glucose infusion rate, was reduced by 40% compared with control rats. At steady-state, 6DIG uptake was significantly stimulated by insulin in insulin-sensitive tissues of control rats (basal versus insulin: diaphragm, p<0.01; muscle, p<0.05; heart, p<0.001), whereas insulin did not stimulate 6DIG uptake in insulin-resistant fructose-fed rats. Moreover, in these tissues, the fractional transfer coefficients of entrance were significantly increased with insulin in control rats (basal vs insulin: diaphragm, p<0.001; muscle, p<0.001; heart, p<0.01) and whereas no significant changes were observed in fructose-fed rats. Conclusion This study sets the stage for the future use of 6DIG as a non-invasive means for the evaluation of insulin resistance by nuclear imaging. PMID:17171359

Effects on reproduction in female offspring from Sprague-Dawley rats fed 10% snakeweed (Gutierrezia microcephala) throughout pregnancy and concurrent treatment with safflower oil.

PubMed

Staley, E C; Smith, G S; Greenberg, J A

1995-10-01

Previous studies determined that safflower oil administration provided protection against the embryotoxicity seen following ingestion of 10% snakeweed (Gutierrezia microcephala) throughout pregnancy. Sixty-two young primiparous female rats born in those studies were paired with adult male Sprague-Dawley rats. After 4 d they were removed and carried their litters to term. Observations were made of the presence and extent of reproductive effects attributable to the 10% snakeweed exposure and differences in fecundity that were attributable to dosing with safflower oil or normal saline during the snakeweed exposure. Of the 62 rats, 50 carried litters to term and approximated the reproductive efficiency of normal primiparous Sprague-Dawley rats. There was no significant difference between the fecundity of females born to rats fed the 10% snakeweed and dosed with safflower oil, those born of rats fed snakeweed dosed with normal saline, or those fed a snakeweed-free diet and dosed with normal saline. Regardless of the diet or treatment administered, dams carrying their litters to parturition gave birth to healthy, normo-reproductive offspring. While the toxic principles in Gutierrezia species plants may act as estrogenic or anti-estrogenic compounds, they did not impair fertility in the female offspring of dosed rats.

Effects of dietary phytase on body weight gain, body composition and bone strength in growing rats fed a low-zinc diet.

PubMed

McClung, James P; Stahl, Chad H; Marchitelli, Louis J; Morales-Martinez, Nelson; Mackin, Katherine M; Young, Andrew J; Scrimgeour, Angus G

2006-03-01

Phytic acid, a major phosphorous storage compound found in foodstuffs, is known to form insoluble complexes with nutritionally essential minerals, including zinc (Zn). Phytases are enzymes that catalyze the removal of these minerals from phytic acid, improving their bioavailability. The objective of the present study was to determine the ability of dietary phytase to affect body weight, body composition, and bone strength in growing rats fed a high phytic acid, low Zn diet. Rats (n = 20) were fed either a control (AIN-93) or phytase supplemented (Natuphos, BASF, 1,500 phytase units (FTU)/kg) diet for a period of 8 weeks. Phytase supplementation resulted in increased (P<.05) bone and plasma Zn, but no change in plasma inorganic phosphorous or bone levels of Ca, Fe, or Mg. The addition of phytase to the diets resulted in a 22.4% increase (P<.05) in body weight at the end of the study as compared with rats fed a control diet. Dual x-ray absorptiometry (DXA) revealed that phytase supplementation resulted in increase lean body mass (LBM, P<.001) and increased bone mineral content (BMC, P<.001) as compared with feeding the control diet. Bone studies indicated that femurs and tibias from phytase supplemented rats had greater mass (P<.05) and were stronger (P<.05) than rats fed the control diet. This data suggest that the addition of phytase to low Zn diets results in improved Zn status, which may be responsible for beneficial effects on growth, body composition, and bone strength.

A mitochondrial-targeted ubiquinone modulates muscle lipid profile and improves mitochondrial respiration in obesogenic diet-fed rats.

PubMed

Coudray, Charles; Fouret, Gilles; Lambert, Karen; Ferreri, Carla; Rieusset, Jennifer; Blachnio-Zabielska, Agnieszka; Lecomte, Jérôme; Ebabe Elle, Raymond; Badia, Eric; Murphy, Michael P; Feillet-Coudray, Christine

2016-04-14

The prevalence of the metabolic syndrome components including abdominal obesity, dyslipidaemia and insulin resistance is increasing in both developed and developing countries. It is generally accepted that the development of these features is preceded by, or accompanied with, impaired mitochondrial function. The present study was designed to analyse the effects of a mitochondrial-targeted lipophilic ubiquinone (MitoQ) on muscle lipid profile modulation and mitochondrial function in obesogenic diet-fed rats. For this purpose, twenty-four young male Sprague-Dawley rats were divided into three groups and fed one of the following diets: (1) control, (2) high fat (HF) and (3) HF+MitoQ. After 8 weeks, mitochondrial function markers and lipid metabolism/profile modifications in skeletal muscle were measured. The HF diet was effective at inducing the major features of the metabolic syndrome--namely, obesity, hepatic enlargement and glucose intolerance. MitoQ intake prevented the increase in rat body weight, attenuated the increase in adipose tissue and liver weights and partially reversed glucose intolerance. At the muscle level, the HF diet induced moderate TAG accumulation associated with important modifications in the muscle phospholipid classes and in the fatty acid composition of total muscle lipid. These lipid modifications were accompanied with decrease in mitochondrial respiration. MitoQ intake corrected the lipid alterations and restored mitochondrial respiration. These results indicate that MitoQ protected obesogenic diet-fed rats from some features of the metabolic syndrome through its effects on muscle lipid metabolism and mitochondrial activity. These findings suggest that MitoQ is a promising candidate for future human trials in the metabolic syndrome prevention.

Body weight loss, effective satiation and absence of homeostatic neuropeptide compensation in male Sprague Dawley rats schedule fed a protein crosslinked diet.

PubMed

Cassie, Nikki; Anderson, Richard L; Wilson, Dana; Pawsey, Anne; Mercer, Julian G; Barrett, Perry

2017-10-01

Food structure contributes to the induction of satiation and the maintenance of satiety following intake of a meal. There is evidence from human studies that protein-crosslinking of a milk-protein based meal may enhance satiety, but the mechanism underpinning this effect is unknown. We investigated whether a rat model would respond in a similar manner and might provide mechanistic insight into enhanced satiety by structural modification of a food source. Rats were schedule fed a modified AIN-93M based diet in a liquid form or protein-crosslinked to produce a soft-solid form. This was compared to a modified AIN-93M solid diet. Average daily caloric intake was in the order solid > liquid > crosslinked. Body composition was unaltered in the solid group, but there was a loss of fat in the liquid group and a loss of lean and fat tissue in the crosslinked group. Compared to rats fed a solid diet, acute responses in circulating GLP-1, leptin and insulin were eliminated or attenuated in rats fed a liquid or crosslinked diet. Quantification of homeostatic neuropeptide expression in the hypothalamus showed elevated levels of Npy and Agrp in rats fed the liquid diet. Measurement of food intake after a scheduled meal indicated that reduced energy intake of liquid and crosslinked diets is not due to enhancement of satiety. When continuously available ad-libitum, rats fed a liquid diet showed reduced weight gain despite greater 24 h caloric intake. During the dark phase, caloric intake was reduced, but compensated for during the light phase. We conclude that structural modification from a liquid to a solidified state is beneficial for satiation, with less of a detrimental effect on metabolic parameters and homeostatic neuropeptides. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anti-steatotic and anti-inflammatory effects of Hovenia dulcis Thunb. extracts in chronic alcohol-fed rats.

PubMed

Choi, Ra-Yeong; Woo, Moon-Jae; Ham, Ju Ri; Lee, Mi-Kyung

2017-06-01

The anti-steatotic and anti-inflammatory effects of fruit water extract (FW) and seed ethanol extract (SE) of Hovenia dulcis Thunb. in chronic alcohol-fed rats were investigated. Rats were fed a liquid diet containing 36% calories from alcohol and orally administered FW or SE (300 and 500mg/kg/day). Both FW and SE reduced hepatic lipid contents and droplets, serum lipid concentration and inflammatory markers (hs-CRP, TNF-α and IL-6) levels compared with the alcohol control group. Alcohol led to significant decreases in the hepatic fatty acid oxidative gene (Ppargc1a, Cpt1a and Acsl1) levels, while it significantly increased the Myd88 and Tnfa gene levels. However, FW or SE supplementation significantly up-regulated gene expression of Ppargc1a, Ppara, Cpt1a and Acsl1, and down-regulated gene expression of Myd88, Tnfa and Crp compared with the alcohol control group. FW or SE supplementation also significantly decreased hepatic activities of fatty acid synthase and phosphatidate phosphohydrolase in chronic alcohol-fed rats. Plasma alcohol and acetaldehyde levels, hepatic enzyme activity and protein expression of CYP2E1 were lowered by FW or SE supplementation. These results indicate that both FW and SE play an important role in improvement of alcoholic hepatic steatosis and inflammation via regulation of lipid and inflammation metabolism. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Hypocholesterolemic effects of low calorie structured lipids on rats and rabbits fed on normal and atherogenic diet.

PubMed

Kanjilal, Sanjit; Kaki, Shiva Shanker; Rao, Bhamidipati V S K; Sugasini, Dhavamani; Rao, Yalagala Poornachandra; Prasad, Rachapudi B N; Lokesh, Belur R

2013-01-01

The hypocholesterolemic effects of two low calorie structured lipids (SL1 and SL2) containing essential fatty acids, prepared by lipase catalysed interesterification of ethyl behenate respectively with sunflower and soybean oils were studied in rats and rabbits. The feeding experiment conducted on rats as well as rabbits, fed on normal and atherogenic diet containing 10% of SL1 and SL2 (experimental) and sunflower oil (control) indicated no adverse effects on growth and food intake. However, the structured lipids beneficially lowered serum and liver lipids, particularly cholesterol, LDL cholesterol, triglycerides and also maintains the essential fatty acid status in serum and liver. The lipid deposition observed in the arteries of rabbits fed on atherogenic diets was significantly reduced when structured lipids were included in the diet. These observations coincided with reduced levels of serum cholesterol particularly LDL cholesterol observed in experimental groups. Therefore the structured lipids, designed to have low calorific value also beneficially lower serum lipids and lipid deposition in animals fed on atherogenic diets. Copyright © 2012 Elsevier Ltd. All rights reserved.

Combined oral supplementation of chromium picolinate, docosahexaenoic acid, and boron enhances neuroprotection in rats fed a high-fat diet

PubMed

Orhan, Cemal; Şahin, Nurhan; Tuzcu, Zeynep; Komorowski, James R.; Şahin, Kazım

2017-11-13

Background/aim: A novel complex of a nutritional supplement (CDB) contains chromium picolinate (CrPic), phosphatidylserine (PS), docosahexaenoic acid (DHA), and boron (B). The present study aimed to investigate the effects of CDB on the metabolic profile and memory acquisition in rats fed a high-fat diet (HFD). Materials and methods: Male Wistar rats were divided into six groups and received either a regular diet or HFD supplemented with or without different levels of CDB (0, 11, or 22 mg/kg BW). Results: Rats fed the HFD had greater glucose, insulin, lipid profile, and serum malondialdehyde concentrations, but lower serotonin and tryptophan in the serum and brain and lower Cr concentrations in serum, kidney, brain, and liver (P < 0.0001). CDB complex supplementation reversed all the effects, and the reversal effect was more pronounced with HFD for some parameters. Latency was less (P < 0.05) but probe was greater (P < 0.0001) for rats fed a regular diet. Increasing CDB complex levels in the diets resulted in a linear decrease in latency (P < 0.0002) but a linear increase in probe (P < 0.0002). Conclusion: Findings of the present work indicate that the CDB complex could be considered as an alternative treatment for preventing certain metabolic diseases and improving neurological functions, such as learning and memory.

Effects of high molecular weight alcohols from sugar cane fed alone or in combination with plant sterols on lipid profile and antioxidant status of Wistar rats.

PubMed

Kitts, David D; Kopec, Aneta; Zawistowski, Jerzy; Popovich, David G

2012-10-01

The effect of feeding a mixture of high molecular weight alcohols derived from sugarcane (SCA), both alone and in combination with phytosterols (PS), on changes in plasma lipids, organ cholesterol accumulation, and antioxidant status of Wistar rats was undertaken. Three separate experiments were conducted and each experiment had 3 subsets. In experiment 1, rats were fed on an AIN-76, semi-synthetic diet supplemented with 0%, 0.5%, and 5% SCA w/w. The second experiment consisted of feeding rats an atherogenic diet (AIN-76+0.5% cholesterol) containing 0%, 0.5%, and 5% SCA w/w. The third experiment consisted of feeding rats an atherogenic diet that contained 2% PS in combination with 0%, 0.5%, and 5% SCA. Rats fed the atherogenic diet exhibited significant elevations in total and low-density lipoprotein cholesterol, and significant reductions in the high-density lipoprotein/total cholesterol ratio, regardless of the presence of 0.5% or 5% SCA mixture. Serum cholesterol increased 29% to 35% in these animals compared with animals fed the nonatherogenic diets. In contrast, animals fed atherogenic diets that contained 2% PS exhibited no difference in serum lipids compared with counterparts fed nonatherogenic diets. The combined presence of SCA with PS had no effect on further lowering plasma cholesterol. No changes in C-reactive protein were observed, but plasma oxygen radical scavenging capacity values significantly (p < 0.05) decreased when rats were fed the atherogenic diets that contained the combination of PS and SCA. This result corresponded to an apparent greater (p < 0.05) susceptibility of red blood cells to oxidative stress.

A Morphologic and Biochemical Study of Nutritional Nephrocalcinosis in Female Rats Fed Semipurified Diets

PubMed Central

Woodard, James C.

1971-01-01

Nephrocalcinosis occurred in weanling female rats fed a semipurified diet for 8 weeks. Mineralization of the inner cortex began after 3 weeks on the semipurified diet, and was most severe after 8 weeks. Intraluminal calcification was observed first in the pars recta of the proximal convoluted tubule; calcification of cytoplasmic organelles or basement membranes of the tubular epithelium was not observed. At the end of 8 weeks, some mineral deposits were seen within Henle's loops of the outer medulla. Histochemical studies demonstrated that the deposits contained calcium and phosphorus and had a glycoprotein matrix; electron diffraction studies indicated that the main mineral phase was hydroxyapatite. No differences in serum calcium or phosphorus or in the ultrastructural characteristics of the thyroid parafollicular cells and the parathyroid parenchymal cells were observed between animals fed the semipurified diet and those fed a commercial chow. The urinary excretion of calcium and magnesium was less and urinary citrate excretion was greater in animals fed the semipurified diet. ImagesFig 1Fig 2Fig 3Fig 4Fig 5Fig 8Fig 9Fig 6Fig 7 PMID:5096368

Rice bran protein hydrolysates reduce arterial stiffening, vascular remodeling and oxidative stress in rats fed a high-carbohydrate and high-fat diet.

PubMed

Senaphan, Ketmanee; Sangartit, Weerapon; Pakdeechote, Poungrat; Kukongviriyapan, Veerapol; Pannangpetch, Patchareewan; Thawornchinsombut, Supawan; Greenwald, Stephen E; Kukongviriyapan, Upa

2018-02-01

Rice bran protein hydrolysates (RBPH) contain highly nutritional proteins and antioxidant compounds which show benefits against metabolic syndrome (MetS). Increased arterial stiffness and the components of MetS have been shown to be associated with an increased risk of cardiovascular disease. This study aimed to investigate whether RBPH could alleviate the metabolic disorders, arterial stiffening, vascular remodeling, and oxidative stress in rats fed a high-carbohydrate and high-fat (HCHF) diet. Male Sprague-Dawley rats were fed either a standard chow and tap water or a HCHF diet and 15 % fructose solution for 16 weeks. HCHF rats were treated orally with RBPH (250 or 500 mg/kg/day) for the final 6 weeks of the experimental period. Rats fed with HCHF diet had hyperglycemia, insulin resistance, dyslipidemia, hypertension, increased aortic pulse wave velocity, aortic wall hypertrophy and vascular remodeling with increased MMP-2 and MMP-9 expression. RBPH supplementation significantly alleviated these alterations (P < 0.05). Moreover, RBPH reduced the levels of angiotensin-converting enzyme (ACE) and tumor necrosis factor-alpha in plasma. Oxidative stress was also alleviated after RBPH treatment by decreasing plasma malondialdehyde, reducing superoxide production and suppressing p47 phox NADPH oxidase expression in the vascular tissues of HCHF rats. RBPH increased plasma nitrate/nitrite level and up-regulated eNOS expression in the aortas of HCHF-diet-fed rats, indicating that RBPH increased NO production. RBPH mitigate the deleterious effects of HCHF through potential mechanisms involving enhanced NO bioavailability, anti-ACE, anti-inflammatory and antioxidant properties. RBPH could be used as dietary supplements to minimize oxidative stress and vascular alterations triggered by MetS.

