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1

[Model study of afobazole distribution in pregnant and lactating female rats and infant rat pups].  

PubMed

Afobazole and M-11, its major metabolite were detected in placental and embryonic rat tissues after single peroral administration to pregnant female rats at a dose of 100 mg/kg. The anxiolytic drug and its metabolite are also detected in rat milk and body of the breast-fed infant rat pups after 4 days of daily administration (200 mg/kg, per os) to lactating female rats. PMID:20919552

Shreder, O V; Kolyvanov, G B; Litvin, A A; Bastrygin, D V; Shreder, E D; Solomina, A S; Viglinskaia, A O; Zabrodina, V V; Zherdev, V P; Durnev, A D; Seredenin, S B

2010-08-01

2

Disposition of low doses of 14C-bisphenol A in male, female, pregnant, fetal, and neonatal rats.  

PubMed

Bisphenol A (BPA) is a weak xenestrogen (ADI = 50 microg kg(-1), US EPA) which is mass-produced, with potential for human exposure. To study absorption, distribution, excretion, and metabolism of BPA, BPA labeled with carbon-14 was administered p.o. to male and female Fischer (F344) rats at relatively low doses (20, 100, and 500 microg kg(-1)), and i.v. injected at 100 and 500 microg kg(-1). 14C-BPA (500 microg kg(-1)) was also administered orally to pregnant and lactating rats to examine the transfer of radioactivity to fetuses, neonatal rats, and milk. Radioluminographic determination using phosphor imaging plates was employed to achieve highly sensitive determination of radioactivity. Absorption ratios of radioactivity after three oral doses were high (35-82%); parent 14C-BPA in the circulating blood was quite low, however, suggesting considerable first-pass effect. After an oral dose of 100 microg kg(-1) 14C-BPA, the radioactivity was distributed and eliminated rapidly, but remained in the intestinal contents, liver, and kidney for 72 h. The major metabolite in the plasma and urine was BPA glucuronide, whereas most of the BPA was excreted with the feces as free BPA. A second peak in the time-course of plasma radioactivity suggested enterohepatic recirculation of BPA glucuronide. There was limited distribution of 14C-BPA to the fetus and neonate after oral administration to the dam. Significant radioactivity was not detected in fetuses on gestation days 12 and 15. On day 18, however, radioactivity was detected in the fetal intestine and urinary bladder 24 h after oral dosing of 14C-BPA to the pregnant rats. Part of radioactivity was transferred to neonatal rats from the milk of the treated lactating dam and remained in the intestine of the neonates after 24-h nursing by an untreated dam. PMID:15902421

Kurebayashi, Hideo; Nagatsuka, Shin-Ichiro; Nemoto, Hiroyuki; Noguchi, Hideyo; Ohno, Yasuo

2005-05-01

3

Pregnant growth restricted female rats have bone gains during late gestation which contributes to second generation adolescent and adult offspring having normal bone health.  

PubMed

Low birth weight, due to uteroplacental insufficiency, results in programmed bone deficits in the first generation (F1). These deficits may be passed onto subsequent generations. We characterized the effects of being born small on maternal bone health during pregnancy; and aimed to characterize the contribution of the maternal environment and germ line effects to bone health in F2 offspring from mothers born small. Bilateral uterine vessel ligation (or sham) surgery was performed on female F0 WKY rats on gestational day 18 (term 22days) to induce uteroplacental insufficiency and fetal growth restriction. Control and Restricted F1 female offspring were allocated to a non-pregnant or pregnant group. To generate F2 offspring, F1 females were allocated to either non-embryo or embryo transfer groups. Embryo transfer was performed on gestational day 1, where second generation (F2) embryos were gestated (donor-in-recipient) in either a Control (Control-in-Control, Restricted-in-Control) or Restricted (Control-in-Restricted, Restricted-in-Restricted) mother. Restricted F1 females were born 10-15% lighter than Controls. Restricted non-pregnant females had shorter femurs, reduced trabecular and cortical bone mineral contents, trabecular density and bone geometry measures determined by peripheral quantitative computed tomography (pQCT) compared to non-pregnant Controls. Pregnancy restored the bone deficits that were present in F1 Restricted females. F2 non-embryo transfer male and female offspring were born of normal weight, while F2 embryo transfer males and females gestated in a Control mother (Control-in-Control, Restricted-in-Control) were heavier at birth compared to offspring gestated in a Restricted mother (Restricted-in-Restricted, Control-in-Restricted). Male F2 Restricted embryo groups (Restricted-in-Control and Restricted-in-Restricted) had accelerated postnatal growth. There was no transmission of bone deficits present at 35days or 6months in F2 offspring. Embryo transfer procedure had confounding effects preventing the separation of maternal environment and germ line contribution to outcomes. Deficits present in F1 non-pregnant Restricted females were absent during late gestation, indicating that pregnant F1 Restricted females experienced gains in bone. These beneficial maternal pregnancy adaptations may have prevented transmission of bone deficits to F2 offspring. PMID:25659207

Anevska, Kristina; Gallo, Linda A; Tran, Melanie; Jefferies, Andrew J; Wark, John D; Wlodek, Mary E; Romano, Tania

2015-05-01

4

Antioxidant therapy and streptozotocin-induced diabetes in pregnant rats  

Microsoft Academic Search

The aim of our study was to analyse the effect of chronic hyperglycaemia on lipid peroxidation and scavenging enzyme activity\\u000a in pregnant animals and their offspring supplemented and not supplemented with vitamin E – a natural antioxidant. Thirty pregnant\\u000a female Wistar rats were used in our experiments. Diabetes was induced on day 7 of pregnancy using a single does of

M. Kinalski; A. ?ledziewski; B. Telejko; W. Zarzycki; I. Kinalska

1999-01-01

5

Effects of exposure to microwaves on cellular immunity and placental steroids in pregnant rats.  

PubMed Central

OBJECTIVES: Microwaves produce various detrimental changes based on actions of heat or non-specific stress, although the effects of microwaves on pregnant organisms has not been uniform. This study was designed to clarify the effect of exposure to microwaves during pregnancy on endocrine and immune functions. METHODS: Natural killer cell activity and natural killer cell subsets in the spleen were measured, as well as some endocrine indicators in blood--corticosterone and adrenocorticotrophic hormone (ACTH) as indices of the hypothalamic-pituitary-adrenal axis--beta-endorphin, oestradiol, and progesterone in six female virgin rats and six pregnant rats (nine to 11 days gestation) exposed to microwaves at 10 mW/cm2 incident power density at 2450 MHz for 90 minutes. The same measurements were performed in control rats (six virgin and six pregnant rats). RESULTS: Skin temperature in virgin and pregnant rats increased immediately after exposure to microwaves. Although splenic activity of natural killer cells and any of the subset populations identified by the monoclonal antibodies CD16 and CD57 did not differ in virgin rats with or without exposure to microwaves, pregnant rats exposed to microwaves showed a significant reduction of splenic activity of natural killer cells and CD16+CD57-. Although corticosterone and ACTH increased, and oestradiol decreased in exposed virgin and pregnant rats, microwaves produced significant increases in beta-endorphin and progesterone only in pregnant rats. CONCLUSIONS: Microwaves at the power of 10 mW/cm2 produced activation of the hypothalamic-pituitary-adrenal axis and increased oestradiol in both virgin and pregnant rats, suggesting that microwaves greatly stress pregnant organisms. These findings in pregnant rats suggest that--with exposure to microwaves--pregnancy induces immunosuppression, which could result in successful maintainance of pregnancy. This enhancement of adaptability to heat stress with pregnancy may be mediated by activation of placental progesterone and placental or pituitary beta-endorphin. PMID:9423582

Nakamura, H; Seto, T; Nagase, H; Yoshida, M; Dan, S; Ogino, K

1997-01-01

6

Effects of stress early in gestation on hippocampal neurogenesis and glucocorticoid receptor density in pregnant rats.  

PubMed

Pregnancy is a time of marked neural, physiological and behavioral plasticity in the female and is often a time when women are more vulnerable to stress and stress-related diseases, such as depression and anxiety. Unfortunately the impact of stress during gestation on neurobiological processes of the mother has yet to be fully determined, particularly with regard to changes in the hippocampus; a brain area that plays an important role in stress-related diseases. The present study aimed to determine how stress early in pregnancy may affect hippocampal plasticity in the pregnant female and whether these effects differ from those in virgin females. For this purpose, adult age-matched pregnant and virgin female Sprague-Dawley rats were divided into two conditions: (1) Control and (2) Stress. Females in the stress condition were restrained during days 5-11 of gestation and at matched time-points in virgin females. All pregnant females received an injection of bromodeoxyuridine (BrdU) on day 1 of gestation and were sacrificed 21days later. The same procedure was carried out at matched time points in virgin females. Results show that for number of Ki67-immunoreactive (ir) cells and doublecortin (DCX)-ir cells, there were significant interactions between reproductive state (pregnant/virgin) and stress exposure (p=.05, p=.04, respectively) with control virgin and stressed pregnant females having more Ki67-ir cells than control pregnant females and more DCX-ir cells than stressed virgin females. Results also show that pregnant females had significantly greater glucocorticoid receptor (GR) density in the CA1, CA3 and granule cell layer compared to virgin females. In addition, there was a main effect of stress on GR density in the CA3 region, with stressed females having significantly lower GR density compared to control females (p=.01). This work adds to our understanding of how stress and reproductive state affect plasticity in the female hippocampus. PMID:25655215

Pawluski, J L; Császár, E; Savage, E; Martinez-Claros, M; Steinbusch, H W M; van den Hove, D

2015-04-01

7

Tenofovir rescue therapy in pregnant females with chronic hepatitis B  

PubMed Central

AIM: To evaluate the safety and efficacy of tenofovir monotherapy in pregnant females resistant to lamivudine or telbivudine. The effect of tenofovir on the fetus was also assessed. METHODS: The clinical data of 17 females were reviewed in this study. Adverse events and pregnancy outcomes from January 1, 2011 to June 30, 2013 were evaluated in the Department of Gynecology and Obstetrics of Beijing Ditan Hospital, Capital Medical University, Beijing, China. These pregnant females developed lamivudine (LAM)- or telbivudine (LdT)-resistant chronic hepatitis B and received tenofovir (TDF) therapy (300 mg/d), and its curative effect, maternal and perinatal adverse events, fetal growth and development, and neonatal prognosis were evaluated. RESULTS: The median hepatitis B virus (HBV) DNA level in the pregnant females with LAM or LdT resistance was 5.9 (range, 4.2-7.2) log10 copies/mL before the initiation of TDF. Ten of these females had abnormal alanine aminotransferase (ALT) levels. The patients were treated with TDF for a median of 24 wk (range, 12-40 wk). Fourteen females (82.4%) had an HBV DNA level of < 500 copies/mL at the time of delivery. This decrease was statistically significant (P < 0.0001). Serum ALT levels were normalized in all subjects with an elevated serum ALT level at baseline (P = 0.0003). There were no significant changes in serum creatinine and phosphorus levels during TDF treatment. In addition, no adverse events related to TDF treatment were observed. Seventeen females delivered 17 live infants, and all infants had good Apgar scores. The mean birth weight was 3226.5 ± 331.7 g, and the mean length at birth was 50.4 ± 1.1 cm. The growth and development of the infants was normal at birth, and no infants had birth defects related to TDF treatment. Eleven infants completed HBV vaccination and had no evidence of vertical transmission. CONCLUSION: The use of TDF in pregnant females with chronic HBV and LAM or LdT resistance was safe and effective. PMID:25741161

Hu, Yu-Hong; Liu, Min; Yi, Wei; Cao, Yan-Jun; Cai, Hao-Dong

2015-01-01

8

Gastric inhibitory polypeptide and gastric acid secretion in pregnant rats.  

PubMed

The effects of pregnancy on the basal and pentagastrin-stimulated gastric acid secretion and the level of plasma gastric inhibitory polypeptide (GIP) in rats were studied on pentobarbital-anaesthetized non-pregnant rats and rats in the 1st, 2nd, or 3rd week of gestation. Acid output was determined by titration of the gastric perfusate. Basal secretion was collected for 45 min before a 30 min infusion of pentagastrin (8 micrograms/ml/300 g body weight). Concentration of plasma GIP was measured by a radioimmunoassay (RIA). The immunoreactivity of GIP-like substance in the extract of the rat placenta collected from the rat at day 21 of gestation was examined by RIA. The biological activity of GIP-like substance in the rat placenta extract was tested by the reduction of pentagastrin-stimulated gastric acid secretion in male rats. The basal level of gastric secretion was higher in late pregnancy as compared with the non-pregnant rats. Pentagastrin induced a greater increase of gastric acid secretion in early but not late pregnant rats as compared with the non-pregnant animals. The basal and post-pentagastrin level of plasma GIP was higher in rats in late pregnancy. Both immunoreactivity and biological activity of GIP exist in the rat placenta extract. These results suggest that the normalization of gastric acid secretion in late pregnant rats is at least in part due to the production of GIP-like substance from placenta. PMID:7716131

Chen, T S; Yeh, G H; Pu, H F; Doong, M L; Lu, C C; Liu, S R; Young, T K; Ho, L T; Chang, F Y; Wang, P S

1995-01-01

9

Megaloblastic hematopoiesis in a 20 year old pregnant female  

PubMed Central

Summary Background: Nitrous oxide can cause disordered blood cell proliferation and lead to pancytopenia and altered immune function. Case Report: A young pregnant female patient presented after binge nitrous oxide abuse with altered mental status and abnormal vital signs. From her initial assessment she was noted to have pancytopenia and was found to have megaloblastic, hyper-cellular changes in a subsequent bone marrow biopsy. This presentation was determined to be secondary to toxic effects after heavy use of nitrous oxide. Conclusions: Nitrous oxide exposure, including use as an inhalant, over 12 hours can lead to bone marrow abnormalities such as megaloblastic hematopoiesis. PMID:23569553

Trivette, Evan T.; Hoedebecke, Kyle; Berry-Cabán, Cristóbal S.; Jacobs, Brandy R.

2013-01-01

10

Upregulation of aquaporin 2 water channel expression in pregnant rats.  

PubMed Central

Water retention is characteristic of pregnancy but the mechanism(s) of the altered water metabolism has yet to be elucidated. The collecting duct water channel, aquaporin 2 (AQP2), plays a pivotal role in the renal water regulation, and we hypothesized that AQP2 expression could be modified during pregnancy. Sprague-Dawley female rats were studied on days 7 (P7), 14 (P14), and 20 (P20) of pregnancy, and expression of AQP2 in papillae was examined. Nonpregnant (NP) littermates were used as controls. Plasma osmolalities were significantly lower in pregnant rats by day 7 of gestation (P7 283.8+/-1.82, P14 284.3+/-1.64, P < 0.001, P20 282. 4+/-1.32, P < 0.0001, vs. NP 291.8+/-1.06 mosmol/kgH2O). However, plasma vasopressin concentrations in pregnant rats were not significantly different than in nonpregnant rats (NP 1.03+/-0.14, P7 1.11+/-0.21, P14 1.15+/-0.21, P20 1.36+/-0.24 pg/ml, NS). The mRNA of AQP2 was increased early during pregnancy: AQP2/beta actin: P7 196+/-17.9, P14 200+/-6.8, and P20 208+/-15.5%, P < 0.005 vs. NP (100+/-11.1%). AQP2 protein was also increased during pregnancy: AQP2 protein: P7 269+/-10.0, P14 251+/-12.0, P < 0.0001, and P20 250+/-13.6%, P < 0.001 vs. NP (100+/-12.5%). The effect of V2 vasopressin receptor antagonist, OPC-31260, was then investigated. AQP2 mRNA was suppressed significantly by OPC-31260 administration to P14 rats (AQP2/beta actin: P14 with OPC-31260 39.6+/-1.7%, P < 0.001 vs. P14 with vehicle) and was decreased to the same level of expression as NP rats receiving OPC-31260. Similar findings were found with the analysis of AQP2 protein. The decreased plasma osmolality of P14 rats was not modified by OPC-31260. The results of the study indicate that upregulation of AQP2 contributes to the water retention in pregnancy through a V2 receptor-mediated effect. In addition to vasopressin, other factors may be involved in this upregulation. PMID:9486978

Ohara, M; Martin, P Y; Xu, D L; St John, J; Pattison, T A; Kim, J K; Schrier, R W

1998-01-01

11

Exploring signet-ring cells in pregnant female  

PubMed Central

Introduction Primary signet-ring cell carcinoma (SRCC) of the colon and rectum are rare form, which present at an advanced stage and have poor prognosis. Different treatment policies of SRCC during different gestational age of pregnancy are explored from the literature. Case study A 26-year-old young pregnant female with 10-week gestation presented with constipation and blood in stools and on per rectal examination a tender circumferential stricture was present 2 cm above the anal verge. Magnetic resonant imaging (MRI) pelvis of the patient revealed rectal thickening, the biopsy of which revealed characteristic appearance of “linitis plastica” and diagnosed as poorly differentiated adenocarcinoma with signet ring morphology with wide spread positivity for cytokeratin & p53. With this diagnosis, patient underwent medical termination of pregnancy (MTP). Discussion SRCC of the colon comprises about only 1% of all cases of colon cancer. When compared with other types of adenocarcinoma, patients with SRCC in the colon are younger and more likely to experience lymph node metastasis. Its incidence in pregnancy is estimated to be less than 0.1%. Certainly, any pregnant patient who reports rectal bleeding or has hemoccult positive stool on examination deserves careful evaluation to rule out cancer. The complex treatment of colorectal cancer in pregnancy is based on the gestational age of the fetus, tumor stage and need for emergent vs. elective management. PMID:25830043

Gogia, Pooja; Atri, Rajeev; Dhankhar, Rakesh; Kaushal, Vivek; Singh, Sunita; Sen, Rajeev; Pal, Manoj; Lathwal, Amit

2015-01-01

12

Body Weight and Brown Fat Activity in Hyperphagic Cafeteria-Fed Female Rats and Their Offspring  

Microsoft Academic Search

Presenting pregnant rats with a varied choice of human food items (a cafeteria diet) caused a slight reduction in total protein intake and significant increases in energy intake (32%) and weight gain compared to pregnant females fed stock diet (controls). Cafeteria-fed mothers gave birth to the same number and weight of pups as controls, and these grew normally, but were

Nancy J. Rothwell; Michael J. Stock

1986-01-01

13

Gastric inhibitory polypeptide and gastric acid secretion in pregnant rats  

Microsoft Academic Search

The effects of pregnancy on the basal and pentagastrin-stimulated gastric acid secretion and the level of plasma gastric inhibitory polypeptide (GIP) in rats were studied on pentobarbital-anaesthetized non pregnant rats and rats in the 1st, 2nd, or 3rd week of gestation. Acid output was determined by titration of the gastric perfusate. Basal secretion was collected for 45 min before a

T.-S. Chen; G.-H. Yeh; H.-F. Pu; M.-L. Doong; C.-C. Lu; S.-R. Liu; T.-K. Young; L.-T. Ho; F.-Y. Chang; P. S. Wanga

1995-01-01

14

GESTATIONAL EXPOSURE TO NONYLPHENOL CAUSES PRECOCIOUS MAMMARY GLAND DEVELOPMENT IN FEMALE RAT OFFSPRING  

EPA Science Inventory

This study examined whether or not exposure to 4-nonylphenol (NP) during late gestation affects reproductive and mammary development in the offspring of female rats. Time pregnant Long Evans rats were gavaged with NP (10 or 100 mg/kg), atrazine (ATR, 100 mg/kg), or corn oil on ge...

15

Mortality associated with using medetomidine and ketamine for general anesthesia in pregnant and nonpregnant Wistar rats.  

PubMed

Medetomidine and ketamine are injectable drugs that can be used in combination to induce general anesthesia in rats. After noticing a high incidence of morbidity and mortality in pregnant Wistar rats given medetomidine and ketamine for anesthesia, the authors further investigated the effects of this combination of anesthetic drugs in both pregnant and nonpregnant Wistar rats. The time to recumbency and the duration of general anesthesia were similar between pregnant and nonpregnant rats. Pregnancy status did not affect the rats' pulse rate, respiratory rate, rectal temperature, oxygen saturation or perfusion index during 2 h of anesthesia. Pregnant rats had significantly lower blood glucose concentrations than nonpregnant rats at all time points, though blood glucose concentrations increased in both groups. The mortality rate was ?15% both for nonpregnant rats and for pregnant rats. Researchers using medetomidine and ketamine to anesthetize Wistar rats should carefully monitor the rats in order to minimize mortality. PMID:24845007

Callahan, Lauren M; Ross, Simone M; Jones, Megan L; Musk, Gabrielle C

2014-06-01

16

Hematological and serum biochemical values in pregnant and postpartum females of the squirrel monkey (Saimiri sciureus).  

PubMed

The hematological and serum biochemical values of a total of 18 pregnant female squirrel monkeys were determined during the pre- and postpartum period. Pregnancy was determined by abdominal palpation in adult females cohabiting with robust males. The mean body weight of the pregnant females gradually increased toward parturition and dramatically decreased at parturition due to delivery of the infant monkey. The red blood cell count, hematocrit and hemoglobin levels diminished toward parturition and then increased to their normal levels by week 6 after delivery. The Wintrobe constant, MCHC, did not fluctuate, but MCH and MCV values increased in late pregnancy and the early nursing periods. The mean white blood cell count varied between 65.8 and 87.3 (x 10(2)/mm3) during the experimental periods. The mean serum total cholesterol concentration and glutamic-oxaloacetic transaminase activity were lower in the pregnant group during the mid- and late gestation stage than in nonpregnant and nursing females. The mean serum total protein and albumin values were lower in pregnant females than in the controls. Alkaline phosphatase activity increased in late pregnancy and the nursing periods. Since the pregnant females examined gave birth to healthy newborn monkeys and nursed them normally, the hematological and serum biochemical measurements should represent the physiological values for squirrel monkeys during pregnancy and the postpartum period. PMID:8689579

Suzuki, T; Suzuki, N; Shimoda, K; Nagasawa, H

1996-01-01

17

Use of urinary renal biomarkers to evaluate the nephrotoxic effects of melamine or cyanuric acid in non-pregnant and pregnant rats.  

PubMed

Although traditional assessments of renal damage detect loss of kidney function, urinary renal biomarkers are proposed to indicate early changes in renal integrity. The recent adulteration of infant formula and other milk-based foods with melamine revealed a link between melamine ingestion and nephropathy. Thus, the effects of melamine and related analogs (e.g., cyanuric acid) should be assessed in other potentially sensitive groups. We evaluated whether urinary Kim-1, clusterin, and osteopontin could detect the effects of high doses of melamine or cyanuric acid in pregnant and non-pregnant female rats gavaged with 1000?mg/kg bw/day for 10 days. We demonstrate that these biomarkers can differentiate the severity of effects induced by melamine or cyanuric acid. All melamine-treated animals experienced adverse effects; however, pregnant rats were most sensitive as indicated by increased SCr, BUN, and kidney weights, decreased body weight, and presence of renal crystals. These effects coincided with elevated urinary biomarker levels as early as day 2 of exposure. One cyanuric acid-treated rat displayed effects similar to melamine, including increased urinary biomarker levels. This work illustrates that these biomarkers can detect early effects of melamine or cyanuric acid crystal-induced nephropathy and further supports the use of urinary protein immunoassays as a powerful, non-invasive method to assess nephrotoxicity. PMID:25455896

Bandele, O J; Stine, C B; Ferguson, M; Black, T; Olejnik, N; Keltner, Z; Evans, E R; Crosby, T C; Reimschuessel, R; Sprando, R L

2014-12-01

18

Recovery from developmental nonylphenol exposure is possible for female rats.  

PubMed

Nonylphenol (NP) is an environmental endocrine-disrupting chemical that has been detected in human cord blood and milk. Developmental exposure to NP is unavoidable and can lead to hyperadrenalism, a syndrome that resembles Cushing's disease and has a life-long impact on the affected individual. In this study, we investigated the recovery of female rats from developmental exposure to NP and the effects of such exposure on future generations. Female rats were time-mated, and rats in the experimental group (NP group) were administered NP in drinking water (2?g/mL) throughout gestation and lactation. Pregnant females in the control group were given water only (Veh group). The resulting litters were recognized as the first-generation F1 offspring. The F1 females were time-mated with non-sibling F1 males within the same treatment group. NP was not administered after the F0 generation. The treatment procedures for F3 offspring were identical to those for the F2 generation. The experimental results showed that the observed characteristics of the F3 NP generation had reverted to normal and resembled those of the F3 Veh generation. Thus, our study indicated that developmental exposure to NP resulted in a life-long impact on the exposed individual, but that recovery to the "normal" state was possible if further NP exposure was prevented. PMID:25106109

Chang, Ling-Ling; Wun, Wan-Song A; Wang, Paulus S

2014-09-25

19

A BBDR-HPT Axis Model for the Pregnant Rat and Fetus: Evaluation of Iodide Deficiency  

EPA Science Inventory

A biologically based dose response (BBDR) model for the hypothalamic-pituitarythyroid (HPT) axis for the pregnant rat and fetus is being developed to advance understanding of thyroid hormone disruptions and developmental neurotoxicity (DNT). The model for the pregnant rat and fet...

20

Progesterone withdrawal stimulates mammary gland tubulin polymerization in pregnant rats.  

PubMed

The size of the polymerized tubulin pool in mammary glands of late pregnant rats increased 2.4-fold 24 h after bilateral ovariectomy using a [3H]colchicine binding assay for tubulin. The total (free plus polymerized) tubulin concentration was not altered. Stimulation of tubulin polymerization as well as the induced rise in lactose content were both completely inhibited in rats that had been fitted with progesterone implants at the time of surgery. The increase in polymerized tubulin was not blocked by 17 beta-estradiol implants, although this treatment did partially inhibit the rise in tissue lactose following ovariectomy. The results indicate that increased polymerization during induced lactogenesis reflects a shift of free tubulin into the polymerized pool and that this shift is related to the withdrawal of progesterone. PMID:2986954

Loizzi, R F

1985-06-01

21

ATRAZINE DISPOSITION IN PREGNANT AND LACTATING LONG-EVANS RATS  

EPA Science Inventory

Atrazine (ATR) is a widely used herbicide shown to delay early mammary development in female offspring of gestationally exposed rats. The effects of ATR can be induced by in utero exposure and/or suckling from a dam exposed during late pregnancy, but ATR is reported to have a hal...

22

The effects of spaceflight on mammary metabolism in pregnant rats  

NASA Technical Reports Server (NTRS)

The effects of spaceflight on mammary metabolism of 10 pregnant rats was measured on Day 20 of pregnancy and after parturition. Rats were flown on the space shuttle from Day 11 through Day 20 of pregnancy. After their return to earth, glucose oxidation to carbon dioxide increased 43% (P < 0.05), and incorporation into fatty acids increased 300% (P < 0.005) compared to controls. It is unclear whether the enhanced glucose use is due to spaceflight or a response to landing. Casein mRNA and gross histology were not altered at Day 20 of pregnancy. Six rats gave birth (on Day 22 to 23 of pregnancy) and mammary metabolic activity was measured immediately postpartum. The earlier effects of spaceflight were no longer apparent. There was also no difference in expression of beta-casein mRNA. It is clear from these studies that spaceflight does not impair the normal development of the mammary gland, its ability to use glucose, nor the ability to express mRNA for a major milk protein.

Plaut, K.; Maple, R.; Vyas, C.; Munaim, S.; Darling, A.; Casey, T.; Alberts, J. R.

1999-01-01

23

Angiotensin-II-dependent changes in alpha-1 adrenoceptor vascular expression in pregnant rats.  

PubMed

Vessels from pregnant animals show a blunted response to adrenergic agonists. In this work, we explored if pregnancy reduces alpha(1)-adrenergic receptor (alpha(1)-AR)-mediated vascular smooth muscle protein expression as well as agonist-induced contraction in rat aorta, and if angiotensin II (Ang II) levels during pregnancy are related to these changes. Female Wistar rats were divided randomly into nonpregnant (NP) and pregnant groups (first week: P1, second week: P2, third week: P3). Subsets of animals were treated with captopril (5 mg kg(-1) day(-1) for 7 days; n = 6). Phenylephrine (PHE) concentration-response curves were constructed (1 x 10(-9) to 3.1 x 10(-5) mol/l) and alpha(1A)-, alpha(1B)- and alpha(1D)-AR were measured in the aorta by immunoblot. Captopril decreased alpha-AR expression in the NP group. In contrast, pregnancy decreased alpha(1A)-, alpha(1B)- and alpha(1D)-AR levels and captopril prevented this reduction. PHE sensitivity was decreased in the thoracic and abdominal aorta in the P2 group, with no changes in E(max ), and E(max) was decreased in the abdominal aorta in all experimental groups. Our results suggest that Ang II levels during pregnancy are related to a decrease in aortic alpha(1)-AR expression. The physiological meaning of this finding remains to be established. PMID:19923872

López-Sánchez, Pedro; Valdés, Ismael Bracho; Godínez-Hernández, Daniel; Bobadilla-Lugo, Rosa A

2009-01-01

24

Cadmium toxicity in the thyroid gland of pregnant rats  

SciTech Connect

The toxic effects of cadmium on the thyroid gland of pregnant rats were studied with an electron microscope and an X-ray microanalyzer. Serum levels of thyroid hormones (T3 and T4) were also analyzed. Deterioration of the rough-surfaced endoplasmic reticulum occurred in the thyroid follicular epithelium on the fifth day of cadmium treatment. Large intracellular vacuoles, which arose from dilated cisternae of the rough-surfaced endoplasmic reticulum, were fused together, and marked swelling of the mitochondria was also noted. Thyroglobulin-secreting granules at the apical cytoplasm were decreased in number. By energy dispersive X-ray microanalysis, cadmium peaks were preferentially obtained from swollen mitochondria in the follicular epithelial cells. Serum levels of T3 and T4 were significantly decreased in cadmium-treated rats dams when compared to those of controls. In the present experiment, cycloheximide also caused degenerative changes in the rough-surfaced endoplasmic reticulum and the disappearance of thyroglobulin-secreting granules. Cycloheximide is a known inhibitor of protein synthesis on cytosolic ribosomes. These results indicated that accumulated cadmium in the mitochondria of thyroid follicular epithelial cells might disturb the oxidative phosphorylation of this organelle and the loss of energy supply possibly caused the inhibition of the synthesis and release of thyroid hormones.

Yoshizuka, M.; Mori, N.; Hamasaki, K.; Tanaka, I.; Yokoyama, M.; Hara, K.; Doi, Y.; Umezu, Y.; Araki, H.; Sakamoto, Y. (Department of Anatomy, School of Medicine, University of Occupational and Environmental Health, Kitakyushu (Japan))

1991-08-01

25

Placental transport of vitamin B12 in the pregnant rat  

PubMed Central

Placental transport of vitamin B12 was studied in the pregnant rat in two series of experiments. In the first series animals were given cyanocobalamin-57Co intravenously at various stages of gestation. High specific activity tracer was used and doses of B12 were 1-2 ng per animal. The rats were killed from 15 min to 24 hr after injection and the fetuses, placentas, and serum were assayed for radioactivity. In the second series using uninjected animals, absolute amounts of vitamin B12 in fetuses and placentas were measured at stages of gestation from day 12 through day 20. There was a progressive increase in B12 transferred to the fetus during gestation. Although the quantity of vitamin B12 transported per 24 hr was proportional to fetal weight, the amount transported per gram of placenta increased tenfold from day 10 through day 19. Uptake of tracer B12 by placenta was initially rapid; however, no radioactivity appeared in the fetus until 2 hr after injection. The actual amount of B12 in placenta increased throughout gestation, and the placental concentration of B12 was greater than maternal plasma and fetal tissue concentrations at all times measured. These data suggest that the ability of placenta to transport B12 increased throughout gestation, and that the rate-limiting step in the transport process was either the passage of B12 from the maternal to the fetal side of placenta or the transfer from placenta into fetal plasma. PMID:5552402

Graber, Stanley E.; Scheffel, Ursula; Hodkinson, Barbara; McIntyre, Patricia A.

1971-01-01

26

Placentophagia in Weanling Female Laboratory Rats  

PubMed Central

Placentophagia is common in parturient mammals and offers physiological and behavioral advantages for mothers. In natural environments, weanlings are often present during the birth of younger siblings, but it is unknown if weanling rats are placentophagic or prefer placenta over other substances. To examine this, primiparous rats were remated during the postpartum estrus and weanling females remained in the nest during their mother’s next parturition. Continuous observation revealed that 58% of weanlings were placentophagic. To determine if this placentophagia occurs away from parturient mothers, weanling females still living in their natal nest were offered placenta, liver, or cake frosting in a novel chamber. They ingested more placenta and liver than frosting. Thus, many weanling female laboratory rats are placentophagic during birth of younger siblings but do not selectively prefer placenta when tested outside their natal nest. Consequences of placentophagia by weanlings are unknown, but it may promote their alloparenting or postpartum mothering. PMID:24604548

Harding, Kaitlyn M.; Lonstein, Joseph S.

2014-01-01

27

Ivermectin reduces sexual behavior in female rats.  

PubMed

Ivermectin (IVM) is an antiparasitic drug that is widely used in domestic animals. In mammals, IVM acts as a ?-aminobutyric acid (GABA) receptor agonist. This neurotransmitter plays an important role in the regulation of female sexual behavior. The present study investigated the effects of therapeutic (0.2 mg/kg) and high (1.0 mg/kg) IVM doses on female sexual behavior in physiological and pharmacological conditions. Female rats in estrus or treated with estradiol valerate to induce sexual behavior 24 h before the experiments were used. Ivermectin was administered 15 min before the sexual observations. The number of lordosis events in 10 mounts was recorded to calculate the lordosis quotient. The intensity of lordosis (0 [no lordosis], 1 [low lordosis], 2 [normal lordosis] and 3 [exaggerated lordosis]) was scored. In estrus and hormonal treated female rats, both IVM doses decreased the intensity of the lordosis reflex and the percentage of females that presented high levels of lordosis (exaggerated lordosis). However, the number of females that presented lordosis was unaltered. We conclude that in both hormonal conditions, 0.2mg/kg IVM treatment reduced female sexual behavior and the execution of the lordosis reflex. The present results may be useful for avoiding the side effects of this drug in veterinary practice. PMID:24681284

Moreira, N; Bernardi, M M; Spinosa, H S

2014-01-01

28

Effect of Acipimox on Plasma Lipids and Glucose/Insulin in Pregnant Rats  

PubMed Central

To determine how a reduction in maternal hypertriglyceridemia during late pregnancy may affect glucose/insulin relationships, pregnant and virgin rats were orally treated with acipimox, a potent antilipolytic agent. In 20-day pregnant rats receiving 80 mg of acipimox, plasma triglycerides (TG), free fatty acids (FFA), and glycerol decreased more than in virgin rats shortly after the drug (up to 7 hours), when compared with animals treated with distilled water, whereas plasma glucose level was unaffected by the treatment in either group of rats. When acipimox was given every 12 hours from day 17 to day 20 of pregnancy, plasma TG, FFA, and glycerol levels progressively increased, whereas they either decreased or did not change in virgin rats receiving the same treatment, with no effect in plasma glucose levels in either group. Fetal body weight was lower than in controls in 20-day pregnant rats that received acipimox for 3 days. On day 20 of pregnancy, 3 hours after receiving acipimox or distilled water, rats received a 2 g glucose/kg oral load and it was found that the change in plasma glucose was similar in both groups, whereas the increase in plasma insulin was greater in pregnant rats treated with acipimox. However, no difference was found in either variable after the oral glucose load in virgin rats receiving acipimox or distilled water. No differences in plasma glucose levels were found after intravenous (IV) administration of insulin in pregnant rats treated or not treated with acipimox. In conclusion, present results show that administration of acipimox during the last days of gestation inhibited lipolysis and decreased fetal weight. Over a short period of time, in pregnant rats, reductions of plasma FFA and TG after acipimox treatment improved the glucose-induced insulin release, but did not seem to have any effect in peripheral insulin resistance. PMID:12546276

Sánchez-Vera, I.; Viana, M.; Herrera, E.; Indart, A.