Effect of berberine on the ratio of high-molecular weight adiponectin to total adiponectin and adiponectin receptors expressions in high-fat diet fed rats.

PubMed

Wu, Yue-Yue; Zha, Ying; Liu, Jun; Wang, Fang; Xu, Jiong; Chen, Zao-Ping; Ding, He-Yuan; Sheng, Li; Han, Xiao-Jie

2016-11-17

To assess the effects of berberine (BBR) on high-molecular weight (HMW) adiponectin and adiponectin receptors (adipoR1/adipoR2) expressions in high-fat (HF) diet fed rats. Forty Wistar male rats were randomly assigned into a normal diet fed group and three HF diet (fat for 45% calories) fed groups (n=10 for each group). All rats underwent 12 weeks of feeding. After 4 weeks feeding, rats in the two of three HF diet fed groups were treated with 150 mg·kg -1 ·day -1 BBR (HF+LBBR group) and 380 mg·kg -1 ·day -1 BBR (HF+HBBR group) by gavage once a day respectively for the next 8 weeks while the rats in other groups treated with vehicle (NF+Veh and HF+Veh). Body weight and food intake were observed and recorded on daily basis. At the end of 12 weeks, the blood, liver, epididymal fat tissues and quadriceps femoris muscles were collected. Fasting insulin, plasma fasting glucose, serum free fatty acid (FFA), total adiponectin and HMW adiponectin levels were measured by enzyme linked immunosorbent assay method. Glucose tolerance test (GTT) and insulin tolerance test (ITT) were performed to determine the insulinsensitizing. Meanwhile the homeostasis model assessment (HOMA) method was used to determine insulin resistance (HOMA-IR). The expressions of adipoR1, adipoR2 and adenosine monophophate activated protein kinase (AMPK) phosphorylation level in skeletal muscle and liver tissue were detected by Western blot. Liver and kidney toxicity were evaluated during treatment. The body weight of rats in high- or low-dose BBR group reduced as well as HOMA-IR, FFA concentrations and fasting insulin levels decreased compared with HF+Veh group (P<0.05). BBR also increased the ratio of HMW to total adiponectin in high fat-fed rats compared with rats in the HF+Veh group. High- and low-dose BBR increased adipoR1 expression in skeletal muscle by over 6- and 2-fold (P<0.05), respectively, and high-dose BBR also increased adipoR2 expression in liver tissue by over 2-fold (P<0.05). BBR

Biomechanical properties of the mandible, as assessed by bending test, in rats fed a low-quality protein.

PubMed

Bozzini, Carlos E; Champin, Graciela M; Alippi, Rosa M; Bozzini, Clarisa

2013-04-01

The present study describes the effects of feeding growing rats with diets containing increasing concentrations of wheat gluten (a low quality protein, G) on both the morphometrical and the biomechanical properties of the mandible. Female rats were fed one of six diets containing different concentrations (5-30%) of G between the 30th and 90th days of life. Control rats were fed a diet containing 20% casein (C), which allows a normal growth and development of the bone. Mandibular growth was estimated directly on excised and cleaned bones by taking measurements between anatomical points. Mechanical properties of the right hemimandibles were determined by using a three-point bending mechanical test to obtain a load/deformation curve and estimate the structural properties of the bone. Bone material properties were calculated from structural and geometric properties. The left hemimandibles were ashed and the ash weight obtained. Calcium content was determined by atomic energy absorption. Results were summarised as means±SEM. Comparisons between parameters were performed by ANOVA and post-test. None of the G-fed groups could achieve a normal growth performance as compared to the C-fed control group. Like body size, age-related increments in mandibular weight, length, height and area (index of mandibular size) were negatively affected by the G diets, as was the posterior part of the bone (posterior to molar III). The cross-sectional geometry of the mandible (cross-sectional area and rectangular moment of inertia) as well as its structural properties (yielding load, fracture load, and stiffness) were also severely affected by the G diets. However, material properties (Young's modulus and maximum elastic stress) and calcium concentration in ashes and the degree of mineralisation were unaffected. The differences in strength and stiffness between treated and control rats seemed to be the result of an induced loss of gain in bone growth and mass, in the absence of changes in

Hypocholesterolemic effect of sericin-derived oligopeptides in high-cholesterol fed rats.

PubMed

Lapphanichayakool, Phakhamon; Sutheerawattananonda, Manote; Limpeanchob, Nanteetip

2017-01-01

The beneficial effect of cholesterol-lowering proteins and/or peptides derived from various dietary sources is continuously reported. A non-dietary protein from silk cocoon, sericin, has also demonstrated cholesterol-lowering activity. A sericin hydrolysate prepared by enzymatic hydrolysis was also expected to posses this effect. The present study was aimed at investigating the cholesterol-lowering effect of sericin peptides, so called "sericin-derived oligopeptides" (SDO) both in vivo and in vitro. The results showed that SDO at all three doses tested (10 mg kg -1  day -1 , 50 mg kg -1  day -1 , and 200 mg kg -1  day -1 ) suppressed serum total and non-HDL cholesterol levels in rats fed a high-cholesterol diet. Triglyceride and HDL-cholesterol levels were not significantly changed among all groups. The fecal contents of bile acids and cholesterol did not differ among high-cholesterol fed rats. SDO dose-dependently reduced cholesterol solubility in lipid micelles, and inhibited cholesterol uptake in monolayer Caco-2 cells. SDO also effectively bound to all three types of bile salts including taurocholate, deoxytaurocholate, and glycodeoxycholate. Direct interaction with bile acids of SDO may disrupt micellar cholesterol solubility, and subsequently reduce the absorption of dietary cholesterol in intestines. Taking all data together, SDO or sericin peptides exhibit a beneficial effect on blood cholesterol levels and could be potentially used as a health-promoting dietary supplement or nutraceutical product.

Preventive Effects of Drinking Hydrogen-Rich Water on Gingival Oxidative Stress and Alveolar Bone Resorption in Rats Fed a High-Fat Diet

PubMed Central

Yoneda, Toshiki; Tomofuji, Takaaki; Kunitomo, Muneyoshi; Ekuni, Daisuke; Irie, Koichiro; Azuma, Tetsuji; Machida, Tatsuya; Miyai, Hisataka; Fujimori, Kouhei; Morita, Manabu

2017-01-01

Obesity induces gingival oxidative stress, which is involved in the progression of alveolar bone resorption. The antioxidant effect of hydrogen-rich water may attenuate gingival oxidative stress and prevent alveolar bone resorption in cases of obesity. We examined whether hydrogen-rich water could suppress gingival oxidative stress and alveolar bone resorption in obese rats fed a high-fat diet. Male Fischer 344 rats (n = 18) were divided into three groups of six rats each: a control group (fed a regular diet and drinking distilled water) and two experimental groups (fed a high-fat diet and drinking distilled water or hydrogen-rich water). The level of 8-hydroxydeoxyguanosine was determined to evaluate oxidative stress. The bone mineral density of the alveolar bone was analyzed by micro-computerized tomography. Obese rats, induced by a high-fat diet, showed a higher gingival level of 8-hydroxydeoxyguanosine and a lower level of alveolar bone density compared to the control group. Drinking hydrogen-rich water suppressed body weight gain, lowered gingival level of 8-hydroxydeoxyguanosine, and reduced alveolar bone resorption in rats on a high-fat diet. The results indicate that hydrogen-rich water could suppress gingival oxidative stress and alveolar bone resorption by limiting obesity. PMID:28098768

Preventive Effects of Drinking Hydrogen-Rich Water on Gingival Oxidative Stress and Alveolar Bone Resorption in Rats Fed a High-Fat Diet.

PubMed

Yoneda, Toshiki; Tomofuji, Takaaki; Kunitomo, Muneyoshi; Ekuni, Daisuke; Irie, Koichiro; Azuma, Tetsuji; Machida, Tatsuya; Miyai, Hisataka; Fujimori, Kouhei; Morita, Manabu

2017-01-13

Obesity induces gingival oxidative stress, which is involved in the progression of alveolar bone resorption. The antioxidant effect of hydrogen-rich water may attenuate gingival oxidative stress and prevent alveolar bone resorption in cases of obesity. We examined whether hydrogen-rich water could suppress gingival oxidative stress and alveolar bone resorption in obese rats fed a high-fat diet. Male Fischer 344 rats ( n = 18) were divided into three groups of six rats each: a control group (fed a regular diet and drinking distilled water) and two experimental groups (fed a high-fat diet and drinking distilled water or hydrogen-rich water). The level of 8-hydroxydeoxyguanosine was determined to evaluate oxidative stress. The bone mineral density of the alveolar bone was analyzed by micro-computerized tomography. Obese rats, induced by a high-fat diet, showed a higher gingival level of 8-hydroxydeoxyguanosine and a lower level of alveolar bone density compared to the control group. Drinking hydrogen-rich water suppressed body weight gain, lowered gingival level of 8-hydroxydeoxyguanosine, and reduced alveolar bone resorption in rats on a high-fat diet. The results indicate that hydrogen-rich water could suppress gingival oxidative stress and alveolar bone resorption by limiting obesity.

Seaweed supplements normalise metabolic, cardiovascular and liver responses in high-carbohydrate, high-fat fed rats.

PubMed

Kumar, Senthil Arun; Magnusson, Marie; Ward, Leigh C; Paul, Nicholas A; Brown, Lindsay

2015-02-02

Increased seaweed consumption may be linked to the lower incidence of metabolic syndrome in eastern Asia. This study investigated the responses to two tropical green seaweeds, Ulva ohnoi (UO) and Derbesia tenuissima (DT), in a rat model of human metabolic syndrome. Male Wistar rats (330-340 g) were fed either a corn starch-rich diet or a high-carbohydrate, high-fat diet with 25% fructose in drinking water, for 16 weeks. High-carbohydrate, high-fat diet-fed rats showed the signs of metabolic syndrome leading to abdominal obesity, cardiovascular remodelling and non-alcoholic fatty liver disease. Food was supplemented with 5% dried UO or DT for the final 8 weeks only. UO lowered total final body fat mass by 24%, systolic blood pressure by 29 mmHg, and improved glucose utilisation and insulin sensitivity. In contrast, DT did not change total body fat mass but decreased plasma triglycerides by 38% and total cholesterol by 17%. UO contained 18.1% soluble fibre as part of 40.9% total fibre, and increased magnesium, while DT contained 23.4% total fibre, essentially as insoluble fibre. UO was more effective in reducing metabolic syndrome than DT, possibly due to the increased intake of soluble fibre and magnesium.

Cardiac catecholamines in rats fed copper deficient or copper adequate diets containing fructose or starch

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

Scholfield, D.J.; Fields, M.; Beal, T.

1989-02-09

The symptoms of copper (Cu) deficiency are known to be more severe when rats are fed a diet with fructose (F) as the principal carbohydrate. Mortality, in males, due to cardiac abnormalities usually occurs after five weeks of a 62% F, 0.6 ppm Cu deficient diet. These effects are not observed if cornstarch (CS) is the carbohydrate (CHO) source. Studies with F containing diets have shown increased catecholamine (C) turnover rates while diets deficient in Cu result in decreased norepinephrine (N) levels in tissues. Dopamine B-hydroxylase (EC 1.14.17.1) is a Cu dependent enzyme which catalyzes the conversion of dopamine (D)more » to N. An experiment was designed to investigate the effects of CHO and dietary Cu on levels of three C in cardiac tissue. Thirty-two male and female Sprague-Dawley rats were fed Cu deficient or adequate diets with 60% of calories from F or CS for 6 weeks. N, epinephrine (E) and D were measured by HPLC. Statistical analysis indicates that Cu deficiency tends to decrease N levels, while having the reverse effect on E. D did not appear to change. These findings indicate that Cu deficiency but not dietary CHO can affect the concentration of N and E in rat cardiac tissue.« less

Seaweed Supplements Normalise Metabolic, Cardiovascular and Liver Responses in High-Carbohydrate, High-Fat Fed Rats

PubMed Central

Kumar, Senthil Arun; Magnusson, Marie; Ward, Leigh C.; Paul, Nicholas A.; Brown, Lindsay

2015-01-01

Increased seaweed consumption may be linked to the lower incidence of metabolic syndrome in eastern Asia. This study investigated the responses to two tropical green seaweeds, Ulva ohnoi (UO) and Derbesia tenuissima (DT), in a rat model of human metabolic syndrome. Male Wistar rats (330–340 g) were fed either a corn starch-rich diet or a high-carbohydrate, high-fat diet with 25% fructose in drinking water, for 16 weeks. High-carbohydrate, high-fat diet-fed rats showed the signs of metabolic syndrome leading to abdominal obesity, cardiovascular remodelling and non-alcoholic fatty liver disease. Food was supplemented with 5% dried UO or DT for the final 8 weeks only. UO lowered total final body fat mass by 24%, systolic blood pressure by 29 mmHg, and improved glucose utilisation and insulin sensitivity. In contrast, DT did not change total body fat mass but decreased plasma triglycerides by 38% and total cholesterol by 17%. UO contained 18.1% soluble fibre as part of 40.9% total fibre, and increased magnesium, while DT contained 23.4% total fibre, essentially as insoluble fibre. UO was more effective in reducing metabolic syndrome than DT, possibly due to the increased intake of soluble fibre and magnesium. PMID:25648511

Effects of Lactobacillus fermented soymilk and soy yogurt on hepatic lipid accumulation in rats fed a cholesterol-free diet.

PubMed

Kitawaki, Ryoko; Nishimura, Yuko; Takagi, Naohiro; Iwasaki, Mitsuhiro; Tsuzuki, Kimiko; Fukuda, Mitsuru

2009-07-01

We examined the effects of lactic acid fermented soymilk, in which part of the soymilk was replaced with okara (soy yogurt), on plasma and hepatic lipid profiles in rats fed a cholesterol-free diet. Additionally, we investigated the effects of soy yogurt on hepatic gene expression in rats using DNA microarray analysis. Male Sprague-Dawley rats aged 5 weeks (n=5/group) were fed a control diet (AIN-93) or a test diet in which 20% of the diet was replaced by soy yogurt for 7 weeks. Soy yogurt consumption did not affect body weight or adipose tissue weight as compared with control diet. In the soy yogurt group, the liver weight and hepatic triglyceride content were significantly lower than the control group, and the level of plasma cholesterol was also lower. Furthermore, DNA microarray analysis indicated that soy yogurt ingestion down-regulated the expression of the SREBP-1 gene and enzymes related to lipogenesis in the rat liver, while expression of beta-oxidation-related genes was up-regulated. These results suggest that soy yogurt is beneficial in preventing hepatic lipid accumulation in rats.

Lipid peroxide, alpha-tocopherol and retinoid levels in plasma and liver of rats fed diets containing beta-carotene and 13-cis-retinoic acid.

PubMed

Alam, S Q; Alam, B S

1983-12-01

The effect of feeding large amounts of beta-carotene and 13-cis-retinoic acid (RA) on plasma and liver levels of alpha-tocopherol, lipid peroxides and retinoids was studied. Groups of young male rats were fed semipurified diets supplemented with 0, 100 mg/kg beta-carotene, 20 and 100 mg/kg 13-cis-RA. After feeding the various diets for 11 weeks, rats were killed and the concentrations of lipid peroxides, alpha-tocopherol, and retinoids were measured in blood plasma and liver. Peroxide levels were increased and alpha-tocopherol levels were decreased in plasma as well as liver of rats fed diets containing 13-cis-RA; this effect seems to be dose dependent, beta-Carotene had no significant effect on either of the above parameters. There was a decrease in the liver and plasma concentrations of retinol in rats fed 13-cis-RA; the levels of RA were generally higher in these two groups. The results suggest that the mechanism whereby 13-cis-RA increases the tissue peroxide levels may be related to its ability to decrease alpha-tocopherol levels.

Diet-induced thermogenesis is lower in rats fed a lard diet than in those fed a high oleic acid safflower oil diet, a safflower oil diet or a linseed oil diet.

PubMed

Takeuchi, H; Matsuo, T; Tokuyama, K; Shimomura, Y; Suzuki, M

1995-04-01

The objectives of the present study were to examine the effects of dietary fats differing in fatty acid composition on diet-induced thermogenesis, sympathetic activity in brown adipose tissue and body fat accumulation in rats. Rats were meal-fed for 12 wk an isoenergetic diet based on lard, high oleic acid safflower oil, safflower oil or linseed oil, and norepinephrine turnover rates in brown adipose tissue were then estimated. Whole-body oxygen consumption after the meal indicated that diet-induced thermogenesis was significantly lower in rats fed the lard diet than in those fed the other diets. The norepinephrine turnover rate in the interscapular brown adipose tissue was also significantly lower in the lard diet group than in the other diet groups. The carcass fat content was significantly higher in the lard diet group than in the other diet groups, whereas the abdominal adipose tissue weights were the same in all diet groups. These results suggest that the intake of animal fats rich in saturated fatty acids, compared with the intake of vegetable oils rich in monounsaturated or polyunsaturated fatty acids, decreases diet-induced thermogenesis by a decline of sympathetic activity in brown adipose tissue, resulting in the promotion of body fat accumulation.