2002-01-01

29

Peripheral effect of a kappa opioid receptor antagonist on nociception evoked by formalin injected in TMJ of pregnant rats.  

PubMed

The effect of sex hormones on orofacial pain modulation is poorly understood. Therefore, this study aimed to investigate the effect of hormonal changes as a result of pregnancy, as well as that of the kappa (kappa) opioid receptor antagonist on female rats' sensitivity to the temporomandibular joint (TMJ) formalin test. Initially, female rats at estrus and pregnant females on day 19 of pregnancy received a 50 microl formalin (1.5%) injection in the right TMJ. The pregnant females showed a reduction in nociceptive responses to the TMJ formalin test when compared with those at estrus. Then, the selective kappa-opioid receptor antagonist nor-Binaltorphimine (nor-BNI), was co-administered with the formalin. Next, additional groups received the kappa (200 microg) receptor antagonist or 0.9% NaCl 24 hours prior to the periarticular injection of formalin. Co-administration of nor-BNI with formalin into the TMJ region had no significant effect. The pre-injection of selective kappa-opioid receptor antagonist, nor-BNI, significantly enhanced the nociceptive behavioral responses in pregnant females. When applied in the contralateral TMJ, nor-BNI did not affect the magnitude of the nociceptive response induced by formalin. It can be concluded that: 1) The increase of the sex hormone levels, as result of pregnancy, induces a reduction of nociceptive behavioral responses to the TMJ formalin test; 2) the peripheral kappa opioid receptor activation, by endogenous opioid agonists release, is involved in the antinociception to TMJ formalin test, induced by pregnancy. PMID:15620581

Arthuri, Mariana Trevisani; Gameiro, Gustavo Hauber; Tambeli, Cláudia Herrera; de Arruda Veiga, Maria Cecília Ferraz

2005-01-21

30

The UF Family of hybrid phantoms of the pregnant female for computational radiation dosimetry  

NASA Astrophysics Data System (ADS)

Efforts to assess in utero radiation doses and related quantities to the developing fetus should account for the presence of the surrounding maternal tissues. Maternal tissues can provide varying levels of protection to the fetus by shielding externally-emitted radiation or, alternatively, can become sources of internally-emitted radiation following the biokinetic uptake of medically-administered radiopharmaceuticals or radionuclides located in the surrounding environment—as in the case of the European Union’s SOLO project (Epidemiological Studies of Exposed Southern Urals Populations). The University of Florida had previously addressed limitations in available computational phantom representation of the developing fetus by constructing a series of hybrid computational fetal phantoms at eight different ages and three weight percentiles. Using CT image sets of pregnant patients contoured using 3D-DOCTORTM, the eight 50th percentile fetal phantoms from that study were systematically combined in RhinocerosTM with the UF adult non-pregnant female to yield a series of reference pregnant female phantoms at fetal ages 8, 10, 15, 20, 25, 30, 35 and 38?weeks post-conception. Deformable, non-uniform rational B-spline surfaces were utilized to alter contoured maternal anatomy in order to (1) accurately position and orient each fetus and surrounding maternal tissues and (2) match target masses of maternal soft tissue organs to reference data reported in the literature.

Maynard, Matthew R.; Long, Nelia S.; Moawad, Nash S.; Shifrin, Roger Y.; Geyer, Amy M.; Fong, Grant; Bolch, Wesley E.

2014-08-01

31

Effect of Transverse Aortic Constriction on Cardiac Structure, Function and Gene Expression in Pregnant Rats  

PubMed Central

Background There is an increased risk of heart failure and pulmonary edema in pregnancies complicated by hypertensive disorders. However, in a previous study we found that pregnancy protects against fibrosis and preserves angiogenesis in a rat model of angiotensin II induced cardiac hypertrophy. In this study we test the hypothesis that pregnancy protects against negative effects of increased afterload. Methods Pregnant (gestational day 5.5–8.5) and non-pregnant Wistar rats were randomized to transverse aortic constriction (TAC) or sham surgery. After 14.2±0.14 days echocardiography was performed. Aortic blood pressure and left ventricular (LV) pressure-volume loops were obtained using a conductance catheter. LV collagen content and cardiomyocyte circumference were measured. Myocardial gene expression was assessed by real-time polymerase chain reaction. Results Heart weight was increased by TAC (p<0.001) but not by pregnancy. Cardiac myocyte circumference was larger in pregnant compared to non-pregnant rats independent of TAC (p?=?0.01), however TAC per se did not affect this parameter. Collagen content in LV myocardium was not affected by pregnancy or TAC. TAC increased stroke work more in pregnant rats (34.1±2.4 vs 17.5±2.4 mmHg/mL, p<0.001) than in non-pregnant (28.2±1.7 vs 20.9±1.5 mmHg/mL, p?=?0.06). However, it did not lead to overt heart failure in any group. In pregnant rats, ?-MHC gene expression was reduced by TAC. Increased in the expression of ?-MHC gene was higher in pregnant (5-fold) compared to non-pregnant rats (2-fold) after TAC (p?=?0.001). Nine out of the 19 genes related to cardiac remodeling were affected by pregnancy independent of TAC. Conclusions This study did not support the hypothesis that pregnancy is cardioprotective against the negative effects of increased afterload. Some differences in cardiac structure, function and gene expression between pregnant and non-pregnant rats following TAC indicated that afterload increase is less tolerated in pregnancy. PMID:24586871

Songstad, Nils Thomas; Johansen, David; How, Ole-Jacob; Kaaresen, Per Ivar; Ytrehus, Kirsti; Acharya, Ganesh

2014-01-01

32

Opposite metabolic response to fenofibrate treatment in pregnant and virgin rats  

Microsoft Academic Search

The level of maternal circulating triglycerides during late pregnancy has been correlated to newborns' weight in humans. To investigate the response to fenofi- brate, a hypotriglyceridemic agent, in pregnant rats, 0, 100, or 200 mg of fenofibrate\\/kg body weight as oral doses were given twice a day from day 16 of gestation and studied at day 20. Virgin rats were

Ana Soria; Carlos Bocos; Emilio Herrera

33

Selective arterial embolisation of bilateral angiomyolipomata in a symptomatic pregnant female.  

PubMed

Renal angiomyolipoma (RA) is a rare benign tumour that can expand rapidly during pregnancy due to oestrogen and other hormonal factors. Complications associated with expanding renal angiomyolipomata are spontaneous retroperitoneal haemorrhage secondary to acute rupture and thrombosis of the renal vein or inferior vena cava. MRI is recommended for diagnostic purposes in pregnancy; however, this modality is not always readily available. In the present report, we describe the first case of bilateral selective arterial embolisation for renal angiomyolipomata presenting symptomatically in a previously healthy pregnant female. PMID:24259526

Davis, Niall F; Kelly, Rory; Lee, Michael J; Mohan, Ponnusamy

2013-01-01

34

Protective effect of Petroselinum crispum extract in abortion using prostadin-induced renal dysfunction in female rats  

PubMed Central

Objective: Present study investigated the effects of parsley extract on pregnant rat kidneys which have undergone clinical abortion using prostaglandins. The renal protective effect of parsley extract was evaluated in pregnant rats which had an abortion. Parsley was used due to its antioxidant properties. Materials and Methods: Fifty-four female rats were divided in 9 groups of 6: control pregnant, two pregnant groups which received parsley extract and prostadin, two non-pregnant groups treated with parsley extract and prostadin, a group administered with both treatments, and three groups which received parsley extract in pre-implantation, implantation, and post-implantation periods of embryos. Ethanolic extract (5 mg/kg) was given daily to animals for 18 days of pregnancy period. Parameters such as malondialdehyde (MDA), total antioxidant statues (TAS), creatinine, and urea were measured using biochemical assays. Histopathologic studies were also done with Hematoxylin-Eosin staining method. Results: After 18 days of treatment, significant differences were observed in serum creatinine, urea, and MDA and TAS levels. Kidney cross-sections showed edema in prostadin-treated rats while improvements in parsley + prostadin -treated rats were observed. Conclusion: These results suggested that ethanolic extract of Petroselinum crispum reduced the dysfunction in rats kidney caused by prostadin-induced abortion and could have beneficial effect in reducing the progression of prostaglandin-induced edema. PMID:25386393

Rezazad, Maryam; Farokhi, Farah

2014-01-01

35

Testosterone and muscle hypertrophy in female rats  

NASA Technical Reports Server (NTRS)

The effects of chronic treatment with testosterone propionate (TP) on compensatory muscle hypertropy in female rats are examined. The 48 female rats were placed in one of four test groups: (1) no overload (synergist removal), no TP, (2) overload, no TP, (3) no overload + TP, and (4) overload + TP. The technique used to administer the TP is described. The preparation of the plantaris muscle, the analysis of pyruvate oxidation and the determination of malate and lactate dehydrogenases and the noncollogen protein are explained. The results which reveal the effect of overload and TP on body weight, noncollogen protein concentration, lactate and malate dehydrogenase activities, and pyruvate oxidation are presented and discussed. It is concluded that in terms of body weight, protein content, pyruvate, glycolysis, and oxidative metabolisms chronic TP treatments do not change compensatory muscle hypertropy.

Kuhn, F. E.; Max, S. R.

1985-01-01

36

Does L-arginine availability during the early pregnancy alters the immune response of Trypanosoma cruzi infected and pregnant Wistar rats?  

PubMed

Chagas disease induces a strong immune response and L-arginine is an essential amino acid which plays an important role in homeostasis of the immune system. The aims of this study were to evaluate parasitemia, corticosterone levels, production of nitric oxide (NO), fetal morphological measurements, and histology of heart and placenta. Twenty pregnant Wistar rats (180-220 g) were grouped in: pregnant control (PC), pregnant control and L-arginine supplied (PCA), pregnant infected (PI), pregnant infected and L-arginine supplied (PIA). Females were infected with 1×10(5) trypomastigotes of the Y strain (3rd day of pregnancy). Animals were supplied with 21 mg of L-arginine/kg/day during 14 days. PIA showed significant decreased levels of corticosterone and parasitemia. For control groups, any alteration in NO production was found with L-arginine supplementation; for PIA, enhanced nitrite concentrations were observed as compared to PI. Weights and lengths of fetuses were higher in L-arginine treated and infected pregnant rats as compared to untreated ones. Placental weight from the PIA group was significantly increased when compared to PI. In L-arginine treated animals, cardiac tissue showed reduced amastigote burdens. PIA and PI displayed similar placental parasitism. Based on these results, L-arginine supplementation may be potentially useful for the protection against Trypanosoma cruzi during pregnancy. PMID:24786713

da Costa, Cássia Mariana Bronzon; de Freitas, Murilo Rodrigues Barbosa; Brazăo, Vânia; dos Santos, Carla Domingues; Sala, Miguel Angel; do Prado Júnior, José Clovis; Abrahăo, Ana Amélia Carraro

2014-07-01

37

PROLACTIN-ADRENAL INTERACTIONS IN THE IMMATURE FEMALE RAT  

E-print Network

University, .llichigan (U. S. A.).) Both the adrenal glands and prolactin have been shown to participate relationship between prolactin and the adrenal glands in the immature female rat. Sprague-Dawley rats were usedPROLACTIN-ADRENAL INTERACTIONS IN THE IMMATURE FEMALE RAT Marie GELATO, J. DIBBET* S. MARSHALL J

Paris-Sud XI, Université de

38

ALTERED ZN STATUS BY A-HEDERIN IN THE PREGNANT RAT AND ITS RELATIONSHIP TO ADVERSE DEVELOPMENTAL OUTCOME  

EPA Science Inventory

The hypothesis that hepatic metallothionein (MT) induction in the pregnant animal results in a Zn deficiency in the embryo was tested by treating pregnant rats with a-hederin, reported to induce MT in rat liver. orphological development was assessed in term fetuses. ingle dose of...

39

Disposition of Orally Administered 2,2Bis(4-hydroxyphenyl)propane (Bisphenol A) in Pregnant Rats and the Placental Transfer to Fetuses  

Microsoft Academic Search

We studied the disposition of bisphenol A (BPA) in pregnant female F344\\/DuCrj(Fischer) rats and its placental transfer to fetuses after a single oral administration of 1 g\\/kg BPA dissolved in propylene glycol. BPA in maternal blood, liver, and kidney reached maximal concentrations (14.7, 171, and 36µg\\/g) 20 min after the administration and gradually decreased. The levels were 2-5% of the

Osamu Takahashi; Shinshi Oishi

2000-01-01

40

Mechanical properties of normotensive and hypertensive female rat carotid arteries  

E-print Network

female rat carotid arteries to applied loads considering active and passive responses in the longitudinal and circumferential directions, and (3) to compare the female response in both groups to data available for males. The first objective provides...

Smith, Katherine Elizabeth

2002-01-01

41

EFFECTS OF BROMODICHLOROMETHANE (BDCM) ON EX VIVO LUTEAL FUNCTION IN THE PREGNANT F344 RAT  

EPA Science Inventory

EFFECTS OF BROMODICHLOROMETHANE (BDCM) ON EX VIVO LUTEAL FUNCTION IN THE PREGNANT F344 RAT. S. R. Bielmeier1, A. S. Murr2, D. S. Best2, J. M. Goldman2, and M. G. Narotsky2 1 Curriculum in Toxicology, Univ. of North Carolina, Chapel Hill, NC, USA 2 Reproductive T...

42

DEVELOPMENTAL EFFECTS OF TRICHLOROACETONITRILE ADMINISTERED IN CORN OIL TO PREGNANT LONG-EVANS RATS  

EPA Science Inventory

Trichloroacetonitrile (TCAN) is a by-product of the chlorine disinfection of water containing natural organic material. When administered by gavage to pregnant Long-Evans rats in a medium-chain triglyceride vehicle, tricaprylin oil (Tricap), at a volume of 10 ml/kg, TCAN induced ...

43

Time of birth and daily activity mediated by feeding rhythms in the pregnant rat  

E-print Network

Time of birth and daily activity mediated by feeding rhythms in the pregnant rat M. J. BOSC, Agnčs, France. Summary. The temporal relationship between time of birth and daily physical activity has been for three hours per day from 2, 9, 14 and 21 h, respectively. In groups 9PF and 14PF, births were clustered

Boyer, Edmond

44

FAILURE OF PHENOBARBITAL TO INDUCE RAT HEPATIC MICROSOMAL UDP-GLUCURONYLTRANSFERASE TOWARD PHENOLPHTHALEIN  

EPA Science Inventory

Phenobarbital pretreatment was found not to induce Triton X-100 activated hepatic microsomal neonatal UDP-glucuronyltransferase activity towards phenolphthalein in male, female and pregnant female rats....

45

Thermal physiology of pregnant and lactating female and male long-eared bats, Nyctophilus geoffroyi and N. gouldi  

Microsoft Academic Search

During roosting in summer, reproductive female bats appear to use torpor less frequently and at higher body temperatures (T\\u000a b) than male bats, ostensibly to maximise offspring growth. To test whether field observations result from differences in thermal\\u000a physiology or behavioural thermoregulation during roosting, we measured the thermoregulatory response and energetics of captive\\u000a pregnant and lactating female and male long-eared

Christopher Turbill; Fritz Geiser

2006-01-01

46

Fever suppression in near-term pregnant rats is dissociated from LPS-activated signaling pathways.  

PubMed

Near-term pregnant rats show a suppressed fever response to LPS that is associated with reduced induction of cyclooxygenase (COX)-2 in the hypothalamus. The objective of this study is to explore whether the LPS-activated signaling pathways in the fever-controlling region of the hypothalamus are specifically altered at near term. Three rat groups consisting of 15-day pregnant rats, near-term 21- to 22-day pregnant rats, and day 5 lactating rats were injected with a febrile dose of LPS (50 mug/kg ip). The hypothalamic preoptic area and the organum vasculosum of the lamina terminalis (OVLT) were collected 2 h after LPS injection. The activation of three transcription modulators, nuclear factor-kappaB (NF-kappaB), extracellular signal-regulated kinase 1/2 (ERK1/2), and signal transducer and activator of transcription 5 (STAT5), was assessed using semiquantitative Western blot analysis. LPS activated the NF-kappaB pathway in all rat groups, and this response was not altered at near term. ERK1/2 and STAT5 were constitutively activated during all reproductive stages, and their levels were not significantly affected by LPS injection. Plasma levels of the proinflammatory cytokines (IL-1beta, IL-6, TNF-alpha, and IFN-gamma), anti-inflammatory cytokines (IL-4, IL-10, and IL-1 receptor antagonist), and corticosterone were unaffected during the three reproductive stages after LPS challenge. We observed a sharp decrease in the expression of a prostaglandin-producing enzyme called lipocalin-prostaglandin D2 synthase in near-term pregnant and lactating rats. Thus fever suppression at near term is not due to an alteration in either LPS-activated intracellular signaling pathways or LPS-induced pro- and anti-inflammatory cytokine production. PMID:16037126

Mouihate, A; Ellis, S; Harré, E-M; Pittman, Q J

2005-11-01

47

Protective effects of Allium sativum against defects of hypercholesterolemia on pregnant rats and their offspring  

PubMed Central

Sixty fertile female and male albino rats of Wistar strain (I male/ 3 females) were used in the present study. The females were divided into four groups of ten rats each. Group 1 received water and standard feeds for thirty-four days. Group 2 was fed with a cholesterol-containing diet (1%) for two weeks prior to onset of gestation and maintained administration till parturition, produce atherosclerosis (34 days). Group 3 received intragastric administration of 100mg homogenate of garlic (Allium sativum)/kg body weight for three weeks prior to onset of gestation as well as throughout the gestation period. Group 4 intragastrically administered garlic for one week of group B and maintained with combined garlic-treatment for the mentioned period. At parturition, the pregnant were sacrificed and serum total cholesterol (TCL), triglycerides (TG), HDL, LDL and creatine kinase activity (CK) were determined. The total numbers of offspring were recorded and examined morphological for congenital abnormalities. Biopsies of heart and dorsal aorta of both pregnant and their offspring (1 day-age) were processed for investigation at light and transmission electron microscopy. The skeleton of the newborn of different experimental groups were stained with alizarin red s and mor-phometric assessment of mandibular and appendicular bone length. The study revealed that the myocardium of atherosclerotic mother exhibited leuhkocytic inflammatory cell infiltration associated with necrosis, eosinophilia of myocardiai fibers, and edema of blood vessels. Ultrastructural studies revealed swelling of mitochondria, disruption of cristae in the myocardiai muscle fibers. The dorsal aorta possessed accumulation of extra-cellular lipid in intima lining of endothelium. The collagenous fibrils in the tunica adventitia became fragile and loosely separated from each other. Numerous foamy lipid loaden cells were detected within the tunica intima causing deterioration of the elastic fibers, resulting in fibrinoid necrosis. Oral supplementation with Allium sativum (100 mg/ kg) ameliorated these effects in myocardium muscle of mothers and offspring; however the dorsal aorta of mothers showed partial amelioration. Hypercholesterolemic mothers exhibited marked alterations in serum TCL, TG, LDL and CK activity. Supplementation with Allium sativum ameliorated the drastic biochemical alterations. Concerning pregnancy, hypercholesterolemia increased the incidence of abortion and abnormalities of the newborn including decreased body weight, reduced ossification of axial (mandible) and appendicular bones. All these effects were markedly ameliorated by supplementation with Allium sativum. The author finally concluded that hypercholesterolemia exhibits pathological alterations of myocardiai muscles reducing its optimal capacity for pumping blood to different body organs along with atherosclerosis of dorsal aorta which intern affect the progress of gestation and development of both morphological and skeletal abnormalities. Allium sativum-supplementation leads to amelioration of both mother and their offspring investigated parameters as a result of its antioxidant activity. PMID:20607041

El-Sayyad, Hassan I; Abou-El-Naga, Amoura M; Gadallah, Abdelalim A; Bakr, Iman H

2010-01-01

48

Fetal programming of adult hypertension in female rat offspring exposed to androgens in utero  

PubMed Central

Aims The influence of prenatal factors on the development of arterial hypertension has gained considerable interest in recent years. We examined the effects of prenatal testosterone treatment on blood pressure in adult female rats. Further, to define the mechanisms whereby blood pressure may be raised, we examined vascular endothelial function and nitric oxide synthesis. Methods and Results Testosterone propionate (0.5mg/kg/day;SC) or vehicle was administered to pregnant Sprague-Dawley rats from gestational day 15–19. Maternal feed intake and plasma levels of steroid hormones were measured in the dams. In the female offspring, birth weight, growth rate, blood pressure, vascular reactivity, eNOS expression, and nitric oxide production were examined. In the pregnant rats, testosterone-treatment increased plasma testosterone levels by 2-fold without any significant changes in 17?-estradiol, progesterone and corticosterone levels. Testosterone-treatment did not affect maternal feed intake. The pups born to testosterone mothers were smaller in size but exhibited catch-up growth. The blood pressure in the testosterone offspring at 6 months of age was significantly higher compared to controls. Endothelium-intact mesenteric arteries from testosterone group exhibited increased contractile responses to phenylephrine, decreased vasodilation to acetylcholine and unaltered responses to sodium nitroprusside in comparison to control rats. Testosterone rats demonstrated decreased expression for eNOS, and reduced nitric oxide production. Conclusions Our data show that elevated plasma maternal testosterone levels: (1) causes low birth weight followed by catch-up growth and hypertension in female offspring; (2) alters endothelium-dependent vascular responses. The endothelial dysfunction is associated with decreased activity/expression of eNOS. PMID:21450421

Sathishkumar, K.; Elkins, Rebekah; Yallampalli, Uma; Balakrishnan, Meena; Yallampalli, Chandrasekhar

2011-01-01

49

Toxicokinetic aspects of thiocyanate after oral exposure to cyanide in female Wistar rats in different physiological states.  

PubMed

Cyanide (CN) is an ion that has been well studied in toxicology and has been associated with several intoxication episodes: the ingestion of contaminated foods and water, chemical war, suicides, homicides, occupational exposures and the use of certain medicines. The aim of the present study was to determine the toxicokinetic parameters of thiocyante (SCN), the main metabolite of CN, after oral administration of potassium cyanide (KCN) to female rats at diestrus, gestational and lactational periods. Female Wistar rats were divided into three equal groups: virgins in the diestrus phase of the estrus cycle, females at the 14th day of gestation and females at the 14th day of lactation. Each group of rats received 3.0?mg of potassium cyanide per kilogram (KCN/kg body weight) by gavage, and blood was collected at several time points. We also collected amniotic fluid from pregnant rats and milk from the nursing rats to analyze thiocyanate concentration. The results showed that SCN levels were significantly increased in serum, milk and amniotic fluid after administration of KCN. In conclusion, the results of the present study evidence that the metabolism of CN varies greatly considering the physiologic state of the female rat, being females at estrus probably more exposed by these substances than at gestation and lactation because in these states there are other compartments, fetus and milk, which may capture these substances, as demonstrated by the V(d) values. PMID:23841473

de Sousa, Altamir Benedito; Górniak, Silvana Lima

2014-01-01

50

Effect of afobazole administered to pregnant rats during organogenesis on prenatal development of fetuses.  

PubMed

Experiments on pregnant rats have demonstrated the absence of damaging effect of Afobazole administered during the antenatal period on organogenesis in fetuses. Afobazole in a dose of 5 mg/kg given to pregnant rats on gestation days 6-16 reduced pre- and post-implantation fetal mortality and improved fertility; 20-day-old embryos had no developmental abnormalities and did not differ from controls by craniocaudal size, body weight, and skeleton ossification. Afobazole in a dose of 100 mg/kg reduced pre- and post-implantation fetal mortality, but had no effect on fertility. No congenital malformations were found in the fetuses, but they were characterized by lower craniocaudal size, body weight, and number of ossification foci in the sternum and spine. PMID:25403398

Bugayova, L I; Denisova, T D; Morozova, Yu A; Sergeeva, S A; Kharlamov, I V

2014-11-01

51

The effects of pregnancy, lactation, and primiparity on object-in-place memory of female rats.  

PubMed

Maternal physiology and behavior change dramatically over the course of pregnancy to nurture the fetus and prepare for motherhood. Further, the experience of motherhood itself continues to influence brain functioning well after birth, shaping behavior to promote the survival of offspring. To meet these goals, cognitive abilities, such as spatial memory and navigation, may be enhanced to facilitate foraging behavior. Existing studies on pregnant and maternal rats demonstrate enhanced cognitive function in specific spatial domains. We adopted a novel object-in-place task to assess the ability of female rats to integrate information about specific objects in specific locations, a critical element of foraging behavior. Using a longitudinal design to study changes in spatial memory across pregnancy and motherhood, an advantage in the object-in-place memory of primiparous female rats compared to nulliparous females emerged during lactation not during pregnancy, and was maintained after weaning at 42 days postpartum. This enhancement was not dependent on the non-mnemonic variables of anxiety or neophobia. Parity did not affect the type of learning strategy used by females to locate a cued escape platform on a dual-solution water maze task. Results indicate that the enhancement of object-in-place memory, a cognitive function that facilitates foraging, emerged after pregnancy during the postpartum period of lactation and persisted for several weeks after weaning of offspring. PMID:24211441

Cost, Katherine Tombeau; Lobell, Thomas D; Williams-Yee, Zari N; Henderson, Sherryl; Dohanich, Gary

2014-01-01

52

SAF values for internal photon emitters calculated for the RPI-P pregnant-female models using Monte Carlo methods.  

PubMed

Estimates of radiation absorbed doses from radionuclides internally deposited in a pregnant woman and her fetus are very important due to elevated fetal radiosensitivity. This paper reports a set of specific absorbed fractions (SAFs) for use with the dosimetry schema developed by the Society of Nuclear Medicine's Medical Internal Radiation Dose (MIRD) Committee. The calculations were based on three newly constructed pregnant female anatomic models, called RPI-P3, RPI-P6, and RPI-P9, that represent adult females at 3-, 6-, and 9-month gestational periods, respectively. Advanced Boundary REPresentation (BREP) surface-geometry modeling methods were used to create anatomically realistic geometries and organ volumes that were carefully adjusted to agree with the latest ICRP reference values. A Monte Carlo user code, EGS4-VLSI, was used to simulate internal photon emitters ranging from 10 keV to 4 MeV. SAF values were calculated and compared with previous data derived from stylized models of simplified geometries and with a model of a 7.5-month pregnant female developed previously from partial-body CT images. The results show considerable differences between these models for low energy photons, but generally good agreement at higher energies. These differences are caused mainly by different organ shapes and positions. Other factors, such as the organ mass, the source-to-target-organ centroid distance, and the Monte Carlo code used in each study, played lesser roles in the observed differences in these. Since the SAF values reported in this study are based on models that are anatomically more realistic than previous models, these data are recommended for future applications as standard reference values in internal dosimetry involving pregnant females. PMID:18697546

Shi, C Y; Xu, X George; Stabin, Michael G

2008-07-01

53

SAF values for internal photon emitters calculated for the RPI-P pregnant-female models using Monte Carlo methods  

SciTech Connect

Estimates of radiation absorbed doses from radionuclides internally deposited in a pregnant woman and her fetus are very important due to elevated fetal radiosensitivity. This paper reports a set of specific absorbed fractions (SAFs) for use with the dosimetry schema developed by the Society of Nuclear Medicine's Medical Internal Radiation Dose (MIRD) Committee. The calculations were based on three newly constructed pregnant female anatomic models, called RPI-P3, RPI-P6, and RPI-P9, that represent adult females at 3-, 6-, and 9-month gestational periods, respectively. Advanced Boundary REPresentation (BREP) surface-geometry modeling methods were used to create anatomically realistic geometries and organ volumes that were carefully adjusted to agree with the latest ICRP reference values. A Monte Carlo user code, EGS4-VLSI, was used to simulate internal photon emitters ranging from 10 keV to 4 MeV. SAF values were calculated and compared with previous data derived from stylized models of simplified geometries and with a model of a 7.5-month pregnant female developed previously from partial-body CT images. The results show considerable differences between these models for low energy photons, but generally good agreement at higher energies. These differences are caused mainly by different organ shapes and positions. Other factors, such as the organ mass, the source-to-target-organ centroid distance, and the Monte Carlo code used in each study, played lesser roles in the observed differences in these. Since the SAF values reported in this study are based on models that are anatomically more realistic than previous models, these data are recommended for future applications as standard reference values in internal dosimetry involving pregnant females.

Shi, C. Y.; Xu, X. George; Stabin, Michael G. [Department of Radiation Oncology, University of Texas Health Science Center, San Antonio, Texas 78229 (United States); Nuclear Engineering and Engineering Physics Program, Rensselaer Polytechnic Institute, Room 1-11, NES Building, Tibbits Avenue, Troy, New York 12180 (United States); Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee 37232-2675 (United States)

2008-07-15

54

Mammary gland proliferation in female rats: effects of the estrous cycle, pseudo-pregnancy and age.  

PubMed

Assessment of mammary gland proliferation in rats is an important endpoint in preclinical safety studies of pharmaceutical compounds. However, existing data on mammary gland proliferation in rats during the estrous cycle is conflicting, and it is unknown whether mammary gland proliferation differs between young and mature female virgin rats. Additionally, it is unclear which of the commonly applied markers of proliferating cells that is optimal for assessment of rat mammary gland proliferation. In this study the caudal thoracic, the abdominal and the cranial inguinal (i.e., the 3rd the 4th and the 5th) mammary gland were collected from 29 young and 26 mature non-treated, virgin female Sprague Dawley rats. Estrous cycle stage was determined from repeated vaginal smears and histological examination of the reproductive organs. Proliferation of mammary epithelium was assessed by immunohistochemistry using three markers: PCNA, Ki67, and BrdU. Proliferation of the mammary epithelium occurred mainly in the terminal end buds in the young animals. Epithelial proliferation was significantly increased during metestrus compared to the other phases. Mammary gland proliferation in pseudo-pregnant females was increased compared to proestrus, estrus and diestrus, but not metestrus. Except during estrus no difference in mammary gland proliferation was observed between young and mature female rats, and no significant differences was observed between different mammary glands. The percentages of PCNA-, Ki67- and BrdU-positive epithelial cells were significantly correlated. In conclusion, the variation in normal proliferation between estrous cycle stages and animals with an irregular estrous cycle should be considered in toxico-pathological studies of mammary gland proliferation. PMID:20951558

Hvid, Henning; Thorup, Inger; Sjögren, Ingrid; Oleksiewicz, Martin B; Jensen, Henrik E

2012-05-01

55

Polycystic ovary syndrome resembling histopathological alterations in ovaries from prenatal androgenized female rats  

PubMed Central

Background The polycystic ovary syndrome (PCOS) affects approximately 6-10% of women of reproductive age and is characterized by chronic anovulation and hyperandrogenism. However, a comprehensive understanding of the mechanisms that dictate androgen overproduction is lacking, which may account for inconsistencies between measures of androgen excess and clinical presentation in individual cases. Methods A rat model of PCOS was established by injecting dehydroepiandrosterone sulfoconjugate (DHEAS) into pregnant females. Rats were administered with DHEAS (60?mg/kg/d) subcutaneously (s.c.) for all 20?days of pregnancy (Group A), or for the first 10?days (Group B), or from day 11 to day 20 (Group C). Controls were administered with injection oil (0.2?ml/day) s.c. throughout pregnancy (Group D). The litter rate, abortion rate, and offspring survival rate in each group were recorded. Serum androgen and estrogen were measured and the morphological features of the ovaries were examined by light and electron microscopy in the offspring of each group. Results We found that rats injected with DHEAS throughout pregnancy (group A) lost fertility. Rats injected with DHEAS during early pregnancy (group B) exhibited more serious aberrations in fertility than both Group C, in which rats were injected with DHEAS during late pregnancy (P?female offspring in Group B, C and D (P?female offspring in the three groups was observed. Conclusions Our results indicate that androgen excess during pregnancy can decrease rat fertility. Excess androgen at the early stage of pregnancy causes high reproductive toxicity, leading to abnormality of ovarian morphology and functions in female offspring. PMID:22607720

2012-01-01

56

Apoptotic genes expression in placenta of clubfoot-like fetus pregnant rats  

PubMed Central

Objective: To investigate the apoptotic gene expression of placenta in an all-trans-retinoic acid (ATRA) induced fetus congenital clubfoot pregnant rat model. Methods: Sprague-Dawley (SD) rats were divided randomly into ATRA-exposed group and control group. On day 10 of pregnancy, a dose of 120 mg/kg ATRA dissolved in mineral oil was given intragastrically to the rats in the ATRA-exposed group and equivalent volume of mineral oil was given intragastrically to the control rats. Fetuses were delivered on day 20 of pregnancy, the placenta was collected for the pathological and biochemical analysis. Results: Clubfoot-like deformity fetuses were observed in the ATRA-exposed group and none with deformity was found in the control group. The pro-apoptosis in placenta of ATRA-exposed group was measured by flow cytometry. Moreover, compared with the control group, lower expression of Bcl-2 and higher expression of BAX were found in the ATRA-exposed group in both mRNA and protein level. Immunohistochemical labeling of Bcl-2 in the control group was more intense while BAX labeling in the ATRA-exposed group was more intense. Additionally, the caspase-3 activity was also significantly increased in the ATRA-exposed group than control group. Conclusion: In our research, we found a pro-apoptosis in placenta in the ATRA-exposed pregnant rats, indicating a possible association between placental apoptosis and congenital clubfoot. PMID:24551289

Jiang, Bo; Zhang, Zhiqun; Zheng, Pengfei; Ju, Li; Tang, Kai; Lou, Yue

2014-01-01

57

Adaptive Plasticity of Vaginal Innervation in Term Pregnant Rats  

PubMed Central

Changes in reproductive status place varied functional demands on the vagina. These include receptivity to male intromission and sperm transport in estrus, barrier functions during early pregnancy, and providing a conduit for fetal passage at parturition. Peripheral innervation regulates vaginal function, which in turn may be influenced by circulating reproductive hormones. We assessed vaginal innervation in diestrus and estrus (before and after the estrous cycle surge in estrogen), and in the early (low estrogen) and late (high estrogen) stages in pregnancy. In vaginal sections from cycling rats, axons immunoreactive for the pan-neuronal marker protein gene product 9.5 (PGP 9.5) showed a small reduction at estrus relative to diestrus, but this difference did not persist after correcting for changes in target size. No changes were detected in axons immunoreactive for tyrosine hydroxylase (sympathetic), vesicular acetylcholine transporter (parasympathetic), or calcitonin gene-related peptide and transient receptor potential vanilloid type 1 (TRPV-1; sensory nociceptors). In rats at 10 days of pregnancy, innervation was similar to that observed in cycling rats. However, at 21 days of pregnancy, axons immunoreactive for PGP 9.5 and each of the subpopulation-selective markers were significantly reduced both when expressed as percentage of sectional area or after correcting for changes in target size. Because peripheral nerves regulate vaginal smooth muscle tone, blood flow, and pain sensitivity, reductions in innervation may represent important adaptive mechanisms facilitating parturition. PMID:21666101

Liao, Zhaohui; Smith, Peter G.