Formation of Short-Chain Fatty Acids, Excretion of Anthocyanins, and Microbial Diversity in Rats Fed Blackcurrants, Blackberries, and Raspberries

PubMed Central

Blanco, Narda; Ahrné, Siv; Molin, Göran

2013-01-01

Introduction. Berries contain high amounts of dietary fibre and flavonoids and have been associated with improved metabolic health. The mechanisms are not clear but the formation of SCFAs, especially propionic and butyric acids, could be important. The potent antioxidant and antimicrobial properties of flavonoids could also be a factor, but little is known about their fate in the gastrointestinal tract. Aim. To compare how blackcurrants, blackberries, raspberries, and Lactobacillus plantarum HEAL19 affect formation of SCFAs, inflammatory status, caecal microbial diversity, and flavonoids. Results and Conclusions. Degradation of the dietary fibre, formation of SCFAs including propionic and butyric acids, the weight of the caecal content and tissue, and the faecal wet and dry weight were all higher in rats fed blackcurrants rather than blackberries or raspberries. However, the microbial diversity of the gut microbiota was higher in rats fed raspberries. The high content of soluble fibre in blackcurrants and the high proportion of mannose-containing polymers might explain these effects. Anthocyanins could only be detected in urine of rats fed blackcurrants, and the excretion was lower with HEAL19. No anthocyanins or anthocyanidins were detected in caecal content or blood. This may indicate uptake in the stomach or small intestine. PMID:23864942

Hypolipidaemic and anti-oxidative potential of encapsulated herb (Terminalia arjuna) added vanilla chocolate milk in high cholesterol fed rats.

PubMed

Sawale, Pravin Digambar; Pothuraju, Ramesh; Abdul Hussain, Shaik; Kumar, Anuj; Kapila, Suman; Patil, Girdhari Ramdas

2016-03-15

Atherosclerosis is associated with coronary artery disease and occurs in developing as well as developed countries. In the present investigation, hypolipidaemic and anti-oxidative properties of encapsulated herb (Terminalia arjuna, 1.8%) added vanilla chocolate dairy drink was evaluated in high cholesterol fed Wistar rats for 60 days. At the end of the experimental period, a significant decrease in the body weight gain by rats receiving the encapsulated herb extract was noted as compared to high cholesterol fed rats. Administration of microencapsulated herb showed a statistically significant decrease in organ weights (epididymal fat and liver). Moreover, a significant decrease in serum lipids such as triglycerides, total cholesterol, low-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol and atherogenic index was observed with encapsulated Terminalia arjuna extract in high cholesterol fed group. Increases in reduced glutathione and decreases in TBARS levels were also reported in both liver and red blood cell lysates with encapsulated herb supplementation. The results demonstrated that the bioactive components (phytosterols, flavanoids, saponins and tannins etc.) which are present in the encapsulated T. arjuna not only withstand the processing conditions but also are effectively released in the intestine and show their effects, such as hypolipidaemic and antioxidant activities, for better treating cardiovascular disease. © 2015 Society of Chemical Industry.

Beneficial effects of gradual intense exercise in tissues of rats fed with a diet deficient in vitamins and minerals: a pilot study.

PubMed

Teixeira, Angélica; Müller, Liz; dos Santos, Alessandra A; Reckziegel, Patrícia; Emanuelli, Tatiana; Rocha, João Batista T; Bürger, Marilise E

2009-05-01

This study evaluated the preliminary effects of intense physical training (swimming) on oxidative stress in rats with nutritional deficiencies. Rats were fed with a standard diet or a diet deficient in vitamins and minerals for 4 months. The deficient diet contained one-fourth of the recommended vitamin and mineral levels for rats. From the second month, half of the animals were subjected to a swimming exercise in a plastic container with water maintained at 34 +/- 1 degrees C for 1 h/d, five times per week, for 11 wk. The rats were subjected to swimming exercise with loads attached to the dorsal region, which were progressively increased according to their body weight (1% to 7%). Sedentary rats were transported to the experimental room and handled as often in a similar way as the exercise group, except that they were not put in water. In the exercised group, blood lactate levels were significantly lower and the heart weight/body weight ratio was significantly higher than in the sedentary group (P < 0.05). Increased lipid peroxidation was observed in the liver, heart, and skeletal muscle of rats fed with the deficient diet, but it was completely reversed by exercise. Exercise also decreased lipid peroxidation levels in the heart and skeletal muscle of rats fed with the standard diet (P < 0.05). This pilot study leads to the continuity of the studies, because the partial results observed suggest that inadequate nutrition may enhance oxidative stress, and that intense chronic physical training may activate antioxidant defenses, possibly by hormesis.

Repeated whiskey binges promote liver injury in rats fed a choline-deficient diet.

PubMed

Nieto, Natalia; Rojkind, Marcos

2007-02-01

Alcoholic liver disease is associated with nutritional deficiency and it may aggravate within the context of fatty liver. We investigated the relationship between alcohol intake (whiskey binge drinking) and a choline-deficient diet (CD) and assessed whether stellate cells could contribute to liver injury in this model. Rats fed the CD diet plus whiskey showed increased liver damage compared to rats fed the CD diet, as demonstrated by H&E staining, elevated transaminases, steatosis, TNF-alpha levels, enhanced CYP2E1 activity, impaired antioxidant defense, elevated lipid peroxidation, and protein carbonyls. The combined treatment triggered an apoptotic response as determined by elevated Bax, caspase-3 activity, cytochrome-c release, and decreased Bcl-2 and Bcl-XL. Stellate cells were activated as increased expression of alpha-Sma was observed over that by the CD diet alone. The combined treatment shifted extracellular matrix remodeling towards a pro-fibrogenic response due to up-regulation of collagen I, TIMP1, and Hsp47 proteins, along with down-regulation of MMP13, MMP2, and MMP9 expression, proteases which degrade collagen I. These events were accompanied by increased phosphorylation of p38, a kinase that elevates collagen I. Repeated alcohol binges in the context of mild steatosis may promote activation of stellate cells and contribute to liver injury.

Ameliorating effect and potential mechanism of Rehmannia glutinosa oligosaccharides on the impaired glucose metabolism in chronic stress rats fed with high-fat diet.

PubMed

Zhang, Ruxue; Zhou, Jun; Li, Maoxing; Ma, Haigang; Qiu, Jianguo; Luo, Xiaohong; Jia, Zhengping

2014-04-15

The aim of this study was to determine whether the Rehmannia glutinosa oligosaccharides (ROS) ameliorate the impaired glucose metabolism and the potential mechanism in chronic stress rats fed with high-fat diet. The rats were fed by a high-fat diet and simultaneously stimulated by chronic stress over 5 weeks. Body weight, fasting plasma glucose, intraperitoneal glucose tolerance test (IPGTT), plasma lipids, gluconeogenesis test (GGT), glycogen content, and corticosterone, insulin and leptin levels were measured. The results showed that ROS administration (100, 200 mg/kg, i.g.) for 5 weeks exerted the effects of increasing the organ weights of thymus and spleen, lowering the fasting plasma glucose level, improving impaired glucose tolerance, increasing the contents of liver and muscle glycogen, decreasing the gluconeogenesis ability, plasma-free fatty acid's level, as well as plasma triglyceride and total cholesterol levels in chronic stress and high-fat fed rats, especially in the group of 200mg/kg; while the plasma corticosterone level was decreased, and plasma leptin level was increased. These results suggest that ROS exert an ameliorating effect of impaired glucose metabolism in chronic stress rats fed with high-fat diet, and the potential mechanism may be mediated through rebuilding the glucose homeostasis in the neuroendocrine immuno-modulation (NIM) network through multilinks and multitargets. Copyright © 2013 Elsevier GmbH. All rights reserved.

Fos-like immunoreactivity in the circadian timing system of calorie-restricted rats fed at dawn: daily rhythms and light pulse-induced changes.

PubMed

Challet, E; Jacob, N; Vuillez, P; Pévet, P; Malan, A

1997-10-03

Daily rhythms of pineal melatonin, body temperature, and locomotor activity are synchronized to the light-dark cycle (LD) via a circadian clock located in the suprachiasmatic nuclei (SCN). A timed caloric restriction in rats fed at dawn induces phase-advances and further phase-stabilization of these rhythms, suggesting that the circadian clock can integrate conflicting daily photic and non-photic cues. The present study investigated the daily expression of Fos-like immunoreactivity (Fos-ir) and light pulse-induced Fos-ir in the SCN, the intergeniculate leaflet (IGL) and the paraventricular thalamic nucleus (PVT) in calorie-restricted rats fed 2 h after the onset of light and in controls fed ad libitum. A daily rhythm of Fos-ir in the SCN was confirmed in control rats, with a peak approximately 2 h after lights on. At this time point (i.e. just prior to the feeding time), the level of SCN Fos-ir was lowered in calorie-restricted rats. Concomitantly, IGL Fos-ir was higher in calorie-restricted vs. control rats. In response to a light pulse during darkness, Fos-ir induction was found to be specifically (i.e. phase-dependently) lowered in the SCN and IGL of calorie-restricted rats. Observed changes of Fos-ir in the PVT were possibly related to the wake state of the animals. This study shows that repetitive non-photic cues presented in addition to a LD cycle affect the Fos expression in the circadian timing system.

Fish protein hydrolysates affect cholesterol metabolism in rats fed non-cholesterol and high-cholesterol diets.

PubMed

Hosomi, Ryota; Fukunaga, Kenji; Arai, Hirofumi; Kanda, Seiji; Nishiyama, Toshimasa; Yoshida, Munehiro

2012-03-01

Fish consumption is well known to provide health benefits in both experimental animals and human subjects. Numerous studies have demonstrated the beneficial effects of various protein hydrolysates on lipid metabolism. In this context, this study examined the effect of fish protein hydrolysates (FPH) on cholesterol metabolism compared with the effect of casein. FPHs were prepared from Alaska pollock meat using papain as a protease. Male Wistar rats were divided into the following four dietary groups of seven rats each: either casein (20%) or FPH (10%) + casein (10%), with or without 0.5% cholesterol and 0.1% sodium cholate. Serum and liver lipid levels, fecal cholesterol and bile acid excretions, and the hepatic expression of genes encoding proteins involved in cholesterol homeostasis were examined. In rats fed the FPH diets compared with casein diets with or without cholesterol and sodium cholate, the indexes of cholesterol metabolism-namely, serum cholesterol, triglyceride, and low-density lipoprotein-cholesterol levels-were significantly lower, whereas fecal cholesterol and bile acid excretions were higher. Rats fed the FPH diets compared with casein with cholesterol exhibited a lower liver cholesterol level via an increased liver cholesterol 7α-hydroxylase (CYP7A1) expression level. This study demonstrates that the intake of FPH has hypocholesterolemic effects through the enhancement of fecal cholesterol and bile acid excretions and CYP7A1 expression levels. Therefore, fish peptides prepared by papain digestion might provide health benefits by decreasing the cholesterol content in the blood, which would contribute to the prevention of circulatory system diseases such as arteriosclerosis.

In vivo assessment of cardiac insulin resistance by nuclear probes using an iodinated tracer of glucose transport.

PubMed

Briat, Arnaud; Slimani, Lotfi; Perret, Pascale; Villemain, Danièle; Halimi, Serge; Demongeot, Jacques; Fagret, Daniel; Ghezzi, Catherine

2007-11-01

Insulin resistance, implying depressed cellular sensitivity to insulin, is a risk factor for type 2 diabetes and cardiovascular disease. This study is the first step towards the development of a technique of insulin resistance measurement in humans with a new tracer of glucose transport, [(123)I]6-deoxy-6-iodo-D-glucose (6DIG). We investigated 6DIG kinetics in anaesthetised control rats and in three models of insulin-resistant rats: fructose fed, Zucker and ZDF. The study of myocardial 6DIG activity was performed under two conditions: first, 6DIG was injected under the baseline condition and then it was injected after a bolus injection of insulin. After each injection, radioactivity was measured over 45 min by external detection via NaI probes, in the heart and blood. A tri-compartment model was developed to obtain fractional transfer coefficients of 6DIG from the blood to the heart. These coefficients were significantly increased with insulin in control rats and did not change significantly in insulin-resistant rats. The ratio of the coefficient obtained under insulin to that obtained under basal conditions gave an index of cardiac insulin resistance for each animal. The mean values of these ratios were significantly lower in insulin-resistant than in control rats: 1.16 +/- 0.06 vs 2.28 +/- 0.18 (p < 0.001) for the fructose-fed group, 0.92 +/- 0.05 vs 1.62 +/- 0.25 (p < 0.01) for the Zucker group and 1.34 +/- 0.06 vs 2.01 +/- 0.26 (p < 0.05) for the ZDF group. These results show that 6DIG could be a useful tracer to image cardiac insulin resistance.

The mitochondrial-targeted antioxidant, MitoQ, increases liver mitochondrial cardiolipin content in obesogenic diet-fed rats.

PubMed

Fouret, Gilles; Tolika, Evanthia; Lecomte, Jérôme; Bonafos, Béatrice; Aoun, Manar; Murphy, Michael P; Ferreri, Carla; Chatgilialoglu, Chryssostomos; Dubreucq, Eric; Coudray, Charles; Feillet-Coudray, Christine

2015-10-01

Cardiolipin (CL), a unique mitochondrial phospholipid, plays a key role in several processes of mitochondrial bioenergetics as well as in mitochondrial membrane stability and dynamics. The present study was designed to determine the effect of MitoQ, a mitochondrial-targeted antioxidant, on the content of liver mitochondrial membrane phospholipids, in particular CL, and its fatty acid composition in obesogenic diet-fed rats. To do this, twenty-four 6week old male Sprague Dawley rats were randomized into three groups of 8 animals and fed for 8weeks with either a control diet, a high fat diet (HF), or a HF diet with MitoQ (HF+MitoQ). Phospholipid classes and fatty acid composition were assayed by chromatographic methods in liver and liver mitochondria. Mitochondrial bioenergetic function was also evaluated. While MitoQ had no or slight effects on total liver fatty acid composition and phospholipid classes and their fatty acid composition, it had major effects on liver mitochondrial phospholipids and mitochondrial function. Indeed, MitoQ both increased CL synthase gene expression and CL content of liver mitochondria and increased 18:2n-6 (linoleic acid) content of mitochondrial phospholipids by comparison to the HF diet. Moreover, mitochondrial CL content was positively correlated to mitochondrial membrane fluidity, membrane potential and respiration, as well as to ATP synthase activity, while it was negatively correlated to mitochondrial ROS production. These findings suggest that MitoQ may decrease pathogenic alterations to CL content and profiles, thereby preserving mitochondrial function and attenuating the development of some of the features of metabolic syndrome in obesogenic diet-fed rats. Copyright © 2015 Elsevier B.V. All rights reserved.

From engineering to editing the rat genome.

PubMed

Meek, Stephen; Mashimo, Tomoji; Burdon, Tom

2017-08-01

Since its domestication over 100 years ago, the laboratory rat has been the preferred experimental animal in many areas of biomedical research (Lindsey and Baker The laboratory rat. Academic, New York, pp 1-52, 2006). Its physiology, size, genetics, reproductive cycle, cognitive and behavioural characteristics have made it a particularly useful animal model for studying many human disorders and diseases. Indeed, through selective breeding programmes numerous strains have been derived that are now the mainstay of research on hypertension, obesity and neurobiology (Okamoto and Aoki Jpn Circ J 27:282-293, 1963; Zucker and Zucker J Hered 52(6):275-278, 1961). Despite this wealth of genetic and phenotypic diversity, the ability to manipulate and interrogate the genetic basis of existing phenotypes in rat strains and the methodology to generate new rat models has lagged significantly behind the advances made with its close cousin, the laboratory mouse. However, recent technical developments in stem cell biology and genetic engineering have again brought the rat to the forefront of biomedical studies and enabled researchers to exploit the increasingly accessible wealth of genome sequence information. In this review, we will describe how a breakthrough in understanding the molecular basis of self-renewal of the pluripotent founder cells of the mammalian embryo, embryonic stem (ES) cells, enabled the derivation of rat ES cells and their application in transgenesis. We will also describe the remarkable progress that has been made in the development of gene editing enzymes that enable the generation of transgenic rats directly through targeted genetic modifications in the genomes of zygotes. The simplicity, efficiency and cost-effectiveness of the CRISPR/Cas gene editing system, in particular, mean that the ability to engineer the rat genome is no longer a limiting factor. The selection of suitable targets and gene modifications will now become a priority: a challenge where

High temperature- and high pressure-processed garlic improves lipid profiles in rats fed high cholesterol diets.

PubMed

Sohn, Chan Wok; Kim, Hyunae; You, Bo Ram; Kim, Min Jee; Kim, Hyo Jin; Lee, Ji Yeon; Sok, Dai-Eun; Kim, Jin Hee; Lee, Kun Jong; Kim, Mee Ree

2012-05-01

Garlic protects against degenerative diseases such as hyperlipidemia and cardiovascular diseases. However, raw garlic has a strong pungency, which is unpleasant. In this study, we examined the effect of high temperature/high pressure-processed garlic on plasma lipid profiles in rats. Sprague-Dawley rats were fed a normal control diet, a high cholesterol (0.5% cholesterol) diet (HCD) only, or a high cholesterol diet supplemented with 0.5% high temperature/high pressure-processed garlic (HCP) or raw garlic (HCR) for 10 weeks. The body weights of the rats fed the garlic-supplemented diets decreased, mostly because of reduced fat pad weights. Plasma levels of total cholesterol (TC), low-density lipoprotein cholesterol, and triglyceride (TG) in the HCP and HCR groups decreased significantly compared with those in the HCD group. Additionally, fecal TC and TG increased significantly in the HCP and HCR groups. It is notable that no significant differences in plasma or fecal lipid profiles were observed between the HCP and HCR groups. High temperature/high pressure-processed garlic contained a higher amount of S-allyl cysteine than raw garlic (P<.05). The results suggest that high temperature/high pressure-processed garlic may be useful as a functional food to improve lipid profiles.

High Temperature- and High Pressure-Processed Garlic Improves Lipid Profiles in Rats Fed High Cholesterol Diets

PubMed Central

Sohn, Chan Wok; Kim, Hyunae; You, Bo Ram; Kim, Min Jee; Kim, Hyo Jin; Lee, Ji Yeon; Sok, Dai-Eun; Kim, Jin Hee; Lee, Kun Jong

2012-01-01

Abstract Garlic protects against degenerative diseases such as hyperlipidemia and cardiovascular diseases. However, raw garlic has a strong pungency, which is unpleasant. In this study, we examined the effect of high temperature/high pressure-processed garlic on plasma lipid profiles in rats. Sprague–Dawley rats were fed a normal control diet, a high cholesterol (0.5% cholesterol) diet (HCD) only, or a high cholesterol diet supplemented with 0.5% high temperature/high pressure-processed garlic (HCP) or raw garlic (HCR) for 10 weeks. The body weights of the rats fed the garlic-supplemented diets decreased, mostly because of reduced fat pad weights. Plasma levels of total cholesterol (TC), low-density lipoprotein cholesterol, and triglyceride (TG) in the HCP and HCR groups decreased significantly compared with those in the HCD group. Additionally, fecal TC and TG increased significantly in the HCP and HCR groups. It is notable that no significant differences in plasma or fecal lipid profiles were observed between the HCP and HCR groups. High temperature/high pressure-processed garlic contained a higher amount of S-allyl cysteine than raw garlic (P<.05). The results suggest that high temperature/high pressure-processed garlic may be useful as a functional food to improve lipid profiles. PMID:22404600

Cafeteria diet overfeeding in young male rats impairs the adaptive response to fed/fasted conditions and increases adiposity independent of body weight.

PubMed

Castro, H; Pomar, C A; Picó, C; Sánchez, J; Palou, A

2015-03-01

We analyzed the effects of a short exposure to a cafeteria diet during early infancy in rats on their metabolic response to fed/fasting conditions in key tissues involved in energy homeostasis. Ten-day-old male pups were fed a control or a cafeteria diet for 12 days and then killed under ad libitum feeding conditions or 12 h fasting. The expression of key genes related to energy metabolism in liver, retroperitoneal white adipose tissue (WAT) and hypothalamus were analyzed. Despite no differences in body weight, cafeteria-fed animals had almost double the fat mass of control rats. They also showed higher food intake, higher leptinemia and altered hypothalamic expression of Neuropetide Y, suggesting a dysfunction in the control of food intake. Unlike controls, cafeteria-fed animals did not decrease WAT expression of Pparg, sterol regulatory element binding transcription factor 1 or Cidea under fasting conditions, and displayed lower Pnpla2 expression than controls. In liver, compared with controls, cafeteria animals presented: (i) lower expression of genes related with fatty acid uptake and lipogenesis under ad libitum-fed conditions; (ii) higher expression of fatty acid oxidation-related genes and glucokinase under fasting conditions; (iii) greater expression of leptin and insulin receptors; and higher protein levels of insulin receptor and the pAMPK/AMPK ratio. A short period of exposure to a cafeteria diet in early infancy in rat pups is enough to disturb the metabolic response to fed/fasting conditions in key tissues involved in energy homeostasis, particularly in WAT, and hence induces an exacerbated body fat accumulation and increased metabolic risk, with no apparent effects on body weight.

Dietary phytic acid modulates characteristics of the colonic luminal environment and reduces serum levels of proinflammatory cytokines in rats fed a high-fat diet.

PubMed

Okazaki, Yukako; Katayama, Tetsuyuki

2014-12-01

Dietary phytic acid (PA; myo-inositol [MI] hexaphosphate) is known to inhibit colon carcinogenesis in rodents. Dietary fiber, which is a negative risk factor of colon cancer, improves characteristics of the colonic environment, such as the content of organic acids and microflora. We hypothesized that dietary PA would improve the colonic luminal environment in rats fed a high-fat diet. To test this hypothesis, rats were fed diets containing 30% beef tallow with 2.04% sodium PA, 0.4% MI, or 1.02% sodium PA + 0.2% MI for 3 weeks. Compared with the control diet, the sodium PA diet up-regulated cecal organic acids, including acetate, propionate, and n-butyrate; this effect was especially prominent for cecal butyrate. The sodium PA + MI diet also significantly increased cecal butyrate, although this effect was less pronounced when compared with the sodium PA diet. The cecal ratio of Lactobacillales, cecal and fecal mucins (an index of intestinal barrier function), and fecal β-glucosidase activity were higher in rats fed the sodium PA diet than in those fed the control diet. The sodium PA, MI, and sodium PA + MI diets decreased levels of serum tumor necrosis factor α, which is a proinflammatory cytokine. Another proinflammatory cytokine, serum interleukin-6, was also down-regulated by the sodium PA and sodium PA + MI diets. These data showed that PA may improve the composition of cecal organic acids, microflora, and mucins, and it may decrease the levels of serum proinflammatory cytokines in rats fed a high-fat, mineral-sufficient diet. Copyright © 2014 Elsevier Inc. All rights reserved.

Rutin attenuates metabolic changes, nonalcoholic steatohepatitis, and cardiovascular remodeling in high-carbohydrate, high-fat diet-fed rats.

PubMed

Panchal, Sunil K; Poudyal, Hemant; Arumugam, Thiruma V; Brown, Lindsay

2011-06-01

Metabolic syndrome (obesity, diabetes, and hypertension) increases hepatic and cardiovascular damage. This study investigated preventive or reversal responses to rutin in high-carbohydrate, high-fat diet-fed rats as a model of metabolic syndrome. Rats were divided into 6 groups: 2 groups were fed a corn starch-rich diet for 8 or 16 wk, 2 groups were fed a high-carbohydrate, high-fat diet for 8 or 16 wk, and 2 groups received rutin (1.6 g/kg diet) in either diet for the last 8 wk only of the 16-wk protocol. Metabolic changes and hepatic and cardiovascular structure and function were then evaluated in these rats. The corn starch-rich diet contained 68% carbohydrate (mainly cornstarch) and 0.7% fat, whereas the high-carbohydrate, high-fat diet contained 50% carbohydrate (mainly fructose) and 24% fat (mainly beef tallow) along with 25% fructose in drinking water (total 68% carbohydrate using mean food and water intakes). The high-carbohydrate, high-fat diet produced obesity, dyslipidemia, hypertension, impaired glucose tolerance, hepatic steatosis, infiltration of inflammatory cells in the liver and the heart, higher cardiac stiffness, endothelial dysfunction, and higher plasma markers of oxidative stress with lower expression of markers for oxidative stress and apoptosis in the liver. Rutin reversed or prevented metabolic changes such as abdominal fat pads and glucose tolerance, reversed or prevented changes in hepatic and cardiovascular structure and function, reversed oxidative stress and inflammation in the liver and heart, and normalized expression of liver markers. These results suggest a non-nutritive role for rutin to attenuate chronic changes in metabolic syndrome.

Leptin, cell proliferation and crypt fission in the gastrointestinal tract of intravenously fed rats.

PubMed

FitzGerald, A J; Mandir, N; Goodlad, R A

2005-02-01

Many peptides, hormones and growth factors have been implicated in the control of cell renewal in the gastrointestinal epithelium. Leptin is present in the stomach and salivary glands and leptin receptors are seen throughout the gut. Leptin can stimulate mitogen-activated protein kinase activity in vitro and short-term infusion has been reported to have a proliferative action on the colon in vivo, suggesting a biological link between obesity, physical activity and colon cancer. Food intake is one of the most important determinants of intestinal mucosal cell renewal, thus any direct effects of leptin on the gut may be hidden. This problem has been avoided experimentally by maintaining animals on total parenteral nutrition (TPN). Male Wistar rats were anaesthetized and cannulae were inserted into the jugular vein to deliver the TPN diet to which had been added 0, 0.5, 2.5, or 10 mg/kg of recombinant murine leptin. Orally fed rats were also studied. After 6 days of treatment, all animals were injected with vincristine and killed 2 h later. Tissue weight was recorded and crypt cell proliferation (arrested metaphases) and crypt fission were scored in 'microdissected' crypts. Leptin infusion led to a small decrease in body weight and in the weight of the caecum. Intestinal cell proliferation was significantly reduced by TPN when compared to the orally fed rats, but the addition of leptin had no effect on the small intestine or colon. Crypt fission was also significantly lowered in the TPN group. Fission was slightly but significantly increased in the proximal and mid-colon of the leptin-treated rats, but was decreased in the distal colon. Although leptin did not significantly alter cell proliferation, it had significant effects on the process of crypt fission in the colon, which varied according to the exact locality.

Dissociation between PGC-1alpha and GLUT-4 expression in skeletal muscle of rats fed a high-fat diet.

PubMed

Higashida, Kazuhiko; Higuchi, Mitsuru; Terada, Shin

2009-12-01

It has recently been reported that a 4-wk high-fat diet gradually increases skeletal muscle peroxisome proliferator activated receptor (PPAR) gamma coactivator-1alpha (PGC-1alpha) protein content, which has been suggested to regulate GLUT-4 gene transcription. However, it has not been reported that a high-fat diet enhances GLUT-4 mRNA expression and protein content in skeletal muscle, suggesting that an increase in PGC-1alpha protein content is not sufficient to induce muscle GLUT-4 biogenesis in a high-fat fed animal. Therefore, we first evaluated the relationship between PGC-1alpha and GLUT-4 expression in skeletal muscle of rats fed a high-fat diet for 4 wk. The PGC-1alpha protein content in rat epitrochlearis muscle significantly increased by twofold after the 4-wk high-fat diet feeding. However, the high-fat diet had no effect on GLUT-4 protein content and induced a 30% decrease in GLUT-4 mRNA expression in rat skeletal muscle (p<0.05). To clarify the mechanism by which a high-fat diet downregulates GLUT-4 mRNA expression, we next examined the effect of PPARdelta activation, which is known to occur in response to a high-fat diet, on GLUT-4 mRNA expression in L6 myotubes. Incubation with 500 nM GW501516 (PPARdelta activator) for 24 h significantly decreased GLUT-4 mRNA in L6 myotubes. Taken together, these findings suggest that a high-fat diet downregulates GLUT-4 mRNA, possibly through the activation of PPARdelta, despite an increase in PGC-1alpha protein content in rat skeletal muscle, and that a posttranscriptional regulatory mechanism maintains GLUT-4 protein content in skeletal muscle of rats fed a high-fat diet.

The involvement of ginseng berry extract in blood flow via regulation of blood coagulation in rats fed a high-fat diet.

PubMed

Kim, Min Hee; Lee, Jongsung; Jung, Sehyun; Kim, Joo Wan; Shin, Jae-Ho; Lee, Hae-Jeung

2017-04-01

The present study investigated the effect of ginseng berry hot water extract (GBx) on blood flow via the regulation of lipid metabolites and blood coagulation in rats fed a high-fat diet (HFD). Sixty rats were divided into five groups in descending order of body weight. Except for the control group, the other four groups were fed a HFD containing 45% kcal from fat for 11 wk without GBx. GBx groups were then additionally treated by gastric gavage with GBx dissolved in distilled water at 50 (GBx 50) mg/kg, 100 (GBx 100) mg/kg, or 150 (GBx 150) mg/kg body weight for 6 wk along with the HFD. To investigate the effects of GBx on rats fed a HFD, biochemical metabolite, blood coagulation assay, and histological analysis were performed. In the experiments to measure the serum levels of leptin and apolipoprotein B/A, GBx treatment attenuated the HFD-induced increases in these metabolites ( p  < 0.05). Adiponectin and apolipoprotein E levels in GBx-treated groups were significantly higher than the HFD group. Prothrombin time and activated partial thromboplastin time were increased in all GBx-treated groups. In the GBx-treated groups, the serum levels of thromboxane A 2 and serotonin were decreased and concentrations of serum fibrinogen degradation products were increased ( p  < 0.05). Moreover, histomorphometric dyslipidemia-related atherosclerotic changes were significantly improved by treatment with GBx. These results suggest the possibility that GBx can ameliorate blood flow by decreasing intima-media thickness via the regulation of blood coagulation factors related to lipid metabolites in rats fed a HFD.

Grape powder consumption affects the expression of neurodegeneration-related brain proteins in rats chronically fed a high-fructose-high-fat diet.

PubMed

Liao, Hsiang; Chou, Liang-Mao; Chien, Yi-Wen; Wu, Chi-Hao; Chang, Jung-Su; Lin, Ching-I; Lin, Shyh-Hsiang

2017-05-01

Abnormal glucose metabolism in the brain is recognized to be associated with cognitive decline. Because grapes are rich in polyphenols that produce antioxidative and blood sugar-lowering effects, we investigated how grape consumption affects the expression and/or phosphorylation of neurodegeneration-related brain proteins in aged rats fed a high-fructose-high-fat (HFHF) diet. Wistar rats were maintained on the HFHF diet from the age of 8 weeks to 66 weeks, and then on an HFHF diet containing either 3% or 6% grape powder as an intervention for 12 weeks. Western blotting was performed to measure the expression/phosphorylation levels of several cortical and hippocampal proteins, including amyloid precursor protein (APP), tau, phosphatidylinositol-3-kinase (PI3K), extracellular signal-regulated kinase (ERK), receptor for advanced glycation end products (RAGEs), erythroid 2-related factor 2 (Nrf2) and brain-derived neurotrophic factor (BDNF). Inclusion of up to 6% grape powder in the diet markedly reduced RAGE expression and tau hyperphosphorylation, but upregulated the expression of Nrf2 and BDNF, as well as the phosphorylation of PI3K and ERK, in the brain tissues of aged rats fed the HFHF diet. Thus, grape powder consumption produced beneficial effects in HFHF-diet-fed rats, exhibiting the potential to ameliorate changes in neurodegeneration-related proteins in the brain. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of boron supplements on bones from rats fed calcium and magnesium deficient diets

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

McCoy, H.; Irwin, A.; Kenney, M.A.

1991-03-15

Sixty female, weanling rats were fed, for 6 wks, diets providing: casein, 20; CHO, 40; fat, 40. Vitamins and minerals, except Ca and Mg, were fed according to AIN'76 recommendations. Gp A (control) was fed 100% AIN Ca, Mg and P with no boron (B) added. Gps CD and CD+B were fed 30% AIN Ca and 100% AIN Mg and P; Gps MD and MD+B were fed 20% AIN Mg and 100% AIN Ca and P; Gps CMD and CMD+B were fed 20% AIN Mg, 30% AIN Ca and 100% AIN P. The +B groups were supplemented with B atmore » 12 mcg/g diet. Femurs (F) and 2 vertebrae (V) were scraped clean, weighed, sealed in saline-wet gauze, and refrigerated overnight. Bones were equilibrated at {sup {approximately}}25C. F lengths and diameters at the breakpoint were measured before a 3-point flexure test. V were subjected to a compression test. Maximum force (kg) at breakpoint was recorded. Data for right and left F and for 2 V were pooled. Although DIET' (CD, MD, CMD) affected numerous characteristics of F and V, B supplementation of diets affected only % moisture in F, Ca concentration in dry F and in F ash for CD and CMD diets. Interactions between B and diet affected F Mg concentrations in bone and in ash. Group CMD+B had higher Mg/g F than CMD. B increased Mg/g ash for CMD, decreased it for CD and did not affect it for MD.« less

Karaya root saponin exerts a hypocholesterolemic response in rats fed a high-cholesterol diet.