2011-01-01

58

Prostaglandin F receptor expression in intrauterine tissues of pregnant rats  

PubMed Central

In this investigation, we studied the expression and localization of rat prostaglandin F (FP) receptor in uterine tissues of rats on gestational Days 10, 15, 18, 20, 21, 21.5 and postpartal Days 1 and 3 using Western blotting analysis, real-time PCR, and immunohistochemistry. A high level of immunoreactivity was observed on gestational Days 20, 21, and 21.5 with the most significant signals found on Day 20. FP receptor protein was expressed starting on gestational Day 15, and a fluctuating unsteady increase was observed until delivery. Uterine FP receptor mRNA levels were low between Days 10 and 18 of gestation (p < 0.05). The transcript level increased significantly on Day 20 and peaked on Day 21.5 just before labor (p < 0.05). There was a positive correlation between FP receptor mRNA expression and serum estradiol levels (rs = 0.78; p < 0.01) along with serum estradiol/progesterone ratios (rs = 0.79; p < 0.01). In summary, we observed an increase FP receptor expression in rat uterus with advancing gestation, a marked elevation of expression at term, and a concominant decrease during the postpartum period. These findings indicate a role for uterine FP receptors in the mediation of uterine contractility at term. PMID:24136214

Kanca, Halit; Yar, Atiye Seda; Helvacio?lu, Fatma; Menev?e, Sevda; Çalgüner, Engin; Erdo?an, Deniz

2014-01-01

59

Female ultrasonic vocalizations have no incentive value for male rats.  

PubMed

Ultrasonic vocalizations (USVs) are emitted in response to a sexual partner before, during, and after copulation. These vocalizations are the so-called 50-kHz USVs and can be subdivided into flat and frequency-modulated (FM) 50-kHz trill calls. In the present series of experiments, the potential unconditioned and conditioned incentive properties of female 50-kHz USVs for male rats were examined. USVs were recorded from sexually receptive females during the precopulatory phase. A complete 10-min song, or single flat or FM trill calls were selected as auditory stimuli for Experiments 1 and 2. As FM trill calls, a multistep call was used in Experiments 1 and 2a, and an upward ramp call was used in Experiment 2b. The auditory stimuli were played back with a loudspeaker to naďve and sexually experienced male rats in a sexual incentive motivation test. The odor of a sexually receptive female rat was also used as an incentive stimulus for comparison. In a third experiment, a devocalized female, a sham female and a male rat were used as incentive stimuli. It was found that the auditory stimuli did not induce approach behavior in naďve and sexually experienced male rats, but the olfactory stimulus did. In addition, the males spent equal amounts of time in the vicinity of devocalized and vocalizing females. These data show that 50-kHz USVs neither are unconditioned nor conditioned incentives for male rats. PMID:23458403

Snoeren, Eelke M S; Ĺgmo, Anders

2013-06-01

60

Conditioned mate-guarding behavior in the female rat.  

PubMed

Female and male rats are often described as having a promiscuous mating strategy, yet simple Pavlovian conditioning paradigms, in which a neutral odor or strain-related cues are paired with preferred sexual reward states during an animal's first sexual experiences, shift this strategy toward copulatory and mate preferences for partners bearing the familiar odor or strain cue. We examined whether female rats given exclusive rewarding copulation with one particular male would display mate-guarding behavior, a strong index of monogamous mating. Ovariectomized, hormone-primed female Long-Evans rats were given their first 10 paced sexual experiences at 4-day intervals with a particular unscented male of the same strain. A final test was conducted in an open field 4-days later in which the primed, partnered female was given access to the male partner and a fully-primed competitor female. In this situation, the partnered females mounted the competitor female repeatedly if she came near the vicinity of the male. This behavior prevented the male from copulating with the competitor, and was not displayed if partnered females could not pace the rate of copulatory behavior efficiently during the training trials, nor was it displayed by the competitor females. Fos expression was examined in both the partnered and competitor females after the final open field test. Partnered females had significantly higher expression within the supraoptic nucleus and nucleus accumbens shell compared to partnered females that did not develop this behavior or competitor females. These data show that females engaged in paced copulation with the same male display mate-guarding when exposed to that male and a competitor female. Increased activation of the SON and NAc may underlie this behavior. PMID:24768651

Holley, Amanda; Shalev, Shy; Bellevue, Shannon; Pfaus, James G

2014-05-28

61

Disruption of Reproductive Aging in Female and Male Rats by Gestational Exposure to Estrogenic Endocrine Disruptors  

PubMed Central

Polychlorinated biphenyls (PCBs) are industrial contaminants and known endocrine-disrupting chemicals. Previous work has shown that gestational exposure to PCBs cause changes in reproductive neuroendocrine processes. Here we extended work farther down the life spectrum and tested the hypothesis that early life exposure to Aroclor 1221 (A1221), a mixture of primarily estrogenic PCBs, results in sexually dimorphic aging-associated alterations to reproductive parameters in rats, and gene expression changes in hypothalamic nuclei that regulate reproductive function. Pregnant Sprague Dawley rats were injected on gestational days 16 and 18 with vehicle (dimethylsulfoxide), A1221 (1 mg/kg), or estradiol benzoate (50 ?g/kg). Developmental parameters, estrous cyclicity (females), and timing of reproductive senescence were monitored in the offspring through 9 months of age. Expression of 48 genes was measured in 3 hypothalamic nuclei: the anteroventral periventricular nucleus (AVPV), arcuate nucleus (ARC), and median eminence (females only) by real-time RT-PCR. Serum LH, testosterone, and estradiol were assayed in the same animals. In males, A1221 had no effects; however, prenatal estradiol benzoate increased serum estradiol, gene expression in the AVPV (1 gene), and ARC (2 genes) compared with controls. In females, estrous cycles were longer in the A1221-exposed females throughout the life cycle. Gene expression was not affected in the AVPV, but significant changes were caused by A1221 in the ARC and median eminence as a function of cycling status. Bionetwork analysis demonstrated fundamental differences in physiology and gene expression between cycling and acyclic females independent of treatment. Thus, gestational exposure to biologically relevant levels of estrogenic endocrine-disrupting chemicals has sexually dimorphic effects, with an altered transition to reproductive aging in female rats but relatively little effect in males. PMID:23592748

Walker, Deena M.; Kermath, Bailey A.; Woller, Michael J.

2013-01-01

62

Propofol Exposure in Pregnant Rats Induces Neurotoxicity and Persistent Learning Deficit in the Offspring  

PubMed Central

Propofol is a general anesthetic widely used in surgical procedures, including those in pregnant women. Preclinical studies suggest that propofol may cause neuronal injury to the offspring of primates if it is administered during pregnancy. However, it is unknown whether those neuronal changes would lead to long-term behavioral deficits in the offspring. In this study, propofol (0.4 mg/kg/min, IV, 2 h), saline, or intralipid solution was administered to pregnant rats on gestational day 18. We detected increased levels of cleaved caspase-3 in fetal brain at 6 h after propofol exposure. The neuronal density of the hippocampus of offspring was reduced significantly on postnatal day 10 (P10) and P28. Synaptophysin levels were also significantly reduced on P28. Furthermore, exploratory and learning behaviors of offspring rats (started at P28) were assessed in open-field trial and eight-arm radial maze. The offspring from propofol-treated dams showed significantly less exploratory activity in the open-field test and less spatial learning in the eight-arm radial maze. Thus, this study suggested that propofol exposure during pregnancy in rat increased cleaved caspsase-3 levels in fetal brain, deletion of neurons, reduced synaptophysin levels in the hippocampal region, and persistent learning deficits in the offspring. PMID:24961766

Xiong, Ming; Li, Jing; Alhashem, Hussain M.; Tilak, Vasanti; Patel, Anuradha; Pisklakov, Sergey; Siegel, Allan; Ye, Jiang Hong; Bekker, Alex

2014-01-01

63

Acute cadmium exposure and ovarian steroidogenesis in cycling and pregnant rats.  

PubMed

The purpose of this study was to evaluate the effect(s) of acute in vivo cadmium (Cd) exposure on steroidogenesis in rat ovaries during different reproductive states. Sprague-Dawley rats were injected subcutaneously on the day of diestrus, or on day 7 or 16 of gestation with a single dose of 0, 3, or 5 mg Cd/kg bw, and evaluated 24 h later. Serum progesterone and estradiol concentrations were determined. Whole-ovary culture was used to evaluate Cd effects on the production of progesterone, testosterone, and estradiol. Liver, kidney, spleen, ovary, placenta, and blood were analyzed for Cd and iron (Fe) concentrations. No general toxic effects, no disruption of estrous cyclicity, and no change in fetal viability were seen. Histologic evaluation revealed moderate Cd-related thecal congestion in ovaries of pregnant rats. The highest Cd concentrations, except for liver, were found in the fetal portion of the placenta. Interestingly, Cd-related decreases in Fe concentration were found in several tissues from rats in proestrus and on gestation day 8, and in fetal placenta from rats on gestation day 17. Cadmium appears to interfere with normal steroidogenesis at a number of sites in the biosynthetic pathway with serum estradiol concentration and ovarian estradiol production the most affected. Acute Cd effects on steroidogenesis are most severe in rats evaluated in proestrus or in early pregnancy, while in late pregnancy steroidogenesis is relatively unaffected. PMID:7881201

Piasek, M; Laskey, J W

1994-01-01

64

Reproductive toxicity study with a novel deoxyguanosine analogue (Metacavir) in pregnant SD rats.  

PubMed

Our preliminary studies demonstrated that Metacavir has potential to become a new anti-HBV agent. The main targets of the toxic effects of Metacavir, in rhesus monkeys, were gastrointestinal tracts, liver, blood, and kidneys, which were not related to mitochondrial effects. In this study, the maternal toxicity, embryo-fetal developmental toxicity and teratogenicity were studied in pregnant Sprague-Dawley rats after intragastric administration of Metacavir (200, 100, 50, 0 mg/kg body weight) during the first 6-15 days of pregnancy. Slower weight gain was observed in 5 out of 21 rats subjected to a 200 mg/kg dose, as well as 2 out of 20 subjected to a 100 mg/kg dose. Compared with the solvent control group, the calibration weight gain in the 200 mg/kg and 100 mg/kg dosage groups respectively, during first 6-20 pregnant days were significantly different (P < 0.01, P < 0.05). Significant dose related adverse effects to other reproductive parameters were not seen in F0 and F1, but the number of stillbirths in high dose group showed notably difference compared with the control group (P < 0.05), while the litter incidence showed no difference. No Metacavir-associated pathological changes were observed. The present research indicated that at a dose of 200 mg/(kg·d) (i.e., 40 times the effective dose in rats), Metacavir shows some maternal toxicity to SD rats. The embryotoxicity in the 200 mg/kg group encompass decreased fetal body weight, and higher fetal mortality rates, compared with the control group. However, the litter incidence showed no statistical difference. All the treated rats displayed normal bone development, no teratogenicity and without adverse effects on fetal development, thus indicating that below a dose of 200 mg/(kg·d) there is no teratogenic side effects. PMID:25523750

Luo, Qihui; Chen, Zhengli; Cheng, Anchun; Wang, Mingshu; Fang, Jing; Peng, Xi; Tang, Li

2015-03-01

65

Effect of hypothyroidism on hormone profiles in virgin, pregnant and lactating rats, and on lactation.  

PubMed

Thyroid dysfunctions can produce reproductive problems. Untreated maternal hypothyroidism has serious consequences on development of offspring, resulting in stunted growth and mental retardation. The effects of propylthiouracyl-induced hypothyroidism (0.1 g l(-1) in drinking water starting 8 days before mating, or given to virgin rats for 30 or 50 days) on the serum profiles of hormones related to reproduction and mammary function (prolactin, growth hormone (GH), progesterone, corticosterone, oestradiol, insulin-like growth factor I (IGF-I), thyroid-stimulating hormone (TSH), triiodothyronine and tetraiodothyronine), and on mammary function in virgin, pregnant and lactating rats, were investigated. Propylthiouracyl treatment severely decreased circulating triiodothyronine and tetraiodothyronine concentrations, and increased serum TSH concentrations. Virgin rats showed prolonged periods of vaginal dioestrus, increased circulating progesterone concentrations and afternoon peaks of prolactin concentration, which are indicative of prolactin-induced pseudopregnancy. Propylthiouracyl-treated virgin rats had mammary development comparable to that of midpregnancy, and half of these rats had increased mammary casein and lactose concentrations. Serum prolactin concentrations were decreased on the afternoon of day 5 of pregnancy, increased during late pregnancy (days 15-21) and were normal during lactation. Circulating GH concentrations decreased on days 15-21 of pregnancy, whereas progesterone concentrations increased during late pregnancy and early lactation. Circulating oestradiol (measured in late pregnancy and in virgin rats), IGF-I and corticosterone concentrations were decreased. Although assessment of mammary histology showed no differences in extent of development, casein content was increased in propylthiouracyl-treated rats on day 21 of pregnancy; litter growth was severely reduced and at day 20 of age the pups were hypothyroid, with decreased GH serum concentrations. An acute suckling experiment was performed on days 10-12 of lactation to determine whether some impairment in mammary function or the suckling reflex might account for these differences. After an 8 h separation of mothers from their litters and 30 min of suckling, circulating prolactin values were not affected by propylthiouracyl treatment, but serum oxytocin concentration and milk excretion were reduced. In conclusion, hypothyroidism induces various alterations in the hormone profiles of virgin and pregnant rats, and induces pseudopregnancies and mammary development in virgin rats. These alterations do not appear to have an overt impact on the outcome of pregnancy and on mammary function during lactation, with the exception of the milk ejection reflex, which may account at least partially for the reduced litter growth. PMID:12968945

Hapon, M B; Simoncini, M; Via, G; Jahn, G A

2003-09-01

66

Comparison of the effects of fetal hypothyroidism on glucose tolerance in male and female rat offspring.  

PubMed

Thyroid hormones are vital for survival of mammalian species and play critical roles in growth, development, and metabolism. Both fetal hypothyroidism and sex can affect carbohydrate metabolism during adult life. This study aims to assess carbohydrate metabolism in male and female offspring born from mothers who were hypothyroid during pregnancy. Pregnant rats were divided into two groups; the controls consumed water and the hypothyroid group received water containing 0.025 % 6-propyl-2-thiouracial throughout gestation. The intravenous glucose tolerance test (0.5 g/kg glucose) was carried out in 3-month-old offspring. Findings showed that compared to controls, male fetal hypothyroid rats during adulthood had glucose intolerance (area under the curve: 446.4 ± 9.7 vs. 486.4 ± 8.8, p < 0.01 in control and fetal hypothyroid groups, respectively) whereas females had improved glucose tolerance (478.1 ± 7.0 vs. 455.9 ± 8.5, p < 0.01). In conclusion, sex could modulate the effects of fetal hypothyroidism on glucose tolerance in rats. PMID:25649149

Bagheripuor, Fatemeh; Ghanbari, Mahboubeh; Zahediasl, Saleh; Ghasemi, Asghar

2015-03-01

67

Aspects of the Development of Housing for the Spaceflight of Pregnant and Lactating Rats with Neonates  

NASA Technical Reports Server (NTRS)

Recent and upcoming spaceflights are investigating the effect of weightlessness on developing neural and organ systems. Pregnant rats and dams with neonates have to be accommodated in cages that support the special requirements of these animals. Extensive ground testing of cage concepts, the effect of launch and landing stresses on the maintenance of pregnancy and maternal behavior at different neonatal ages, and techniques for monitoring adaptability to change are discussed. A spaceflight opportunity for the NlH.R3 payload of rat families at three different postnatal ages demonstrated that the survival of very young animals was not good but that older newborns could be returned to Earth in reasonably good health. The development of cages for the Research Animal Holding Facility (RAHF) to support the flight of neonates on Neurolab was continued and incorporated modifications that were demonstrated by the NIH.R3 flight. Other modifications to the RAHF are discussed. Data from biocompatibility and experiment verification testing are presented.

Hinds, William E.; Mayer, David J.; Evans, Juli; Spratt, Shahn; Lane, Philip K.; Rodriguez, Shari L.; Navidi, Meena; Armstrong, Rachel; Lemos, Bonnie; Dalton, Bonnie P. (Technical Monitor)

1996-01-01

68

Ovarian estrogen acts to feminize the female rat's corpus callosum.  

PubMed

The rat corpus callosum (CC) is sexually dimorphic, with the male CC being larger. Ovariectomy (Ovx) on day 12 has been shown to eliminate this sex difference, with callosal values of Ovx females approaching those of male controls. This suggested that postnatal ovarian estrogen affects the size of the female CC. In the present experiment, one group of female rats received Ovx on day 12, and a second group received Ovx followed by chronic implantation of a silastic tube containing beta-estradiol on day 25. Unmanipulated males and sham females served as controls. Examination of the CC at 110 days confirmed our prior findings that males have larger callosa than females and that the Ovx group had increased CC's compared to sham controls. Our new finding was that estrogen treatment was capable of reversing the effects of Ovx. Ovx+estrogen-treated females had decreased CC size as compared to Ovx alone. Indeed, they also had smaller CC values than control females. These findings indicate that ovarian estrogen plays a role in determining CC morphology and that estrogen in the female acts to inhibit overall callosal growth as measured by changes in gross callosal size. PMID:8431995

Mack, C M; Fitch, R H; Cowell, P E; Schrott, L M; Denenberg, V H

1993-01-15

69

3. Impact of altered gravity on CNS development and behavior in male and female rats  

NASA Astrophysics Data System (ADS)

The present study examined the effect of altered gravity on CNS development. Specifically, we compared neurodevelopment, behavior, cerebellar structure and protein expression in rat neonates exposed perinatally to hypergravity. Pregnant Sprague-Dawley rats were exposed to 1.5G-1.75G hypergravity on a 24-ft centrifuge starting on gestational day (G) 10, through giving birth on G22/G23, and nursing their offspring through postnatal day (P) 21. Cerebellar mass on P6 was decreased in 1.75G-exposed male pups by 27.5 percent; in 1.75G-exposed female pups it was decreased by 22.5 percent. The observed cerebellar changes were associated with alterations in neurodevelopment and motor behavior. Exposure to hypergravity impaired performance on the following neurocognitive tests: (1) righting time on P3 was more than doubled in 1.75G-exposed rats and the effect appeared more pronounced in female pups, (2) startle response on P10 was delayed in both male and female HG pups; HG pups were one-fifth as likely to respond to a clapping noise as SC pups, and (3) performance on a rotorod on P21 was decreased in HG pups; the duration of the stay on rotorod recorded for HG pups of both sexes was one tenth of the SC pups. Furthermore, Western blot analysis of selected cerebellar proteins suggested gender-specific changes in glial and neuronal proteins. On P6, GFAP expression was decreased by 59.2 percent in HG males, while no significant decrease was observed in female cerebella. Synaptophysin expression was decreased in HG male neonates by 29.9 percent and in HG female neonates by 20.7 percent as compared to its expression in SC cerebella. The results of this experiment suggest that perinatal exposure to hypergravity affects cerebellar development and behavior differently in male and female neonates. If one accepts that hypergravity is a good paradigm to study the effect of microgravity on the CNS, and since males and females were shown to respond differently to hypergravity, it can be surmised that males and females may respond differently to the microgravity encountered in space. Supported by NIEHS grant ES11946-01 awarded to E. S-S.

Sajdel-Sulkowska, E. M.; Nguon, K.; Ladd, B.; Sulkowski, V. A.; Sulkowski, Z. L.; Baxter, M. G.

70

Tumorigenic effects of dichloroacetic acid in female F344 rats  

EPA Science Inventory

Introduction: Dichloroacetic acid (DCA) is a halogenated organic acid produced during oxidant disinfection of drinking water. Prior studies indicate that DCA may increase liver tumors in mice. Here we evaluated the hepatic tumorigenicity of DCA in female rats when given alone ...

71

Estrogen Abolishes Latent Inhibition in Ovariectomized Female Rats  

ERIC Educational Resources Information Center

Estrogen is frequently prescribed as a method of birth control and as hormone replacement therapy for post-menopausal women with varied effects on cognition. Here the effects of estrogen on attention were examined using the latent inhibition (LI) behavioral paradigm. Ovariectomized (OVX) female rats were given either estrogen benzoate (EB, 10 or…

Nofrey, Barbara S.; Ben-Shahar, Osnat M.; Brake, Wayne G.

2008-01-01

72

MIREX INDUCES ORNITHINE DECARBOXYLASE ACTIVITY IN FEMALE RAT LIVER  

EPA Science Inventory

Ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine synthesis, was significantly induced in female rat liver following oral administration of the pesticide, mirex. fter dual oral exposure (120 mg/kg; 21 and 4 hrs prior to sacrifice) induction of ODC activity in r...

73

Metabolism and Disposition of Bisphenol A in Female Rats  

Microsoft Academic Search

Bisphenol A (BPA), which is used in the manufacture of polycarbonates, elicits weak estrogenic activity in in vitro and in vivo test systems. The objectives of this study were to compare the patterns of disposition of radioactivity in adult female F-344 and CD rats after oral administration of 14C BPA (100 mg\\/kg), to isolate the glucuronide of BPA and to

Rodney W. Snyder; Susan C. Maness; Kevin W. Gaido; Frank Welsch; Susan C. J. Sumner; Timothy R. Fennell

2000-01-01

74

POSSIBLE ANTIESTROGENIC ACTIVITY OF LINDANE IN FEMALE RATS (JOURNAL VERSION)  

EPA Science Inventory

During chronic treatment of weanling female rats with daily injections (0.069 mmol/kg of gamma-hexachlorocyclohexane (lindane, gamma-HCH), the treatment induced a significant 20% increase in body weight after 110 days. Further investigation with 0, 5, 10, 20 and 40 mg/kg lindane ...

75

Intrauterine Pressure (IUP) Telemetry in Pregnant and Parturient Rats: Potential Applications for Spacecraft and Centrifugation Studies  

NASA Technical Reports Server (NTRS)

Rats exposed to spaceflight or centrifugation from mid-to late pregnancy undergo either more or fewer labor contractions at birth, respectively, as compared to those in normal Earth gravity (1-g). In this paper, we report the development and validation of a new telemetric method for quantifying intrauterine pressure (IUP) in freely-moving, late pregnant and parturient rats. We plan to utilize this technique for studies of labor in altered gravity, specifically, to ascertain forces of uterine during birth, which we believe may be changed in micro- and hypergravity. The technique we describe yields precise, reliable measures of the forces experienced by rat fetuses during parturition. A small, surgically-implantable telemetric pressure sensor was fitted within a fluid-filled balloon. The total volume of the sensor-balloon assembly matched that of a full term rat fetus. Real-time videorecordings of sensor-implanted rat dams and non- implanted control dams enabled us to characterize effects of the intrauterine implant on behavioral aspects of parturition. Contraction frequency, duration, pup-to-pup birth intervals and pup-oriented activities of the dams measured during the peri-birth period were unaffected by the sensor implant. These findings establish intrauterine telemetry as a reliable, non-invasive technique for quantifying intrauterine pressures associated with parturition on Earth and in altered gravity environments. This new technology, readily amenable to spaceflight and centrifugation platforms, will enable us to answer key questions regarding the role of altered labor frequency labor in the adaptation of newborn mammals to hypo- and hypergravity.

Ronca, A. E.; Baer, L. A.; Wade, C. E.

2003-01-01

76

Toxopathological and cytogenetic effects of aflatoxin B1 (AFB1) on pregnant rats.  

PubMed

The present study was carried out to evaluate the toxopathological effects and macro-DNA damage of Aflatoxin B1 (AFB1) in pregnant rats at a dose of 1mg/kg. body wt., given from 6th to 15th day of gestation. The effects and damage are represented by histopathological changes and different types of chromosomal aberrations in dams, in addition to teratogenic changes in the feti. Pregnant dams revealed a significant decrease in their body weights and gross enlargement of the liver. Histologically, the liver showed necrotic areas and congested central vein. The kidneys revealed interstitial hemorrhages, renal casts, degeneration and necrosis. The lungs revealed lymphocytic infiltrates in the interstitial tissue, while the spleen revealed lymphoid depletion. Chromosomal analysis revealed both structural and numerical chromosomal aberration, including centromeric attenuations, chromatid gaps, chromatid breaks, end-to-end associations, fragments, ring chromosomes, deletions, dicentric chromosomes, chromosomal fusions, centric fusions, stickness and hypoployploidy. Centromeric attenuations and end-to-end associations were more frequent than other chromosomal aberrations. Concerning the teratogenic effects in the fetuses, the toxin induced multiple skeletal anomalies. These anomalies included incomplete ossification of skull bones and failure of ossification of long and flat bones. PMID:25023881

Fetaih, Hamdy A; Dessouki, Amina A; Hassanin, Abeer A I; Tahan, Ahmed S

2014-12-01

77

Simulated conditions of microgravity suppress progesterone production by luteal cells of the pregnant rat.  

PubMed

The purpose of this study was to assess whether simulated conditions of microgravity induce changes in the production of progesterone by luteal cells of the pregnant rat ovary using an in vitro model system. The microgravity environment was simulated using either a high aspect ratio vessel (HARV) bioreactor with free fall or a clinostat without free fall of cells. A mixed population of luteal cells isolated from the corpora lutea of day 8 pregnant rats was attached to cytodex microcarrier beads (cytodex 3). These anchorage dependent cells were placed in equal numbers in the HARV or a spinner flask control vessel in culture conditions. It was found that HARV significantly reduced the daily production of progesterone from day 1 through day 8 compared to controls. Scanning electron microscopy showed that cells attached to the microcarrier beads throughout the duration of the experiment in both types of culture vessels. Cells cultured in chamber slide flasks and placed in a clinostat yielded similar results when compared to those in the HARV. Also, when they were stained by Oil Red-O for lipid droplets, the clinostat flasks showed a larger number of stained cells compared to control flasks at 48 h. Further, the relative amount of Oil Red-O staining per milligram of protein was found to be higher in the clinostat than in the control cells at 48 h. It is speculated that the increase in the level of lipid content in cells subjected to simulated conditions of microgravity may be due to a disruption in cholesterol transport and/or lesions in the steroidogenic pathway leading to a fall in the synthesis of progesterone. Additionally, the fall in progesterone in simulated conditions of microgravity could be due to apoptosis of luteal cells. PMID:12365451

Bhat, G K; Yang, H; Sridaran, R

2001-12-01

78

Simulated conditions of microgravity suppress progesterone production by luteal cells of the pregnant rat  

NASA Technical Reports Server (NTRS)

The purpose of this study was to assess whether simulated conditions of microgravity induce changes in the production of progesterone by luteal cells of the pregnant rat ovary using an in vitro model system. The microgravity environment was simulated using either a high aspect ratio vessel (HARV) bioreactor with free fall or a clinostat without free fall of cells. A mixed population of luteal cells isolated from the corpora lutea of day 8 pregnant rats was attached to cytodex microcarrier beads (cytodex 3). These anchorage dependent cells were placed in equal numbers in the HARV or a spinner flask control vessel in culture conditions. It was found that HARV significantly reduced the daily production of progesterone from day 1 through day 8 compared to controls. Scanning electron microscopy showed that cells attached to the microcarrier beads throughout the duration of the experiment in both types of culture vessels. Cells cultured in chamber slide flasks and placed in a clinostat yielded similar results when compared to those in the HARV. Also, when they were stained by Oil Red-O for lipid droplets, the clinostat flasks showed a larger number of stained cells compared to control flasks at 48 h. Further, the relative amount of Oil Red-O staining per milligram of protein was found to be higher in the clinostat than in the control cells at 48 h. It is speculated that the increase in the level of lipid content in cells subjected to simulated conditions of microgravity may be due to a disruption in cholesterol transport and/or lesions in the steroidogenic pathway leading to a fall in the synthesis of progesterone. Additionally, the fall in progesterone in simulated conditions of microgravity could be due to apoptosis of luteal cells.

Bhat, G. K.; Yang, H.; Sridaran, R.

2001-01-01

79

Stress in pregnancy: A new Wistar rat model for human preeclampsia  

Microsoft Academic Search

OBJECTIVE: Our study evaluated the effects of chronic and\\/or acute stress on pregnant and nonpregnant female rats. STUDY DESIGN: The rats were exposed to the sonic stimulus associated with overpopulation between days 7 and 14 of pregnancy. The rats were immobilized 2 days before the vascular reactivity experiments. RESULTS: In 14-day pregnant rats, chronic stress led to lower weight, increased

Nilton H. Takiuti; Soubhi Kahhale; Marcelo Zugaib

2002-01-01

80

Reproductive toxicity associated with acrylamide treatment in male and female rats  

SciTech Connect

The present study was designed to evaluate the influence of acrylamide (ACR) on male and female reproductive function. Male rats received ACR in drinking water (50, 100, or 200 ppm) for up to 10 wk. Copulatory behavior, semen, and (for controls and 100 ppm only) fertility and fetal outcomes were evaluated. Females received ACR (25, 50, 100 ppm) for 2 wk prior to initiation of breeding and then throughout gestation and lactation. Hindlimb splaying was apparent in the 200-ppm males by wk 4; less severe splaying appeared in the 100-ppm group at wk 8. Disruptions in copulatory behavior preceded the appearance of this ataxia. These disruptions in mating performance interfered with ejaculatory processes and subsequent transport of sperm, since semen was found in the uterus of only 1 of the 15 females mated with the 100-ppm males at wk 9. Moreover, only 33% of the females mated with the 100-ppm males were pregnant. Postimplantation loss was also significantly increased in this group. Hindlimb splaying appeared in the females receiving 100 ppm ACR during wk 1-2 of pregnancy. Body weight and fluid intake were also depressed. Dams in the 50-ppm group showed depression in these parameters during the last 2 wk of lactation. ACR did not significantly affect mating performance of the females, pregnancy rates, litter size, or survival. However, ACR did significantly depress pup body weight at birth (100-ppm group) and weight gain during lactation through postweaning, d 42 (50- and 100-ppm groups). Vaginal patency was delayed in the 100-ppm group only.

Zenick, H.; Hope, E.; Smith, M.K.

1986-01-01

81

Pregnant and Operating”: Evaluation of a Germany-wide Survey Among Female Gynaecologists and Surgeons  

PubMed Central

The current law on the protection of expectant and nursing mothers largely rules out surgical activities during pregnancy for female doctors who perform surgical roles in hospitals. The proportion of female junior staff in gynaecology amounts to 80?%, and, for many of these women, surgical further training is not possible following official notification of an existing pregnancy. In a Germany-wide survey of female gynaecologists and surgeons using a questionnaire, it was determined to what extent female doctors worked in surgery during pregnancy, whether it led to complications in the pregnancy, when the employer was notified about the pregnancy, and what desire for change there is with regard to the law on the protection of expectant and nursing mothers. The data from 164 female doctors, of which 136 are gynaecologists and 28 surgeons, was evaluated. On average, the pregnancy was announced during the 14th week of pregnancy (WOP), and the doctor was not allowed to perform surgical activities in the 21st WOP. Female doctors in higher professional roles tended to announce the pregnancy later and ended their surgical activities later. There was no link between the time of ceasing surgical activities and an increased occurrence of complaints or complications during the pregnancy. In total, only 53?% of respondents had an appraisal during pregnancy and 75?% wanted a change in the law on the protection of expectant and nursing mothers. PMID:25278630

Knieper, C.; Ramsauer, B.; Hancke, K.; Woeckel, A.; Ismail, L.; Bühren, A.; Toth, B.

2014-01-01

82

Reproductive effects of hexachlorobenzene in female rats.  

PubMed

Hexachlorobenzene (HCB) is a polyhalogenated aromatic hydrocarbon widely distributed in the environment. In animal testing, HCB has been shown to be a reproductive toxin. Previous investigations of the effects of HCB on ovarian function have yielded equivocal results. Thus, the effects of chronic administration of HCB (1 g kg(-1) body wt.) on the ovary and pituitary hormone levels, hepatic and uterine oestradiol receptors, ovarian histopathological changes and oestrus cycle characteristics were investigated in spontaneously cycling rats. Our data demonstrate that HCB treatment, under the conditions of the present study, reduced circulating levels of oestradiol and prolactin without differences in serum concentrations of progesterone. Follicle-stimulating hormone serum levels were elevated. Hexachlorobenzene treatment resulted in irregularity of cycles, characterized mainly as prolonged periods of oestrus with a reduced number of ova recovered. In addition, HCB administration resulted in significantly decreased uterine nuclear oestrogen receptor levels. Histopathological examination revealed degenerative changes of the ovarian follicles and germinal epithelium and increased numbers of atresic follicles. PMID:10641019

Alvarez, L; Randi, A; Alvarez, P; Piroli, G; Chamson-Reig, A; Lux-Lantos, V; Kleiman de Pisarev, D

2000-01-01

83

Behavioral and Physiological Analyses of Parturition In Pregnant Rats: Insights Derived from Intrauterine Telemetry  

NASA Technical Reports Server (NTRS)

During labor and birth, fetuses are exposed to considerable physical stimulation associated with labor contractions and expulsion from the womb These forces are important for the neonates' adaptation to tile extrauterine environment. To further our understanding of the relationship between labor and postpartum outcome, we developed a novel method for measuring intrauterine pressure (IUP) in freely-moving, late pregnant and parturient rats that enables us to make precise, reliable measures of the forces experienced by rat fetuses during parturition. A small (1.25 x 4 cm) telemetric blood pressure sensor was fitted within a fluid-filled balloon, similar in size to a full term rat fetus. On Gestational day (G) 19 of the rats' 22/23 day pregnancy, each dam was anesthetized and a balloon/sensor unit surgically implanted within the uterus following removal of two fetuses. Comparisons were made between sensor-implanted dams (IMPL) and a control conditions: 1) LAP-R, laparotomy with two fetuses removed or 2) LAP-NR, laparotomy with no fetuses removed. IUP signals were sampled at 10s intervals from the IMPL dams during labor and birth. Dams in all three conditions were videorecorded enabling us to analyze the effect of the implant on behavioral expressions of parturition. Contraction frequency, duration, pup-to-pup birth intervals and pup-oriented activities of the dams measured from one hour prior to the first pup birth until the birth of the third pup were unaffected by the sensor implant. Intrauterine telemetry of freely-moving dams offers significant advantages over conventional hardwired IUP measurement techniques. These findings establish and validate intrauterine telemetry as a reliable, non-invasive technique for quantifying pressures associated with parturition.

Villareal, J.; Mallery, E.; Lynch, A.; Mills, N.; Baer, L.; Wade, C.; Ronca, A.; Dalton, Donnie (Technical Monitor)

2002-01-01

84

Nitric oxide donor-induced inhibition of pregnant rat uterine spontaneous contractile activity and release of nitric oxide from uterus measured by microdialysis.  