PubMed

Afrose, Sadia; Hossain, Md S; Maki, Takaaki; Tsujii, Hirotada

2009-05-01

Different sources of saponins are known to have hypocholesterolemic activity with varying degrees of efficacy. We hypothesize that karaya root saponin would efficiently reduce cholesterol. The aim of this study is to examine the comparative hypocholesterolemic effect of karaya root saponin in rats fed a high-cholesterol diet. Sixty male Wister-Imamichi rats were divided into 5 groups of 12 rats each constituting of the following: control group, soybean saponin-supplemented group, karaya root saponin-supplemented group, quillaja saponin-supplemented group, and tea saponin-supplemented group. Compared with the control diet, both the karaya root- and quillaja saponin-supplemented diets significantly reduced (P < .05) serum cholesterol and atherogenic index. Karaya root saponin significantly increased the serum high-density lipoprotein cholesterol, high-density lipoprotein cholesterol/cholesterol ratio, and fecal cholesterol concentrations (P < .05). The triacylglycerol concentration was significantly reduced only in the quillaja saponin-supplemented rats (P < .05). All the tea, soybean, karaya root, and quillaja saponins significantly reduced low-density lipoprotein cholesterol, and the greatest reduction was observed with karaya root saponin. Highest fecal bile acid concentration was found with quillaja saponin, whereas highest liver bile acid concentration was observed with karaya root saponin-supplemented rats (P < .05). These results collectively suggest that karaya root saponin can efficiently reduce serum cholesterol concentration in rats.

Beneficial effects of calcitriol on hypertension, glucose intolerance, impairment of endothelium-dependent vascular relaxation, and visceral adiposity in fructose-fed hypertensive rats.

PubMed

Chou, Chu-Lin; Pang, Cheng-Yoong; Lee, Tony J F; Fang, Te-Chao

2015-01-01

Besides regulating calcium homeostasis, the effects of vitamin D on vascular tone and metabolic disturbances remain scarce in the literature despite an increase intake with high-fructose corn syrup worldwide. We investigated the effects of calcitriol, an active form of vitamin D, on vascular relaxation, glucose tolerance, and visceral fat pads in fructose-fed rats. Male Wistar-Kyoto rats were divided into 4 groups (n = 6 per group). Group Con: standard chow diet for 8 weeks; Group Fru: high-fructose diet (60% fructose) for 8 weeks; Group Fru-HVD: high-fructose diet as Group Fru, high-dose calcitriol treatment (20 ng / 100 g body weight per day) 4 weeks after the beginning of fructose feeding; and Group Fru-LVD: high-fructose diet as Group Fru, low-dose calcitriol treatment (10 ng / 100 g body weight per day) 4 weeks after the beginning of fructose feeding. Systolic blood pressure was measured twice a week by the tail-cuff method. Blood was examined for serum ionized calcium, phosphate, creatinine, glucose, triglycerides, and total cholesterol. Intra-peritoneal glucose intolerance test, aortic vascular reactivity, the weight of visceral fat pads, adipose size, and adipose angiotensin II levels were analyzed at the end of the study. The results showed that the fructose-fed rats significantly developed hypertension, impaired glucose tolerance, heavier weight and larger adipose size of visceral fat pads, and raised adipose angiotensin II expressions compared with the control rats. High- and low-dose calcitriol reduced modestly systolic blood pressure, increased endothelium-dependent aortic relaxation, ameliorated glucose intolerance, reduced the weight and adipose size of visceral fat pads, and lowered adipose angiotensin II expressions in the fructose-fed rats. However, high-dose calcitriol treatment mildly increased serum ionized calcium levels (1.44 ± 0.05 mmol/L). These results suggest a protective role of calcitriol treatment on endothelial function, glucose

α-Lipoic acid reduced weight gain and improved the lipid profile in rats fed with high fat diet.

PubMed

Seo, Eun Young; Ha, Ae Wha; Kim, Woo Kyoung

2012-06-01

The purpose of this study was to investigate the effects of α-lipoic acid on body weight and lipid profiles in Sprague-Dawley rats fed a high fat diet (HFD). After 4 weeks of feeding, rats on the HFD were divided into three groups by randomized block design; the first group received the high-fat-diet (n = 10), and the second group received the HFD administered with 0.25% α-lipoic acid (0.25LA), and the third group received the high-fat diet with 0.5% α-lipoic acid (0.5LA). The high fat diet with α-lipoic acid supplemented groups had significantly inhibited body weight gain, compared to that in the HFD group (P < 0.05). Organ weights of rats were also significantly reduced in liver, kidney, spleen, and visible fat tissues in rats supplemented with α-lipoic acid (P < 0.05). Significant differences in plasma lipid profiles, such as total lipids, total cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein, were observed between the HFD and 0.5LA groups. The atherogenic index and the plasma high density lipoprotein-cholesterol/total cholesterol ratio improved significantly with α-lipoic acid supplementation in a dose-dependent manner (P < 0.05). Total hepatic cholesterol and total lipid concentration decreased significantly in high fat fed rats supplemented with α-lipoic acid in a dose-dependent manner (P < 0.05), whereas liver triglyceride content was not affected. In conclusion, α-lipoic acid supplementation had a positive effect on weight gain and plasma and liver lipid profiles in rats.

The effects of repetitive vibration on sensorineural function: biomarkers of sensorineural injury in an animal model of metabolic syndrome

PubMed Central

Kiedrowski, Megan; Waugh, Stacey; Miller, Roger; Johnson, Claud; Krajnak, Kristine

2016-01-01

Exposure to hand-transmitted vibration in the work-place can result in the loss of sensation and pain in workers. These effects may be exacerbated by pre-existing conditions such as diabetes or the presence of primary Raynaud's phenomena. The goal of these studies was to use an established model of vibration-induced injury in Zucker rats. Lean Zucker rats have a normal metabolic profile, while obese Zucker rats display symptoms of metabolic disorder or Type II diabetes. This study examined the effects of vibration in obese and lean rats. Zucker rats were exposed to 4 h of vibration for 10 consecutive days at a frequency of 125 Hz and acceleration of 49 m/s2 for 10 consecutive days. Sensory function was checked using transcutaneous electrical stimulation on days 1, 5 and 9 of the exposure. Once the study was complete the ventral tail nerves, dorsal root ganglia and spinal cord were dissected, and levels of various transcripts involved in sensorineural dysfunction were measured. Sensorineural dysfunction was assessed using transcutaneous electrical stimulation. Obese Zucker rats displayed very few changes in sensorineural function. However they did display significant changes in transcript levels for factors involved in synapse formation, peripheral nerve remodeling, and inflammation. The changes in transcript levels suggested that obese Zucker rats had some level of sensory nerve injury prior to exposure, and that exposure to vibration activated pathways involved in injury and re-innervation. PMID:26433044

Lymphatic fatty acids from rats fed human milk and formula containing coconut oil.

PubMed

Roche, M E; Clark, R M

1994-06-01

Human milk and infant formula containing coconut/soy oil were infused into the duodenum of rats to determine the incorporation of capric, lauric, myristic and palmitic acids into lymphatic triacylglycerol (TAG). The proportion of capric and lauric acids in the lymphatic TAG reflected the fatty acid composition of the diet. Based on positional analysis, it appears that more than 50% of the capric and lauric acids could have been absorbed from the intestine as sn-2 monoacylglycerols. In the rats fed human milk, 50% of palmitic acid in lymphatic TAG was in the sn-2 position. Because of the nonrandom distribution of palmitic acid in the lymphatic TAG, the nonspecific lipase in human milk, i.e., bile salt-stimulated lipase, did not appear to be a factor in milk lipid digestion.

Adipocytes play an etiological role in the podocytopathy of high-fat diet-fed rats.

PubMed

Chen, Jinn-Yang; Jian, Deng-Yuan; Lien, Chih-Chan; Lin, Yu-Ting; Ting, Ching-Heng; Chen, Luen-Kui; Hsu, Ting-Chia; Huang, Hsuan-Min; Wu, Yu-Ting; Kuan, Tse-Ting; Chao, Yu-Wen; Wu, Liang-Yi; Huang, Seng-Wong; Juan, Chi-Chang

2016-11-01

Obesity is a risk factor that promotes progressive kidney disease. Studies have shown that an adipocytokine imbalance contributes to impaired renal function in humans and animals, but the underlying interplay between adipocytokines and renal injury remains to be elucidated. We aimed to investigate the mechanisms linking obesity to chronic kidney disease. We assessed renal function in high-fat (HF) diet-fed and normal diet-fed rats, and the effects of preadipocyte- and adipocyte-conditioned medium on cultured podocytes. HF diet-fed and normal diet-fed Sprague Dawley rats were used to analyze the changes in plasma BUN, creatinine, urine protein and renal histology. Additionally, podocytes were incubated with preadipocyte- or adipocyte-conditioned medium to investigate the effects on podocyte morphology and protein expression. In the HF diet group, 24 h urinary protein excretion (357.5 ± 64.2 mg/day vs 115.9 ± 12.4 mg/day, P < 0.05) and the urine protein/creatinine ratio were significantly higher (1.76 ± 0.22 vs 1.09 ± 0.15, P < 0.05), increased kidney weight (3.54 ± 0.04 g vs 3.38 ± 0.04 g, P < 0.05) and the glomerular volume and podocyte effacement increased by electron microscopy. Increased renal expression of desmin and decreased renal expression of CD2AP and nephrin were also seen in the HF diet group (P < 0.05). Furthermore, we found that adipocyte-conditioned medium-treated podocytes showed increased desmin expression and decreased CD2AP and nephrin expression compared with that in preadipocyte-conditioned medium-treated controls (P < 0.05). These findings show that adipocyte-derived factor(s) can modulate renal function. Adipocyte-derived factors play an important role in obesity-related podocytopathy. © 2016 Society for Endocrinology.

Effects of Nonalcoholic Fatty Liver Disease on Hepatic CYP2B1 and in Vivo Bupropion Disposition in Rats Fed a High-Fat or Methionine/Choline-Deficient Diet.

PubMed

Cho, Sung-Joon; Kim, Sang-Bum; Cho, Hyun-Jong; Chong, Saeho; Chung, Suk-Jae; Kang, Il-Mo; Lee, Jangik Ike; Yoon, In-Soo; Kim, Dae-Duk

2016-07-13

Nonalcoholic fatty liver disease (NAFLD) refers to hepatic pathologies, including simple fatty liver (SFL), nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis, that may progress to hepatocellular carcinoma. These liver disease states may affect the activity and expression levels of drug-metabolizing enzymes, potentially resulting in an alteration in the pharmacokinetics, therapeutic efficacy, and safety of drugs. This study investigated the hepatic cytochrome P450 (CYP) 2B1-modulating effect of a specific NAFLD state in dietary rat models. Sprague-Dawley rats were given a methionine/choline-deficient (MCD) or high-fat (HF) diet to induce NASH and SFL, respectively. The induction of these disease states was confirmed by plasma chemistry and liver histological analysis. Both the protein and mRNA levels of hepatic CYP2B1 were considerably reduced in MCD diet-fed rats; however, they were similar between the HF diet-fed and control rats. Consistently, the enzyme-kinetic and pharmacokinetic parameters for CYP2B1-mediated bupropion metabolism were considerably reduced in MCD diet-fed rats; however, they were also similar between the HF diet-fed and control rats. These results may promote a better understanding of the influence of NAFLD on CYP2B1-mediated metabolism, which could have important implications for the safety and pharmacokinetics of drug substrates for the CYP2B subfamily in patients with NAFLD.

Molecular factors involved in the hypolipidemic- and insulin-sensitizing effects of a ginger (Zingiber officinale Roscoe) extract in rats fed a high-fat diet.

PubMed

de Las Heras, Natalia; Valero-Muñoz, María; Martín-Fernández, Beatriz; Ballesteros, Sandra; López-Farré, Antonio; Ruiz-Roso, Baltasar; Lahera, Vicente

2017-02-01

Hypolipidemic and hypoglycemic properties of ginger in animal models have been reported. However, information related to the mechanisms and factors involved in the metabolic effects of ginger at a hepatic level are limited. The aim of the present study was to investigate molecular factors involved in the hypoglycemic and hypolipidemic effects of a hydroethanolic ginger extract (GE) in the liver of rats fed a high-fat diet (HFD). The study was conducted in male Wistar rats divided into the following 3 groups: (i) Rats fed a standard diet (3.5% fat), the control group; (ii) rats fed an HFD (33.5% fat); and (iii) rats fed an HFD treated with GE (250 mg·kg -1 ·day -1 ) for 5 weeks (HFD+GE). Plasma levels of glucose, insulin, lipid profile, leptin, and adiponectin were measured. Liver expression of glycerol phosphate acyltransferase (GPAT), cholesterol 7 alpha-hydroxylase, peroxisome proliferator-activated receptors (PPAR), PPARα and PPARγ, glucose transporter 2 (GLUT-2), liver X receptor, sterol regulatory element-binding protein (SREBP1c), connective tissue growth factor (CTGF), and collagen I was measured. Data were analyzed using a 1-way ANOVA, followed by a Newman-Keuls test if differences were noted. The study showed that GE improved lipid profile and attenuated the increase of plasma levels of glucose, insulin, and leptin in HFD rats. This effect was associated with a higher liver expression of PPARα, PPARγ, and GLUT-2 and an enhancement of plasma adiponectin levels. Furthermore, GE reduced liver expression of GPAT, SREBP1c, CTGF, and collagen I. The results suggest that GE might be considered as an alternative therapeutic strategy in the management of overweight and hepatic and metabolic-related alterations.

Santalbic acid from quandong kernels and oil fed to rats affects kidney and liver P450.

PubMed

Jones, G P; Watson, T G; Sinclair, A J; Birkett, A; Dunt, N; Nair, S S; Tonkin, S Y

1999-09-01

Kernels of the plant Santalum acuminatum (quandong) are eaten as Australian 'bush foods'. They are rich in oil and contain relatively large amounts of the acetylenic fatty acid, santalbic acid (trans-11-octadecen-9-ynoic acid), whose chemical structure is unlike that of normal dietary fatty acids. When rats were fed high fat diets in which oil from quandong kernels supplied 50% of dietary energy, the proportion of santalbic acid absorbed was more than 90%. Feeding quandong oil elevated not only total hepatic cytochrome P450 but also the cytochrome P450 4A subgroup of enzymes as shown by a specific immunoblotting technique. A purified methyl santalbate preparation isolated from quandong oil was fed to rats at 9% of dietary energy for 4 days and this also elevated cytochrome P450 4A in both kidney and liver microsomes in comparison with methyl esters from canola oil. Santalbic acid appears to be metabolized differently from the usual dietary fatty acids and the consumption of oil from quandong kernels may cause perturbations in normal fatty acid biochemistry.

Effects of Yogurt Containing Fermented Pepper Juice on the Body Fat and Cholesterol Level in High Fat and High Cholesterol Diet Fed Rat.

PubMed

Yeon, Su-Jung; Hong, Go-Eun; Kim, Chang-Kyu; Park, Woo Joon; Kim, Soo-Ki; Lee, Chi-Ho

2015-01-01

This experiment investigated whether yogurt containing fermented pepper juice (FPJY) affects cholesterol level in high fat and high cholesterol diet (HFCD) fed rat. Twenty five Sprague-Dawley male rats of 7 wk were divided into 5 groups, and fed following diets for 9 wk; CON (control diet), HFCD (HFCD), PY (HFCD supplemented with 2% of plain yogurt), LFY (HFCD supplemented with 2% of FPJY), and HFY (HFCD supplemented with 5% of FPJY). In the LFY group, hepatic total lipid level decreased significantly compared to the HFCD group (p<0.05). Serum HDL cholesterol level tended to increase and hepatic total cholesterol level decreased and were comparable to the CON group (p>0.05). In HFY group, body weight and hepatic total lipid level significantly decreased over the HFCD group (p<0.05). Serum and hepatic total cholesterol level, kidney, and body fat weights decreased, and were compared to the CON group (p>0.05). Liver weight decreased as FPJY content was increased. Results suggested FPJY would inhibit organ hypertrophy and accumulation of body fat, hepatic lipid, and cholesterol in HFCD fed rat.

Effect of chromium picolinate and melatonin either in single or in a combination in high carbohydrate diet-fed male Wistar rats.

PubMed

Doddigarla, Zephy; Ahmad, Jamal; Parwez, Iqbal

2016-01-01

This study is designed to know the effects of chromium picolinate (CrPic) and melatonin (Mel) each alone and in a combination on high carbohydrate diet-fed (HCD-fed) male Wistar rats that exhibit insulin resistance (IR), hyperglycemia, and oxidative stress. Wistar rats have been categorized into five groups. Each group consisted of six male Wistar rats, control rats (group I), HCD (group II), HCD + CrPic (group III), HCD + Mel (group IV), and HCD + CrPic + Mel (group V). Insignificant differences were observed in serum levels of superoxide dismutase, nitric oxide, and zinc in group III, group IV, and group V when each group was compared with group II rats respectively. Significant differences were observed in group III, group IV, and group V when each group was compared with group II in homeostasis model assessment-estimated IR (P < 0.05, <0.0.05, <0.05), and in the levels of blood glucose (P < 0.05, <0.0.05, <0.05), total cholesterol (P < 0.05, <0.001, <0.001), triacylglycerols (<0.05, <0.001, <0.001), high density lipoprotein cholesterol (P < 0.05, <0.001, <0.001), malondialdehyde (P < 0.05, <0.05, <0.001), catalase (P <0.05, <0.05, <0.05), glutathione (P < 0.05, <0.05, <0.05), Mel (P < 0.05, <0.05, <0.001), and copper (P < 0.05, <0.05, < 0.001). In view of these results, HCD-fed male Wistar rats that are destined to attain IR and T2DM through diet can be prevented by giving CrPic and Mel administration in alone or in a combination. © 2015 International Union of Biochemistry and Molecular Biology.

Blunted hypothalamic ghrelin signaling reduces diet intake in rats fed a low-protein diet in late pregnancy

USDA-ARS?s Scientific Manuscript database

Diet intake in pregnant rats fed a low-protein (LP) diet was significantly reduced during late pregnancy despite elevated plasma levels of ghrelin. In this study, we hypothesized that ghrelin signaling in the hypothalamus is blunted under a low-protein diet condition and therefore, it does not stimu...

Influence of carbohydrate and fat intake on diet-induced thermogenesis and brown fat activity in rats fed low protein diets.

PubMed

Rothwell, N J; Stock, M J

1987-10-01

Voluntary intake of protein, fat and carbohydrate (CHO) was modified by feeding young rats either a control purified diet [% metabolizable energy (ME): protein 21, fat 7, CHO 72], a control diet plus sucrose solution (20%) to drink (final intakes 17, 6 and 77% ME as protein, fat and CHO, respectively) or a low protein diet substituted with either CHO (8, 7 and 85% ME as protein, fat and CHO, respectively) or fat (8, 20 and 72% ME as protein, fat and CHO, respectively). Total ME intakes corrected for body size were similar for all rats, but body weight, energy gain and net energetic efficiency were lower in both low protein-fed groups than in the control group. The acute thermogenic response (% rise in oxygen consumption) to a standard balanced-nutrient meal was higher (12%) in sucrose-supplemented and in low protein groups (15-16%) than in control rats (8%). Brown adipose tissue protein content and thermogenic capacity (assessed from purine nucleotide binding to isolated mitochondria) were greater than control values in sucrose-fed and protein-deficient animals, and the greatest levels of activity were seen in low protein-fed rats with a high fat intake. The results demonstrate that the changes in energy balance, thermogenesis and brown adipose tissue activity that result from protein deficiency cannot be ascribed to changes in the level of energy intake or to a specific increase in the amount or proportion of either CHO or fat. They suggest that the protein-to-energy ratio must be the primary influence on thermogenesis and brown fat activity in these animals.

Transfer of 45Ca and 36Cl at the blood-nerve barrier of the sciatic nerve in rats fed low or high calcium diets

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

Wadhwani, K.C.; Murphy, V.A.; Rapoport, S.I.

1991-04-01

Unidirectional fluxes of 45Ca, 36Cl, and of (3H)mannitol from blood into the sciatic nerve and cerebral cortex were determined from 5- and 15-min uptakes of these tracers after an intravenous (i.v.) bolus injection in awake rats. Rats were fed diets for 8 wk, that had either a low (0.01% wt/wt), normal (0.67%), or high (3%) Ca content. Plasma (Ca) was 32% less and 11% more in rats fed low (LOCA) and high Ca diets (HICA), respectively, than in rats fed a normal Ca diet (CONT). The mean permeability-surface area product (PA) of 45Ca at the blood-nerve barrier was about eightfoldmore » higher than at the blood-brain barrier in the same animals and did not differ significantly between groups (greater than 0.05). Mean PA ratios of 45Ca/36Cl for the blood-nerve and blood-brain barriers in CONT rats, 0.52 {plus minus} 0.04 and 0.40 {plus minus} 0.02, respectively, were not significantly different from corresponding ratios in LOCA and HICA groups, and corresponded to the aqueous limiting diffusion ratio (0.45). The authors results show no evidence for concentration-dependent transport of Ca over a plasma (Ca) range of 0.8-1.4 mmol/liter at the blood-nerve barrier of the rat peripheral nerve, and suggest that Ca and Cl exchange slowly between nerve and blood via paracellular pathways.« less

Effects of dietary carbohydrate replaced with wild rice (Zizania latifolia (Griseb) Turcz) on insulin resistance in rats fed with a high-fat/cholesterol diet.

PubMed

Han, Shufen; Zhang, Hong; Qin, Liqiang; Zhai, Chengkai

2013-02-15

Wild rice (WR) is a very nutritious grain that has been used to treat diabetes in Chinese medicinal practice. City diet (CD) is based on the diet consumed by Asian area residents in modern society, which is rich in saturated fats, cholesterol and carbohydrates. The present study was aimed at evaluating the effects of replacing white rice and processed wheat starch of CD with WR as the chief source of dietary carbohydrates on insulin resistance in rats fed with a high-fat/cholesterol diet. Except the rats of the low-fat (LF) diet group, the rats of the other three groups, including to high-fat/cholesterol (HFC) diet, CD and WR diet, were fed with high-fat/cholesterol diets for eight weeks. The rats fed with CD exhibited higher weight gain and lower insulin sensitivity compared to the rats consuming a HFC diet. However, WR suppressed high-fat/cholesterol diet-induced insulin resistance. WR decreased liver homogenate triglyceride and free fatty acids levels, raised serum adiponectin concentration and reduced serum lipocalin-2 and visfatin concentrations. In addition, the WR diet potently augmented the relative expressions of adiponectin receptor 2, peroxisome proliferator-activated receptors, alpha and gamma, and abated relative expressions of leptin and lipocalin-2 in the tissues of interest. These findings indicate that WR is effective in ameliorating abnormal glucose metabolism and insulin resistance in rats, even when the diet consumed is high in fat and cholesterol.

Structural changes of gut microbiota during berberine-mediated prevention of obesity and insulin resistance in high-fat diet-fed rats.

PubMed

Zhang, Xu; Zhao, Yufeng; Zhang, Menghui; Pang, Xiaoyan; Xu, Jia; Kang, Chaoying; Li, Meng; Zhang, Chenhong; Zhang, Zhiguo; Zhang, Yifei; Li, Xiaoying; Ning, Guang; Zhao, Liping

2012-01-01

Berberine, a major pharmacological component of the Chinese herb Coptis chinensis, which was originally used to treat bacterial diarrhea, has recently been demonstrated to be clinically effective in alleviating type 2 diabetes. In this study, we revealed that berberine effectively prevented the development of obesity and insulin resistance in high-fat diet (HFD)-fed rats, which showed decreased food intake. Increases in the levels of serum lipopolysaccharide-binding protein, monocyte chemoattractant protein-1, and leptin and decrease in the serum level of adiponectin corrected for body fat in HFD-fed rats were also significantly retarded by the co-administration of berberine at 100 mg/kg body weight. Bar-coded pyrosequencing of the V3 region of 16S rRNA genes revealed a significant reduction in the gut microbiota diversity of berberine-treated rats. UniFrac principal coordinates analysis revealed a marked shift of the gut microbiota structure in berberine-treated rats away from that of the controls. Redundancy analysis identified 268 berberine-responding operational taxonomic units (OTUs), most of which were essentially eliminated, whereas a few putative short-chain fatty acid (SCFA)-producing bacteria, including Blautia and Allobaculum, were selectively enriched, along with elevations of fecal SCFA concentrations. Partial least square regression models based on these 268 OTUs were established (Q(2)>0.6) for predicting the adiposity index, body weight, leptin and adiponectin corrected for body fat, indicating that these discrete phylotypes might have a close association with the host metabolic phenotypes. Taken together, our findings suggest that the prevention of obesity and insulin resistance by berberine in HFD-fed rats is at least partially mediated by structural modulation of the gut microbiota, which may help to alleviate inflammation by reducing the exogenous antigen load in the host and elevating SCFA levels in the intestine.

Reduced carotid baroreceptor distensibility-induced baroreflex resetting contributes to impairment of sodium regulation in rats fed a high-fat diet.

PubMed

Abe, Chikara; Nagai, Yuko; Yamaguchi, Aoi; Aoki, Hitomi; Shimizu, Shuji; Akiyama, Tsuyoshi; Kawada, Toru; Sugimachi, Masaru; Morita, Hironobu

2015-04-15

Decreased carotid arterial compliance has been reported in obese subjects and animals. Carotid baroreceptors are located at the bifurcation of the common carotid artery, and respond to distension of the arterial wall, suggesting that higher pressure is required to obtain the same distension in obese subjects and animals. A hyperosmotic NaCl solution induces circulatory volume expansion and arterial pressure (AP) increase, which reflexively augment renal excretion. Thus, we hypothesized that sodium regulation via the baroreflex might be impaired in response to chronic hyperosmotic NaCl infusion in rats fed a high-fat diet. To examine this hypothesis, we used rats fed a high-fat (Fat) or normal (NFD) diet, and measured mean AP, water and sodium balance, and renal function in response to chronic infusion of hyperosmotic NaCl solution via a venous catheter. Furthermore, we examined arterial baroreflex characteristics with static open-loop analysis and distensibility of the common carotid artery. Significant positive water and sodium balance was observed on the 1st day of 9% NaCl infusion; however, this disappeared by the 2nd day in Fat rats. Mean AP was significantly higher during 9% NaCl infusion in Fat rats compared with NFD rats. In the open-loop analysis of carotid sinus baroreflex, a rightward shift of the neural arc was observed in Fat rats compared with NFD rats. Furthermore, distensibility of the common carotid artery was significantly reduced in Fat rats. These results indicate that a reduced baroreceptor distensibility-induced rightward shift of the neural arc might contribute to impairment of sodium regulation in Fat rats. Copyright © 2015 the American Physiological Society.

Ketoprofen and antinociception in hypo-oestrogenic Wistar rats fed on a high sucrose diet.

PubMed

Jaramillo-Morales, Osmar Antonio; Espinosa-Juárez, Josué Vidal; García-Martínez, Betzabeth Anali; López-Muñoz, Francisco Javier

2016-10-05

Non-steroidal anti-inflammatory drugs such as ketoprofen are the most commonly used analgesics for the treatment of pain. However, no studies have evaluated the analgesic response to ketoprofen in conditions of obesity. The aim of this study was to analyse the time course of nociceptive pain in Wistar rats with and without hypo-oestrogenism on a high sucrose diet and to compare the antinociceptive response using ketoprofen. Hypo-oestrogenic and naïve rats received a hyper caloric diet (30% sucrose) or water ad libitum for 17 weeks, the thermal nociception ("plantar test" method) and body weight were tested during this period. A biphasic response was observed: thermal latency decreased in the 4th week (hyperalgesia), while from 12th to 17th week, thermal latency increased (hypoalgesia) in hypo-oestrogenic rats fed with high sucrose diet compared with the hypo-oestrogenic control group. At 4th and 17th weeks, different doses of ketoprofen (1.8-100mg/kg p.o.), were evaluated in all groups. The administration of ketoprofen at 4th and 17th weeks showed dose-dependent effects in the all groups; however, a greater pharmacological efficacy was observed in the 4th week in the hypo-oestrogenic animals that received sucrose. Nevertheless, in all the groups significantly diminish the antinociceptive effects in the 17th week. Our data showed that nociception was altered in the hypo-oestrogenic animals that were fed sucrose (hyperalgesia and hypoalgesia). Ketoprofen showed a dose-dependent antinociceptive effect at both time points. However, hypo-oestrogenism plus high-sucrose diet modifies the antinociceptive effect of ketoprofen. Copyright © 2016 Elsevier B.V. All rights reserved.

Dietary L-cysteine improves the antioxidative potential and lipid metabolism in rats fed a normal diet.

PubMed

Lee, Seulki; Han, Kyu-Ho; Nakamura, Yumi; Kawakami, Sakura; Shimada, Ken-ichiro; Hayakawa, Touru; Onoue, Hirotake; Fukushima, Michihiro

2013-01-01

L-cysteine works as a precursor of the antioxidant, glutathione. We investigated the effects of L-cysteine (1% and 2%) on lipid metabolism and the antioxidative system in rats fed a normal diet. Administering L-cysteine dependently decreased the food intake, fat mass weight and body weight dose. Dietary L-cysteine also decreased the triglyceride levels in the serum and liver. However, there were no significant differences in the hepatic TBARS and glutathione (GSH) levels among the groups. The activities of catalase and glutathione reductase in the rats receiving 2% L-cysteine were significantly higher (p<0.05) than in the control rats. These results suggest that dietary L-cysteine dose-dependently affected the antioxidative enzyme activities, and the lipid levels in the serum and liver which might be related to the reduced food intake.

Benzo(a)pyrene (B(a)P) metabolism and in vitro formation of B(a)P-DNA adducts by hepatic microsomes from rats fed diets containing corn and menhaden oils

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

Dharwadkar, S.; Bellow, J.; Ramanathan, R.

1986-03-01

Dietary unsaturated fat is required for maximum induction of hepatic mixed function oxidases responsible for activating carcinogens which may bind covalently to DNA. The aim of this study was to assess the influence of dietary fat type on in vitro B(a)P metabolism and B(a)P-DNA adduct formation. Male rats were starved 2 days and refed diet devoid of fat, or containing 20% corn oil (CO) or 20% menhaden oil (MO) for 4 days. Both dietary fats increased Vmax for B(a)P hydroxylation without affecting Km. Phenobarbital (PB) administration increased Vmax in all animals but Km was increased only in rats fed themore » fat diets. PB resulted in decreased B(a)P metabolism when conducted at 15 =M only in rats fed the two fat diets even in the presence of increased cytochrome P-450 (P-450). This effect was due to a decrease in B(a)P metabolism at low substrate concentrations in PB treated fat-fed animals. Binding of B(a)P to calf-thymus DNA was increased in animals fed both fats which was enhanced further by PB only in rats fed the CO and MO diets. When the data are calculated as B(a)P metabolized per unit of P-450, PB seems to induce a P-450 in fat-fed animals having lower affinity and capacity for B(a)P metabolism and activation.« less

Evaluation of treadmill exercise effect on muscular lipid profiles of diabetic fatty rats by nanoflow liquid chromatography-tandem mass spectrometry

NASA Astrophysics Data System (ADS)

Lee, Jong Cheol; Kim, Il Yong; Son, Yeri; Byeon, Seul Kee; Yoon, Dong Hyun; Son, Jun Seok; Song, Han Sol; Song, Wook; Seong, Je Kyung; Moon, Myeong Hee

2016-07-01

We compare comprehensive quantitative profiling of lipids at the molecular level from skeletal muscle tissues (gastrocnemius and soleus) of Zucker diabetic fatty rats and Zucker lean control rats during treadmill exercise by nanoflow liquid chromatography-tandem mass spectrometry. Because type II diabetes is caused by decreased insulin sensitivity due to excess lipids accumulated in skeletal muscle tissue, lipidomic analysis of muscle tissues under treadmill exercise can help unveil the mechanism of lipid-associated insulin resistance. In total, 314 lipid species, including phospholipids, sphingolipids, ceramides, diacylglycerols (DAGs), and triacylglycerols (TAGs), were analyzed to examine diabetes-related lipid species and responses to treadmill exercise. Most lysophospholipid levels increased with diabetes. While DAG levels (10 from the gastrocnemius and 13 from the soleus) were >3-fold higher in diabetic rats, levels of most of these decreased after exercise in soleus but not in gastrocnemius. Levels of 5 highly abundant TAGs (52:1 and 54:3 in the gastrocnemius and 48:2, 50:2, and 52:4 in the soleus) displaying 2-fold increases in diabetic rats decreased after exercise in the soleus but not in the gastrocnemius in most cases. Thus, aerobic exercise has a stronger influence on lipid levels in the soleus than in the gastrocnemius in type 2 diabetic rats.

Response of rats fed diets low in glucose and glucose precursors to low levels of glucose, starch and chemically modified starch.

PubMed

Chen, S C; Tsai, S; Nesheim, M C

1980-05-01

Several levels of glucose or starches were added to a basal diet that was free of available carbohydrate and low in carbohydrate precursors and fed to male, weanling rats. Rats fed such diets were highly responsive to dietary carbohydrate in growth rate, blood glucose levels and blood ketone bodies. There were no significant differences in the activities of pancreatic amylase, liver glucokinase, glucose-6-phosphatase and fructose-1,6-diphosphatase when dietary carbohydrate varied from 1.5 to 6% of the diet. Under these feeding conditions, a minimum of 6% by weight or 5.8% of the dietary calories has to be provided by carbohydrate to allow the rat an optimum rate of growth. Such diets that are low in glucose precursors were employed as an assay system for glucose availability from chemically cross-bonded starches with various degrees of phosphate crosslinkage. The data showed that introducing low levels of phosphate crosslinkages into the starch had little effect on the glucose availability from the starch.

Cytokine and Chemokine Expression Associated with Steatohepatitis and Hepatocyte Proliferation in Rats Fed Ethanol Via Total Enteral Nutrition

USDA-ARS?s Scientific Manuscript database

Sprague-Dawley rats were intragastrically fed low carbohydrate-containing ethanol (EtOH) diets via total enteral nutrition for up to 49 d. Induction of EtOH metabolism and appearance of steatosis preceded development of oxidative stress, inflammation, and cell death. A transitory peak of tumor necro...