PubMed

Our aim was to study whether nitric oxide (NO) donor-induced inhibition of pregnant rat myometrium contractility correlates with the release of NO. Uterine rings from mid-pregnant and late pregnant Sprague-Dawley rats were used for isometric tension recording. Concentration-response relationships to sodium nitroprusside (SNP), nitroglycerine (NTG) and diethylamine (DEA)/NO were assessed. The time course of NO release after addition to the organ chambers of the 3 NO-donors was assessed by the detection of NO products NOx (NO3+NO2) using the microdialysis probe by a HPLC-NO detector system. DEA/ NO induced greater inhibition of the spontaneous contractile activity of uterine rings from mid-pregnant rats than SNP or NTG. In uterine rings from late pregnant rats, however, the maximal inhibition of the contractility by all 3 NO-donors were significantly less. The NOx levels measured in the uterine ring walls from either mid-pregnant or late pregnant rats significantly increased after DEA/ NO as compared to the basal levels or the levels after NTG or SNP. The decrease of NO-donor-induced inhibition of rat myometrium contractility, with unchanged formation of NOx, at term, suggests that the changes in NO signaling are responsible for gestational age-dependent attenuation of the inhibitory effect. PMID:16483178

Okawa, T; Asano, K; Takahashi, H; Sato, A; Vedernikov, Y P; Saade, G R; Gafield, R E

2005-12-01

85

Mixed pituitary adenoma-gangliocytoma in a female albino rat  

Microsoft Academic Search

A mixed intrasellar pituitary adenoma-gangliocytoma was found incidentally in an aged female Sprague-Dawley-derived rat. The animal was killed at the end of a 104-week carcinogenicity study. At necropsy, the pituitary fossa was occupied by a large, hemorrhagic nodule compressing and displacing the base of the brain. The lesion consisted of large areas of a prolactin-secreting adenoma surrounding a central island

Virgilio Pace; Elias Perentes

2001-01-01

86

Quantitative alterations in the liver and adrenal gland in pregnant rats induced by Pyralene 3000  

SciTech Connect

Polychlorinated biphenyls (PCBs) are among the most widespread environmental pollutants known in the world. The half-life of PCBs is very long and, therefore, once released into the environment, they accumulate in food chains and tissues of various mammals, including man. Their presence can cause numerous toxic effects, e.g., hepatotoxicity, immunotoxicity, dermatotoxicity, neurotoxicity, and disorders of the reproductive system, among others. These effects depend on the distribution route in the organism, the rate of metabolism and excretion. Their characteristics are closely associated with the number and position of the chlorine atoms in the molecule. Previous studies of trichlorobiphenyl distributions in various tissues demonstrated that low chlorinated trichlorobiphenyls do no accumulate in endocrine organs, whereas higher chlorinated biphenyls, such as hexa- and octachlorobiphenyl, are deposited and retained in the adrenal gland. A selective distribution of radioabelled tetrachlorobiphenyl to the zona fasciculata, accompanied by morphometric evidence of the hypertrophy of the zona fasciculata, was also noted. The purpose of this study was to examine changes in the tissue structure of the pregnant rat liver and adrenal gland induced experimentally by Pyralene 3000 administration. We chose this commercial low chlorinated PCB because it was in use in Slovenia and, discharged from the electroindustrial plants, caused a serious incidence of environmental pollution in the region of Bela Krajina. Our further aim was to research the transplacental influences of Pyralene 3000 in rats. 17 refs., 1 fig., 3 tabs.

Vreci, M.; Sek, S.; Lorger, J.; Bavdek, S. [Univ. of Ljubljana, Gerbiceva (Slovenia); Pogacnik, A.

1995-06-01

87

Influence of protein deficiency on hexachlorocyclohexane and malathion toxicity in pregnant rats.  

PubMed

The effects of protein deprivation and 60 mg hexachlorocyclohexane (HCH)/kg or 500 mg malathion/kg body weight were studied in pregnant rats fed a diet containing 16% (control) or 5% (protein-deficient) casein throughout gestation. Three po doses of HCH or malathion on the 6th, 10th and 14th day of gestation resulted in maternal toxicity and fetal growth retardation. No skeletal anomalies were noted except for poor ossification in the protein-deficient dams, which was further exaggerated on exposure to HCH or malathion. Malathion caused more severe maternal and fetal toxicity compared to the HCH-dosed rats. Depletion in glutathione (GSH) and decreased activities of GSH peroxidase, GSH reductase and glucose-6-phosphate dehydrogenase were observed from the protein deficiency and pesticide exposure. Impairment of GSH-dependent routes of detoxification was noticed from exposure to HCH or malathion during pregnancy. The lipid peroxide content was elevated from protein deficiency and was magnified with pesticide exposure. PMID:7504364

Prabhakaran, S; Shameem, F; Devi, K S

1993-10-01

88

Disposition of perfluorodecanoic acid in male and female rats  

SciTech Connect

The elimination, tissue distribution, and metabolism of (1-14C)PFDA were examined in male and female rats for 28 days after a single ip dose (9.4 mumol/kg, 5 mg/kg). A sex difference in the fecal elimination of perfluorodecanoic acid (PFDA) was observed with 51 and 24% of the administered 14C being recovered in the feces of male and female rats, respectively, by 28 days post-treatment. The cumulative excretion of PFDA-derived 14C in the urine in 28 days was less than 5% of the administered dose in both sexes. The sex-related difference in the rate of fecal elimination resulted in the observed difference in whole body elimination t1/2 of PFDA in males (t1/2 = 23 days) and females (t1/2 = 45 days). The liver contained the highest concentration of PFDA-derived 14C in both males and females, followed by the plasma and kidneys. The heart, fat pads, testes, and gastrocnemius muscle of males, and the ovaries of females contained much lower concentrations of PFDA. The reason for the high percentage of the ip dose of (1-14C)PFDA in the liver (53% males and 41% females, 2 hr post-treatment) was further examined using an in situ nonrecirculating liver perfusion technique. It was shown that approximately 25% of the (14C)PFDA in the perfusate was extracted by the liver in a single pass. The basis for the sex difference in fecal elimination of PFDA does not appear to be due to a sex difference in biliary excretion. In a 6-hr period, male and female rats with kidneys ligated eliminated essentially the same percentage dose of (14C)PFDA into bile. We had hypothesized that the persistence of PFDA in rats was due to formation of a PFDA-containing lipids. However, no evidence that PFDA is conjugated to form persistent hybrid lipids was obtained, nor were polar metabolites of PFDA detected in urine or bile.

Vanden Heuvel, J.P.; Kuslikis, B.I.; Van Rafelghem, M.J.; Peterson, R.E. (Univ. of Wisconsin, Madison (USA))

1991-03-01

89

Disposition of orally administered 2,2-Bis(4-hydroxyphenyl)propane (Bisphenol A) in pregnant rats and the placental transfer to fetuses.  

PubMed Central

We studied the disposition of bisphenol A (BPA) in pregnant female F344/DuCrj(Fischer) rats and its placental transfer to fetuses after a single oral administration of 1 g/kg BPA dissolved in propylene glycol. BPA in maternal blood, liver, and kidney reached maximal concentrations (14.7, 171, and 36 microg/g) 20 min after the administration and gradually decreased. The levels were 2-5% of the maximum 6 hr after the administration. The maximal concentration of BPA in fetuses (9 microg/g) was also attained 20 min after the administration. BPA levels then gradually reduced in a similar manner to maternal blood. These results suggest that the absorption and distribution of BPA in maternal organs and fetuses are extremely rapid and that the placenta does not act as a barrier to BPA. PMID:11049811

Takahashi, O; Oishi, S

2000-01-01

90

Role of Reactive Oxygen Species in Hypertension Produced by Reduced Uterine Perfusion in Pregnant Rats  

PubMed Central

BACKGROUND Although recent studies indicate preeclampsia (PE) is associated with increased oxidative stress, the role of reactive oxygen species in the hypertension associated with PE remains unclear. We sought to test the hypothesis that placental ischemia increases oxidative stress which in turn, contributes to hypertension. METHODS Reduction in uterine perfusion pressure (RUPP) was induced by placing silver clips on the abdominal aorta and the ovarian arteries on day 14 of pregnancy. On day 20 of pregnancy, mean arterial pressure (MAP) was measured and oxidative stress was assessed in renal and placental tissues whereas systemic administration of tempol, a superoxide dismutase (SOD) mimetic, was used to evaluate the contribution of reactive oxygen species on RUPP-induced hypertension. RESULTS MAP (120 ± 2 mm Hg vs.106 ± 3 mm Hg), placental levels of 8-isoprostane (1.9 ± 0.4 ng/g tissue vs. 0.8 ± 0.1 ng/g tissue), and malondialdehyde (MDA) (6.9 ± 0.6 ?mol/g tissue vs. 3.9 ± 0.4 ?mol/g tissue) were increased, whereas renal cortical SOD activity was decreased in RUPP rats (1.2 ± 0.1 units/mg protein vs. 1.6 ± 0.1 units/ mg protein) at day 20 of gestation (20 dG) compared to controls. Chronic treatment with tempol attenuated the hypertension (RUPP + tempol 112 ± 2 mm Hg vs. RUPP, 120 ± 2 mm Hg) associated with RUPP, whereas tempol had no effect on MAP (NP, 106 ± 3 vs. NP + tempol, 108 ± 2) in control rats. CONCLUSION The results of this study indicate that placental ischemia decreases innate antioxidant activity resulting in elevated oxidative stress which appears to play a role in mediating hypertension associated with chronic RUPP in pregnant rats. PMID:18670418

Sedeek, Mona; Gilbert, Jeffrey S.; LaMarca, Babbette B.; Sholook, Myssara; Chandler, Derrick L.; Wang, Yuping; Granger, Joey P.

2009-01-01

91

Release of Zn from maternal tissues in pregnant rats deficient in Zn or Zn and Ca  

SciTech Connect

Earlier studies have shown that diets that increase tissue catabolism reduce the teratogenic effects of Zn deficiency. The hypothesis that Zn may be released from body tissues when the metabolic state is altered was further tested. Nonpregnant Sprague Dawley females were injected with Zn-65; after equilibration, the two major pools of Zn, bone and muscle, had different specific activities (SA), muscle being much higher. Females were mated and fed diets adequate in Zn and Ca (C) or deficient in Zn (ZnD) or deficient in both Zn and Ca (ZnCaD). Calculations using weight loss in ZnD and ZnCaD rats, Zn content of maternal bone and muscle, and total fetal Zn at term indicated that in ZnCaD rats a relatively small amount of Zn from bone early in pregnancy was sufficient to prevent abnormal organogenesis, but most fetal Zn came from breakdown of maternal muscle in the last 3 days of pregnancy. Isotope data supported this conclusion. SA of Zn in ZnD fetuses was equal and high, indicating that most Zn came from the same maternal tissue. High muscle SA prior to mating, and increased SA in tibia and liver during pregnancy suggest that muscle provided Zn for other maternal tissues as well as fetuses. In contrast, SA in C fetuses was less than 30% of that of the D groups, consistent with the earlier hypothesis that most fetal Zn in C rats is accrued directly from the diet.

Hurley, L.S.; Masters, D.G.; Lonnerdal, B.; Keen, C.L.

1986-03-05

92

Female-specific hypertension loci on rat chromosome 13  

PubMed Central

A 3.7 Mb region of rat chromosome 13 (45.2–49.0 Mb) affects blood pressure (BP) in females only, indicating the presence of gender-specific BP loci in close proximity to the Renin locus. In the present study, we used a series of Dahl salt-sensitive/Mcwi (SS)-13 Brown Norway (BN) congenic rat strains to further resolve BP loci within this region. We identified 3 BP loci affecting female rats only, of which the 2 smaller loci (line9BP3 and line9BP4) were functionally characterized by sequence and expression analysis. Compared with SS, the presence of a 591 Kb region of BN chromosome 13 (line9BP3) significantly lowered BP by 21 mmHg on an 8% NaCl diet (153±7 vs 174±5 mmHg, P<0.001). Unexpectedly, the addition of 23 Kb of BN chromosome 13 (line9BP4) completely erased the female-specific BP protection on 8% NaCl diet, suggesting that BN hypertensive allele(s) reside in this region. The congenic interval of the protective line 9F strain contains 3 genes (Optc, Prelp, and Fmod) and the hypertensive line 9E contains 1 additional gene (Btg2). Sequence analysis of the 2 BP loci revealed a total of 282 intergenic variants, with no coding variants. Analysis of gene expression by RT-qPCR revealed strain- and gender-specific differences in Prelp, Fmod, and Btg2 expression, implicating these as novel candidate genes for female-specific hypertension. PMID:23817491

Hoffman, Matthew J.; Flister, Michael J.; Nunez, Lizbeth; Xiao, Bing; Greene, Andrew S.; Jacob, Howard J.; Moreno, Carol

2013-01-01

93

Somatomotor and sensory urethral control of micturition in female rats.  

PubMed

In rats, axons of external urethral sphincter (EUS) motoneurons travel through the anastomotic branch of the pudendal nerve (ABPD) and anastomotic branch of the lumbosacral trunk (ABLT) and converge in the motor branch of the sacral plexus (MBSP). The aim of the present study was to determine in female rats the contribution of these somatomotor pathways and urethral sensory innervation from the dorsal nerve of the clitoris on urinary continence and voiding. EUS electromyographic (EMG) activity during cystometry, leak point pressure (LPP), and voiding efficiency (VE) were assessed in anesthetized virgin Sprague-Dawley female rats before and after transection of the above nerve branches. Transection of the MBSP eliminated EUS EMG, decreased LPP by 50%, and significantly reduced bladder contraction duration, peak pressure, intercontraction interval, and VE. Transection of the ABPD or ABLT decreased EUS EMG discharge and LPP by 25% but did not affect VE. Transection of the dorsal nerve of the clitoris did not affect LPP but reduced contraction duration, peak pressure, intercontraction interval, and VE. We conclude that somatomotor control of micturition is provided by the MBSP with axons travelling through the ABPD and ABLT. Partial somatomotor urethral denervation induces mild urinary incontinence, whereas partial afferent denervation induces voiding dysfunction. ABPD and ABLT pathways could represent a safeguard ensuring innervation to the EUS in case of upper nerve damage. Detailed knowledge of neuroanatomy and functional innervation of the urethra will enable more accurate animal models of neural development, disease, and dysfunction in the future. PMID:25339694

Cruz, Yolanda; Pastelín, César; Balog, Brian M; Zaszczurynski, Paul J; Damaser, Margot S

2014-12-01

94

Renal epithelial sodium channel is critical for blood pressure maintenance and sodium balance in the normal late pregnant rat.  

PubMed

Normal pregnancy is a state marked by avid sodium retention and plasma volume expansion. Insufficient plasma volume expansion results in the compromised maternal state of intrauterine growth restriction, which afflicts ?5% of all human pregnancies. We have recently shown that renal epithelial sodium channel (ENaC) activity in vivo in the late pregnant (LP) rat is increased. To determine the importance of the renal versus extrarenal ENaC in sodium retention and blood pressure regulation during pregnancy, we have chronically blocked the ENaC pharmacologically with daily subcutaneous injections of benzamil and genetically using intrarenal transfection of ?ENaC short hairpin RNA. Compared with untreated LP control animals, LP rats treated with benzamil retain less sodium and have reduced mean arterial blood pressure. Furthermore, LP rats treated with benzamil had lower maternal body weight gain. Intrarenal transfection of ?ENaC short hairpin RNA versus scrambled small RNA successfully decreased renal ?ENaC mRNA expression in LP rats. Intrarenal transfection of ?ENaC short hairpin RNA reduced maternal sodium retention, body weight gain and pup weight. Redundant physiological systems that protect blood pressure and sodium homeostasis were unable to compensate for the loss of ENaC activity in the pregnant rat. These findings demonstrate that the renal ENaC is necessary for maintaining pregnancy-mediated sodium retention, volume expansion and blood pressure regulation. PMID:24563165

West, Crystal A; Han, Weiquing; Li, Ningjun; Masilamani, Shyama M E

2014-05-01

95

Clinostat rotation induces apoptosis in luteal cells of the pregnant rat  

NASA Technical Reports Server (NTRS)

Recent studies have shown that microgravity induces changes at the cellular level, including apoptosis. However, it is unknown whether microgravity affects luteal cell function. This study was performed to assess whether microgravity conditions generated by clinostat rotation induce apoptosis and affect steroidogenesis by luteal cells. Luteal cells isolated from the corpora lutea of Day 8 pregnant rats were placed in equal numbers in slide flasks (chamber slides). One slide flask was placed in the clinostat and the other served as a stationary control. At 48 h in the clinostat, whereas the levels of progesterone and total cellular protein decreased, the number of shrunken cells increased. To determine whether apoptosis occurred in shrunken cells, Comet and TUNEL assays were performed. At 48 h, the percentage of apoptotic cells in the clinostat increased compared with that in the control. To investigate how the microgravity conditions induce apoptosis, the active mitochondria in luteal cells were detected with JC-1 dye. Cells in the control consisted of many active mitochondria, which were evenly distributed throughout the cell. In contrast, cells in the clinostat displayed fewer active mitochondria, which were distributed either to the outer edge of the cell or around the nucleus. These results suggest that mitochondrial dysfunction induced by clinostat rotation could lead to apoptosis in luteal cells and suppression of progesterone production.

Yang, Hyunwon; Bhat, Ganapathy K.; Sridaran, Rajagopala

2002-01-01

96

Re-Adaptation to 1-G of Pregnant Rats Following Exposure to Spaceflight or Centrifugation  

NASA Technical Reports Server (NTRS)

Late-pregnant rat dams were flown on a 9-day Space Shuttle mission or exposed to 1.5, 1.75 or 2-g centrifugation and compared with 1 .O-g vivarium controls. Exposure to altered gravity began on the 11th day and recovery occurred on the 20th day of the dams' 22-day pregnancy. In the 1 st experiment, comparisons were made between Flight (FLT), Synchronous (SYN; identically-housed) and Vivarium (VIV) controls. In the 2nd experiment, comparisons were made between dams centrifuged at 2-G, 1.75-G, 1.5-G, Rotational controls (1.08-G) or Stationary controls (1 G). Within three hours of recovery from either spaceflight or centrifugation, the dams' locomotor behavior was videotaped for 2 min. FLT dams showed dramatically reduced movement relative to both SYN and VIV control conditions, with significantly greater amounts of locomotor activity observed in SYN as compared to VIV dams. Significantly greater locomotor activity was observed in SYN as compared to VIV controls. In the second experiment, no differences were observed between dams exposed either 1, 1.5, 1.75, or 2-G. In both studies, the dams showed similar patterns of hindlimb rearing. Together, these findings provide quantitative evidence for decreased locomotor activity during re-adaptation to 1-g following spaceflight, but not centrifugation.

Johnson, K. E.; Ronca, A. E.; Alberts, J. R.

2003-01-01

97

Female rat hippocampal cell density after conditioned place preference.  

PubMed

The hippocampus is important for learning tasks, such as conditioned place preference (CPP), which is widely used as a model for studying the reinforcing effects of drugs with dependence liability. Long-term opiate use may produce maladaptive plasticity in the brain structures involved in learning and memory, such as the hippocampus. We investigated the phenomenon of conditioning with morphine on the cell density of female rat hippocampus. Forty-eight female Wistar rats weighing on average 200-250 g were used. Rats were distributed into eight groups. Experimental groups received morphine daily (three days) at different doses (2.5, 5, 7.5 mg/kg) and the control-saline group received normal saline (1 ml/kg), and then the CPP test was performed. Three sham groups received only different doses (2.5, 5, 7.5 mg/kg) of morphine without CPP test. Forty-eight hours after behavioural testing animals were decapitated under chloroform anaesthesia and their brains were fixed, and after tissue processing, slices were stained with cresyl violet for neurons and phosphotungstic acid haematoxylin for astrocytes. The maximum response was obtained with 5 mg/kg of morphine. The density of neurons in CA1 and CA3 areas of hippocampus after injection of morphine and CPP was decreased. The number of astrocytes in different areas of hippocampus was increased after injection of morphine and CPP. It seems that the effective dose was 5 mg/kg, as it led to the CPP. We concluded that both injection of mor phine and CPP can decrease the density of neurons and also increase the number of astrocytes in the rat hippocampus. PMID:24594056

Jahanshahi, M; Shaabani, R; Nikmahzar, E G; Babakordi, F

2014-01-01

98

Antimullerian Hormone and Its Receptor Gene Expression in Prenatally Androgenized Female Rats  

PubMed Central

Background: Anti-mullerian hormone (AMH) levels reflect the number of small antral follicles in ovaries and expression changes of AMH and its receptor are suspected to be involved in the pathogenesis of polycystic ovary syndrome (PCOS). Objectives: The aim of this study was to evaluate gene expression of AMH and its receptor in immature and adult rats prenatally exposed to androgen excess. Materials and Methods: Six pregnant Wistar rats in the experimental group were treated by subcutaneous injection of 5 mg free testosterone on day 20 of pregnancy, while controls (n = 6) received only 500 mL of solvent. Female pups of each mother were randomly divided into three groups as day 0 (newborn), 10-day old and days 75-85 (adult). RNAs were extracted from ovarian tissues and relative expression levels for AMH and its receptor genes were measured using TaqMan Real-Time PCR. Serum AMH and testosterone levels were measured using ELISA method. Results: Relative AMH expression decreased in newborns, 10-day olds and adults (0.806, 0.443 and 0.809 fold, respectively). AMHR expression was higher in newborns and adults (1.432 and 1.057 fold, respectively), while it decreased by 0.263 fold in 10-day olds, although none of them were significant (P > 0.05). In addition, AMH levels were consistent with the results of gene expression. Testosterone hormone levels from 10 day-olds to adults were significantly increased in both study groups (P = 0.016). Conclusions: While AMH receptor expression was higher in experimental rats, their serum concentrations of AMH were decreased. Further researches with greater sample sizes and measurement of bioactive forms of hormones are recommended to confirm the findings of this study. PMID:25745494

Daneshian, Zahra; Ramezani Tehrani, Fahimeh; Zarkesh, Maryam; Norooz Zadeh, Mahsa; Mahdian, Reza; Zadeh Vakili, Azita

2015-01-01

99

Iron deficiency is associated with food insecurity in pregnant females in the United States: National Health and Nutrition Examination Survey 1999-2010.  

PubMed

Food-insecure pregnant females may be at greater risk of iron deficiency (ID) because nutrition needs increase and more resources are needed to secure food during pregnancy. This may result in a higher risk of infant low birth weight and possibly cognitive impairment in the neonate. The relationships of food insecurity and poverty income ratio (PIR) with iron intake and ID among pregnant females in the United States were investigated using National Health and Nutrition Examination Survey 1999-2010 data (n=1,045). Food security status was classified using the US Food Security Survey Module. One 24-hour dietary recall and a 30-day supplement recall were used to assess iron intake. Ferritin, soluble transferrin receptor, or total body iron classified ID. Difference of supplement intake prevalence, difference in mean iron intake, and association of ID and food security status or PIR were assessed using ?(2) analysis, Student t test, and logistic regression analysis (adjusted for age, race, survey year, PIR/food security status, education, parity, trimester, smoking, C-reactive protein level, and health insurance coverage), respectively. Mean dietary iron intake was similar among groups. Mean supplemental and total iron intake were lower, whereas odds of ID, classified by ferritin status, were 2.90 times higher for food-insecure pregnant females compared with food-secure pregnant females. Other indicators of ID were not associated with food security status. PIR was not associated with iron intake or ID. Food insecurity status may be a better indicator compared with income status to identify populations at whom to direct interventions aimed at improving access and education regarding iron-rich foods and supplements. PMID:24953790

Park, Clara Y; Eicher-Miller, Heather A

2014-12-01

100

Prenatal Testosterone Induces Sex-Specific Dysfunction in Endothelium-Dependent Relaxation Pathways in Adult Male and Female Rats1  

PubMed Central

ABSTRACT Prenatal testosterone (T) exposure impacts postnatal cardiovascular function, leading to increases in blood pressure with associated decreased endothelium-dependent vascular relaxation in adult females. Endothelial function in males is not known. Furthermore, which of the endothelial pathways contributes to endothelial dysfunction and if there exists sex differences are not known. The objective of this study was to characterize the relative contribution of nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF) to the impaired endothelium-dependent vasodilation in prenatal T-exposed adult males and females. Offspring of pregnant rats treated with T propionate or its vehicle were examined. Telemetric blood pressure levels and endothelium-dependent vascular reactivity were assessed with wire myography. Levels of nitric oxide synthase (NOS3) and Kcnn3 and Kcnn4 channel expression were examined in mesenteric arteries. Mean arterial pressure was significantly higher in T males and females than in controls. Endothelium-dependent acetylcholine relaxation was significantly lower in both T males and females. EDHF-mediated relaxation was specifically blunted in T males (Emax = 48.64% ± 3.73%) compared to that in control males (Emax = 81.71% ± 3.18%); however, NO-mediated relaxation was specifically impaired in T females (Emax = 36.01% ± 4.29%) compared with that in control females (Emax = 54.56% ± 6.37%). Relaxation to sodium nitroprusside and levcromakalim were unaffected with T-treatment. NOS3 protein was decreased in T females but not in T males. Kcnn3 expression was decreased in both T males and females compared to controls. These findings suggest that prenatal T leads to an increase in blood pressure in the adult offspring, associated with blunting of endothelial cell-associated relaxation and that the effects are sex-specific: EDHF-related in males and NO-related in females. PMID:23966325

Chinnathambi, Vijayakumar; Yallampalli, Chandrasekhar; Sathishkumar, Kunju

2013-01-01

101

2-Hydroxyestradiol enhances binge onset in female rats and reduces prefrontal cortical dopamine in male rats.  

PubMed

Women are more likely to suffer from a bingeing-related eating disorder, which is surprising, since estradiol reduces meal size and is associated with reduced binge frequency. This apparent contradiction may involve the estradiol metabolite, 2-hydroxyestradiol. We previously reported that female rats had faster escalations in shortening intake during the development of bingeing than did males, but acute administration of 2-hydroxyestradiol increased the intake of vegetable shortening to a greater extent in male rats once bingeing was established. Here, we report two separate studies that follow up these previous findings. In the first, we hypothesized that chronic exposure to 2-hydroxyestradiol would promote escalation of bingeing during binge development in ovariectomized female rats. In the second, we hypothesized that acute exposure to 2-hydroxyestradiol would enhance dopamine signaling in the prefrontal cortex after bingeing was established in male rats. In study 1, non-food-deprived female rats were separated into 3 groups: ovariectomized (OVX) with chronic 2-hydroxyestradiol supplementation (E), OVX with vehicle supplementation (O), and intact with vehicle (I). Each group was given access to an optional source of dietary fat (shortening) on Mon, Wed, and Fri for 4 weeks. 2-hydroxyestradiol supplementation prevented OVX-induced weight gain and enhanced escalation of shortening intake over the four-week period (ps<0.05). Additionally, in week 4, rats in the E group ate significantly more shortening than I controls, less chow than either the O or I group, and had a higher shortening to chow ratio than O or I (ps<0.05). Study 2 indicated that acute injection of 2-hydroxyestradiol abolished shortening-evoked dopamine efflux in the prefrontal cortex of bingeing male rats (p<0.05). Together, these studies indicate that 2-hydroxyestradiol can exacerbate bingeing as it develops and can suppress dopamine signaling in the prefrontal cortex once bingeing is established. PMID:23116652

Babbs, R K; Unger, E L; Corwin, R L W

2013-01-01

102

Runaway and Pregnant: Risk Factors Associated with Pregnancy in a National Sample of Runaway\\/Homeless Female Adolescents  

Microsoft Academic Search

Purpose: Homeless youth are at particularly high risk for teen pregnancy; research indicates as many as 20% of homeless young women become pregnant. These pregnant and homeless teens lack financial resources and adequate health care, resulting in increased risk for low- birth-weight babies and high infant mortality. This study investigated individual and family-level predictors of teen pregnancy among a national

Sanna J. Thompson; Kimberly A. Bender; Carol M. Lewis; Rita Watkins

103

Neonatal injections of methoxychlor decrease adult rat female reproductive behavior.  

PubMed

Methoxychlor (MXC), a commonly used pesticide, has been labeled as an endocrine disruptor. To evaluate the impact of neonatal exposure to MXC on female reproduction, female Sprague-Dawley rats were given subcutaneous injections on postnatal days 1, 3, and 5. The injections contained 1.0mg MXC, 2.0mg MXC, 10 ?g 17?-estradiol benzoate (positive control), or sesame oil (vehicle). The injections of MXC had no effect on anogenital distance or day of vaginal opening. Treatment with either 2.0mg MXC or estradiol significantly increased the total number of days with vaginal keratinization. Treatment with MXC had no effect on ability to exhibit a mating response as an adult female, although the high dose MXC (2.0) and the positive control (estradiol) animals demonstrated a decrease in degree of receptivity, a decrease in proceptive behavior and an increase in rejection behavior. These data suggest that higher doses of MXC given directly to pups during the neonatal period can act as an estrogen and alter aspects of the nervous system, impacting adult reproductive characteristics. PMID:21726579

Bertolasio, Jennifer; Fyfe, Susanne; Snyder, Ben W; Davis, Aline M

2011-12-01

104

Immunization of Wistar female rats with 255-Gy-irradiated Toxoplasma gondii: preventing parasite load and maternofoetal transmission.  

PubMed

Toxoplasmosis, caused by an obligate intracellular protozoan parasite, Toxoplasma gondii, is an worldwide parasitic disease, with significant importance for animal production and considerable impact to the public health. This study was aimed to evaluate the dynamic of the distribution of T.gondii in tissues of female Wistar rats and their puppies tissues, after the immunization by oral rote with irradiated tachyzoites. One week after pregnancy confirmation, rats was challenged by gavage with T. gondii bradyzoites, oocysts or tachyzoites of T. gondii. Forty-eight pregnant rats were grouped as follow: immunized and challenged with bradyzoites (BZ*); non-immunized and challenged with bradyzoites (BZ); immunized and challenged with oocysts (OC*); non-immunized and challenged with oocysts (OC); immunized and challenged with tachyzoites (TZ*); non-immunized and challenged with tachyzoites (TZ); only immunized (I); control group (C). After parturition the rats were sacrificed and the tissues were researched for the DNA of T. gondii by polymerase chain reaction (PCR) and the parasite load determined by the quantitative PCR (qPCR). It was verified that the immunization with irradiated tachyzoites of T. gondii induced the reduction of parasitic load in most organs analyzed, although not prevent the establishment of infection with the parasite. And also, the immunization showed a favorable effect on the birth rate and litter size. PMID:25169764

Camossi, Lucilene Granuzzio; Fornazari, Felipe; Richini-Pereira, Virgínia Bodelăo; da Silva, Rodrigo Costa; Cardia, Daniel Fontana Ferreira; Langoni, Helio

2014-10-01

105

Adverse effects of 4-tert-octylphenol on the production of oxytocin and hCG in pregnant rats  

PubMed Central

Endocrine-disrupting chemicals (EDCs) are exogenous substances that alter the structure or function of the endocrine system. 4-Tert-octylphenol (OP) is one of the most representative EDCs and has estrogenic effects. In this study, we examined the effects of ethinyl estradiol (EE) and OP on the pituitary gland, placenta, and uterus of pregnant rats. Expression levels of human chorionic gonadotropin (hCG), oxytocin (OT), and contraction-associated proteins (CAPs) were determined, and uterine contractile activity was measured by uterine contraction assay. EE and OP both increased mRNA expression of OT and hCG in the pituitary gland but not the placenta. Since OT and hCG control uterine contraction, we next examined CAP expression in the uterus. Expression of 15-hydroxyprostaglandin-dehydrogenase (PGDH) was upregulated by OP, whereas expression of other CAPs was unaffected. To clarify the effect of OP on uterine contraction in pregnant rats, uterine contraction assay was performed. The 17?-Estradiol (E2) did not affect contraction of primary uterine cells harvested from pregnant rats in a 3D collagen gel model. However, OP showed different effects from E2 by significantly reducing contraction activity. In summary, we demonstrated that OP interferes with regulation of OT and hCG in the pituitary gland as well as PGDH in the uterus, thereby reducing uterine contraction activity. This result differs from the action of endogenous E2. Collectively, these findings suggest that exposure to EDCs such as OP during pregnancycan reduce uterine contractile ability, which may result in contraction-associated adverse effects such as metratonia, bradytocia, and uterine leiomyomata. PMID:25324873

Kim, Jun; Kang, Eun-Jin; Park, Mee-Na; Lee, Jae-Eon; Hong, So-Hye; An, Sung-Min; Kim, Seung-Chul; Hwang, Dae-Youn

2014-01-01

106

Morphologic and histologic abnormalities in female and male rats treated with anabolic steroids  

Microsoft Academic Search

A two-part study was performed to determine the ef fects of high doses of anabolic steroids on weight, appetite, and organ histology. Initially, 30 white Wistar rats, 15 males and 15 females, were treated weekly with either 0.52 cc of physiologic saline or nandrolone decanoate. After 6 weeks, female treated and control rats had comparable weight gains, but male treated

Janet A. Yu-Yahiro; Roger H. Michael; David V. Nasrallah; Brian Schofield

1989-01-01

107

Prenatal Testosterone Exposure Leads to Hypertension That Is Gonadal Hormone-Dependent in Adult Rat Male and Female Offspring1  

PubMed Central

ABSTRACT Prenatal testosterone exposure impacts postnatal reproductive and endocrine function, leading to alterations in sex steroid levels. Because gonadal steroids are key regulators of cardiovascular function, it is possible that alteration in sex steroid hormones may contribute to development of hypertension in prenatally testosterone-exposed adults. The objectives of this study were to evaluate whether prenatal testosterone exposure leads to development of hypertension in adult males and females and to assess the influence of gonadal hormones on arterial pressure in these animals. Offspring of pregnant rats treated with testosterone propionate or its vehicle (controls) were examined. Subsets of male and female offspring were gonadectomized at 7 wk of age, and some offspring from age 7 to 24 wk received hormone replacement, while others did not. Testosterone exposure during prenatal life significantly increased arterial pressure in both male and female adult offspring; however, the effect was greater in males. Prenatal androgen-exposed males and females had more circulating testosterone during adult life, with no change in estradiol levels. Gonadectomy prevented hyperandrogenism and also reversed hypertension in these rats. Testosterone replacement in orchiectomized males restored hypertension, while estradiol replacement in ovariectomized females was without effect. Steroidal changes were associated with defective expression of gonadal steroidogenic genes, with Star, Sf1, and Hsd17b1 upregulation in testes. In ovaries, Star and Cyp11a1 genes were upregulated, while Cyp19 was downregulated. This study showed that prenatal testosterone exposure led to development of gonad-dependent hypertension during adult life. Defective steroidogenesis may contribute in part to the observed steroidal changes. PMID:22302690

Chinnathambi, Vijayakumar; Balakrishnan, Meena; Yallampalli, Chandrasekhar; Sathishkumar, Kunju

2012-01-01

108

Prenatal testosterone exposure leads to hypertension that is gonadal hormone-dependent in adult rat male and female offspring.  

PubMed

Prenatal testosterone exposure impacts postnatal reproductive and endocrine function, leading to alterations in sex steroid levels. Because gonadal steroids are key regulators of cardiovascular function, it is possible that alteration in sex steroid hormones may contribute to development of hypertension in prenatally testosterone-exposed adults. The objectives of this study were to evaluate whether prenatal testosterone exposure leads to development of hypertension in adult males and females and to assess the influence of gonadal hormones on arterial pressure in these animals. Offspring of pregnant rats treated with testosterone propionate or its vehicle (controls) were examined. Subsets of male and female offspring were gonadectomized at 7 wk of age, and some offspring from age 7 to 24 wk received hormone replacement, while others did not. Testosterone exposure during prenatal life significantly increased arterial pressure in both male and female adult offspring; however, the effect was greater in males. Prenatal androgen-exposed males and females had more circulating testosterone during adult life, with no change in estradiol levels. Gonadectomy prevented hyperandrogenism and also reversed hypertension in these rats. Testosterone replacement in orchiectomized males restored hypertension, while estradiol replacement in ovariectomized females was without effect. Steroidal changes were associated with defective expression of gonadal steroidogenic genes, with Star, Sf1, and Hsd17b1 upregulation in testes. In ovaries, Star and Cyp11a1 genes were upregulated, while Cyp19 was downregulated. This study showed that prenatal testosterone exposure led to development of gonad-dependent hypertension during adult life. Defective steroidogenesis may contribute in part to the observed steroidal changes. PMID:22302690

Chinnathambi, Vijayakumar; Balakrishnan, Meena; Yallampalli, Chandrasekhar; Sathishkumar, Kunju

2012-05-01

109

The effects of topiramate and sex hormones on energy balance of male and female rats  

Microsoft Academic Search

OBJECTIVE: The effects of topiramate (TPM) on components of energy balance were tested in male and female rats that were (i) left intact, (ii) castrated or (iii) castrated with replacement therapies consisting of testosterone administration in orchidectomized (OCX) rats and of estradiol or progesterone treatments in ovariectomized (OVX) rats.METHODS: TPM was mixed into the diet and administered at a dose

D Richard; F Picard; C Lemieux; J Lalonde; P Samson; Y Deshaies

2002-01-01

110

A Novel Telometric Metric for In-Situ Measurement of Intrauterine Pressure (IUP) in Pregnant and Parturient Rats  

NASA Technical Reports Server (NTRS)

During labor and birth, considerable forces exerted on fetuses help instigate certain adaptive postpartum responses (viz., breathing and suckling). To make precise, reliable measures of the forces experienced by rat fetuses during parturition, we developed a novel method for measuring intrauterine pressure (IUP) in late pregnant rats. A small (1.25 x 4cm) telemetric blood pressure sensor is fitted within a fluid-filled balloon, similar in size to a full term rat fetus. The balloon is surgically implanted in the uterus on Gestational Day 19 of the rats' 22-day pregnancy. During birth, dams are able to deliver their pups and the balloon. IUP arsenals are recorded during labor (G22 or 23) and birth. Data derived from a group of implanted rats indicated that pressures on the balloon increased across the period of birth, reaching 18 mmHg during labor, 25 mmHg during pup births and 39 mmHg just prior to delivery of the balloon. These data are within the range reported for conventional IUP measurement techniques. Dams are simultaneously videotaped, enabling us to analyze behavioral expressions of labor contractions and to integrate in-situ and behavioral findings.

Baer, Lisa A.; LaFramboise, M. N.; Hills, E. M.; Daly, M. E.; Mills, N. A.; Wade, C. E.; Ronca, A. E.; Dalton, Bonnie (Technical Monitor)

2001-01-01

111

EFFECTS OF EPICHLOROHYDRIN ON MALE AND FEMALE REPRODUCTION IN LONG-EVANS RATS  

EPA Science Inventory

Male and female Long-Evans rats were treated with epichlorohydrin (ECH) by oral gavage (males: 12.5, 25, and 50 mg/kg/day; females: 25, 50, and 100 mg/kg/day) for 21 and 14 days respectively, prior to mating trials with untreated animals. Treated females were further dosed until ...

112

Extracts from rabbit skin inflamed by the vaccinia virus attenuate bupivacaine-induced spinal neurotoxicity in pregnant rats?  

PubMed Central

Extracts from rabbit skin inflamed by the vaccinia virus can relieve pain and promote repair of nerve injury. The present study intraperitoneally injected extracts from rabbit skin inflamed by the vaccinia virus for 3 and 4 days prior to and following intrathecal injection of bupivacaine into pregnant rats. The pain threshold test after bupivacaine injection showed that the maximum possible effect of tail-flick latency peaked 1 day after intrathecal injection of bupivacaine in the extract-pretreatment group, and gradually decreased, while the maximum possible effect in the bupivacaine group continued to increase after intrathecal injection of bupivacaine. Histological observation showed that after 4 days of intrathecal injection of bupivacaine, the number of shrunken, vacuolated, apoptotic and caspase-9-positive cells in the dorsal root ganglion in the extract-pretreatment group was significantly reduced compared with the bupivacaine group. These findings indicate that extracts from rabbit skin inflamed by the vaccinia virus can attenuate neurotoxicity induced by intrathecal injection of bupivacaine in pregnant rats, possibly by inhibiting caspase-9 protein expression and suppressing nerve cell apoptosis. PMID:25206391

Cui, Rui; Xu, Shiyuan; Wang, Liang; Lei, Hongyi; Cai, Qingxiang; Zhang, Hongfei; Wang, Dongmei

2013-01-01

113

Extracts from rabbit skin inflamed by the vaccinia virus attenuate bupivacaine-induced spinal neurotoxicity in pregnant rats.  

PubMed

Extracts from rabbit skin inflamed by the vaccinia virus can relieve pain and promote repair of nerve injury. The present study intraperitoneally injected extracts from rabbit skin inflamed by the vaccinia virus for 3 and 4 days prior to and following intrathecal injection of bupivacaine into pregnant rats. The pain threshold test after bupivacaine injection showed that the maximum possible effect of tail-flick latency peaked 1 day after intrathecal injection of bupivacaine in the extract-pretreatment group, and gradually decreased, while the maximum possible effect in the bupivacaine group continued to increase after intrathecal injection of bupivacaine. Histological observation showed that after 4 days of intrathecal injection of bupivacaine, the number of shrunken, vacuolated, apoptotic and caspase-9-positive cells in the dorsal root ganglion in the extract-pretreatment group was significantly reduced compared with the bupivacaine group. These findings indicate that extracts from rabbit skin inflamed by the vaccinia virus can attenuate neurotoxicity induced by intrathecal injection of bupivacaine in pregnant rats, possibly by inhibiting caspase-9 protein expression and suppressing nerve cell apoptosis. PMID:25206391

Cui, Rui; Xu, Shiyuan; Wang, Liang; Lei, Hongyi; Cai, Qingxiang; Zhang, Hongfei; Wang, Dongmei

2013-04-15

114

Decreased Seizure Threshold in an Eclampsia-Like Model Induced in Pregnant Rats with Lipopolysaccharide and Pentylenetetrazol Treatments  

PubMed Central

Objective Eclampsia is a poorly understood but potentially fatal complication of pregnancy. Research to date on this disorder has been hampered by the lack of a suitable animal model. To correct this deficiency, this report describes the generation of a rat eclampsia-like model using pentylenetetrazol (PTZ) in a previously established rat preeclampsia model. Method Rats were administered lipopolysaccharide (1.0 µg/kg) by tail vein injection on gestational day 14 to establish preeclampsia (PE). PE and control rats (non-pregnant, NP; normal-pregnant, P) were injected intraperitoneally (i.p.) with PTZ (40 mg/kg) to induce seizures. In separate experiments, MgSO4 (270 mg/kg IP) was injected in advance of PTZ into PE rats to observe its effect on PTZ-induced seizures. Results PE conditions were verified in rats after LPS administration by significantly higher blood pressure (P<0.01) and urinary albumin excretion (P<0.05), elevated sFlt-1 (P<0.05) and decreased PlGF serum levels (P<0.05), and evidence of hepatic dysfunction compared to control groups. PTZ successfully induced seizure activity in all groups studied. Latency to seizure was significantly (P<0.01) less in the PE-PTZ group (73.2±6.6 sec.) than in PTZ-treated controls (107.0±7.4 sec.). Pretreatment with MgSO4 prolonged (P<0.05) latency to seizure, shortened seizure duration and decreased seizure rates. Significant increased (P<0.05) in the serum levels of the inflammatory cytokines TNF-? and IL-1? in PE and PE-PTZ groups, and decreased (P<0.05) in their levels following MgSO4 administration. Conclusion This PTZ-induced eclampsia-like rat model is comparable to the human condition of eclampsia and may serve as a useful research tool for future studies of this disease. The increased inflammatory cytokines in preeclampsia are coincident with a decreased threshold for PTZ-induced seizures, suggesting that an inflammatory mechanism may contribute to the susceptibility to seizure activity and inflammation might have an important role in eclampsia. PMID:24586695

Huang, Qian; Liu, Lei; Hu, Bihui; Di, Xiaodan; Brennecke, Shaun Patrick; Liu, Huishu

2014-01-01

115

Chronic Di-n-butyl Phthalate Exposure in Rats Reduces Fertility and Alters Ovarian Function During Pregnancy in Female Long Evans Hooded Rats  

Microsoft Academic Search

Testis function in fetal and peripubertal male rats is disrupted by subchronic exposure to phthalate esters (PEs). In contrast to the male rat, it is generally held that reproduction in female rats is much less sensitive to phthalate-induced disruption. However, the current study demonstrates that oral administration of dibutyl phthalate (DBP) to female Long Evans (LE) hooded rats from weaning,

L. E. Gray; John Laskey; Joseph Ostby

2006-01-01

116

Transient Receptor Potential C4/5 Like Channel Is Involved in Stretch-Induced Spontaneous Uterine Contraction of Pregnant Rat  

PubMed Central

Spontaneous myometrial contraction (SMC) in pregnant uterus is greatly related with gestational age and growing in frequency and amplitude toward the end of gestation to initiate labor. But, an accurate mechanism has not been elucidated. In human and rat uterus, all TRPCs except TRPC2 are expressed in pregnant myometrium and among them, TRPC4 are predominant throughout gestation, suggesting a possible role in regulation of SMC. Therefore, we investigated whether the TRP channel may be involved SMC evoked by mechanical stretch in pregnant myometrial strips of rat using isometric tension measurement and patch-clamp technique. In the present results, hypoosmotic cell swelling activated a potent outward rectifying current in G protein-dependent manner in rat pregnant myocyte. The current was significantly potentiated by 1µM lanthanides (a potent TRPC4/5 stimulator) and suppressed by 10µM 2-APB (TRPC4-7 inhibitor). In addition, in isometric tension experiment, SMC which was evoked by passive stretch was greatly potentiated by lanthanide (1µM) and suppressed by 2-APB (10µM), suggesting a possible involvement of TRPC4/5 channel in regulation of SMC in pregnant myometrium. These results provide a possible cellular mechanism for regulation of SMC during pregnancy and provide basic information for developing a new agent for treatment of premature labor. PMID:25598665

Chung, Seungsoo; Kim, Young-Hwan; Joeng, Ji-Hyun

2014-01-01

117

Antenatal Hypoxia Induces Programming of Reduced Arterial Blood Pressure Response in Female Rat Offspring: Role of Ovarian Function  

PubMed Central

In utero exposure to adverse environmental factors increases the risk of cardiovascular disease in adulthood. The present study tested the hypothesis that antenatal hypoxia causes a gender-dependent programming of altered arterial blood pressure response (BP) in adult offspring. Time-dated pregnant rats were divided into normoxic and hypoxic (10.5% O2 from days 15 to 21 of gestation) groups. The experiments were conducted in adult offspring. Antenatal hypoxia caused intrauterine growth restriction, and resulted in a gender-dependent increase Angiotensin II (Ang II)-induced BP response in male offspring, but significant decrease in BP response in female offspring. The baroreflex sensitivity was not significantly altered. Consistent with the reduced blood pressure response, antenatal hypoxia significantly decreased Ang II-induced arterial vasoconstriction in female offspring. Ovariectomy had no significant effect in control animals, but significantly increased Ang II-induced maximal BP response in prenatally hypoxic animals and eliminated the difference of BP response between the two groups. Estrogen replacement in ovariectomized animals significantly decreased the BP response to angiotensin II I only in control, but not in hypoxic animals. The result suggests complex programming mechanisms of antenatal hypoxia in regulation of ovary function. Hypoxia-mediated ovary dysfunction results in the phenotype of reduced vascular contractility and BP response in female adult offspring. PMID:24905716

Xiao, DaLiao; Huang, Xiaohui; Xue, Qin; Zhang, Lubo

2014-01-01

118

Effects of acute ethanol exposure on hepatic metallothionein, zinc and glutathione in male and female rats  

SciTech Connect

The purpose of this study was to determine the simultaneous responses of hepatic metallothionein (MT), zinc (Zn) and glutathione (GSH) in male and female rats to an acute ethanol dose. In male rats, hepatic MT has been shown to be induced by an acute ethanol dose. The Sprague-Dawley rats were fed the Lieber-DeCarli control diet for a five day period and then divided into 6 groups: baseline females and males, ethanol-treated females and males, pair-fed females and males. At t=0, baseline rats were killed, ethanol-treated rats were given ethanol by intragastric tube, and pair-fed rats were given ethanol by intragastric tube, and pair-fed rats were given an isocaloric sucrose solution by intragastric tube. At t=24 h, the ethanol-treated and pair-fed rats were killed. Livers were assayed for MT. Zn and GSH. Concentrations of blood ethanol (BEC) were significantly greater for male than female rats. A two way ANOVA with the independent variables being time and sex was performed to analyze differences for hepatic MT, Zn and GSH. For rats dosed with ethanol and killed 24 h later compared with rats at baseline, hepatic MT was significantly greater and hepatic Zn and GSH were not significantly different. Hepatic MT, Zn and GSH were not significantly different by sex. A significant correlation existed between hepatic Zn/g and MT/g. In conclusion, 24 h after an acute dose of ethanol, female as well as male rats responded with the induction of hepatic MT; and enough cysteine was available for the induction of hepatic MT and the maintenance of hepatic GSH levels. The measurement of Zn bound to hepatic MT rather than total hepatic Zn would be desirable to discern if changes in Zn distribution occur.

Harris, J.; Harrell, B. (Univ. of Kansas Medical Center, Kansas City (United States))

1991-03-15

119

In Adolescence, Female Rats Are More Sensitive to the Anxiolytic Effect of Nicotine Than Are Male Rats  

Microsoft Academic Search

Anxiety may play an important role in the onset of smoking, particularly in young girls. This study examined whether there were sex differences in the effects of nicotine on anxiety in adolescent rats and whether social isolation modified these effects. Male and female adolescent rats were housed in groups of the same sex or in social isolation for seven days

Survjit Cheeta; Elaine E Irvine; Sonia Tucci; Jasdeep Sandhu; Sandra E File

2001-01-01

120

Standardised Models for Inducing Experimental Peritoneal Adhesions in Female Rats  

PubMed Central

Animal models for adhesion induction are heterogeneous and often poorly described. We compare and discuss different models to induce peritoneal adhesions in a randomized, experimental in vivo animal study with 72 female Wistar rats. Six different standardized techniques for peritoneal trauma were used: brushing of peritoneal sidewall and uterine horns (group 1), brushing of parietal peritoneum only (group 2), sharp excision of parietal peritoneum closed with interrupted sutures (group 3), ischemic buttons by grasping the parietal peritoneum and ligating the base with Vicryl suture (group 4), bipolar electrocoagulation of the peritoneum (group 5), and traumatisation by electrocoagulation followed by closure of the resulting peritoneal defect using Vicryl sutures (group 6). Upon second look, there were significant differences in the adhesion incidence between the groups (P < 0.01). Analysis of the fraction of adhesions showed that groups 2 (0%) and 5 (4%) were significantly less than the other groups (P < 0.01). Furthermore, group 6 (69%) was significantly higher than group 1 (48%) (P < 0.05) and group 4 (47%) (P < 0.05). There was no difference between group 3 (60%) and group 6 (P = 0.2). From a clinical viewpoint, comparison of different electrocoagulation modes and pharmaceutical adhesion barriers is possible with standardised models. PMID:24809049

Kraemer, Bernhard; Wallwiener, Christian; Rajab, Taufiek K.; Brochhausen, Christoph; Wallwiener, Markus; Rothmund, Ralf

2014-01-01

121

14-C-NAPHTHYL, 14-C-METHYL AND 14-C-CARBONYL CARBARYL DISTRIBUTION IN THE PREGNANT MOUSE AND RAT  

EPA Science Inventory

The distribution of carbaryl labeled with 14C in the ring, methyl or carbonyl groups was determined in pregnant mice and rats. Three identical concurrent experiments were performed using each of the three radiolabeled compounds in each of the species so that the different moietie...

122

Regional differences in the pituitary distribution of luteinizing hormone in the gonadectomized and proestrous female rat  

EPA Science Inventory

Previous data have shown regional differences in the presence of anterior pituitary luteinizing hormone (LH) that generally correlate with comparable disparities in the distribution of gonadotropes throughout the gland. In female rats, the differences are apparent over the estro...

123

DEVELOPMENTAL ATRAZINE EXPOSURE SUPPRESSES IMMUNE FUNCTION IN MALE, BUT NOT FEMALE SPRAGUE-DAWLEY RATS  

EPA Science Inventory

Developmental Atrazine Exposure Suppresses Immune Function in Male, but not Female Sprague-Dawley Rats Andrew A. Rooney,*,1 Raymond A. Matulka,? and Robert Luebke? *College of Veterinary Medicine, Anatomy, Physiological Sciences and Radiology, NCSU, Raleigh, North...

124

Placental ischemia in pregnant rats impairs cerebral blood flow autoregulation and increases blood–brain barrier permeability  

PubMed Central

Abstract Cerebrovascular events contribute to ~40% of preeclampsia/eclampsia?related deaths, and neurological symptoms are common among preeclamptic patients. We previously reported that placental ischemia, induced by reducing utero?placental perfusion pressure, leads to impaired myogenic reactivity and cerebral edema in the pregnant rat. Whether the impaired myogenic reactivity is associated with altered cerebral blood flow (CBF) autoregulation and the edema is due to altered blood–brain barrier (BBB) permeability remains unclear. Therefore, we tested the hypothesis that placental ischemia leads to impaired CBF autoregulation and a disruption of the BBB. CBF autoregulation, measured in vivo by laser Doppler flowmetry, was significantly impaired in placental ischemic rats. Brain water content was increased in the anterior cerebrum of placental ischemic rats and BBB permeability, assayed using the Evans blue extravasation method, was increased in the anterior cerebrum. The expression of the tight junction proteins: claudin?1 was increased in the posterior cerebrum, while zonula occludens?1, and occludin, were not significantly altered in either the anterior or posterior cerebrum. These results are consistent with the hypothesis that placental ischemia mediates anterior cerebral edema through impaired CBF autoregulation and associated increased transmission of pressure to small vessels that increases BBB permeability leading to cerebral edema. PMID:25168877

Warrington, Junie P.; Fan, Fan; Murphy, Sydney R.; Roman, Richard J.; Drummond, Heather A.; Granger, Joey P.; Ryan, Michael J.

2014-01-01

125

Effect of Lifelong Nicotine Inhalation on Bone Mass and Mechanical Properties in Female Rat Femurs  

Microsoft Academic Search

.   As tobacco smoking has been identified as a risk factor in the development of osteoporosis, possible deleterious effects\\u000a of nicotine inhalation on bone mineral density (BMD) and mechanical properties of the femur in female rats were studied. Female\\u000a Sprague Dawley rats were exposed to nicotine vapour 20 hours a day 5 days a week for 2 years. The nicotine

U. Syversen; L. Nordsletten; J. A. Falch; J. E. Madsen; O. G. Nilsen; H. L. Waldum

1999-01-01

126

Long-term consequences of uninephrectomy in male and female rats.  

PubMed

We investigated the effects of uninephrectomy (UNX) in 6-week-old male and female rats on blood pressure (BP), renal sodium handling, salt sensitivity, oxidative stress, and renal injury over 18 months postsurgery, studying control sham-operated and UNX-operated rats at 6, 12, and 18 months postsurgery, evaluating their renal sodium handling, BP, urinary isoprostanes, N-acetyl-?-D-glucosaminidase, and proteinuria before and after a 2-week high-salt intake period. At 18 months, plasma variables were measured and kidney samples were taken for the analysis of renal morphology and tissue variables. BP was increased at 6 months in male UNX rats versus controls and at 12 and 18 months in both male and female UNX rats and was increased in male versus female UNX groups at 18 months. UNX did not affect water and sodium excretion under basal conditions and after the different test in male and female rats at different ages. However, the renal function curve was shifted to the right in both male and female UNX rats. High-salt intake increased BP in both UNX groups at 6, 12, and 18 months and in the female control group at 18 months, and it increased proteinuria, N-acetyl-?-D-glucosaminidase, and isoprostanes in both UNX groups throughout the study. Renal lesions at 18 months were more severe in male versus female UNX rats. In summary, long-term UNX increased the BP, creatinine, proteinuria, pathological signs of renal injury, and salt sensitivity. Earlier BP elevation was observed and morphological lesions were more severe in male than in female UNX rats. PMID:23071124

Rodríguez-Gómez, Isabel; Wangensteen, Rosemary; Pérez-Abud, Rocío; Quesada, Andrés; Del Moral, Raimundo G; Osuna, Antonio; O'Valle, Francisco; de Dios Luna, Juan; Vargas, Félix

2012-12-01

127

Green tea polyphenols mitigate deterioration of bone microarchitecture in middle-aged female rats  

Microsoft Academic Search

Our previous study demonstrated that green tea polyphenols (GTP) benefit bone health in middle-aged female rats without (sham, SH) and with ovariectomy (OVX), because of GTP's antioxidant capacity. The current study further evaluates whether GTP can restore bone micro-structure in both gonad-intact and gonadal-hormone-deficient middle-aged female rats. A 16-week study was performed based on a 2 (SH vs. OVX)×3 (no

Chwan-Li Shen; James K. Yeh; Barbara J. Stoecker; Ming-Chien Chyu; Jia-Sheng Wang

2009-01-01

128

A cognitive rehabilitation paradigm effective in male rats lacks efficacy in female rats.  

PubMed

Cognitive dysfunction, as a consequence of dementia, is a significant cause of morbidity lacking efficacious treatment. Females comprise at least half of this demographic but have been vastly underrepresented in preclinical studies. The current study addressed this gap by assessing the protective efficacy of physical exercise and cognitive activity on learning and memory outcomes in a rat model of vascular dementia. Forty ovariectomized Sprague-Dawley rats (?6 months old) were exposed to either a diet high in saturated fats and refined sugars or standard laboratory chow and underwent either chronic bilateral carotid occlusion or Sham surgery. Learning and memory abilities were evaluated using standard cognitive outcomes over the ensuing 6 months, followed by histologic analyses of hippocampal CA1 neurons. In Experiment 1, we confirmed hypoperfusion-induced cognitive dysfunction using a 2 × 2 (Surgery × Diet) experimental design, without alterations in hippocampal architecture. In Experiment 2, hypoperfused animals were either exposed to alternating days of physical (wheel running) and cognitive activity (modified Hebb-Williams maze) or sedentary housing. In contrast to males, this combination rehabilitation paradigm did not improve cognition or histopathologic outcomes in hypoperfused animals. These findings, highlighting differences between female and male animals, show the necessity of including both sexes in preclinical experimentation. PMID:25052554

Langdon, Kristopher D; Granter-Button, Shirley; Harley, Carolyn W; Moody-Corbett, Frances; Peeling, James; Corbett, Dale

2014-10-01

129

FEMALE RATS DISPLAY ENHANCED REWARDING EFFECTS OF ETHANOL THAT ARE HORMONE DEPENDENT  

PubMed Central

Background Ethanol abuse is a major health and economic concern, particularly for females who appear to be more sensitive to the rewarding effects of ethanol. This study compared sex differences to the rewarding and aversive effects of ethanol using place-conditioning procedures in rats. Methods Separate groups of adult (male, female, ovariectomized [OVX] female) and adolescent (male and female) rats received ethanol (0, 0.5, 1.0, 2.0 or 2.5 g/kg; ip) and were confined to their initially non-preferred side of our conditioning apparatus for 30 minutes. On alternate days, they received saline and were confined to the other side. Following 5 drug pairings, the rats were re-tested for preference behavior. Separate cohorts of the same groups of rats were injected with a similar dose range of ethanol and blood ethanol levels (BELs) were compared 30 minutes later. Results Ethanol produced rewarding or aversive effects in a dose-dependent manner. An intermediate dose of ethanol (1.0 g/kg) produced rewarding effects in adult female but not male or OVX female rats, suggesting that ovarian hormones facilitate the rewarding effects of ethanol. Similarly, this intermediate dose of ethanol produced rewarding effects in adolescent female but not male rats. The highest dose of ethanol (2.5 g/kg) produced aversive effects that were similar across all adult groups. However, the aversive effects of ethanol were lower in adolescents than adults, suggesting that adolescents are less sensitive to the aversive effects of ethanol. The aversive effects of ethanol did not vary across the estrous cycle in intact adult females. There were also no group differences in BELs, suggesting that our results are not related to ethanol metabolism. Conclusion Our results in rats suggest that human females may be more vulnerable to ethanol abuse due to enhanced rewarding effects of this drug that are mediated by the presence of ovarian hormones. PMID:23909760

Torres, Oscar V.; Walker, Ellen M.; Beas, Blanca S.; O’Dell, Laura E.

2013-01-01

130

A calcium-deficient diet in pregnant, nursing rats induces hypomethylation of specific cytosines in the 11?-hydroxysteroid dehydrogenase-1 promoter in pup liver.  

PubMed

Prenatal undernutrition affects offspring phenotype via changes in the epigenetic regulation of specific genes. We hypothesized that pregnant females that were fed a calcium (Ca)-deficient diet would have offspring with altered hepatic glucocorticoid-related gene expression and altered epigenetic gene regulation. Female Wistar rats ate either a Ca-deficient or control diet from 3 weeks before conception to 21 days after parturition. Pups were allowed to nurse from their original mothers and then euthanized on day 21. Methylation of individual cytosine-guanine dinucleotides in the phosphoenolpyruvate carboxykinase (Pck1), peroxisome proliferator-activated receptor ? (Ppara), glucocorticoid receptor (Nr3c1), 11?-hydroxysteroid dehydrogenase-1 (Hsd11b1), and 11?-hydroxysteroid dehydrogenase-2 (Hsd11b2) promoters was measured in liver tissue using pyrosequencing. For each gene, quantitative real-time polymerase chain reaction was used to assess mRNA levels in liver tissue. Overall Hsd11b1 methylation was lower in the Ca-deficient group than in the control group; however, overall methylation of each other gene did not differ between groups. Serum corticosterone levels in male pups from Ca-deficient dams were higher than those in control pups. Expression of Pck1 and Nr3c1 was lower in the Ca-deficient group than in the control group. A Ca-deficient diet for a dam during gestation and early nursing may alter glucocorticoid metabolism and lead to higher intracellular glucocorticoid concentrations in the hepatic cells of her offspring; moreover, this abnormal glucocorticoid metabolism may induce the metabolic complications that are associated with Ca deficiency. These findings indicated that prenatal nutrition affected glucocorticoid metabolism in offspring in part by affecting the epigenome of offspring. PMID:24176236

Takaya, Junji; Iharada, Anna; Okihana, Hiroyuki; Kaneko, Kazunari

2013-11-01

131

Changes in geometrical and biomechanical properties of immature male and female rat tibia  

NASA Technical Reports Server (NTRS)

The differences in the geometry and mechanical properties of immature male and female rat tibiae were detailed in order to provide comparative data for spaceflight, exercise, or disease experiments that use immature rats as an animal model. The experiment focuses on the particularly rapid period of growth that occurs in the Sprague-Dawley rat between 40 and 60 d of age. Tibial length and middiaphysical cross-sectional data were analyzed for eight different groups of rats according to age and sex, and tibial mechanical properties were obtained via three-point bending tests to failure. Results indicate that, during the 15 d period of rapid growth, changes in rat tibial geometry are more important than changes in bone material properties for influencing the mechanical properties of the tibia. Male tibiae changed primarily in structural properties, while in the female rats major changes in mechanical properties of the tibia were only attributable to changes in the structural properties of the bone.

Zernicke, Ronald F.; Hou, Jack C.-H.; Vailas, Arthur C.; Nishimoto, Mitchell; Patel, Sanjay

1990-01-01

132

[Characteristics of load dependent relaxation of normal and hypertrophied myocardium in male and female rats].  

PubMed

Under monocrotaline treatment of rat right ventricle myocardium preparations significant changes in morphometric indices for male, but not for female preparations are adduced as compared to the control group. Peculiarities of adaptation of mechanocalcium uncoupling mechanism, one of important regulation mechanisms of rat myocardial contractility, were first revealed. Myocardial pressure overload results in the increase of time to peak force without alteration of characteristic time of isometric tension, relaxation for male rats under myocardial hypertrophy compared with control group rats. In addition, the decrease of the load dependent relaxation index in the male rats was obtained. Characteristics of myocardial contractility of female rats have not significant changes as compared to the control group. PMID:25697012

Balakin, A A; Kuznetsov, D A; Lisin, R V; Protsenko, Iu L

2014-09-01

133

Excess Androgen During Puberty Disrupts Circadian Organization in Female Rats  

PubMed Central

Circadian clocks have been described in each tissue of the hypothalamo-pituitary-ovarian axis. Although a role for the clock in the timing of ovulation is indicated, the impact of diseases that disrupt fertility on clock function or the clocks' role in the etiology of these pathologies has yet to be fully appreciated. Polycystic ovary syndrome (PCOS) is a particularly devastating endocrinopathy, affecting approximately 10% of women at childbearing age. Common features of PCOS are a polycystic ovary, amenorrhea, and excess serum androgen. Approximately 40% of these women have metabolic syndrome, including hyperinsulinemia, dyslipidemia, and hyperleptinemia. It has been suggested that excess androgen is a critical factor in the etiology of PCOS. We have examined the effects of androgen excess during puberty on the phase of circadian clocks in tissues of the metabolic and hypothalamo-pituitary-ovarian axes. Female period1-luciferase (per1-luc) rats were exposed to androgen (5?-dihydrotestosterone [DHT]) or placebo for 4-6 weeks (short term) or 9-15 weeks (long term). As expected, DHT-treated animals gained more weight than controls and had disrupted estrous cycles. At the end of treatment, tissues, including the liver, lung, kidney, white adipose, cornea, pituitary, oviduct, and ovarian follicles, were cultured, and per1-luc expression in each was recorded. Analysis of per1-luc expression revealed that DHT exposure increased phase distribution of multiple oscillators, including ovarian follicles, liver, and adipose, and altered phase synchrony between animals. These data suggest that excess androgen during puberty, a common feature of PCOS, negatively affects internal circadian organization in both the reproductive and metabolic axes. PMID:23417420

Murphy, Zachary C.; Menaker, Michael

2013-01-01

134

The role of oxytocin and vasopressin in conditioned mate guarding behavior in the female rat.  

PubMed

We have shown previously that female rats given their first copulatory experiences with the same male rat display mate guarding behavior in the presence of that male provided a female competitor is also present. Females given access to the familiar male show more Fos induction within regions of the brain that contain oxytocin (OT) and vasopressin (AVP) cell bodies, notably the supraoptic (SON) and paraventricular nuclei (PVN) relative to females given sexual experience with different males. The present experiments examined whether the Fos induction we previously observed within the SON and PVN occurred within OT and/or AVP neurons, and whether exogenous administration of OT or AVP prior to female rats first sexual experience could potentiate the acquisition of mate guarding behavior. Female rats that display conditioned mate guarding had significantly more double-labeled Fos/OT neurons in both SON and PVN, and significantly more Fos/AVP neurons in the PVN. Peripheral administration of OT or AVP prior to their first sexual experience with the familiar male facilitated different aspects of mate guarding: OT augmented affiliative behaviors and presenting responses whereas AVP augmented interference behavior. These results indicate that female rats' first experiences with sexual reward when paired with the same male induce changes to bonding networks in the brain. Moreover peripheral administration of OT or AVP during their first sexual experience can augment different aspects of mate guarding behavior. PMID:25724299

Holley, Amanda; Bellevue, Shannon; Vosberg, Daniel; Wenzel, Kerstin; Roorda, Sieger; Pfaus, James G

2015-05-15

135

Estradiol-Dependent Decrease in the Orexigenic Potency of Ghrelin in Female Rats  

Microsoft Academic Search

Ghrelin, the only known orexigenic gut hormone, is se- creted mainly from the stomach, increases with fasting and before meal initiation in humans and rats, and increases food intake after central or peripheral administration. To investigate sex differences in the action of ghrelin, we assessed the effects of exogenous ghrelin in intact male and female rats, the effects of exogenous

Deborah J. Clegg; Lynda M. Brown; Jeffrey M. Zigman; Christopher J. Kemp; April D. Strader; Stephen C. Benoit; Stephen C. Woods; Michela Mangiaracina; Nori Geary

136

Green tea polyphenols attenuate deterioration of bone microarchitecture in female rats with systemic chronic inflammation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Introduction: Our previous study demonstrated that green tea polyphenols (GTP) benefit bone health in female rats with chronic inflammation, because of GTP’s antioxidant capacity. The current study further evaluates whether GTP can restore bone microstructure along with related mechanism in rats wit...

137

EFFECT OF CONAZOLE FUNGICIDES ON REPRODUCTIVE DEVELOPMENT IN THE FEMALE RAT  

EPA Science Inventory

Three triazole fungicides were evaluated for effects on female rat reproductive development. Rats were exposed via feed to propiconazole (P) (100, 500, or 2500 ppm), myclobutanil (M) (100, 500, or 2000 ppm), or triadimefon (T) (100, 500, or 1800 ppm) from gestation day 6 to postn...

138

Immunocytochemical Investigation of Nuclear Progestin Receptor Expression within Dopaminergic Neurones of the Female Rat Brain  

Microsoft Academic Search

Progesterone influences most processes involved in female reproduction, including ovulation, sexual behaviour, pregnancy, parturition, lactation and maternal behaviour. One neurotransmitter through which progesterone might regulate many of these functions is dopamine. To determine where in the brain progesterone might alter dopaminergic activity necessary for these and other processes in rats via cell nuclear progestin receptors, ovariectomized rats were injected subcutaneously

J. S. Lonstein; J. D. Blaustein

2004-01-01

139

Oral contraceptive administration aggravates nitric oxide synthesis inhibition-induced high blood pressure in female rats  

Microsoft Academic Search

The use of estrogen–progestogen oral contraceptive (OC) is associated with high blood pressure, although mechanisms responsible are still unclear. This study sought to investigate the effects of administration of OC on high blood pressure resulting from nitric oxide (NO) synthesis inhibition in female Sprague–Dawley rats. Rats were given ethinyl estradiol in combination with norgestrel and were treated with NO synthase

L. A. Olatunji; A. O. Soladoye

2008-01-01

140

Binge Eating Proneness Emerges During Puberty in Female Rats: A Longitudinal Study  

E-print Network

Binge Eating Proneness Emerges During Puberty in Female Rats: A Longitudinal Study Kelly L. Klump Puberty is a critical risk period for binge eating and eating disorders characterized by binge eating eating during puberty in a rat model. We predicted that there would be minimal differences in binge

Sisk, Cheryl

141

Osteoprotective Effect of Alfacalcidol in Female Rats with Systemic Chronic Inflammation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Studies have shown that alfacalcidol (a hydroxylated form of vitamin D) mitigates glucocorticoid-induced bone loss. This study was undertaken to explore the mechanism and bone microarchitecture of alfacalcidol in rats with systemic chronic inflammation. Thirty female rats (3-month-old) assigned to ...

142

Androgens Increase Spine Synapse Density in the CA1 Hippocampal Subfield of Ovariectomized Female Rats  

Microsoft Academic Search

The effects of androgen on the density of spine synapses on pyramidal neurons in the CA1 area of the hippocampus were studied in ovariectomized (OVX) adult female rats. Treatment of OVX rats with testosterone propionate (TP; 500 g\\/d, s.c., 2 d) significantly increased spine synapse density (from 0.661 0.016 spine synapse\\/m 3 in OVX rats to 1.081 0.018 spine synapse\\/m

Csaba Leranth; Tibor Hajszan; Neil J. MacLusky

2004-01-01

143

The role of odors and ultrasonic vocalizations in female rat (Rattus norvegicus) partner choice.  