The effect of losartan and carvedilol on renal haemodynamics and altered metabolism in fructose-fed Sprague-Dawley rats.

PubMed

Abdulla, Mohammed H; Sattar, Munavvar A; Abdullah, Nor A; Johns, Edward J

2012-09-01

The aim of this study is to assess the effects of losartan and carvedilol on metabolic parameters and renal haemodynamic responses to angiotensin II (Ang II) and adrenergic agonists in the model of fructose-fed rat. Thirty-six Sprague-Dawley rats were fed for 8 weeks either 20% fructose solution (F) or tap water (C) ad libitum. F or C group received either losartan or carvedilol (10 mg/kg p.o.) daily for the last 3 weeks of the study (FL and L) and (FCV and CV), respectively, then in acute studies the renal vasoconstrictor actions of Ang II, noradrenaline (NA), phenylephrine (PE) and methoxamine (ME) were determined. Data, mean±SEM were analysed using ANOVA with significance at P <0.05. Losartan and carvedilol decreased the area under the glucose tolerance curve of the fructose-fed group. The responses (%) to NA, PE, ME and Ang II in F were lower (P <0.05) than C (F vs. C, 17±2 vs. 38±3; 24±2 vs. 48±2; 12±2 vs. 34±2; 17±2 vs. 26±2), respectively. L had higher (P <0.05) responses to NA and PE while CV had blunted (P <0.05) responses to NA, PE and Ang II compared to C (L, CV vs. C, 47±3, 9±2 vs. 38±3; 61±3, 29±3 vs. 48±2; 16±3, 4±3 vs. 26±2), respectively. FL but not FCV group had enhanced (P <0.05) responses to NA, PE and ME compared to F (FL vs. F, 33±3 vs. 17±2; 45±3 vs. 24±2; 26±3 vs. 12±2), respectively. Losartan and carvedilol had an important ameliorating effect on fructose-induced insulin resistance. Losartan treatment could be an effective tool to restore normal vascular reactivity in the renal circulation of the fructose-fed rat.

Muscle protein turnover in rats treated with corticosterone (CC) or/and nandrolone decanoate (ND) and fed an adequate or a low-protein diet

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

Santidrian, S.; Cuevillas, F.; Goena, M.

1986-03-01

In order to investigate the possible antagonistic effect between glucocorticoids and androgens on muscle protein turnover, the authors have measured the fractional rates of gastrocnemius muscle protein synthesis (k/sub s/) and degradation (k/sub d/) by the constant-intravenous-infusion method using L-//sup 14/C/-tyrosine in rats receiving via s.c. per 100 g b.wt. 10 mg of CC, or 2 mg of ND or CC+ND at the indicated doses, and fed either an 18% or 5% protein diets over a period of 5 days. As an additional index of protein synthesis, RNA activity (g of synthesized protein/day/g RNA) was determined as well. Results showedmore » that as compared to vehicle-injected animals fed the adequate diet, CC-treated rats exhibited a reduction of muscle k/sub d/, while ND-treated rats had an outstanding increase of muscle k/sub s/. However, rats receiving CC+ND showed k/sub s/ and k/sub d/ values similar to those displayed by control animals. Nevertheless, when the steroids were injected to rats fed the low-protein diet, CC has a catabolic effect on muscle protein but by reducing k/sub s/, while the anabolic action of ND is still displayed but by a significant reduction of muscle k/sub d/. CC+ND given to these protein-deficient rats caused an increase in muscle k/sub s/ and a reduction in k/sub d/. These results might indicate that, at least in part, ND antagonizes the catabolic action of high doses of CC on muscle protein metabolism.« less

Creatine supplementation prevents fatty liver in rats fed choline-deficient diet: a burden of one-carbon and fatty acid metabolism.

PubMed

Deminice, Rafael; de Castro, Gabriela Salim Ferreira; Francisco, Lucas Vieira; da Silva, Lilian Eslaine Costa Mendes; Cardoso, João Felipe Rito; Frajacomo, Fernando Tadeu Trevisan; Teodoro, Bruno Gonzaga; Dos Reis Silveira, Leonardo; Jordao, Alceu Afonso

2015-04-01

To examine the effects of creatine (Cr) supplementation on liver fat accumulation in rats fed a choline-deficient diet. Twenty-four rats were divided into 3 groups of 8 based on 4 weeks of feeding an AIN-93 control diet (C), a choline-deficient diet (CDD) or a CDD supplemented with 2% Cr. The CDD diet was AIN-93 without choline. The CDD significantly increased plasma homocysteine and TNFα concentration, as well as ALT activity. In liver, the CDD enhanced concentrations of total fat (55%), cholesterol (25%), triglycerides (87%), MDA (30%), TNFα (241%) and decreased SAM concentrations (25%) and the SAM/SAH ratio (33%). Cr supplementation prevented all these metabolic changes, except for hepatic SAM and the SAM/SAH ratio. However, no changes in PEMT gene expression or liver phosphatidylcholine levels were observed among the three experimental groups, and there were no changes in hepatic triglyceride transfer protein (MTP) mRNA level. On the contrary, Cr supplementation normalized expression of the transcription factors PPARα and PPARγ that were altered by the CDD. Further, the downstream targets and fatty acids metabolism genes, UCP2, LCAD and CPT1a, were also normalized in the Cr group as compared to CDD-fed rats. Cr supplementation prevented fat liver accumulation and hepatic injures in rats fed with a CDD for 4 weeks. Our results demonstrated that one-carbon metabolism may have a small role in mitigating hepatic fat accumulation by Cr supplementation. The modulation of key genes related to fatty acid oxidation pathway suggests a new mechanism by which Cr prevents liver fat accumulation. Copyright © 2015 Elsevier Inc. All rights reserved.

Altered susceptibility of an obese rat model to 13-week subchronic toxicity induced by 3-monochloropropane-1,2-diol.

PubMed

Toyoda, Takeshi; Cho, Young-Man; Akagi, Jun-Ichi; Mizuta, Yasuko; Matsushita, Kohei; Nishikawa, Akiyoshi; Imaida, Katsumi; Ogawa, Kumiko

2017-01-01

3-Monochloropropane-1,2-diol (3-MCPD) is a heat-induced food contaminant that has been shown to be a nongenotoxic renal carcinogen. Although the toxicity of 3-MCPD has been widely investigated for decades, there is a further concern that 3-MCPD might exert more potent toxicity in high-risk population with underlying diseases such as hyperlipidemia associated with obesity. In the present study, we performed a 13-week subchronic toxicity study for 3-MCPD using an obesity rat model to investigate the differences in susceptibility between obese and normal individuals. Male F344 and obese Zucker (lean and fatty) rats were administered 0, 9, 28.5, 90, 285, or 900 ppm 3-MCPD in drinking water for 13 weeks. 3-MCPD treatment decreased body weight gain, increased relative kidney weights, induced anemia, and induced epithelial cell necrosis in epididymal ducts in all 3 strains. The degrees of epididymal damage were higher in F344 and lean rats than in fatty rats, while renal toxicity was most potent in F344 rats and comparable in lean and fatty rats. In contrast, the hematology data indicated that anemia was worse in fatty rats than in F344 and lean rats, and a significant decrease in hematopoietic cells in the bone marrow was observed only in fatty rats. The no-observed-adverse-effect level was estimated to be 28.5 ppm in all 3 strains for 3-MCPD. These results suggested that obese Zucker rats may be more susceptible to 3-MCPD-dependent toxicity in the hematopoietic tissues than their lean counterparts.

Enzymatic and microstructural changes in the liver of experimental rats fed with fatty diet and fresh or heated soy oil concurrently.

PubMed

Jaarin, K; Hwa, Tay Chin; Umar, Nor Aini; Siti Aishah, M A; Das, S

2010-01-01

Consumption of heated edible oils may be harmful. The present study aimed to observe the histological changes due to concurrent consumption of soy oil (either fresh or heated) and fatty diet and the changes in the level of alanine transaminase (ALT) and alkaline phosphatase (ALP). Forty female Spraque-Dawley rats were equally divided into four groups (I to IV). All the rats n groups II, III and IV were ovariectomised. Rats in group I (control) were fed with 2% cholesterol diet, whereas the rats in groups II, III and IV were fed with 2% cholesterol diet fortified with 15% weight/weight (w/w) fresh soy oil (FSO), once heated soy oil (1HSO) and five times heated soy oil (5HSO) respectively, for 16 weeks. Blood was taken for liver enzymes and analysed before and after 16 weeks of study. At the end of the study the animals were sacrificed, and the liver was examined histologically. The specimens were weighed, formalin fixed and the sections were stained with hematoxylin and eosin. Fresh, 1HSO and 5HSO soy oil caused significant increase in serum ALT and ALP compared to their base line values. Fresh, 1HSO and 5HSO soy oil caused microsteatosis, inflammation and necrosis of the liver tissues. However, there was no significant difference in the ALT and ALP enzyme levels amongst the oil fed groups. It is concluded that the effect of both fresh and heated soy oil on these parameters was not affected by repeated heating except for the inflammation.

Osteoactivin expressed during cirrhosis development in rats fed a choline-deficient, L-amino acid-defined diet, accelerates motility of hepatoma cells.

PubMed

Onaga, Masaaki; Ido, Akio; Hasuike, Satoru; Uto, Hirofumi; Moriuchi, Akihiro; Nagata, Kenji; Hori, Takeshi; Hayash, Katsuhiro; Tsubouchi, Hirohito

2003-11-01

Hepatocellular carcinoma (HCC) is closely associated with chronic liver diseases, particularly cirrhosis. However, the genes involved in hepatocarcinogenesis in the context of developing cirrhosis remain unknown. This study aims to identify genes associated with early cirrhosis-associated hepatocarcinogenesis. We examined genes differentially expressed between the livers of normal rats and rats fed a choline-deficient, L-amino acid-defined (CDAA) diet using suppression subtractive hybridization. We examined both the expression in the liver and HCC tissues of osteoactivin (OA), isolated in this screen, and its effect on invasiveness and metastasis. OA mRNA was strongly expressed in the livers of rats fed the CDAA diet for 1-3 months. Moderate expression was sustained for 18 months. OA overexpression increased the invasiveness and metastasis of rat hepatoma cells in vitro and in vivo. In humans, OA expression was not detectable in normal liver tissues. While OA transcripts were detectable in cirrhotic nontumorous liver tissues surrounding HCCs, the majority of HCC tissue samples exhibited higher levels of OA expression than the surrounding normal tissue. These results indicate that OA is a novel factor involved in the progression of HCC via stimulation of tumor invasiveness and metastatic potential.

Anti-aggregatory effect of boswellic acid in high-fat fed rats: involvement of redox and inflammatory cascades

PubMed Central

2016-01-01

Introduction A high-fat diet is one of the main dietary factors promoting platelet aggregation. The present study was conducted to elucidate the involvement of boswellic acid (BA) on the platelet hyperaggregability in HFD-fed rats. As platelet hyperaggregability in HFD rats is closely linked to inflammation and enhanced free radical production, the present study was extended to evaluate the anti-inflammatory and anti-oxidative effect of BA on HFD-promoted platelet aggregation. Material and methods Rats were assigned to normal, HFD-fed, aspirin-treated (30 mg/kg), and BA-treated (250 and 500 mg/kg) groups. Results Boswellic acid administration in a high dose was effective in attenuating the severity of hyperlipidemia and platelet aggregation, indicated by lower collagen/epinephrine-induced platelet aggregation, as evidenced by the significant increase (p < 0.05) in the circulating platelet count and reduction in the number of thrombi in the lungs. Moreover, it attenuated the oxidative stress and the intensity of inflammatory mediators associated with platelet hyperaggregability, as evidenced by the inhibitory effects on interlukin-1β, COX-2 and tumor necrosis factor-α, indicating that the antiplatelet activity of BA is likely a consequence of controlling oxidative stress and inflammation. Conclusions The present data suggest that BA shows a promising anti-aggregatory effect by attenuating the enhanced hyperlipidemia, oxidative stress and inflammation associated with HFD. PMID:27904529

Antihypercholesterolaemic influence of dietary tender cluster beans (Cyamopsis tetragonoloba) in cholesterol fed rats

PubMed Central

Pande, S.; Platel, K.; Srinivasan, K.

2012-01-01

Background & objectives: Cluster beans (Cyamopsis tetragonoloba) are rich source of soluble fibre content and are known for their cholesterol lowering effect. The beneficial anti-hypercholesterolaemic effect of whole dietary cluster beans as a source of dietary fibre was evaluated in high cholesterol diet induced hypercholesterolaemia in experimental rats. Methods: Male Wistar rats (90-95 g) divided in six groups of 10 rats each were used. Freeze dried tender cluster beans were included at 12.5 and 25 per cent levels in the diet of animals maintained for 8 wk either on high (0.5%) cholesterol diet or basal control diet. Results: Significant anti-hypercholesterolaemic effect was seen in cluster bean fed animals, the decrease in serum cholesterol being particularly in the LDL associated fraction. There was also a beneficial increase in HDL associated cholesterol fraction. Hepatic lipid profile showed a significant decrease in both cholesterol and triglycerides as a result of feeding tender cluster beans along with high cholesterol diet. Interpretation & Conclusions: The present experimental results showed the beneficial hypocholesterolaemic and hypolipidimic influences dietary tender cluster beans in atherogenic situation. Studies in human need to be done to confirm the results. PMID:22561629

Effects of dietary inulin, statin, and their co-treatment on hyperlipidemia, hepatic steatosis and changes in drug-metabolizing enzymes in rats fed a high-fat and high-sucrose diet

PubMed Central

2012-01-01

Background Rats fed a high-fat and high-sucrose (HF) diet develop hepatic steatosis and hyperlipidemia. There are several reports that a change in nutritional status affects hepatic levels of drug-metabolizing enzymes. Synthetic inulin is a dietary component that completely evades glucide digestion. Supplementing a HF diet with inulin ameliorates hypertriglycemia and hepatic steatosis, but not hypercholesterolemia. This study aimed at distinguishing the effects of synthetic inulin and 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin), which inhibit cholesterol biosynthesis. Methods We examined effects of co-treatment with synthetic inulin (5%) and fluvastatin (0, 4, and 8 mg/kg, per os) on body weight, epidydimal white adipose tissue weight, serum and hepatic lipid profiles, and hepatic cytochrome P450 (CYP) mRNA and protein profiles in rats fed a standard diet or a HF diet for 3 weeks. Results Treatment with the synthetic inulin (5%) or fluvastatin at 4 mg/kg (lethal dose in rats fed the HF diet, 8 mg/kg) ameliorated the elevation in hepatic triacylglycerol and total cholesterol levels in rats fed the HF diet. Whereas co-treatment with the inulin (5%) and fluvastatin (4 mg/kg) had a tendency to more strongly suppress the elevation in serum levels of very low density lipoprotein triacylglycerol than either treatment alone, no additive or synergistic effect was found in decrease in hepatic lipid levels. Hepatic levels of CYP1A1/2 and CYP2E1 mRNA and protein and methoxyresorufin O-demethylase and ethoxyresorufin O-deethylase activities were reduced in rats fed the HF diet. The synthetic inulin alleviated the reduction in hepatic levels of CYP1A1/2 and CYP2E1 mRNA and protein more strongly than fluvastatin, and no synergistic effects were observed on co-treatment. Furthermore, hepatic levels of aryl hydrocarbon receptor mRNA were decreased in rats fed the HF diet and recovered to near normal values with the intake of dietary inulin, which correlated

Glucose Tolerance, Lipids, and GLP-1 Secretion in JCR:LA-cp Rats Fed a High Protein Fiber Diet

PubMed Central

Reimer, Raylene A.; Russell, James C.