PubMed

Intrasexual competition for access to a female mate is believed to be unusual in wild male rats, which suggests that female choosiness could be more important. It has been shown that females spend more time with one male than with others when tested in a multiple partner paradigm. The male of first entry is visited most. The role of ultrasonic vocalizations (USVs) and male odors in the female rat's initial choice to approach one male instead of another are studied in these experiments. In Experiment 1, female rats were allowed to choose between 3 different intact males, whereas in Experiment 2, females could choose between a devocalized male and 2 intact males. Both experiments started with a 15-min period with inaccessible males followed by a 15-min period with accessible males in which the female could copulate with the males of her choice. The results showed that female rats spent more time with the male of first entry over the males visited subsequently. No differences were found in USV subtype patterns emitted by the different males or the time spent sniffing the different males in the period preceding the choice. In addition, the results of Experiment 2 showed that females visited the silent males as much as the vocalizing males. Thus, the present experiments did not offer any evidence suggesting that USVs or individual differences in male odors play any role in female mate choice. Other factors that were not investigated in this study might be involved in female rat mate selection, but it should also be considered that mate selection could be random. PMID:25133463

Snoeren, Eelke M S; Ĺgmo, Anders

2014-11-01

144

ACUTE CADMIUM EXPOSURE AND OVARIAN STEROIDOGENESIS IN CYCLING AND PREGNANT RATS  

EPA Science Inventory

The purpose of this study was to evaluate the effect(s) of acute in vivo cadmium exposure on steroidogenesis in rat ovaries during different reproductive states. prague-Dawley rats were injected subcutaneously on the day of diestrus, or on day 7 or 16 of gestation with a single d...

145

Sorbitol accumulation in male and female rats consuming starch or fructose diets with or without copper  

SciTech Connect

The present study was designed to examine the relationship between the sex of the rats, tissue sorbitol accumulation and copper deficiency in rats consuming dietary fructose. Rats were provided with a diet containing either 62.7% fructose or starch, and either 6.0 or 0.6 {mu}g copper/g for three weeks. Hepatic copper concentration of all rats consuming the copper-deficient diets was about 40% of copper sufficient rats. Hepatic, renal and thymic sorbitol concentrations were significantly elevated in males consuming the fructose, copper-deficient diet when compared to all other dietary groups regardless of the sex of the rat. Hepatic, renal the thymic fructose concentrations were significantly higher in rats eating fructose as compared to female rats. Hepatic glucose concentration was higher in males and females consuming the fructose, copper-deficient diet when compared to all other dietary groups. Renal glucose concentration was elevated in males as compared to females. These results demonstrate that the pathology and complications of copper deficiency in the male rat consuming fructose closely parallel aberration in tissue sorbitol accumulation.

Lewis, C.G.; Fields, M.; Beal, T. (Dept. of Agriculture, Beltsville, MD (USA))

1989-02-09

146

Behavioral effects of endogenous or exogenous estradiol and progesterone on cocaine sensitization in female rats.  

PubMed

Cocaine sensitization is a marker for some facets of addiction, is greater in female rats, and may be influenced by their sex hormones. We compared the modulatory effects of endogenous or exogenous estradiol and progesterone on cocaine-induced behavioral sensitization in 106 female rats. Ovariectomized female rats received progesterone (0.5 mg/mL), estradiol (0.05 mg/mL), progesterone plus estradiol, or the oil vehicle. Sham-operated control females received oil. Control and acute subgroups received injections of saline, while the repeated group received cocaine (15 mg/kg, ip) for 8 days. After 10 days, the acute and repeated groups received a challenge dose of cocaine, after which locomotion and stereotypy were monitored. The estrous cycle phase was evaluated and blood was collected to verify hormone levels. Repeated cocaine treatment induced overall behavioral sensitization in female rats, with increased locomotion and stereotypies. In detailed analysis, ovariectomized rats showed no locomotor sensitization; however, the sensitization of stereotypies was maintained. Only females with endogenous estradiol and progesterone demonstrated increased locomotor activity after cocaine challenge. Estradiol replacement enhanced stereotyped behaviors after repeated cocaine administration. Cocaine sensitization of stereotyped behaviors in female rats was reduced after progesterone replacement, either alone or concomitant with estradiol. The behavioral responses (locomotion and stereotypy) to cocaine were affected differently, depending on whether the female hormones were of an endogenous or exogenous origin. Therefore, hormonal cycling appears to be an important factor in the sensitization of females. Although estradiol increases the risk of cocaine sensitization, progesterone warrants further study as a pharmacological treatment in the prevention of psychostimulant abuse. PMID:24878606

Souza, M F; Couto-Pereira, N S; Freese, L; Costa, P A; Caletti, G; Bisognin, K M; Nin, M S; Gomez, R; Barros, H M T

2014-06-01

147

Behavioral effects of endogenous or exogenous estradiol and progesterone on cocaine sensitization in female rats  

PubMed Central

Cocaine sensitization is a marker for some facets of addiction, is greater in female rats, and may be influenced by their sex hormones. We compared the modulatory effects of endogenous or exogenous estradiol and progesterone on cocaine-induced behavioral sensitization in 106 female rats. Ovariectomized female rats received progesterone (0.5 mg/mL), estradiol (0.05 mg/mL), progesterone plus estradiol, or the oil vehicle. Sham-operated control females received oil. Control and acute subgroups received injections of saline, while the repeated group received cocaine (15 mg/kg, ip) for 8 days. After 10 days, the acute and repeated groups received a challenge dose of cocaine, after which locomotion and stereotypy were monitored. The estrous cycle phase was evaluated and blood was collected to verify hormone levels. Repeated cocaine treatment induced overall behavioral sensitization in female rats, with increased locomotion and stereotypies. In detailed analysis, ovariectomized rats showed no locomotor sensitization; however, the sensitization of stereotypies was maintained. Only females with endogenous estradiol and progesterone demonstrated increased locomotor activity after cocaine challenge. Estradiol replacement enhanced stereotyped behaviors after repeated cocaine administration. Cocaine sensitization of stereotyped behaviors in female rats was reduced after progesterone replacement, either alone or concomitant with estradiol. The behavioral responses (locomotion and stereotypy) to cocaine were affected differently, depending on whether the female hormones were of an endogenous or exogenous origin. Therefore, hormonal cycling appears to be an important factor in the sensitization of females. Although estradiol increases the risk of cocaine sensitization, progesterone warrants further study as a pharmacological treatment in the prevention of psychostimulant abuse. PMID:24878606

Souza, M.F.; Couto-Pereira, N.S.; Freese, L.; Costa, P.A.; Caletti, G.; Bisognin, K.M.; Nin, M.S.; Gomez, R.; Barros, H.M.T.

2014-01-01

148

Knowledge of malaria prevention among pregnant women and female caregivers of under-five children in rural southwest Nigeria  

PubMed Central

Introduction. The morbidity and mortality from malaria are still unacceptably high in the developing countries, especially among the vulnerable groups like pregnant women and under-five children, despite all control efforts. The knowledge about the preventive measures of malaria is an important preceding factor for the acceptance and use of malaria preventive measures like Insecticide Treated Nets (ITN) by community members. Therefore, this study assessed the knowledge of malaria prevention among caregivers of under-five children and pregnant women in a rural community in Southwest Nigeria. Methodology. This is part of a larger malaria prevention study in rural Southwest Nigeria. A descriptive cross-sectional survey was conducted among pregnant women and caregivers of under-five children in Igbo-Ora, a rural town in Southwest Nigeria using a semi-structured, interviewer-administered questionnaire. Information was obtained on knowledge of malaria prevention, and overall composite scores were computed for knowledge of malaria prevention and ITN use. Data were analyzed using SPSS version 16. Associations between variables were tested using a Chi-square with the level of statistical significance set at 5%. Results. Of the 631 respondents, 84.9% were caregivers of under-five children and 67.7% were married. Mean age was 27.7 ± 6.3 years with 53.4% aged between 20 and 29 years. Majority (91.1%) had at least primary school education and 60.2% were traders. Overall, 57.7% had poor knowledge of malaria prevention. A good proportion (83.5%) were aware of the use of ITN for malaria prevention while 30.6% had poor knowledge of its use. Respondents who were younger (<30 years), had at least primary education and earn <10,000/per month had significantly poor knowledge of ITN use in malaria prevention. Majority (60.0%) respondents had poor attitude regarding use of ITNs. Conclusion. This study showed that the knowledge of malaria prevention is still low among under-five caregivers and pregnant women in rural Southwest Nigeria despite current control measures. There is a need for concerted health education intervention to improve the knowledge of rural dwellers regarding malaria prevention, including the use of ITN. This will go a long way to improving the reported low level of ownership and utilization of ITN in the rural areas. PMID:25755925

Adebayo, Ayodeji M.; Cadmus, Eniola O.

2015-01-01

149

In utero and lactational exposure to TCDD; steroidogenic outcomes differ in male and female rat pups  

Microsoft Academic Search

TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) has a potency to induce decreased fertility and structural reproductive anomalies in male and female mammals. While the activity profile of sex steroid hormone production distinctly differs in developing males and females, we wanted to analyze sex-specific effects of TCDD introduced in utero and via lactation on gonadal steroidogenesis and gonadotropin levels in male and female rat infant

S. A. Myllymaki; T. E. Haavisto; L. J. S. Brokken; M. Viluksela; J. Toppari; J. Paranko

2005-01-01

150

In Utero and Lactational Exposures to Low Doses of Polybrominated Diphenyl Ether-47 Alter the Reproductive System and Thyroid Gland of Female Rat Offspring  

PubMed Central

Background Polybrominated diphenyl ethers (PBDEs) are capable of disrupting thyroid hormone homeostasis. PBDE-47 (2,2?,4,4?-tetrabromodiphenyl ether) is one of the most abundant congeners found in human breast adipose tissue and maternal milk samples. Objectives We evaluated the effects of developmental exposure to low doses of PBDE-47 on the female reproductive system. Methods Pregnant Wistar rats were administered vehicle (peanut oil) or PBDE-47 [140 or 700 ?g/kg body weight (bw)] on gestation day (GD) 6, or 5 mg 6-n-propyl-2-thiouracil (PTU)/L in the drinking water from GD7 through postnatal day (PND) 21. Results In female offspring sacrificed on PND38, there was a significant decrease in ovarian weight after exposure to PTU or 140 ?g/kg PBDE-47. Alterations in folliculogenesis were apparent: we observed a decrease in tertiary follicles and serum estradiol concentrations in the offspring exposed to either PTU or 700 ?g/kg PBDE-47. PTU exposure also resulted in a decrease in primordial follicles. On PND100, persistent effects on the thyroid glands included histologic and morphometric changes after exposure to either PTU or PBDE-47. No relevant changes in reproductive indices were observed after mating the exposed F1 females with nontreated males. Conclusions Administration of PBDE-47 at doses relevant to human exposure led to changes in the rat female reproductive system and thyroid gland. PMID:18335096

Talsness, Chris E.; Kuriyama, Sergio N.; Sterner-Kock, Anja; Schnitker, Petra; Grande, Simone Wichert; Shakibaei, Mehdi; Andrade, Anderson; Grote, Konstanze; Chahoud, Ibrahim

2008-01-01

151

Toxoplasma gondii influences aversive behaviors of female rats in an estrus cycle dependent manner.  

PubMed

The protozoan Toxoplasma gondii (T. gondii) manipulates the behavior of its rodent intermediate host to facilitate its passage to its feline definitive host. This is accomplished by a reduction of the aversive response that rodents show towards cat odors, which likely increases the predation risk. Females on average show similar changes as males. However, behaviors that relate to aversion and attraction are usually strongly influenced by the estrus cycle. In this study, we replicated behavioral effects of T. gondii in female rats, as well as expanded it to two novel behavioral paradigms. We also characterized the role of the estrus cycle in the behavioral effects of T. gondii on female rats. Uninfected females preferred to spend more time in proximity to rabbit rather than bobcat urine, and in a dark chamber rather than a lit chamber. Infected females lost both of these preferences, and also spent more time investigating social novelty (foreign bedding in their environment). Taken together, these data suggest that infection makes females less risk averse and more exploratory. Furthermore, this effect was influenced by the estrus cycle. Uninfected rats preferred rabbit urine to bobcat urine throughout the cycle except at estrus and metestrus. In contrast, infected rats lost this preference at every stage of the cycle except estrus. Commensurate with the possibility that this was a hormone-dependent effect, infected rats had elevated levels of circulating progesterone, a known anxiolytic. PMID:24907696

Golcu, Doruk; Gebre, Rahiwa Z; Sapolsky, Robert M

2014-08-01

152

Prevalence of, and risk factors for, HSV-2 antibodies in sexually transmitted disease patients, healthy pregnant females, blood donors and medical students in Tanzania and Norway.  

PubMed Central

The prevalence of specific HSV-2 antibodies was studied in Tanzanian and Norwegian sexually transmitted disease (STD) patients (1095) and non-STD patients (488). Correlates to demographic and behavioural factors were evaluated. Seropositivity was determined by the non-commercial peptide-55 enzyme-linked immunoassay. The prevalence of HSV-2 antibodies was 70% in Tanzanian and 17% in Norwegian STD patients, 35% in Tanzanian blood donors and pregnant women, and 4, 7 and 14% in Norwegian medical students, blood donors and pregnant women respectively. A higher HSV-2 prevalence was associated with female sex, increasing age, previous STDs, history of genital HSV infection, coitarchal age (age at first intercourse) <15 years and HIV seropositivity. Compared to previous data, the prevalence of HSV-2 antibodies in Tanzanian STD patients has increased remarkably. In Norwegian STD patients our results are consistent with, or lower than, the prevalence previously reported in Western Europe. Demographic rather than behavioural factors were associated with higher prevalence of HSV-2 antibodies in STD patients. PMID:16181514

Nilsen, A.; Mwakagile, D.; Marsden, H.; Langeland, N.; Matre, R.; Haarr, L.

2005-01-01

153

Anatomical differences in uterine sensitivity to prostaglandin F(2alpha) and serotonin in non-pregnant rats.  

PubMed

The ovarian steroids regulate the sensitivity of a population of uterine receptors to prostaglandin F(2alpha), serotonin and oxytocin. However, the uterine sensitivity to prostaglandin F(2alpha) and oxytocin does not coincide with the estrogen-induced increase in the number of receptors. Anatomical differences affect the uterine sensitivity to agonists. We investigated whether anatomical differences between ovarian and cervical uterine regions modulate the hormone-regulated sensitivity to prostaglandin F(2alpha), serotonin and oxytocin. Non-cumulative concentration-response curves for these agonists were recorded for ovarian and cervical uterine segments from adult ovariectomized rats treated with 17beta-estradiol, 17beta-estradiol+progesterone, or vehicle. The ovarian segments displayed a higher maximal response (E(max)) to prostaglandin F(2alpha) and a lower E(max) to serotonin than the cervical segments. Both uterine segments displayed a similar sensitivity to oxytocin. The ovariectomized controls displayed the highest E(max) and the lowest effective concentration 50 (EC(50)) for oxytocin and prostaglandin F(2alpha). Anatomical differences between ovarian and cervical uterine regions modulate the hormonal regulation of uterine sensitivity to serotonin and prostaglandin F(2alpha) in the non-pregnant rat uterus. PMID:12098598

Oropeza, Martha V; Ponce-Monter, Hector; Villanueva-Tello, Teodoro; Palma-Aguirre, José Antonio; Campos, Maria G

2002-06-20

154

Influence of thiouracil-induced hypothyroidism on adrenal and gonadal functions in adult female rats.  

PubMed

The effect of hypothyroidism on adrenals and gonads in adult female rats was investigated throughout the estrous cycle. Hypothyroidism was induced by administration of 4-Methyl-2-Thiouracil (Thiouracil) in the drinking water. The weight of ovaries and adrenals, and the plasma levels of corticosterone decreased in hypothyroid rats as compared with euthyroid rats throughout the estrous cycle. Hypothyroidism resulted in decreased concentrations of plasma LH on the day of diestrus and proestrus, whereas the plasma concentrations of prolactin and progesterone increased as compared with euthyroid rats. The weight of uteri and plasma concentrations of estradiol decreased during the day of diestrus and proestrus in hypothyroid rats as compared with euthyroid rats. To further clarify the dysfunction of hypothalamo-hypophysial-adrenal axis in hypothyroid rats, animals were stressed by immobilization for 3 hr. In hypothyroid rats, a marked increase in plasma levels of ACTH in response to immobilization stress was observed compared to euthyroid control, whereas increases in plasma concentrations of corticosterone were much smaller in hypothyroid than euthyroid rats. These results clearly indicate that hypothyroidism causes both gonadal and adrenal disturbances in adult female rats. The increased concentrations of plasma progesterone may be due to hypersecretion of prolactin during the day of proestrus and estrus, which in turn result in disruption of the estrous cycle. PMID:9592715

Tohei, A; Imai, A; Watanabe, G; Taya, K

1998-04-01

155

Characterization of biliary conjugates of 4,4'-methylenedianiline in male versus female rats  

SciTech Connect

4,4'-Methylenedianiline (4,4'-diaminodiphenylmethane; DAPM) is an aromatic diamine used in the production of numerous polyurethane foams and epoxy resins. Previous studies in rats revealed that DAPM initially injures biliary epithelial cells of the liver, that the toxicity is greater in female than in male rats, and that the toxic metabolites of DAPM are excreted into bile. Since male and female rats exhibit differences in the expression of both phase I and phase II enzymes, our hypothesis was that female rats either metabolize DAPM to more toxic metabolites or have a decreased capacity to conjugate metabolites to less toxic intermediates. Our objective was thus to isolate, characterize, and quantify DAPM metabolites excreted into bile in both male and female bile duct-cannulated Sprague Dawley rats. The rats were gavaged with [{sup 14}C]-DAPM, and the collected bile was subjected to reversed-phase HPLC with radioisotope detection. Peaks eluting from HPLC were collected and analyzed using electrospray MS and NMR spectroscopy. HPLC analysis indicated numerous metabolites in both sexes, but male rats excreted greater amounts of glutathione and glucuronide conjugates than females. Electrospray MS and NMR spectra of HPLC fractions revealed that the most prominent metabolite found in bile of both sexes was a glutathione conjugate of an imine metabolite of a 4'-nitroso-DAPM. Seven other metabolites were identified, including acetylated, cysteinyl-glycine, glutamyl-cysteine, glycine, and glucuronide conjugates. While our prior studies demonstrated increased covalent binding of DAPM in the liver and bile of female compared to male rats, in these studies, SDS-PAGE with autoradiography revealed 4-5 radiolabeled protein bands in the bile of rats treated with [{sup 14}C]-DAPM. In addition, these bands were much more prominent in female than in male rats. These studies thus suggest that a plausible mechanism for the increased sensitivity of female rats to DAPM toxicity may be decreased conjugation of reactive DAPM metabolites, leading to greater levels of protein adduct formation.

Chen, Kan; Cole, Richard B. [Department of Chemistry, University of New Orleans, New Orleans, LA (United States); Santa Cruz, Vicente [Department of Pathology, University of Texas Medical Branch, Galveston, TX (United States); Blakeney, Ernest W. [Department of Chemistry, Centenary College, Shreveport, LA (United States); Kanz, Mary F. [Department of Pathology, University of Texas Medical Branch, Galveston, TX (United States); Dugas, Tammy R. [Department of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center-Shreveport, 1501 Kings Highway, Shreveport, LA 71130 (United States)], E-mail: tdugas@lsuhsc.edu

2008-10-15

156

Reduction of inflammatory pain in female rats after NR2B NMDA cortical antagonism.  

PubMed

Studies have shown that N-methyl-D-aspartate (NMDA) receptors play a critical role in pain processing at different levels of the central nervous system. In this study, we used female adult Wistar rats to examine the effects of antagonizing the NR2B subunit of the NMDA receptor in phasic and tonic pain processes. All the rats underwent stereotaxic surgery for cortical cannula implantation and after at least one week of recovery, rats performed behavioral tests. For evaluating the effects of drugs on motor coordination rats were tested in the rotarod apparatus. Moreover, rats were evaluated in the paw withdrawal latency (PWL) to a noxious thermal stimulus. Furthermore, rats were tested in the formalin-pain test. Rats that received the NR2B antagonist Ro 25-6981 before and after formalin injection showed significantly reduced pain responses in the formalin test, as compared with female control rats (p<0.05). In contrast, no differences among groups were found in the phasic pain test (Hargreaves) and the rotarod test. Taken together, these results suggest that cortical antagonism of the NR2B subunit of NMDA receptors is able to reduce inflammatory pain levels not only before, but after the formalin injection in females at different phases of the estrous cycle. PMID:22420360

Vasquez, Carol; Sánchez, Melany; Herrera, Jairo; Quintero, Gabriel

2012-05-01

157

Evaluation of a sequential multi-modality imaging algorithm for the diagnosis of acute appendicitis in the pregnant female.  

PubMed

The purpose of this study is to evaluate the performance of a sequential multi-modality imaging algorithm for diagnosing acute appendicitis in pregnancy. This IRB-approved, HIPAA compliant study included 127 consecutive pregnant patients imaged for suspected appendicitis between October 2007 and May 2012; all patients initially underwent ultrasound (US) examination, followed by magnetic resonance imaging (MRI) if results of US were negative or equivocal. Computerized tomography (CT) was reserved for cases with inconclusive US and MRI results. The EMR was reviewed, recording results of imaging examinations and clinical outcomes. The diagnostic performance of this sequential multi-modality imaging algorithm was calculated with pathology correlation. Two (1.9 %) of the 127 US examinations reported suspected appendicitis; 125 (98.4 %) were inconclusive. Of the 125 patients with inconclusive US examinations, 103 underwent MRI, of which eight (6.2 %) demonstrated findings of acute appendicitis. Of the 103 patients that received MRI, nine (8.7 %) underwent CT. One patient had a CT performed directly after an inconclusive US exam. No additional cases of appendicitis were detected with CT. The sensitivity and specificity of US alone was 12.5 and 99.2 %, respectively; MRI was 100 and 93.6 %; the sequential multi-modality modality algorithm including US, CT, and MRI was 100 and 98.3 %. The diagnostic performance of this sequential multi-modality imaging algorithm for diagnosing acute appendicitis in pregnancy is high. Given the low yield of US, MRI should be considered the first-line imaging test. Although CT was employed in a small fraction of inconclusive MRI examinations, it still has a role in the diagnostic work-up of the pregnant patient with suspected appendicitis. PMID:25148766

Ramalingam, Vijay; LeBedis, Christina; Kelly, Jacqueline R; Uyeda, Jennifer; Soto, Jorge A; Anderson, Stephan W

2015-04-01

158

Y are you not pregnant: identification of Y chromosome segments in female cattle with decreased reproductive efficiency.  

PubMed

Reproductive efficiency is of economic importance in commercial beef cattle production, since failure to achieve pregnancy reduces the number of calves marketed. Identification of genetic markers with predictive merit for reproductive success would facilitate early selection of females and avoid inefficiencies associated with sub-fertile cows. To identify regions of the genome harboring variation affecting reproductive success, we applied a genome-wide association approach based on the >700,000 SNP marker assay. To include the largest number of individuals possible under the available budget, cows from several populations were assigned to extremes for reproductive efficiency, and DNA was pooled within population and phenotype before genotyping. Surprisingly, pools prepared from DNA of low reproductive cattle returned fluorescence intensity data intermediate between fertile females and males for SNP mapped to the Y chromosome (i.e., male sex chromosome). The presence of Y-associated material in low reproductive heifers or cows was confirmed by Y-directed PCR, which revealed that 21 to 29% of females in the low reproductive category were positive by a Y chromosome PCR test normally used to sex embryos. The presence of the Y chromosome anomaly was further confirmed with application of additional Y-specific PCR amplicons, indicating the likelihood of the presence of some portion of male sex chromosome in female cattle in various beef cattle herds across the U.S. Discovery of this Y anomaly in low reproductive females may make an important contribution to management of reproductive failures in beef cattle operations. PMID:22408089

McDaneld, T G; Kuehn, L A; Thomas, M G; Snelling, W M; Sonstegard, T S; Matukumalli, L K; Smith, T P L; Pollak, E J; Keele, J W

2012-07-01

159

MUSCULAR OXIDATIVE CAPACITY IN OVARIECTOMIZED RATS DISCUSSION ON THE ENDURANCE PERFORMANCE OF FEMALE ATHLETES WITH SPORTS-RELATED-AMENORRHEA  

Microsoft Academic Search

The purpose of this study was to evaluate the effects of ovariectomy on intramuscular energy metabolism in adult rats. Based on the results, we discussed the skeletal muscle metabolism in female athlete with sports related amenorrhea. Twenty-five adult (20-week-old) Sprague-Dawley female rats were used. Fifteen rats underwent ovariectomy (OVX group), and the other ten rats were sham-operated (Sham group). One

Takahiro Sas; Koichi Sairyo; Naoyuki Yoshida; Makoto Ishikawa

160

/sup 20/neon ion- and x-ray-induced mammary carcinogenesis in female rats  

SciTech Connect

One of the proposed uses of heavy ion irradiation is to image lesions of the human female breast. The rat model system was chosen to assess the carcinogenic potential of heavy ion irradiation in the belief that data obtained from rat studies would have a qualitatively predictive value for the human female. Accordingly, female rats were exposed to /sup 20/Ne ions at the BEVALAC and studied for the development of mammary neoplasia for 312 +- 2 days at Brookhaven along with rats exposed concurrently to x-irradiation or to no irradiation. As the dose of either type of radiation was increased the percent of rats with mammary adenocarcinomas, and the percent of rats with mammary fibroadenomas, tended to increase. At a prevalence of 20%, the RBE for /sup 20/Neon ions for mammary adenocarcinomas was estimated to be larger than 5 and for mammary fibroadenomas the RBE was estimated to be less than 2. No conclusion was reached concerning whether or not the RBE might vary with dose. We suggest that /sup 20/Ne ions do have a carcinogenic potential for rat mammary tissue and that this carcinogenic potential is likely to be greater than for x-irradiation. (DT)

Shellabarger, C.J.; Baum, J.W.; Holtzman, S.; Stone, J.P.

1983-01-01

161

Characterization of the vasculature supplying the genital tissues in female rats  

PubMed Central

Introduction The internal pudendal arteries are the key resistance vessels controlling the peripheral circulatory component of sexual responses in both male and females. Previous studies in the male rat demonstrated that this vessel has markedly heightened susceptibility to vascular damage compared to other vessels in the body. Evidence suggests that the female may also be susceptible to vascular pathologies contributing to sexual dysfunction. Aim To characterize the anatomical, morphological and functional properties of the pudendal artery in female rats. Methods The pelvic arteries in young Sprague-Dawley female rats were dissected to generate a composite representation of the vascular gross anatomy. Morphometry was performed on perfusion-fixed pudendal arteries whereas others were mounted in a wire myograph to assess responses to vasoactive drugs. These measures were contrasted with a previous study examining male rats. Main Outcomes Measured Gross anatomy, lumen diameter, wall thickness, cross sectional area and contractile responses in the internal pudendal artery. Results The gross anatomy of the pudendal artery in female rats appears to parallel that found in male rats; acting as the primary feeder vessel of the clitoral, labial and vaginal tissue. Compared to the male rat, the female pudendal artery has a smaller lumen diameter (169±5.7 vs 303±13.8um), wall thickness (14±0.7 vs 47±2.2um) and cross-sectional area (8±0.4 vs 52±3.4×103 ?m2). These structural differences also translate into a decreased contractile capacity of the pudendal arteries from female rats vs. males (8.1±2.7 vs 20±1.4mN). Conclusions Although the gross anatomical features of the vasculature tree supplying the genital tissue in male and female rats appears to have similarities, the tissue specific properties of the vessel itself has a very different structure-function balance. We hypothesize this discordance likely reflects the very different sex-specific roles of this vessel in regulating blood flow during arousal. PMID:22023507

Hannan, Johanna L.; Cheung, Geoffrey L.; Blaser, Mark C.; Pang, Judith J.; Pang, Stephen C.; Webb, R. Clinton; Adams, Michael A.

2011-01-01

162

Correlative Analysis of Behavioral and Physiological Concomitants of Labor in Pregnant Rats  

NASA Technical Reports Server (NTRS)

During parturition, rats exhibit characteristic behavioral expressions of labor. Lordosis contractions, consisting of an elongation of the dams body, are observed beginning several hours prior to neonate births, whereas vertical contractions, repeated rapid lifts of the abdomen, occur immediately preceding the birth of each neonate. We analyzed underlying changes in intrauterine pressure (IUP) using a telemetric sensor that we modified for use in freely-moving rats. This technique enabled us to correlate behavioral expressions of labor contractions with IUP. A small telemetric blood pressure sensor was fitted within a fluid-filled balloon, similar in size to a full term rat fetus. On Gestational day 19 of the rats' 22-day pregnancy, a unit was surgically implanted within the uterus. The dams were simultaneously videotaped, enabling us to directly correlate IUP signals with behavioral expressions of labor contractions. Earlier phases of labor, consisting predominantly of lordosis contractions were characterized by lower pressures relative to later phases during which higher pressures and vertical contractions were frequently observed.

Baer, L. A.; Wade, C. E.; Ronca, A. E.; Dalton, Bonnie (Technical Monitor)

2002-01-01

163

Y are you not pregnant: identification of Y chromosome segments in female cattle with decreased reproductive efficiency  

Technology Transfer Automated Retrieval System (TEKTRAN)

Reproductive efficiency is of economic importance in commercial beef cattle production, as failure to achieve pregnancy reduces the number of calves marketed. Identification of genetic markers with predictive merit for reproductive success would facilitate early selection of females and avoid ineff...

164

Angiotensin type 2 receptor stimulation increases renal function in female, but not male, spontaneously hypertensive rats.  

PubMed

Accumulating evidence suggests that the protective pathways of the renin-angiotensin system are enhanced in women, including the angiotensin type 2 receptor (AT2R), which mediates vasodilatory and natriuretic effects. To provide insight into the sex-specific ability of pharmacological AT2R stimulation to modulate renal function in hypertension, we examined the influence of the AT2R agonist, compound 21 (100-300 ng/kg per minute), on renal function in 18- to 19-week-old anesthetized male and female spontaneously hypertensive rats. AT2R stimulation significantly increased renal blood flow in female hypertensive rats (PTreatment<0.001), without influencing arterial pressure. For example, at 300 ng/kg per minute of compound 21, renal blood flow increased by 14.3±1.8% from baseline. Furthermore, at 300 ng/kg per minute of compound 21, a significant increase in urinary sodium excretion was observed in female hypertensive rats (+180±59% from baseline; P<0.05 versus vehicle-treated rats). This was seen in the absence of any major change in glomerular filtration rate, indicating that the natriuretic effects of AT2R stimulation were likely the result of altered renal tubular function. Conversely, we did not observe any significant effect of AT2R stimulation on renal hemodynamic or excretory function in male hypertensive rats. Finally, gene expression studies confirmed greater renal AT2R expression in female than in male hypertensive rats. Taken together, acute AT2R stimulation enhanced renal vasodilatation and sodium excretion without concomitant alterations in glomerular filtration rate in female hypertensive rats. Chronic studies of AT2R agonist therapy on renal function and arterial pressure in hypertensive states are now required to establish the suitability of AT2R as a therapeutic target for cardiovascular disease, particularly in women. PMID:24842923

Hilliard, Lucinda M; Chow, Charis L E; Mirabito, Katrina M; Steckelings, U Muscha; Unger, Thomas; Widdop, Robert E; Denton, Kate M

2014-08-01

165

Exposure to repeated maternal aggression induces depressive-like behavior and increases startle in adult female rats.  

PubMed

The stress response is a multifaceted physiological reaction that engages a wide range of systems. Animal studies examining stress and the stress response employ diverse methods as stressors. While many of these stressors are capable of inducing a stress response in animals, a need exists for an ethologically relevant stressor for female rats. The purpose of the current study was to use an ethologically relevant social stressor to induce behavioral alterations in adult female rats. Adult (postnatal day 90) female Wistar rats were repeatedly exposed to lactating Long Evans female rats to simulate chronic stress. After six days of sessions, intruder females exposed to defeat were tested in the sucrose consumption test, the forced swim test, acoustic startle test, elevated plus maze, and open field test. At the conclusion of behavioral testing, animals were restrained for 30 min and trunk blood was collected for assessment of serum hormones. Female rats exposed to maternal aggression exhibited decreased sucrose consumption, and impaired coping behavior in the forced swim test. Additionally, female rats exposed to repeated maternal aggression exhibited an increased acoustic startle response. No changes were observed in female rats in the elevated plus maze or open field test. Serum hormones were unaltered due to repeated exposure to maternal aggression. These data indicate the importance of the social experience in the development of stress-related behaviors: an acerbic social experience in female rats precipitates the manifestation of depressive-like behaviors and an enhanced startle response. PMID:22093902

Bourke, Chase H; Neigh, Gretchen N

2012-02-01

166

Exposure to repeated maternal aggression induces depressive-like behavior and increases startle in adult female rats  

PubMed Central

The stress response is a multifaceted physiological reaction that engages a wide range of systems. Animal studies examining stress and the stress response employ diverse methods as stressors. While many of these stressors are capable of inducing a stress response in animals, a need exists for an ethologically relevant stressor for female rats. The purpose of the current study was to use an ethologically relevant social stressor to induce behavioral alterations in adult female rats. Adult (postnatal day 90) female Wistar rats were repeatedly exposed to lactating Long Evans female rats to simulate chronic stress. After six days of sessions, intruder females exposed to defeat were tested in the sucrose consumption test, the forced swim test, acoustic startle test, elevated plus maze, and open field test. At the conclusion of behavioral testing, animals were restrained for 30 minutes and trunk blood was collected for assessment of serum hormones. Female rats exposed to maternal aggression exhibited decreased sucrose consumption, and impaired coping behavior in the forced swim test. Additionally, female rats exposed to repeated maternal aggression exhibited an increased acoustic startle response. No changes were observed in female rats in the elevated plus maze or open field test. Serum hormones were unaltered due to repeated exposure to maternal aggression. These data indicate the importance of the social experience in the development of stress-related behaviors: an acerbic social experience in female rats precipitates the manifestation of depressive-like behaviors and an enhanced startle response. PMID:22093902

Bourke, Chase H.; Neigh, Gretchen N.

2011-01-01

167

Effect of operative stress on food intake and feeding pattern in female rats  

Microsoft Academic Search

Effects of operative stress on food intake, meal size, and meal number were measured in 15 female rats before and after jugular vein catheterization. All rats had 5-d estrous cycles which correlated with cyclical feeding patterns that were most prominent during dark phase eating. In proestrous, meal number peaked (30.3 ± 1.32), and meal size reached a nadir (0.33 ±

Madhu Varma; Jia-Ke Chai; Michael M Meguid; John R Gleason; Zhong-Jin Yang

1999-01-01

168

Effects of androgen and leptin on behavioral and cellular responses in female rats  

Microsoft Academic Search

The causes of anxiety and depression in women with polycystic ovary syndrome (PCOS) remain elusive. To identify steps linking androgen signaling to the regulation of affective symptoms in vivo, we compared behavioral responses in female rats continuously exposed to DHT from puberty (a model of DHT-induced PCOS) and in rats exposed to DHT for 1week.Continuous and 1week of DHT exposure

Yi Feng; Ruijin Shao; Birgitta Weijdegĺrd; Tienpei Wang; Julia Johansson; Shan Sun; Wei Wang; Emil Egecioglu; Hĺkan Billig; Elisabet Stener-Victorin

2011-01-01

169

Whole-body vibration slows the acquisition of fat in mature female rats  

Microsoft Academic Search

Objective:To evaluate the effects of whole-body vibration on fat, bone, leptin and muscle mass.Methods\\/Design:Thirty 7-month-old female 344 Fischer rats were randomized by weight into three groups (baseline, vibration or control; n=8–10 per group). Rats in the vibration group were placed inside individual compartments attached to a Pneu-Vibe vibration platform (Pneumex, Sandpoint, ID, USA) and vibrated at 30–50 Hz (6 mm

G F Maddalozzo; U T Iwaniec; R T Turner; C J Rosen; J J Widrick

2008-01-01

170

Voluntary running improves glucose tolerance and insulin resistance in female spontaneously hypertensive rats  

Microsoft Academic Search

We evaluated the effects of voluntary exercise training on glucose metabolism and measures of insulin sensitivity in female spontaneously hypertensive rats (SHR). Age-matched Wistar-Kyoto rats (WKY) were used as normotensive controls. Exercising SHR were housed in running wheels for 8 weeks (SHRx8) or 16 weeks (SHRx16). At 22 weeks of age, we measured systolic blood pressure, performed oral glucose tolerance

Tanya L. Kinney LaPier; Arthur L. M. Swislocki; Raymond J. Clark; Kenneth J. Rodnick

2001-01-01

171

Perinatal Exposure to the Estrogenic Pollutant Bisphenol A Affects Behavior in Male and Female Rats  

Microsoft Academic Search

FARABOLLINI F., S. PORRINI, AND F. DESSĚ-FULGHERI. Perinatal exposure to the estrogenic pollutant Bisphenol A affects behavior in male and female rats. PHARMACOL BIOCHEM BEHAV 64(4) 687–694, 1999.—Bisphenol A (BPA) is an environmental estrogen with potentially aversive effects on public health. In rats, we studied the effects of perinatal exposure to BPA on nonsocial behaviors partly influenced by gonadal hormones.