2013-01-01

Background We have shown that individually, dietary fiber and protein increase secretion of the anorexigenic and insulinotropic hormone, glucagon-like peptide-1 (GLP-1). Objective Our objective was to combine, in one diet, high levels of fiber and protein to maximize GLP-1 secretion, improve glucose tolerance, and reduce weight gain. Methods and Procedures Lean (+/?) and obese (cp/cp) male James C Russell corpulent (JCR:LA-cp) rats lacking a functional leptin receptor were fed one of four experimental diets (control, high protein (HP), high fiber (HF, prebiotic fiber inulin), or combination (CB)) for 3 weeks. An oral glucose tolerance test (OGTT) was performed to evaluate plasma GLP-1, insulin and glucose. Plasma lipids and intestinal proglucagon mRNA expression were determined. Results Energy intake was lower with the HF diet in lean and obese rats. Weight gain did not differ between diets. Higher colonic proglucagon mRNA in lean rats fed a CB diet was associated with higher GLP-1 secretion during OGTT. The HP diet significantly reduced plasma glucose area under the curve (AUC) during OGTT in obese rats, which reflected both an increased GLP-1 AUC and higher fasting insulin. Diets containing inulin resulted in the lowest plasma triglyceride and total cholesterol levels. Discussion Overall, combining HP with HF in the diet increased GLP-1 secretion in response to oral glucose, but did not improve glucose tolerance or lipid profiles more than the HF diet alone did. We also suggest that glycemic and insulinemic response to prebiotics differ among rat models and future research work should examine their role in improving glucose tolerance in diet-induced vs. genetic obesity with overt hyperleptinemia. PMID:18223610

Effect of Regular Exercise on the Histochemical Changes of d-Galactose-Induced Oxidative Renal Injury in High-Fat Diet-Fed Rats

PubMed Central

Park, Sok; Kim, Chan-Sik; Lee, Jin; Suk Kim, Jung; Kim, Junghyun

2013-01-01

Renal lipid accumulation exhibits slowly developing chronic kidney disease and is associated with increased oxidative stress. The impact of exercise on the obese- and oxidative stress-related renal disease is not well understood. The purpose of this study was to investigate whether a high-fat diet (HFD) would accelerate d-galactose-induced aging process in rat kidney and to examine the preventive effect of regular exercise on the obese- and oxidative stress-related renal disease. Oxidative stress was induced by an administration of d-galactose (100 mg/kg intraperitoneally injected) for 9 weeks, and d-galactose-treated rats were also fed with a high-fat diet (60% kcal as fat) for 9 weeks to induce obesity. We investigated the efficacy of regular exercise in reducing renal injury by analyzing Nε-carboxymethyllysine (CML), 8-hydroxygluanine (8-OHdG) and apoptosis. When rats were fed with a HFD for 9 weeks in d-galactose-treated rats, an increased CML accumulation, oxidative DNA damage and renal podocyte loss were observed in renal glomerular cells and tubular epithelial cells. However, the regular exercise restored all these renal changes in HFD plus d-galactose-treated rats. Our data suggested that long-term HFD may accelerate the deposition of lipoxidation adducts and oxidative renal injury in d-galactose-treated rats. The regular exercise protects against obese- and oxidative stress-related renal injury by inhibiting this lipoxidation burden. PMID:24023395

Analysis of gene expression changes in relation to toxicity and tumorigenesis in the livers of Big Blue transgenic rats fed comfrey (Symphytum officinale)

PubMed Central

Mei, Nan; Guo, Lei; Zhang, Lu; Shi, Leming; Sun, Yongming Andrew; Fung, Chris; Moland, Carrie L; Dial, Stacey L; Fuscoe, James C; Chen, Tao

2006-01-01

Background Comfrey is consumed by humans as a vegetable and a tea, and has been used as an herbal medicine for more than 2000 years. Comfrey, however, is hepatotoxic in livestock and humans and carcinogenic in experimental animals. Our previous study suggested that comfrey induces liver tumors by a genotoxic mechanism and that the pyrrolizidine alkaloids in the plant are responsible for mutation induction and tumor initiation in rat liver. Results In this study, we identified comfrey-induced gene expression profile in the livers of rats. Groups of 6 male transgenic Big Blue rats were fed a basal diet and a diet containing 8% comfrey roots, a dose that resulted in liver tumors in a previous carcinogenicity bioassay. The animals were treated for 12 weeks and sacrificed one day after the final treatment. We used a rat microarray containing 26,857 genes to perform genome-wide gene expression studies. Dietary comfrey resulted in marked changes in liver gene expression, as well as in significant decreases in the body weight and increases in liver mutant frequency. When a two-fold cutoff value and a P-value less than 0.01 were selected, 2,726 genes were identified as differentially expressed in comfrey-fed rats compared to control animals. Among these genes, there were 1,617 genes associated by Ingenuity Pathway Analysis with particular functions, and the differentially expressed genes in comfrey-fed rat livers were involved in metabolism, injury of endothelial cells, and liver injury and abnormalities, including liver fibrosis and cancer development. Conclusion The gene expression profile provides us a better understanding of underlying mechanisms for comfrey-induced hepatic toxicity. Integration of gene expression changes with known pathological changes can be used to formulate a mechanistic scheme for comfrey-induced liver toxicity and tumorigenesis. PMID:17118137

Hypertriglyceridemic rats fed high fat diet as a model of metabolic syndrome.

PubMed

Kaprinay, B; Lipták, B; Slovák, L; Švík, K; Knezl, V; Sotníková, R; Gáspárová, Z

2016-12-21

People with metabolic syndrome have higher risk of cardiovascular diseases then those without. The aim of the work was to investigate whether high fat diet administered to Prague hereditary hypertriglyceridemic (HTG) rats can induce signs of metabolic syndrome (MetS). Our results showed that HTG rats fed high fat diet (HTGch) had disturbed glucose metabolism and also lipid metabolism - increased serum triacylglycerols (TAG), total cholesterol (Ch), low-density lipoprotein-Ch (LDL-Ch), and decreased high-density lipoprotein-Ch (HDL-Ch). Their livers proved markers of developing steatosis. Moreover, HTGch had increased blood pressure, yet the vascular endothelium was not significantly damaged. All these changes were accompanied with oxidative stress and tissue damage identified as increased liver concentrations of thiobarbituric acid reactive substances (TBARS) and activity of the lysosomal enzyme N-acetyl-D-glucosaminidase (NAGA). We assume that the model used may be suitable for the study of MetS with no evidence of obesity. Prolongation of the high fat diet duration might have a major impact on all parameters tested, especially on vascular endothelial function.

Manganese supplementation increases adiponectin and lowers ICAM-1 and creatinine blood levels in Zucker type 2 diabetic rats, and downregulates ICAM-1 by upregulating adiponectin multimerization protein (DsbA-L) in endothelial cells.

PubMed

Burlet, Elodie; Jain, Sushil K

2017-05-01

Blood and tissue levels of manganese (Mn) are lower in type 2 diabetic and atherosclerosis patients compared with healthy subjects. Adiponectin has anti-diabetic and anti-atherogenic properties. Impairment in Disulfide bond A-like protein (DsbA-L) is associated with low adiponectin levels and diabetes. This study investigates the hypothesis that the beneficial effects of Mn supplementation are mediated by adiponectin and DsbA-L. At 6 weeks of age, Male Zucker diabetic fatty rats (ZDF) were randomly divided into two groups: diabetic controls and Mn-supplemented diabetic rats. Each rat was supplemented with Mn (D+Mn, 16 mg/kg BW) or water (placebo, D+P) daily for 7 weeks by oral gavage. For cell culture studies, Human Umbilical Vein Endothelial Cells (HUVEC) or 3T3L1 adipocytes were pretreated with Mn (0-10 µM MnCl 2 ) for 24 h, followed by high glucose (HG, 25 mM) or normal glucose (5 mM) exposure for another 24 h. Mn supplementation resulted in higher adiponectin (p = 0.01), and lower ICAM-1 (p = 0.04) and lower creatinine (p = 0.04) blood levels compared to those in control ZDF rats. Mn-supplemented rats also caused reduced oxidative stress (ROS) and NADPH oxidase, and higher DsbA-L expression in the liver (p = 0.03) of ZDF rats compared to those in livers of control rats; however, Fe levels in liver were lower but not significant (p = 0.08). Similarly, treatment with high glucose (25 mM) caused a decrease in DsbA-L, which was prevented by Mn supplementation in HUVEC and adipocytes. Mechanistic studies with DsbA-L siRNA showed that the beneficial effects of Mn supplementation on ROS, NOX4, and ICAM-1 expression were abolished in DsbA-L knock-down HUVEC. These studies demonstrate that DsbA-L-linked adiponectin mediates the beneficial effects observed with Mn supplementation and provides evidence for a novel mechanism by which Mn supplementation can increase adiponectin and reduce the biomarkers of endothelial dysfunction in diabetes.

Proteomic Profiles of Adipose and Liver Tissues from an Animal Model of Metabolic Syndrome Fed Purple Vegetables

PubMed Central

Ayoub, Hala M; McDonald, Mary Ruth; Sullivan, James Alan; Tsao, Rong; Meckling, Kelly A

2018-01-01

Metabolic Syndrome (MetS) is a complex disorder that predisposes an individual to Cardiovascular Diseases and type 2 Diabetes Mellitus. Proteomics and bioinformatics have proven to be an effective tool to study complex diseases and mechanisms of action of nutrients. We previously showed that substitution of the majority of carbohydrate in a high fat diet by purple potatoes (PP) or purple carrots (PC) improved insulin sensitivity and hypertension in an animal model of MetS (obese Zucker rats) compared to a control sucrose-rich diet. In the current study, we used TMT 10plex mass tag combined with LC-MS/MS technique to study proteomic modulation in the liver (n = 3 samples/diet) and adipose tissue (n = 3 samples/diet) of high fat diet-fed rats with or without substituting sucrose for purple vegetables, followed by functional enrichment analysis, in an attempt to elucidate potential molecular mechanisms responsible for the phenotypic changes seen with purple vegetable feeding. Protein folding, lipid metabolism and cholesterol efflux were identified as the main modulated biological themes in adipose tissue, whereas lipid metabolism, carbohydrate metabolism and oxidative stress were the main modulated themes in liver. We propose that enhanced protein folding, increased cholesterol efflux and higher free fatty acid (FFA) re-esterification are mechanisms by which PP and PC positively modulate MetS pathologies in adipose tissue, whereas, decreased de novo lipogenesis, oxidative stress and FFA uptake, are responsible for the beneficial effects in liver. In conclusion, we provide molecular evidence for the reported metabolic health benefits of purple carrots and potatoes and validate that these vegetables are good choices to replace other simple carbohydrate sources for better metabolic health. PMID:29642414

Chronic effects of aerobic exercise on gene expression of LOX-1 receptor in the heart of rats fed with high fat diet

PubMed Central

Riahi, Simin; Mohammadi, Mohammad Taghi; Sobhani, Vahid; Soleimany, Mansureh

2015-01-01

Objective(s): Lectin-like low density lipoprotein receptor (LOX-1) has pivot role in vascular complications, which is upregulated in numerous pathological conditions. Since exercise has beneficial effects in prevention of hyperlipidemic complications, present study examined protective effects of aerobic exercise through reduction of LOX-1 expression in heart during dyslipidemia. Materials and Methods: Four groups of rats were used (N=25): Normal, Normal and exercise, High fat and High fat and exercise. High fat diet (HFD) was made by adding 10% animal oil, 2% cholesterol and 0.5% colic acid to standard rodent chow. Exercise protocol consisted of swimming 1 hr/day, and 5 days/week for 8 weeks. Plasma lipids were evaluated at the end of experiment, 48 hr after final session of exercise. At the end, rats were sacrificed and heart was removed for determination of malondialdehyde (MDA) content, and LOX-1 expression. Results: HFD meaningfully changed lipid profile (>50%), but chronic exercise had no significant effects on lipid profile. LOX-1 expression was significantly increased in heart of rats fed with HFD, while swimming exercise considerably reduced gene expression of LOX-1. MDA content was significantly enhanced in rats fed with HFD (4.37±0.6 nmol/mg, P<0.01) compared to normal group (1.56±0.48 nmol/mg), whereas swimming exercise decreased MDA level of heart in rats fed with HFD (2.28±0.32, P<0.01). Conclusion: Findings indicated that swimming exercise is able to diminish heart expression of LOX-1 receptor concomitant reduction of oxidative stress. Since these parameters are involved in generation of dyslipidemic complications, swimming exercise is a good candidate to reduce these complications. PMID:26557970

Modulation of oxidative stress, inflammation, autophagy and expression of Nrf2 in hippocampus and frontal cortex of rats fed with açaí-enriched diets.

PubMed

Poulose, Shibu M; Bielinski, Donna F; Carey, Amanda; Schauss, Alexander G; Shukitt-Hale, Barbara

2017-06-01

Açaí (Euterpe spp.), an exotic palm fruit, has recently emerged as a promising source of natural antioxidants with wide pharmacological and nutritional value. In this study, two different species of açaí pulp extracts, naturally grown in two distinct regions of the Amazon, namely, Euterpe oleracea Mart. (habitat: Brazilian floodplains of the Amazon) and Euterpe precatoria Mart. (habitat: Bolivian Amazon), were studied for their effects on brain health and cognition. Neurochemical analyses were performed in critical brain regions associated with memory and cognition of 19-month-old açaí-fed rats, in whom the cognitive benefits of açaí had been established. Results indicated significant reductions (P< 0.05) in prooxidant NADPH-oxidoreductase-2 (NOX2) and proinflammatory transcription factor NF-κB in açaí-fed rats. Measurement of Nrf2 expression, a transcription factor for antioxidant enzymes, and a possible link between oxidative stress, neuroinflammation and autophagy mechanisms, indicated significant overexpression (P<0.005) in the hippocampus and frontal cortex of the açaí-fed rats. Furthermore, significant activation of endogenous antioxidant enzymes GST and SOD were also observed in the açaí-fed animals when compared to control. Analysis of autophagy markers such as p62, phospho-mTOR, beclin1 and MAP1B-LC3 revealed differential expression in frontal cortex and hippocampus, mostly indicating an upregulation in the açaí-fed rats. In general, results were more profound for EP than EO in hippocampus as well as frontal cortex. Therefore, an açaí-enriched diet could possibly modulate Nrf2, which is known to modulate the intracellular redox status, thereby regulating the ubiquitin-proteosomal pathway, ultimately affecting cognitive function in the aging brain.

Effect of hepatocyte growth factor on endogenous hepatocarcinogenesis in rats fed a choline-deficient L-amino acid-defined diet.

PubMed

Nakanishi, Chihiro; Moriuchi, Akihiro; Ido, Akio; Numata, Masatsugu; Kim, Il-Deok; Kusumoto, Kazunori; Hasuike, Satoru; Abe, Hiroo; Nagata, Kenji; Akiyama, Yutaka; Uto, Hirofumi; Kataoka, Hiroaki; Tsubouchi, Hirohito

2006-07-01

Hepatocyte growth factor (HGF) is a promising agent for the treatment of intractable liver disease, due to its mitogenic, anti-apoptotic, and anti-fibrotic effects. We investigated the effect of recombinant human HGF (rh-HGF) on the development of both hepatocellular carcinoma (HCC) and preneoplastic nodules in rats fed a choline-deficient L-amino acid-defined (CDAA) diet, an animal model of hepatocarcinogenesis resembling human development of HCC with cirrhosis. From weeks 13 to 48 of the CDAA diet, rh-HGF (0.1 or 0.5 mg/kg/day) was administered intravenously to rats in four-week cycles, with treatment for five consecutive days of each week for two weeks, followed by a two-week washout period. Treatment with rh-HGF significantly inhibited the development of preneoplastic nodules in a dose-dependent manner at 24 weeks. Although the numbers and areas of the preneoplastic nodules in rats treated with rh-HGF were equivalent to those in mock-treated rats by 60 weeks, the incidence of HCC was reduced by HGF treatment. Although one rat treated with low-dose rh-HGF exhibited a massive HCC, which occupied almost the whole liver, and lung metastases, HGF treatment did not increase the overall frequency of HCC. Administration of high-dose rh-HGF, however, induced an increase in the urinary excretion of albumin, leading to decreased serum albumin at 60 weeks. These results indicate that long-term administration of rh-HGF does not accelerate hepatocarcinogenesis in rats fed a CDAA diet. However, these findings do not completely exclude the potential of HGF-induced hepatocarcinogenesis; this issue must be resolved before rh-HGF can be used for patients with intractable liver diseases, especially those with cirrhosis.

Influence of chronic stress on the compositions of hepatic cholesterol and triglyceride in male Wistar rats fed a high fat diet.

PubMed

Gao, Siyuan; Han, Xue; Fu, Jihua; Yuan, Xiaoling; Sun, Xing; Li, Qiang

2012-07-01

  We determined the influence of chronic stress (CS) on the compositions of hepatic cholesterol and triglyceride (TG) in rats fed a high fat diet (HFD).   Male Wistar rats were fed either a standard diet or a HFD and half of the HFD fed rats were given CS (electric foot shock assisted with noise) for 8 weeks.   Compared with the control group, the levels of hepatic total cholesterol (TC) and TG were significantly elevated in the HFD and HFD with chronic stress (HFD+CS) groups, and the more severe elevations of them were found in the HFD group. Inversely, the more severe elevations of hepatic water-soluble parts of TC and TG were found in the HFD+CS group, as the elevations of low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol in liver and serum, tumor necrosis factor-α, interleukin-1β and malondialdehyde in liver. Meanwhile, downregulated mRNA expressions of hepatic liver X receptor-α (LXR-α) and peroxisome proliferator-activated receptor-γ (PPAR-γ) were also more severe in the HFD+CS group.   CS can aggravate the high levels of water-soluble compositions of hepatic TC and TG induced by HFD as it aggravates hepatic inflammation and oxidative stress; in spite of that, however, it cannot further promote hepatic lipidosis. This is consistent with the downregulated mRNA expressions of LXR-α and PPAR-γ. © 2012 The Japan Society of Hepatology.

Tissue accumulation and urinary excretion of chromium in rats fed diets containing graded levels of chromium chloride or chromium picolinate.

PubMed

Yoshida, Munehiro; Hatakeyama, Erika; Hosomi, Ryota; Kanda, Seiji; Nishiyama, Toshimasa; Fukunaga, Kenji

2010-08-01