F Farabollini; S Porrini

1999-01-01

172

[Characterization of depression-like behavior in prenatally stressed female rats during ovary cycle].  

PubMed

The aim of the present work was a comparative analysis of dynamics of depression-like behavior in prenatally stressed and non-prenatally stressed female rats in the key phases of the ovary cycle. It was found that non-stressed female rats demonstrated high level of depression-like behavior in proestrous phase as compared to the diestrous phase, whereas these rats showed low level of depression-like behavior in estrous phase in Porsolt's test. On the contrary, there were no significant differences in extent of depression-like behavior between prenatally stressed rats in the diestrous and proestrous, although in the phase of estrous in these animals an increase in level of depression-like behavior was noted. Thus, the results of this study indicated pronounced effects of prenatal stress on the character of depression-like behavior of females in different phases of ovary cycle. This study revealed leveling and reversed action of prenatal stress on depression-like behavior in key phases of sexual cycle in female rats. PMID:22645947

Fedotova, Iu O; Kriukova, N N; Pivina, S G; Ordian, N E

2012-03-01

173

Age-related differences in the secretion of calcitonin in female rats.  

PubMed

The mechanism that causes hypercalcitonemia in female rats and is associated with aging was investigated. Young (3 mo), adult (8 mo), middle-aged (12 mo), and old (21 mo) rats were infused with CaCl2 and were bled from a jugular catheter after a CaCl2 challenge. To mimic some of the hormonal changes caused by aging, the anterior pituitary (AP)-grafted ovariectomized rats with hyperprolactinemic syndrome were used to mimic the physiological status of aging. The rat thyroid gland was incubated with or without ovine prolactin (oPRL; 40 or 80 ng/ml) at 37 degreesC for 30 min. Old rats possessed the lowest levels of plasma estradiol and progesterone yet had the highest levels of plasma prolactin and calcitonin (CT) compared with young, adult, and middle-aged rats. The basal release of thyroid CT in vitro in thyroid glands gradually increased with age. Compared with cortex (CX)-grafted rats, the AP-grafted rats possessed higher levels of plasma PRL, basal and CaCl2-induced levels of plasma CT, and the release of thyroid CT in thyroid glands. After stimulation with oPRL, the in vitro release of thyroid CT increased in both CX- and AP-grafted rats. These results suggest that the hypersecretion of CT in old rats is due at least in part to hyperprolactinemia. PMID:9814990

Lu, C C; Tsai, S C; Wang, S W; Huang, W J; Wang, P S

1998-11-01

174

Effect of restricted food supply to pregnant rats inhaling carbon monoxide on fetal weight, compared with cigarette smoke exposure  

SciTech Connect

Although many studies have shown that cigarette smoking during gestation retarded the intrauterine fetal growth, resulting in the decreased birth weight in babies born to smoking mothers, neither causal substance nor mechanism of action to disturb fetal growth has been firmly established yet. Based on the human and animal studies, researchers have implied that fetal hypoxia induced by carbon monoxide (CO) in the cigarette smoke to be responsible for the event. A shortage in energy intake in smoking mothers also has been suspected to cause the retardation in fetal development. In the previous results (Tachi and Aoyama 1983), the weight increment in CO exposed animals was greater than that in the smoke exposed group. The phenomenon seemed to indicate that the reduction in the food intake occurs in animals which inhale the cigarette smoke, and induces the disturbance of fetal development in association with CO. In the present study, so as to evaluate the role of energy intake upon the fetal development in utero, the experiment of paired feeding with pregnant rats exposed to cigarette smoke is designed in animals which inhale the cigarette smoke, CO, or room air, following after the observation of the quantity of food taken by mothers exposed to cigarette smoke, CO, or room air.

Tachi, N.; Aoyama, M.

1986-12-01

175

Down-regulation of circadian clock gene period 2 in uterine endometrial stromal cells of pregnant rats during decidualization.  

PubMed

Circadian rhythms are modulated in a variety of peripheral tissues, including in the uterus where endometrial stromal cells (UESCs) undergo proliferation and differentiation (decidualization) during gestation. Here the authors focused on circadian rhythms in UESCs during implantation and decidualization in rodents. As revealed by analyses of cultured UESCs from pregnant Per2 promoter-dLuc transgenic rats, Per2 oscillation of ?24 ?h was observed in response to dexamethasone. Per2 oscillation was enhanced in UESCs during implantation, whereas they were attenuated during decidualization. In vivo studies showed that PER2 protein in the uteri displayed a peak at zeitberger time 4 (ZT 4) (day 4.50 of gestation) and a trough at ZT 12 (day 4.83), indicating its circadian rhythmicity. Conversely, no significant circadian rhythm of the PER2 protein was observed during decidualization. Fluorescent immunohistochemical studies also supported circadian rhythmicity of the PER2 protein in its intracellular distribution. In accordance with Per2 mRNA expression, a circadian rhythm of vascular endothelial growth factor (Vegf) gene expression, having several E-box or E-box-like sites at the upstream of the transcription start site, was observed during implantation, showing a peak at ZT 0 and a trough at ZT 12. In contrast, Vegf mRNA expression displayed no circadian rhythm during decidualization. Collectively, the present results prove that Per2 oscillation is down-regulated in UESCs during decidualization. It is strongly suggested that cellular differentiation in UESCs interferes with circadian clockwork. PMID:21182399

Uchikawa, Miho; Kawamura, Madoka; Yamauchi, Nobuhiko; Hattori, Masa-Aki

2011-02-01

176

Different Diabetogenic Response to Moderate Doses of Streptozotocin in Pregnant Rats, and Its Long-Term Consequences in the Offspring  

PubMed Central

Diabetes during pregnancy results in congenital malformations and long-term postnatal diseases. Experimental models are still needed to investigate the mechanism responsible for these alterations. Thus, by the administration of different doses of streptozotocin (STZ) (0, 25, 30, or 35 mg/kg body weight, intravenous) at the onset of pregnancy in rats, the present study sought an appropriate animal model for this pathology. At day 6 of pregnancy, plasma glucose was progressively higher with an increasing STZ dose, and in rats receiving the 35-mg dose, 2 subgroups were detected: some animals had plasma glucose levels above controls but below 200 mg/dL (mildly diabetic, MD), whereas others had levels above 400 mg/dL (severely diabetic, SD). At day 20 of pregnancy, the MD rats had normal glycemia, but after an oral glucose load (2 g/kg body weight), plasma glucose increased more and insulin increased less than in controls. The SD rats maintained their hyperglycemia and had a greatly impaired oral glucose tolerance. At day 20, fetuses of SD dams were fewer, weighed less, and had enhanced plasma glucose and triglycerides and decreased insulin, whereas those from MD dams did not differ from controls. At birth, newborns from MD dams had higher body weight, plasma insulin, and liver triglycerides as well as total body lipid concentrations than controls, and on day 21, remained macrosomic and showed higher plasma glucose and liver triglyceride concentrations. At 70 days of age, offspring of MD dams had impaired oral glucose tolerance but normal plasma insulin change in the case of females, whereas plasma insulin increased less in males. These alterations were manifest more in those offspring from dams that had > 50% macrosomic newborns than in those from dams that had < 50% macrosomic newborns. In conclusion, whereas our MD rats mimic the changes taking place in gestational diabetic women and show the long-term risk of macrosomia, the SD rats are more similar to uncontrolled diabetics. Thus these two rat models, obtained with moderate amounts of STZ, could be used to study the pathophysiological consequences of these different diabetic conditions. PMID:14630572

López-Soldado, Iliana

2003-01-01

177

Effects of Obesity on Bone Mass and Quality in Ovariectomized Female Zucker Rats  

PubMed Central

Obesity and osteoporosis are two chronic conditions that have been increasing in prevalence. Despite prior data supporting the positive relationship between body weight and bone mineral density (BMD), recent findings show excess body weight to be detrimental to bone mass, strength, and quality. To evaluate whether obesity would further exacerbate the effects of ovariectomy on bone, we examined the tibiae and fourth lumbar (L4) vertebrae from leptin receptor-deficient female (Leprfa/fa) Zucker rats and their heterozygous lean controls (Leprfa/+) that were either sham-operated or ovariectomized (Ovx). BMD of L4 vertebra was measured using dual-energy X-ray absorptiometry, and microcomputed tomography was used to assess the microstructural properties of the tibiae. Ovariectomy significantly (P < 0.001) decreased the BMD of L4 vertebrae in lean and obese Zucker rats. Lower trabecular number and greater trabecular separation (P < 0.001) were also observed in the tibiae of lean- and obese-Ovx rats when compared to sham rats. However, only the obese-Ovx rats had lower trabecular thickness (Tb.Th) (P < 0.005) than the other groups. These findings demonstrated that ovarian hormone deficiency adversely affected bone mass and quality in lean and obese rats while obesity only affected Tb.Th in Ovx-female Zucker rats. PMID:25309751

Feresin, Rafaela G.; Johnson, Sarah A.; Elam, Marcus L.; Arjmandi, Bahram H.

2014-01-01

178

Preventive Role of Estradiol on Kidney Injury Induced by Renal Ischemia-Reperfusion in Male and Female Rats  

PubMed Central

Background: Renal ischemia-reperfusion (RIR) is the main cause of renal failure. The incidence of RIR injury seems to be gender-related due to female sex hormone; estrogen. This study was designed to investigate the protective role of estrogen against RIR injury in male and ovariectomized female rats. Methods: Thirty-nine Wistar rats were used in this study as male and ovariectomized female rats in the sham-operated, RIR, and estradiol-treated plus RIR groups. The RIR was induced by clamping the renal vessels for 45 min and then 24 h of reperfusion. All animals finally were sacrificed for the measurements. Results: The serum levels of creatinine and blood urea nitrogen and kidney tissue damage score significantly increased in both male and female RIR rats (P < 0.05). Estradiol however significantly attenuated theses parameters (P < 0.05) toward normal levels in female (P < 0.05), but not in male rats. Kidney weight increased in both genders and estradiol intensified it in the male rats (P < 0.05). Uterus weight was increased by estradiol in female rats (P < 0.05) and testis weight did not alter in male rats. Conclusions: Estradiol demonstrated a protective role against RIR injury in female rats; however, estradiol as an antioxidant could not protect the male kidney from RIR injury. PMID:25830011

Iran-Nejad, Akram; Nematbakhsh, Mehdi; Eshraghi-Jazi, Fatemeh; Talebi, Ardeshir

2015-01-01

179

Early consumption of blueberry diet protects against sex steroid deficiency-induced bone loss in adult female rats  

Technology Transfer Automated Retrieval System (TEKTRAN)

We studied the effects of blueberry consumption in early development on bone loss in ovariectomized (OVX) female rats later in life. Weanling female rats were fed AIN-93G semi-purified diets supplemented with 10% whole blueberry powder from PND 21 to PND34 (short-term group), or PND21 to PND81 (chro...

180

Enhanced mesenteric arterial responsiveness to angiotensin II is androgen receptor-dependent in prenatally protein-restricted adult female rat offspring.  

PubMed

Gestational protein restriction results in intrauterine growth restriction and hypertension in adult female growth-restricted rats. Enhanced vascular responsiveness to angiotensin II is observed, and blockade of the renin-angiotensin system abolishes hypertension in adult growth-restricted rats, suggesting that the renin-angiotensin system contributes to intrauterine growth restriction-induced hypertension. Moreover, growth-restricted adult rats have higher plasma testosterone levels, and antiandrogen treatment abolishes hypertension, indicating an important role for testosterone. We hypothesized that androgens may play a pivotal role in the enhanced responsiveness to Ang II and hypertension. Female offspring of pregnant rats fed 20% protein (control) or 6% protein diet (protein restricted), at 6 mo of age, were studied. Plasma testosterone and mean arterial pressure in protein-restricted offspring were significantly higher compared to controls. Flutamide treatment (10 mg/kg/day subcutaneously for 10 days) reduced mean arterial pressure in protein-restricted offspring but was without significant effect in controls. Vascular Agtr1/Agtr2 ratio was significantly higher in protein-restricted offspring, an effect that was reversed by flutamide. Flutamide treatment did not have any effect on Agtr1/Agtr2 ratio in controls. Enhanced contractile response to angiotensin II in mesenteric arteries was observed in protein-restricted offspring compared with control. Flutamide treatment reversed the enhanced contractile response to angiotensin II in protein-restricted offspring without significant effect in controls. Vascular reactivity to phenylephrine was similar between the control and protein-restricted offspring with and without flutamide treatment, suggesting that enhanced contractile response and flutamide's reversal effect is specific to angiotensin II. These results suggest that prenatally protein-restricted rats exhibit an enhanced responsiveness to angiotensin II that is testosterone-dependent. PMID:25550341

Sathishkumar, Kunju; Balakrishnan, Meena P; Yallampalli, Chandrasekhar

2015-02-01

181

Exercise improves learning and memory impairments in sleep deprived female rats.  

PubMed

Inadequate sleep is a common problem in modern societies. It has been previously shown that female rats are more vulnerable to the deleterious effects of sleep deprivation on cognitive functions. Physical exercise has been suggested to attenuate the cognitive impairments induced by sleep deprivation in male rats. The objective of the current study was to investigate the effects of physical exercise on cognitive functions of female rats following paradoxical sleep deprivation. Intact and ovariectomized (OVX) female Wistar rats were used in the present study. The exercise protocol was 4 weeks of treadmill running. The multiple platform method was applied for the induction of 72h paradoxical sleep deprivation and the cognitive function was evaluated using Morris water maze (MWM). Plasma corticosterone level was evaluated in separate groups of study. ANOVA and repeated measures were used to analyze the data and P<0.05 was considered statistically significant. Throughout the investigation, significant learning impairment was observed in sleep-deprived OVX rats compared to the intact and the other OVX groups. Short term memory impairment was observed in both sleep-deprived OVX and intact groups. Physical exercise alleviated the PSD-induced learning and memory impairments in both intact and OVX groups. Corticosterone levels were not statistically significant among the different groups. The results of our study confirmed the negative effects of PSD on cognitive functions in female rats and regular physical exercise seems to protect rats from these effects. Further studies are suggested to be carried out in order to evaluate the possible underlying mechanisms, and also to evaluate the possible interactions between sex hormones and PSD-induced cognitive impairments. PMID:25447468

Saadati, Hakimeh; Esmaeili-Mahani, Saeed; Esmaeilpour, Khadije; Nazeri, Masoud; Mazhari, Shahrzad; Sheibani, Vahid

2015-01-01

182

Induction of "male-specific" cytochrome P450 isozymes in female rats by oxandrolone.  

PubMed

Oxandrolone (OXA) (5 alpha-androstan-2-oxa-17 alpha-methyl-17 beta-ol-3-one) is a clinically useful, synthetic, anabolic androgen steroid hormone. OXA was administered to rats orally twice daily for 3 days at 75 mg/kg to study the effect on hepatic cytochrome P450 (P450) isozymes. Western blots were performed on the hepatic microsomal fraction and probed with isozyme-specific monoclonal antibodies. Microsomes were also tested for catalytic activity in a testosterone metabolism assay. Data from Western blots revealed that, in female rats, there were increased levels of two male-specific isozymes, P4502C11 and P4503A2, as well as P4503A1. In contrast, male rats showed little or no change in expression of these P450 isozymes after OXA treatment. The 6 beta-hydroxylation of testosterone, which is catalyzed predominantly by P4503A1 and P4503A2, increased approximately 10-fold in female rats after treatment with OXA (from 0.05 +/- 0.01 to 0.52 +/- 0.05 nmol/min/mg protein), but only relatively small changes were seen in the male rats (from 1.02 +/- 0.05 to 1.38 +/- 0.07 nmol/min/mg protein). To investigate if the changes seen in P4503A1 and P4503A2 protein and activity were caused, at least in part, by an increase in mRNA levels, Northern blot analysis was performed. P4503A2 mRNA was increased dramatically in the female rat liver after OXA treatment, but only small increases in P4503A1 mRNA were seen. This data indicate that OXA induces P450 isozymes in the female but not in the male rat liver, probably through transcriptional activation, and some of these induced isozymes are male-specific. PMID:8591733

Waskiewicz, M J; Choudhuri, S; Vanderbeck, S M; Zhang, X J; Thomas, P E

1995-11-01

183

Efficacy of Female Rat Models in Translational Cardiovascular Aging Research  

PubMed Central

Cardiovascular disease is the leading cause of death in women in the United States. Aging is a primary risk factor for the development of cardiovascular disease as well as cardiovascular-related morbidity and mortality. Aging is a universal process that all humans undergo; however, research in aging is limited by cost and time constraints. Therefore, most research in aging has been done in primates and rodents; however it is unknown how well the effects of aging in rat models translate into humans. To compound the complication of aging gender has also been indicated as a risk factor for various cardiovascular diseases. This review addresses the systemic pathophysiology of the cardiovascular system associated with aging and gender for aging research with regard to the applicability of rat derived data for translational application to human aging. PMID:25610649

Rice, K. M.; Fannin, J. C.; Gillette, C.; Blough, E. R.

2014-01-01

184

Oxytocin differentially affects sucrose taking and seeking in male and female rats.  

PubMed

Oxytocin has a modulatory role in natural and drug reward processes. While the role of oxytocin in pair bonding and reproduction has been extensively studied, sex differences in conditioned and unconditioned behavioral responses to oxytocin treatment have not been fully characterized. Here, we determined whether male and female rats would show similar dose response curves in response to acute oxytocin on measures of locomotor activity, sucrose seeking, and sucrose intake. Male and freely cycling female rats received vehicle or oxytocin (0.1, 0.3, 1, 3mg/kg, IP) injections before behavioral tests designed to assess general motor activity, as well as sucrose self-administration and seeking. Lower doses of oxytocin decreased motor activity in a novel environment in females relative to males. Likewise, lower doses of oxytocin in females decreased responding for sucrose during maintenance of sucrose self-administration and reinstatement to sucrose-conditioned cues. However, sucrose seeking in response to a sucrose prime was only decreased by the highest oxytocin dose in both sexes. In general, oxytocin had similar effects in both sexes. However, females were more sensitive to lower doses of oxytocin than males. These findings are consistent with the notion that oxytocin regulates many of the same behaviors in males and females, but that the effects are typically more profound in females. Therapeutic use of oxytocin should include sex as a factor in determining dose regimens. PMID:25647756

Zhou, Luyi; Ghee, Shannon M; See, Ronald E; Reichel, Carmela M

2015-04-15

185

The Time of Prenatal Androgen Exposure Affects Development of Polycystic Ovary Syndrome-Like Phenotype in Adulthood in Female Rats  

PubMed Central

Background: Polycystic ovary syndrome (PCOS) is one of the most common reproductive disorders in women. Previous studies have shown that prenatal exposure of female fetuses to androgen can be considered an important factor in the development of PCOS. Objectives: In the present study we aimed to examine the effects of prenatal exposure of female rat fetuses to previously documented doses of testosterone on different embryonic days on the development of PCOS phenotype in adulthood. Materials and Methods: Pregnant rats were divided into four groups, experimental and control groups. Three mg of free testosterone was administered subcutaneously to experimental group 1 on gestational days 16-19, daily and 20 mg on day 20, to experimental group 2, and the controls received solvent at the same times. Female offspring of these mothers aged between 90-100 days were examined for development and function of the reproductive system. Independent-sample student t test was used to compare the results between the experimental groups and controls. Results: Anogenital distance (P < 0.001) and clitoris length were significantly increased in the offspring of both experimental groups (P < 0.001 and P < 0.05 respectively). Nipples were not formed in the offspring of experimental group 1, whereas in experimental group 2 the number of nipples was unchanged. Vaginal length was significantly decreased in the offspring of experimental group 1 (P < 0.001), whereas in experimental group 2, no significant difference was observed. In the offspring of experimental group 1, hormonal profiles did not differ, but in experimental group 2, levels of testosterone (P < 0.05) and LH (P < 0.01) were significantly increased, but estrogen (P < 0.05) and anti-Mullerian hormone levels (P < 0.001) were significantly decreased. A significant increase in the number of preantral and antral follicles was observed in the ovaries of offspring of experimental group 1 (P < 0.05); whereas there was no such a difference in experimental group 2. Conclusions: The time of prenatal exposure to androgens may have a significant role in the development of PCOS. Increased prenatal androgen levels are associated with hormonal changes and morphological disorders of the reproductive system. Therefore, avoiding exposure to androgen excess during critical periods of fetal development may prevent or reduce adulthood PCOS manifestations caused by prenatal excess androgen. PMID:24910644

Ramezani Tehrani, Fahimeh; Noroozzadeh, Mahsa; Zahediasl, Saleh; Piryaei, Abbas; Hashemi, Somayeh; Azizi, Fereidoun

2014-01-01

186

Hypothermia and delayed fever in the male and female rat exposed to chlorpyrifos  

Microsoft Academic Search

Chlorpyrifos (CHL) is a commonly used organophosphate (OP) pesticide which irreversibly inhibits acetylcholinesterase activity in the CNS. Little is known regarding the thermoregulatory effects of CHL when administered orally and whether the sensitivity to CHL is affected by sex. To address these issues, male and female rats of the Long-Evans strain were administered 0, 10, 50, or 80 mg\\/kg CHL

Christopher J. Gordon; Tholeathcus A. Grantham; Ying Yang

1997-01-01

187

Female rats are more vulnerable to the long-term consequences of neonatal inflammatory injury  

E-print Network

pain responses. As previous studies examining the impact of neonatal injury on nociception have been. Published by Elsevier B.V. All rights reserved. Keywords: Sex differences; Inflammation; Neonate; Pain 1Female rats are more vulnerable to the long-term consequences of neonatal inflammatory injury Jamie

Murphy, Anne Z.

188

A possible physiological role of taurine in the adult female rat liver  

E-print Network

A possible physiological role of taurine in the adult female rat liver Y. PIERRE, Fernande. In agreement with previous results (Awapara, 1956), we noted that the tau- rine level in the liver of the adult as a concentration (ymoles/g of liver). Furthermore, we observ- ed a significant decrease of the taurine level

Paris-Sud XI, Université de

189

OFFSPRING MORTALITY AND MATERNAL LUNG PATHOLOGY IN FEMALE RATS FED HEXACHLOROBENZENE  

EPA Science Inventory

Female Sprague-Dawley CD rats were fed 0, 60, 80, 100, 120 and 140 ppm hexachlorobenzene (HCB) continuously in the diet and 2 successive litters raised. These doses were selected to range from approximately the no observable effect level to lethality in suckling offspring of trea...

190

Estrogen receptor-like immunoreactivity in the medullary and spinal dorsal horn of the female rat  

Microsoft Academic Search

Using an immunohistochemical technique, we demonstrate that large numbers of neurons in the laminar spinal trigeminal nucleus and spinal gray matter of the female rat express estrogen receptors (ER). Densely packed ER-immunoreactive neurons were present in lamina II, but labeled neurons were also present in lamina I, the neck of the dorsal horn, and in lamina X. Labeling was present

Ĺsa Amandusson; Ola Hermanson; Anders Blomqvist

1995-01-01

191

ENHANCED ESTROGENIC RESPONSES AND SENSITIVITY TO AZOSYMETHANE FOLLOWING DIETARY SOY ISOFLAVONE SUPPLEMENTATION IN OLDER FEMALE RATS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soy isoflavones are becoming popular supplements among middle-aged women based on their potential protection against cancer and their use as alternative hormone replacement therapy. We investigated the effects of dietary soy isoflavones and age on early stage colon cancer in female rats. Young, matu...

192

17ß-Estradiol Is Necessary for Extinction of Cocaine Seeking in Female Rats  

ERIC Educational Resources Information Center

Human and preclinical models of addiction demonstrate that gonadal hormones modulate acquisition of drug seeking. Little is known, however, about the effects of these hormones on extinction of drug-seeking behavior. Here, we investigated how 17ß-estradiol (E[subscript 2]) affects expression and extinction of cocaine seeking in female rats. Using a…

Twining, Robert C.; Tuscher, Jennifer J.; Doncheck, Elizabeth M.; Frick, Karyn M.; Mueller, Devin

2013-01-01

193

REPRODUCTIVE TOXICITY ASSOCIATED WITH ACRYLAMIDE TREATMENT IN MALE AND FEMALE RATS  

EPA Science Inventory

The present study was designed to evaluate the influence of acrylamide (ACR) on male and female reproductive function. Male rats received ACR in drinking water (50, 100, or 200 ppm) for up to 10 wk. Copulatory behavior, semen, and (for controls and 100 ppm only) fertility and fet...

194

In utero phthalate effects in the female rat: a model for MRKH syndrome##  

EPA Science Inventory

Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome is characterized by uterine and vaginal canal aplasia in normal karyotype human females and is a syndrome with poorly defined etiology. Reproductive toxicity of phthalate esters (PEs) occurs in rat offspring exposed in utero, a phen...

195

In Utero Phthalate Effects in the Female Rat: A Model for MRKH Syndrome  

EPA Science Inventory

Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome is characterized by uterine and vaginal canal aplasia in normal karyotype human females and is a syndrome with poorly define etiology. Reproductive toxicity of phthlate esters (PEs) occurs in rat offspring exposed in utero. a phenome...

196

NONYLPHENOL AND ATRAZINE INDUCE INVERSE EFFECTS ON MAMMARY GLAND DEVELOPMENT IN FEMALE RATS EXPOSED IN UTERO  

EPA Science Inventory

Nonylphenol and Atrazine Induce Inverse Effects on Mammary Gland Development in Female Rats Exposed In Utero. HJ Moon1, SY Han1, CC Davis2, and SE Fenton2 1 Department of Toxicology, NITR, Korea FDA, 5Nokbun-Dong, Eunpyung-Gu, Seoul, Korea and 2 Reproductive Toxicology Divi...

197

Effects of altered food intake during pubertal development in male and female Wistar rats  

EPA Science Inventory

The U.S.EPA is currently validating assays that will be used in a Tier I Screening Battery to detect endocrine disrupting chemicals. A primary concern with the Protocols for the Assessment of Pubertal Development and Thyroid Function in Juvenile Male and Female Rats is that a non...

198

The effects of ovariectomy on binge eating proneness in adult female rats Kelly L. Klump a,  

E-print Network

The effects of ovariectomy on binge eating proneness in adult female rats Kelly L. Klump a: Binge eating Bulimia nervosa Ovariectomy Animal models Ovarian hormones Ovarian hormones are associated with binge eating in women, however findings are limited by the lack of experimental control inherent

Sisk, Cheryl

199

Monosodium Glutamate Disruption of Behavioral and Endocrine Function in the Female Rat  

Microsoft Academic Search

Experiments weie conducted to determine the effects of neonatal administration of L-monosodium glutamate (MSG) on behavioral and endocrine function in the female rat. Administration of MSG (4 mg\\/kg body weight) at days 1, 3, 5, 7 and 9 in neonates results in a delay of vaginal opening (VO) and the absence of ovulation at the time of VO. However, some

Jorge F. Rodriguez-Sierra; R. Sridaran; Charles A. Blake

1980-01-01

200

PREGNANCY ALTERATIONS FOLLOWING XENOBIOTIC-INDUCED DELAYS IN OVULATION IN THE FEMALE RAT  

EPA Science Inventory

Female rats were exposed to the formamidine pesticide chlordimeform (50 mg/kg) or sodium pentobarbital (35 mg/kg) at selected times during the estrous cycle and the effect of this treatment on pregnancy outcome was evaluated. When exposed on the afternoon of vaginal proestrus, bo...

201

EFFECT OF LINDANE ON HORMONAL CONTROL OF REPRODUCTIVE FUNCTION IN THE FEMALE RAT  

EPA Science Inventory

The effect of the gamma isomer of 1,2,3,4,5,6-hexachlorocyclohexane (Y-HCH), lindane, on reproductive funtion in the female rat was examined in two experiments. n the first experiment, chronic treatment with 0, 5, 10, 20, and 40 mg/kg lindane delayed vaginal opening and disrupted...

202

Effects of Hypergravity Exposure On Plasma Oxytocin Concentrations In Pregnant and Lactating Rat Dams  

NASA Technical Reports Server (NTRS)

Rat dams and offspring were exposed to 1.5-g, 1.75-g or 2.0-g hypergravity (hg) from Gestational day (G) 11 until Postnatal day (P) 10. To ascertain the role of maternal factors in reduced postnatal body weights of offspring developed in hg, the dams' lactational hormones were measured. Oxytocin (OT), the major hormone responsible for milk ejection, was reduced in hg dams whereas prolactin (Prl), involved in milk production, was unchanged. Video analyses of nursing behavior revealed that hg dams spent more time nursing relative to 1-g controls. We hypothesized impaired milk transfer from dam to pup, however pup body weight gains following a discrete suckling episode were comparable across conditions. Changes in lactational hormones and nursing behavior by dams exposed to hg do not account for reduced body masses of their offspring.

Baer, Lisa A.; Wade, Charles E.; Ronca, April E.; Dalton, Bonnie (Technical Monitor)

2002-01-01

203

[Effects of pseudolaric acid B on blood flows of endometrium and myometrium in pregnant rats].  

PubMed

Effects of pseudolaric acid B (PB) on endo- and myo-metrial blood flows were measured by hydrogen gas clearance technique in 336 pentobarbital-anesthetized rats divided into control and 2 medicated groups (ig PB 20 and 30 mg.kg-1 on d 7-9 of pregnancy). Measurements of endo- and myo-metrial blood flows were done on d 7-14 of pregnancy. Results showed that the endo- and myo-metrial blood flows were reduced by 33-66% and 30-65% respectively, vs ig 1% CMC 0.5 ml (P less than 0.01). Uterine weight during d 10-14 of pregnancy stopped gain. The systemic arterial pressure remained relatively unchanged. It is concluded that PB causes a significant decrease of blood flow in both endo- and myometrium, which is accounted as the most important cause of embryo's death. PMID:1819897

Wang, W C; Gu, Z P; Koo, A; Chen, W S

1991-09-01

204

Mechanisms of vasodilatation in pregnancy: studies of the role of prostaglandins and nitric-oxide in changes of vascular reactivity in the in situ blood perfused mesentery of pregnant rats.  

PubMed Central

1. To examine the possible mechanisms of the vasodilatation and blunted pressor responses in late pregnancy, we have studied vascular reactivity of the in situ blood perfused mesenteric resistance vessels of 18-20 day pregnant Wistar-Kyoto rats (WKY). 2. Intra-arterial mean blood pressure (MBP) was lower in pregnant rats than in nonpregnant controls. There was no significant difference in basal mesenteric perfusion pressure (BPP) between groups. 3. Vascular reactivity to electrical stimulation (ES) or intra-arterial noradrenaline (NA), angiotensin II (AII) and arginine vasopressin (AVP) was decreased in the preparations from pregnant rats compared to that from nonpregnant controls. Noradrenaline spillover into mesenteric venous blood following ES was similar in pregnant and nonpregnant animals. 4. Indomethacin (5 mg kg-1, i.v.), an inhibitor of cyclo-oxygenase, induced significant increases in reactivity to ES in both pregnant and nonpregnant groups while potentiating the responses to NA and AII in nonpregnant animals only and having no effect on AVP-induced contractions in the preparations from either pregnant or nonpregnant animals. 5. NG-nitro-L-arginine (L-NOARG) (5 mg kg-1, i.v.), an inhibitor of nitric-oxide synthase, increased MBP and BPP in both pregnant and nonpregnant animals, but the difference in MBP between groups was still evident. 6. L-NOARG enhanced mesenteric vascular responses to ES, NA and AII in both pregnant and nonpregnant groups. Only the difference in NA responses between groups was abolished after pretreatment with L-NOARG. 7. These data show that vasoconstrictor responses to a variety of agonists are decreased in the in situ blood-perfused mesenteric resistance vessels of pregnant rats.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 6 PMID:8358537

Chu, Z. M.; Beilin, L. J.

1993-01-01

205

Mechanisms of vasodilatation in pregnancy: studies of the role of prostaglandins and nitric-oxide in changes of vascular reactivity in the in situ blood perfused mesentery of pregnant rats.  

PubMed

1. To examine the possible mechanisms of the vasodilatation and blunted pressor responses in late pregnancy, we have studied vascular reactivity of the in situ blood perfused mesenteric resistance vessels of 18-20 day pregnant Wistar-Kyoto rats (WKY). 2. Intra-arterial mean blood pressure (MBP) was lower in pregnant rats than in nonpregnant controls. There was no significant difference in basal mesenteric perfusion pressure (BPP) between groups. 3. Vascular reactivity to electrical stimulation (ES) or intra-arterial noradrenaline (NA), angiotensin II (AII) and arginine vasopressin (AVP) was decreased in the preparations from pregnant rats compared to that from nonpregnant controls. Noradrenaline spillover into mesenteric venous blood following ES was similar in pregnant and nonpregnant animals. 4. Indomethacin (5 mg kg-1, i.v.), an inhibitor of cyclo-oxygenase, induced significant increases in reactivity to ES in both pregnant and nonpregnant groups while potentiating the responses to NA and AII in nonpregnant animals only and having no effect on AVP-induced contractions in the preparations from either pregnant or nonpregnant animals. 5. NG-nitro-L-arginine (L-NOARG) (5 mg kg-1, i.v.), an inhibitor of nitric-oxide synthase, increased MBP and BPP in both pregnant and nonpregnant animals, but the difference in MBP between groups was still evident. 6. L-NOARG enhanced mesenteric vascular responses to ES, NA and AII in both pregnant and nonpregnant groups. Only the difference in NA responses between groups was abolished after pretreatment with L-NOARG. 7. These data show that vasoconstrictor responses to a variety of agonists are decreased in the in situ blood-perfused mesenteric resistance vessels of pregnant rats. Increase in endothelial-dependent nitric oxide generation could contribute to the vasodilatation seen in pregnancy but other mechanisms might also be involved. Cyclo-oxygenase products are not responsible for any decreased contractile responses in this preparation. PMID:8358537

Chu, Z M; Beilin, L J

1993-06-01

206

The role of adrenoceptors in the central nervous system in male and female rat sexual behavior.  

PubMed

Three different phases can be distinguished in rats' sexual cycle, the introductory (precopulatory), the copulatory and the executive (ejaculatory) phases. In this review, a new analysis of existing pharmacological data is made, both in male and female rats, in which the different aspects of sexual behavior are taken into account. An effort is made to distinguish pharmacological effects on sexual behavior from a possible physiological role of noradrenaline. In addition, new data on the role of ?2-adrenoceptors on female sexual behavior is presented. The new analysis suggests that noradrenaline has a stimulatory role on the executive phase of male sexual behavior, while the introductory and copulatory phases remain unaffected. Adrenoceptors play a role in the regulation of sexual behavior in the medial preoptic area and the lateral septum. In female rats, noradrenaline also does not play a vital role in the introductory phase. Only the lordosis behavior of the copulatory phase is sometimes affected by adrenergic agents, but only under a certain hormonal condition. The medial preoptic area, the ventromedial nucleus, the arcuate ventromedial nucleus and median eminence are involved in the regulation of female sexual behavior. The new data suggest that ?2-adrenoceptors play no major role on any indices of female sexual behavior. PMID:25218984

Snoeren, Eelke M S

2015-04-15

207

Heightened cocaine-induced locomotor activity in adolescent compared to adult female rats  

PubMed Central

Initiation and experimentation with illicit drugs often occurs in adolescence. Evidence suggests that adolescent rats are more sensitive to some of the effects of drugs of abuse than adult rats. The present study investigated whether adolescent and adult female Sprague Dawley rats differ in cocaine-induced locomotor activity. Animals were placed in the test environment for 30 minutes, and then administered an intraperitoneal (IP) injection of either cocaine (20 mg/kg) or saline (0.9%). Both adult and adolescent animals showed significant increases in locomotor activity as a result of cocaine administration compared to saline controls. Interestingly, cocaine induced significantly more locomotor activity in the adolescent females compared to the adults, demonstrating that cocaine acts differently in developing animals. PMID:16166180

Catlow, Briony J.; Kirstein, Cheryl L.

2007-01-01

208

Adolescent peer-rejection persistently alters pain perception and CB1 receptor expression in female rats.  

PubMed

Peer-interactions are particularly important during adolescence and teenagers display enhanced sensitivity toward rejection by peers. Social rejection has been shown to induce alterations in pain perception in humans. However, the neurobiological consequences of adolescent social rejection have yet to be extensively characterized, and no appropriate animal model is available. Here, we propose inadequate playful interactions in adolescent rats as a novel animal model for social peer-rejection and examine potential long-term consequences into adulthood. Acute social pairing of female adolescent Wistar rats with an age-matched rat from the less playful Fischer344 strain was found to alter social play and decrease pain reactivity, indicating Fischer rats as inadequate social partners for Wistar animals. Therefore, in a second experiment, adolescent female Wistar rats were either reared with another Wistar rat (adequate social rearing; control) or with a Fischer rat (inadequate social rearing; play-deprived). Beginning on day 50, all Wistar rats were group housed with same-strain partners and tested for behavioral, neurobiological and endocrine differences in adulthood. Playful peer-interactions were decreased during adolescence in play-deprived animals, without affecting social contact behavior. Consequently, adult play-deprived rats showed decreased pain sensitivity and increased startle reactivity compared to controls, but did not differ in activity, anxiety-related behavior or social interaction. Both groups also differed in their endocrine stress-response, and expression levels of the cannabinoid CB1 receptor were increased in the thalamus, whereas FAAH levels were decreased in the amygdala. The present animal model therefore represents a novel approach to assess the long-term consequences of peer-rejection during adolescence. PMID:23669059

Schneider, Peggy; Hannusch, Christin; Schmahl, Christian; Bohus, Martin; Spanagel, Rainer; Schneider, Miriam

2014-02-01

209

The emission of stress-induced 22-kHz calls in female rats is independent of testosterone levels.  

PubMed

Although emission of ultrasonic calls in rats induced by stress, referred to as "22-kHz calls," is dependent on circulating testosterone levels in males, it is still unknown whether the same testosterone-based regulation is applicable to female rats. In this study, we investigated the sex difference in the emission of air-puff-induced 22-kHz calls in rats on the basis of the hypothesis that female rats would emit fewer 22-kHz calls, and assessed whether male-like circulating testosterone levels can also influence the emission of 22-kHz calls in females. The experimental results showed that female rats emit significantly fewer 22-kHz calls than male rats. However, male-like circulating testosterone levels have little effect on the emission of 22-kHz calls in females. Hence, it is suggested that there is a sex difference in stress-induced 22-kHz calls in rats and, in contrast to male rats, the emission of 22-kHz calls in female rats may be independent of circulating testosterone levels, as tested in response to air-puff stimulation. PMID:25597917

Inagaki, Hideaki; Mori, Yuji

2015-03-01

210

Kisspeptin antagonist prevents RF9-induced reproductive changes in female rats.  

PubMed

The aim of this study was to determine the modulatory effects of peptide 234 (p234) (an antagonist of GPR54 receptors) on kisspeptin and RF9 (an RFamide-related peptide antagonist)-induced changes in reproductive functions and energy balance in female rats. Female Sprague-Dawley rats were weaned on postnatal day (pnd) 21. The animals were intracerebroventricularly cannulated under general anesthesia on pnd 23. Groups of female rats were injected with kisspeptin, RF9, p234, kisspeptin plus p234, or RF9 plus p234, daily. The experiments were ended on the day of first diestrus following pnd 60. Kisspeptin or RF9 alone advanced vaginal opening (VO), which was delayed by administration of kisspeptin antagonist alone. In the rats given kisspeptin plus p234 or RF9 plus p234, VO was not different from control rats. Kisspeptin and RF9 elicited significant elevations in circulating LH levels. Coadministrations of kisspeptin or RF9 with p234 decreased LH levels significantly. The use of p234 alone did not cause any significant change in LH secretion. Kisspeptin decreased both food intake and body weight while RF9 decreased only food intake without affecting body weight. The effects of kisspeptin on energy balance were also reversed by central administration of p234. In conclusion, kisspeptin antagonist, p234, modulates the effects of kisspeptin on reproductive functions and energy balance, whereas RF9 seems to exert only its effects on reproductive functions by means of GPR54 signaling in female rats. PMID:25713426

Sahin, Zafer; Canpolat, Sinan; Ozcan, Mete; Ozgocer, Tuba; Kelestimur, Haluk

2015-05-01

211

The Effects of Ovariectomy on Binge Eating Proneness in Adult Female Rats  

PubMed Central

Ovarian hormones are associated with binge eating in women, however findings are limited by the lack of experimental control inherent in human studies. Animal research that manipulates ovarian hormone status and examines individual differences in extreme binge eating proneness are needed to model clinical phenotypes in humans and to confirm causal effects. The purpose of this study was to examine the effects of adult ovariectomy on overall binge eating risk and extreme binge eating phenotypes using the binge eating resistant (BER)/ binge eating prone (BEP) rat model. We predicted that palatable food consumption would significantly increase after ovariectomy in all rats because ovarian hormones generally suppress food intake. If differences in responsiveness to ovarian hormones underlie BER/BEP phenotypes, then differences in binge eating between BER and BEP rats would be eliminated or diminished after ovariectomy. Changes in palatable food (PF) intake were compared in BER and BEP rats before and after ovariectomy in two samples of adult females. Findings were highly similar in the two samples. PF intake increased significantly following ovariectomy in all rats. However, BEP rats consistently consumed larger amounts of PF than BER rats, both before and after ovariectomy. The consistency of findings across two samples of rats provides strong support for activational effects of ovarian hormones on binge eating. However, the immunity of extreme binge eating phenotypes to ovarian hormone ablation suggests that other, earlier mechanisms (e.g., organizational hormone effects or hormone-independent effects) determine the expression of binge eating phenotypes. PMID:21376721

Klump, Kelly L.; Suisman, Jessica L.; Culbert, Kristen M.; Kashy, Deborah A.; Keel, Pamela K.; Sisk, Cheryl L.

2011-01-01

212

Effects of Maternal Behavior Induction and Pup Exposure on Neurogenesis in Adult, Virgin Female Rats  

PubMed Central

The states of pregnancy and lactation bring about a range of physiological and behavioral changes in the adult mammal that prepare the mother to care for her young. Cell proliferation increases in the subventricular zone (SVZ) of the female rodent brain during both pregnancy and lactation when compared to that in cycling, diestrous females. In the present study, the effects of maternal behavior induction and pup exposure on neurogenesis in nulliparous rats were examined in order to determine whether maternal behavior itself, independent of pregnancy and lactation, might affect neurogenesis. Adult, nulliparous, Sprague-Dawley, female rats were exposed daily to foster young in order to induce maternal behavior. Following the induction of maternal behavior each maternal subject plus females that were exposed to pups for a comparable number of test days, but did not display maternal behavior, and subjects that had received no pup exposure were injected with bromodeoxyuridine (BrdU, 90 mg/kg, i.v.). Brain sections were double-labeled for BrdU and the neural marker, NeuN, to examine the proliferating cell population. Increases in the number of double-labeled cells were found in the maternal virgin brain when compared with the number of double-labeled cells present in non-maternal, pup-exposed nulliparous rats and in females not exposed to young. No changes were evident in the dentate gyrus of the hippocampus as a function of maternal behavior. These data indicate that in nulliparous female rats maternal behavior itself is associated with the stimulation of neurogenesis in the SVZ. PMID:19712726

Furuta, Miyako; Bridges, Robert S.

2009-01-01

213

Intravenous self-administration of mephedrone, methylone and MDMA in female rats.  

PubMed

Male rats will intravenously self-administer (IVSA) the substituted cathinone stimulants ("bath salts") mephedrone (4-methylmethcathione) and methylone (3,4-methylenedioxymethcathinone) robustly, whereas the IVSA of 3,4-methylenedioxymethamphetamine (MDMA) is inconsistent in many rat models. There are no data available on the self-administration of these drugs in female rats, thus a study was undertaken to contrast them directly. Groups of female Wistar rats were trained to self-administer mephedrone, methylone or MDMA (0.5 mg/kg/inf) under a Fixed-Ratio (FR) 1 schedule of reinforcement for 14 sessions. Following the acquisition interval, animals were evaluated in FR (0.0, 0.125, 0.25, 0.5, 1.0, 2.5 mg/kg/inf) and PR (0.125, 1.0 mg/kg/inf) dose-substitution procedures. The results show that female rats acquired the self-administration of all three compounds with intakes in mephedrone-trained rats that were significantly higher than that of methylone-trained or MDMA-trained rats. In dose-substitution under either FR or PR contingencies, however, the potencies of all three drugs were similar within the original training groups. The mephedrone-trained animals exhibited higher intakes of all drugs during dose-substitution, indicating lasting consequences of the training drug. Abuse liability of these three compounds is therefore predicted to be similar in established stimulant users but may differ in liability if they are primary drugs of initiation. PMID:25600245

Creehan, Kevin M; Vandewater, Sophia A; Taffe, Michael A

2015-05-01

214

Vascular damage in obese female rats with hypoestrogenism.  

PubMed

Increase in body weight and adiposity has deleterious consequences on health. The aim of this study was to compare morphological and metabolic changes in the arterial vessels of Wistar rats with conditions of obesity, hypoestrogenism, and hypoestrogenism plus obesity. Ovariectomized rats (hypoestrogenic condition) received 30 % sugar in drinking water plus standard diet during 10 weeks. The hypoestrogenic-obese (HE-OB) group presented increase in weight, blood pressure, hypertriglyceridemia, and hyperglycemia compared with other groups. The morphological study in aortic vessels from HE showed damage in endothelial smooth muscle tissue compared with the other groups. Adipose cells volume in HE-OB (59.33?±?2.38 ?(3)?×?10(5)) and obese (OB) (54.95?±?1.36 ?(3)?×?10(5)) groups were significantly larger than control group (36.38?±?0.98 ?(3)?×?10(5)). In the HE group adipocyte hyperplasia was observed, while in OB group adipocyte hypertrophy and hyperplasia was shown. The vascular reactivity in HE-OB and OB groups presented decrease in the relaxation to acetylcholine compared with control conditions (p?

Lima-Mendoza, Luis Angel; Colado-Velázquez, Juventino; Mailloux-Salinas, Patrick; Espinosa-Juárez, Josué V; Gómez-Viquez, Norma L; Molina-Muńoz, Tzindilu; Huang, Fengyang; Bravo, Guadalupe

2014-03-01

215

Effects of iron polymaltose complex, ferrous fumarate and ferrous sulfate treatments in anemic pregnant rats, their fetuses and placentas.  

PubMed

Although oral iron preparations are widely prescribed to prevent and to treat iron deficiency anemia in pregnancy, comparative data on their effects to the mother, fetus and placenta are limited. In this study, the effects of oral iron polymaltose complex (IPC), ferrous fumarate (FF) and ferrous sulfate (FS) were compared in anemic pregnant rats, their fetuses and placentas. Hematological variables and oxidative stress markers in the liver, heart and kidneys of the dams and fetuses as well as the markers for oxidative stress, inflammation and hypoxia in placentas were assessed. Pregnancy outcome was measured by number of fetuses, and by neonate and placental weight. All therapies were comparably effective in correcting anemia. FS and FF, but not IPC, resulted in liver damage in dams and oxidative stress in dams, fetuses and placentas. FS group presented the highest catalase and GPx levels in dams, fetuses and placentas. IPC, but not FF or FS, restored normal TNF-? and IL6 expression levels in placentas whereas FS-treated animals presented the highest cytokine levels, suggesting a local inflammatory reaction. Anemia-induced high levels of HIF-1? were partially lowered by IPC and FF but further elevated by FS. Most of the negative effects associated with IDA were resolved by IPC treatment. Especially FS treatment was found to elicit hepatic damage in the dams, oxidative stress in the dams, fetuses and placenta as well as inflammation and high levels of HIF-1? in the placenta. Pregnancy outcome of FFand FS-treated animals was worse than that of IPC-treated animals. PMID:23547731

Toblli, Jorge E; Cao, Gabriel; Oliveri, Leda; Angerosa, Margarita

2013-06-01

216

The response of Dahl salt-sensitive and salt-resistant female rats to a space flight model  

NASA Technical Reports Server (NTRS)

Vitamin D metabolism in the Dahl salt-sensitive (S) rat, a model of salt-induced hypertension, differs from that in the Dahl salt-resistant (R) rat. We have tested the hypothesis that differences in vitamin D metabolism would render the Dahl S rat more susceptible than the Dahl R rat to the effects of a space flight model. Dahl female rats were tail suspended (hind limb unloaded) for 28 days, while fed a low salt (3 g/kg sodium chloride) diet. Plasma 25-OHD concentrations of S rats were significantly lower than that of R rats. Plasma 1,25-(OH)2D concentration was 50% lower in unloaded than in loaded S rats, but was unaffected in unloaded R rats. The left soleus muscle weight and breaking strength of the left femur (torsion test) were 50% and 25% lower in unloaded than in loaded S and R rats. The mineral content of the left femur, however, was significantly lower (by 11%) only in unloaded S rats. We conclude that female S rats are more vulnerable than female R rats to decreases in plasma 1,25-(OH)2D concentration and femur mineral content during hind limb unloading, but equally vulnerable to muscle atrophy and reduced breaking strength of the femur.

Thierry-Palmer, Myrtle; Cephas, Stacy; Cleek, Tammy; Sayavongsa, Phouyong; Arnaud, Sara B.

2003-01-01

217

Participation of intraluteal progesterone and prostaglandin F2 alpha in LH-induced luteolysis in pregnant rat.  

PubMed

We examined the participation of the intraluteal levels of progesterone (P4) and prostaglandin F2 alpha (PGF2 alpha) in the induction of luteolysis by LH and its relationship with the induction of the 20 alpha-hydroxysteroid dehydrogenase activity (20 alpha-HSD). Subcutaneous administration of four doses of 10 microgram ovine LH (oLH) at 0800, 0900, 1000 and 1100 h on day 19 of pregnancy induced a decrease in the activity of the enzyme 3 beta-HSD 24 and 48 h after treatment and an increase in luteal 20 alpha-HSD activity 48 h after oLH treatment when compared with control rats. Intraluteal and serum P4 levels were lower than control values 24 and 48 h after oLH treatment, with a significant increase in luteal PGF2 alpha content and a decrease in corpus luteum (CL) weight 48 h after oLH treatment. Intrabursal ovarian (i.b.) treatment with an inhibitor of PG's biosynthesis (diclofenac) (70 microgram/ovary) or P4 (3 microgram/ovary) on day 20 of pregnancy, prevented the increase in 20 alpha-HSD activity observed 48 h after oLH treatment, without any effect on 3 beta-HSD activity. The i.b. administration of P4 prevented the increase in intraluteal PGF2 alpha content induced by oLH treatment and the increases in 20 alpha-HSD activity and intraluteal PGF2 alpha content observed in control animals on day 21 of pregnancy. The inhibition of PG biosynthesis also prevents the decrease in intraluteal and serum P4 level induced by oLH. These results provide good evidence of the important participation of intraluteal P4 and PGF2 alpha on the oLH-induced luteolysis in pregnant rats. We also found the P4 produced by the CL is involved, in part, in the regulation of luteal PG synthesis. Thus, the early decline in 3 beta-HSD activity and the consequent fall in intraluteal P4 content, may trigger the synthesis of PGs and thereafter the increase in luteal 20 alpha-HSD activity to establish luteolysis. PMID:9518870

Stocco, C O; Deis, R P

1998-02-01

218

Effects of Hypergravity Exposure on Plasma Oxytocin (OT) Concentrations in Pregnant and Lactating Rat Dams  

NASA Technical Reports Server (NTRS)

From pregnancy to weaning there is a progressive elevation of plasma oxytocin (OT) levels associated with nursing activity, irrespective of litter size. In the present study, we analyzed the effects of continuous 1.5G, 1.75G and 2.0G hypergravity exposure on OT plasma concentration in prepartum (Gestation Day 20) (G20) and lactating (Postnatal day) (P10) rat dams. For this study, litter size was controlled with a yoking procedure established in our lab where individual control litters were yoked-matched to individual hypergravity litters. We reviewed all data at hypergravity irrespective of gravitational level and compared the values with the controls in both G20 (HG, n=15;SC, n=9) and P10 (HG, n=21;SC, n=16). Results showed that over time, we did observe the expected OT increase in both groups. In G20 dams, measurement of OT concentrations showed no significance. However, at P10, measurements of OT concentrations suggest a reduction of about 20% compared to established controls in our laboratory, 0.9+/-0.09 ng/ml for the controls and 0.7+/-0.06 ng/ml for centrifuged animals (p<0.02). These data suggest that exposure to centrifugation may reduce OT levels during lactation. When these plasma samples were obtained, the dams were removed from the litters, and values were not adjusted for the size of the litters. The reduction in OT with centrifugation may reflect a decrease in nursing activity or a decreased responsiveness of the mammary hypothalamic axis. In addition, we have analyzed data on plasma prolactin concentrations and mammary gland development, which may give additional insight to the results of our OT measurements.

Baer, Lisa A.; Wade, Charles E.; Plaut, Karen; Ronca, April E.; Dalton, Bonnie (Technical Monitor)

2002-01-01

219

Prenatal Bystander Stress Alters Brain, Behavior, and the Epigenome of Developing Rat Offspring  

Microsoft Academic Search

The prenatal environment, including prenatal stress, has been extensively studied in laboratory animals and humans. However, studies of the prenatal environment usually directly stress pregnant females, but stress may come ‘indirectly’, through stress to a cage-mate. The current study used indirect prenatal bystander stress and investigated the effects on the gross morphology, pre-weaning behavior, and epigenome of rat offspring. Pregnant

Richelle Mychasiuk; Nichole Schmold; Slava Ilnytskyy; Olga Kovalchuk; Bryan Kolb; Robbin Gibb

2011-01-01

220

Development of behavioral and hormonal disorders in prenatally stressed female rats on the model of posttraumatic stress disorder.  

PubMed

The dynamics of changes in behavioral and hormonal manifestations of a pathological state in mature female rats born by mothers exposed to daily restraint stress on days 15-19 of pregnancy were studied in the experimental model of posttraumatic stress disorder (stress-restress paradigm). Experiments demonstrated increased anxiety in control and prenatally stressed female rats after combined stress followed by restress. This parameter remained enhanced until day 10 after restress in control rats and day 30 in prenatally stressed animals. The severity of depression increased on days 1 and 10 after restress in prenatally stressed female rats. Basal activity of the pituitary-adrenocortical axis increased only in prenatally stressed female rats under these conditions. This parameter increased 1 day after restress and decreased after day 30. It was concluded that prenatal stress could increase the predisposition to post-stress mental pathologies in experimental animals, which are manifested in increased severity and duration of behavioral and hormonal impairments. PMID:25065308

Pivina, S G; Akulova, V K; Rakitskaya, V V; Ordyan, N E

2014-07-01

221

Neonatal stress affects the aging trajectory of female rats on the endocrine, temperature, and ventilatory responses to hypoxia.  

PubMed

Human and animal studies on sleep-disordered breathing and respiratory regulation show that the effects of sex hormones are heterogeneous. Because neonatal stress results in sex-specific disruption of the respiratory control in adult rats, we postulate that it might affect respiratory control modulation induced by ovarian steroids in female rats. The hypoxic ventilatory response (HVR) of adult female rats exposed to neonatal maternal separation (NMS) is ?30% smaller than controls (24), but consequences of NMS on respiratory control in aging female rats are unknown. To address this issue, whole body plethysmography was used to evaluate the impact of NMS on the HVR (12% O2, 20 min) of middle-aged (MA; ?57 wk old) female rats. Pups subjected to NMS were placed in an incubator 3 h/day for 10 consecutive days (P3 to P12). Controls were undisturbed. To determine whether the effects were related to sexual hormone decline or aging per se, experiments were repeated on bilaterally ovariectomized (OVX) young (?12 wk old) adult female rats. OVX and MA both reduced the HVR significantly in control rats but had little effect on the HVR of NMS females. OVX (but not aging) reduced the anapyrexic response in both control and NMS animals. These results show that hormonal decline decreases the HVR of control animals, while leaving that of NMS female animals unaffected. This suggests that neonatal stress alters the interaction between sex hormone regulation and the development of body temperature, hormonal, and ventilatory responses to hypoxia. PMID:25652536

Fournier, Sébastien; Gulemetova, Roumiana; Baldy, Cécile; Joseph, Vincent; Kinkead, Richard

2015-04-01

222

Lycopene intake facilitates the increase of bone mineral density in growing female rats.  

PubMed

Intake of the antioxidant lycopene has been reported to decrease oxidative stress and have beneficial effects on bone health. However, few in vivo studies have addressed these beneficial effects in growing female rodents or young women. The aim of this study was to investigate the effect of lycopene intake on bone metabolism through circulating oxidative stress in growing female rats. Six-week-old Sprague-Dawley female rats were randomly divided into 3 groups according to the lycopene content in their diet: 0, 50, and 100 ppm. The bone mineral density (BMD) of the lumbar spine and the tibial proximal metaphysis increased with lycopene content in a dose-dependent manner; the BMD in 100 ppm group was significantly higher than in the 0 ppm group. The urine deoxypyridinoline concentrations were significantly lower in the 50 and 100 ppm groups than in the 0 ppm group, and the serum bone-type alkaline phosphatase activity was significantly higher in 100 ppm group than in the 0 ppm group. No difference in systemic oxidative stress level was observed; however, the oxidative stress level inversely correlated with the tibial BMD. Our findings suggested that lycopene intake facilitates bone formation and inhibits bone resorption, leading to an increase of BMD in growing female rats. PMID:24975219

Iimura, Yuki; Agata, Umon; Takeda, Satoko; Kobayashi, Yuki; Yoshida, Shigeki; Ezawa, Ikuko; Omi, Naomi

2014-01-01

223

Raloxifene Prevents Skeletal Fragility in Adult Female Zucker Diabetic Sprague-Dawley Rats  

PubMed Central

Fracture risk in type 2 diabetes is increased despite normal or high bone mineral density, implicating poor bone quality as a risk factor. Raloxifene improves bone material and mechanical properties independent of bone mineral density. This study aimed to determine if raloxifene prevents the negative effects of diabetes on skeletal fragility in diabetes-prone rats. Adult Zucker Diabetic Sprague-Dawley (ZDSD) female rats (20-week-old, n?=?24) were fed a diabetogenic high-fat diet and were randomized to receive daily subcutaneous injections of raloxifene or vehicle for 12 weeks. Blood glucose was measured weekly and glycated hemoglobin was measured at baseline and 12 weeks. At sacrifice, femora and lumbar vertebrae were harvested for imaging and mechanical testing. Raloxifene-treated rats had a lower incidence of type 2 diabetes compared with vehicle-treated rats. In addition, raloxifene-treated rats had blood glucose levels significantly lower than both diabetic vehicle-treated rats as well as vehicle-treated rats that did not become diabetic. Femoral toughness was greater in raloxifene-treated rats compared with both diabetic and non-diabetic vehicle-treated ZDSD rats, due to greater energy absorption in the post-yield region of the stress-strain curve. Similar differences between groups were observed for the structural (extrinsic) mechanical properties of energy-to-failure, post-yield energy-to-failure, and post-yield displacement. These results show that raloxifene is beneficial in preventing the onset of diabetes and improving bone material properties in the diabetes-prone ZDSD rat. This presents unique therapeutic potential for raloxifene in preserving bone quality in diabetes as well as in diabetes prevention, if these results can be supported by future experimental and clinical studies. PMID:25243714

Hill Gallant, Kathleen M.; Gallant, Maxime A.; Brown, Drew M.; Sato, Amy Y.; Williams, Justin N.; Burr, David B.

2014-01-01

224

Female Infertility  

MedlinePLUS

Infertility is a term doctors use if a woman hasn't been able to get pregnant after ... woman keeps having miscarriages, it is also called infertility. Female infertility can result from physical problems, hormone ...

225

Effects of acute ethanol administration of female rat liver as a function of aging  

SciTech Connect

Female Fischer 344 rats, aged 4, 14, and 25 months, received 4.0 g/kg of ethanol by intraperitoneal (i.p.) injection. Blood alcohol concentrations 2.5, 6 and 16 hr after ethanol injection were similar in the three age groups. Hepatic glutathione (GSH) levels were diminished 6 hr after ethanol injection, and there were no age-dependent differences in the depleted levels (3.2 {plus minus} 0.1, 3.5 {plus minus} 0.2, and 3.0 {plus minus} 0.5 {mu}g GSH/g liver). However, GSH contents in livers of young-adult rats approached control levels after 16 hr, whereas they remained depressed in older rats. Serum levels of hepatic enzymes were significantly elevated 6 hr after ethanol administration. The increases were greater in middle-aged and old rats than in young-adult rats. The results suggest that middle-aged and old rats are more susceptible than young rats to the acute toxicity of ethanol.

Rikans, L.E.; Snowden, C.D. (Univ. of Oklahoma College of Medicine, Oklahoma City (USA))

1989-01-01

226

Protocol for studying extinction of conditioned fear in naturally cycling female rats.  

PubMed

Extinction of conditioned fear has been extensively studied in male rodents. Recently, there have been an increasing number of studies indicating that neural mechanisms for certain behavioral tasks and response behaviors are different in females and males. Using females in research studies can represent a challenge because of the variation of gonadal hormones during their estrous cycle. This protocol describes well-established procedures that are useful in investigating the role of estrogen in fear extinction memory consolidation in female rats. Phase of the estrous cycle and exogenous estrogen administration prior to extinction training can influence extinction recall 24 hr later. The vaginal swabbing technique for estrous phase identification described here aids the examination and manipulation of naturally cycling gonadal hormones. The use of this basic rodent model may further delineate the mechanisms by which estrogen can modulate fear extinction memory in females. PMID:25741747

Maeng, Lisa Y; Cover, Kara K; Landau, Aaron J; Milad, Mohammed R; Lebron-Milad, Kelimer

2015-01-01

227

Protocol for Studying Extinction of Conditioned Fear in Naturally Cycling Female Rats  

PubMed Central

Extinction of conditioned fear has been extensively studied in male rodents. Recently, there have been an increasing number of studies indicating that neural mechanisms for certain behavioral tasks and response behaviors are different in females and males. Using females in research studies can represent a challenge because of the variation of gonadal hormones during their estrous cycle. This protocol describes well-established procedures that are useful in investigating the role of estrogen in fear extinction memory consolidation in female rats. Phase of the estrous cycle and exogenous estrogen administration prior to extinction training can influence extinction recall 24 hr later. The vaginal swabbing technique for estrous phase identification described here aids the examination and manipulation of naturally cycling gonadal hormones. The use of this basic rodent model may further delineate the mechanisms by which estrogen can modulate fear extinction memory in females. PMID:25741747

Maeng, Lisa Y.; Cover, Kara K.; Landau, Aaron J.; Milad, Mohammed R.; Lebron-Milad, Kelimer

2015-01-01

228

Glutamate release in the ventromedial hypothalamus of the female rat during copulation: modulation by estradiol.  

PubMed

Binding of glutamate or its ionotropic receptor agonists in the ventromedial hypothalamus (VMH) of female rats inhibits both appetitive and consummatory aspects of sexual behavior. Because vaginocervical stimulation activates glutamate neurons in the VMH, and administration of estradiol benzoate (EB) and progesterone (P) delays this effect, the present study examined the effects of hormonal priming on glutamate release within the VMH of female rats paired with sexually vigorous males. Ovariectomized, sexually experienced rats were implanted with guide cannula aimed at the ventrolateral VMH, through which microdialysis probes were inserted prior to testing. Females were assigned randomly to one of three hormone treatment conditions: EB+P, EB alone, or the oil vehicle. Testing was conducted over 5h, including a 120-min period of habituation to the testing chamber, a 60-min period of baseline sample collection, and a 120-min period during which a sexually vigorous male was introduced into the testing chamber. Dialysates were collected every 20min during the test and were analyzed for glutamate using HPLC. Females primed with oil had large and significant increases in glutamate release from baseline once the male was introduced to the chamber. Treatment with EB alone decreased glutamate release in response to male cues. Although treatment with EB+P did not differ significantly from EB alone, the degree of reduced glutamate release was less than with EB alone. These results indicate that priming with EB reduces glutamate transmission in the VMH in response to male cues. Taken together with our previous findings, estradiol blunts the activation of glutamate neurons in the VMH thus allowing female rats to copulate. PMID:24333845

Georgescu, M; Afonso, V M; Graham, M D; Pfaus, J G

2014-02-01

229

High salt diet increases the pressor response to stress in female, but not male ETB-receptor-deficient rats.  

PubMed

Acute stress in both rodents and humans causes a transient rise in blood pressure associated with an increase in plasma endothelin-1 (ET-1). High salt (HS) intake also increases ET-1 production, and interestingly, blunts the pressor response to acute air jet stress in rats. We previously reported that female rats lacking functional ETB receptors everywhere except sympathetic nerves (ETB def) had a greater degree of hypertension in response to a HS diet compared to their male counterparts when measured by the tail cuff method. However, we now report that salt-induced hypertension is not different between sexes when measured by telemetry. Therefore, additional experiments were designed to test the hypothesis that female ETB def rats are more sensitive to acute stress when on a HS diet. The pressor response, measured by telemetry, to acute air jet stress was similar between male transgenic control (Tg control) and ETB def rats following chronic HS intake. In contrast, female ETB def rats had a significantly greater pressor response (about twofold higher) than female or male Tg control or male ETB def rats maintained on HS, a finding that cannot be explained by increased vascular reactivity to ET-1 in female rats as we observed that male ETB def rats had a greater pressor response to i.v. infusion of ET-1 compared to females. Furthermore, HS feeding exacerbated the pressor response to ET-1 in both male and female ETB def rats. Given our previous studies demonstrating that the ETA receptor functions to reduce the pressor response to acute stress, these findings further support a role for the ET receptor system in the pressor response to acute stress and that female rats have reduced ETA receptor activity when on a HS diet compared to males. PMID:25802361

Speed, Joshua S; D'Angelo, Gerard; Wach, Paul A; Sullivan, Jennifer C; Pollock, Jennifer S; Pollock, David M

2015-03-01

230

High salt diet increases the pressor response to stress in female, but not male ETB-receptor-deficient rats  

PubMed Central

Acute stress in both rodents and humans causes a transient rise in blood pressure associated with an increase in plasma endothelin-1 (ET-1). High salt (HS) intake also increases ET-1 production, and interestingly, blunts the pressor response to acute air jet stress in rats. We previously reported that female rats lacking functional ETB receptors everywhere except sympathetic nerves (ETB def) had a greater degree of hypertension in response to a HS diet compared to their male counterparts when measured by the tail cuff method. However, we now report that salt-induced hypertension is not different between sexes when measured by telemetry. Therefore, additional experiments were designed to test the hypothesis that female ETB def rats are more sensitive to acute stress when on a HS diet. The pressor response, measured by telemetry, to acute air jet stress was similar between male transgenic control (Tg control) and ETB def rats following chronic HS intake. In contrast, female ETB def rats had a significantly greater pressor response (about twofold higher) than female or male Tg control or male ETB def rats maintained on HS, a finding that cannot be explained by increased vascular reactivity to ET-1 in female rats as we observed that male ETB def rats had a greater pressor response to i.v. infusion of ET-1 compared to females. Furthermore, HS feeding exacerbated the pressor response to ET-1 in both male and female ETB def rats. Given our previous studies demonstrating that the ETA receptor functions to reduce the pressor response to acute stress, these findings further support a role for the ET receptor system in the pressor response to acute stress and that female rats have reduced ETA receptor activity when on a HS diet compared to males. PMID:25802361

Speed, Joshua S; D'Angelo, Gerard; Wach, Paul A; Sullivan, Jennifer C; Pollock, Jennifer S; Pollock, David M

2015-01-01

231

Estrogenic activity of a hydro-alcoholic extract of Bambusa arundinaceae leaves on female wistar rats  

PubMed Central

To study the estrogenic activity of the hydro-alcoholic extract of Bambusa arundinaceae leaves (HEBA) in female Wistar rats. The dried powdered leaves were extracted with hydroalcoholic mixture (60%), and the resultant extract was subjected for phytochemical analyses to identify different phytoconstituents. HEBA were administered to ovariectomized rats for 7 days at three different doses (viz., 200, 300, 400 mg/kg body weight, p.o.) and their estrogenic activity were compared with each of daily treatment with 0.2 mg/kg body weight, i.p. conjugated equine estrogen as a positive control or olive oil as a negative control. Estrogenic activity was evaluated by doing uterotropic assay, vaginal cytology and measurement of vaginal opening in female Wistar rats. Oral administration of HEBA in ovariectomized immature and mature female Wistar rats in a dose of 400 mg/kg b.w. resulted in significant increase in the uterine wet weight (in mg) (224.82 ± 7.01) and (912.25 ± 27.22) when compared with ovariectomized control rats (111.52 ± 3.17) and (506.67 ± 21.39). HEBA (400 mg/kg b.w., p.o.) treated rats, showing only cornified epithelial cells which was an indication of the presence of the estrogen and also showed 100% vaginal opening. It was observed that HEBA possess significant estrogenic activity at 400 mg/kg b.w., p.o. which was evident by uterotropic assay, measurement of vaginal opening, and histopathological changes. PMID:25709965

Jawaid, Talha; Awasthi, Akanksha; Kamal, Mehnaz

2015-01-01

232

Serotonergic system involvement in the inhibitory action of estrogen on induced sodium appetite in female rats.  

PubMed

This study of the participation of the serotonergic system in the inhibitory effect of estrogen on induced sodium appetite in female rats explores sodium appetite induced by Furosemide and low sodium diet treatment (DEP) in normally cycling rats and in ovariectomized rats with and without estradiol replacement (OVX, OVX+E(2)). We also analyzed the neural activity of serotonergic neurons of the dorsal raphe nucleus (DRN) as well as the activity of other brain nuclei previously found to be involved in sodium and water balance in sodium depleted animals without access to the intake test. For this purpose, we examined the brain Fos, Fos-serotonin and Fos-vasopressin immunoreactivity patterns in diestrus (D), estrus (E), OVX and OVX+E(2) rats subjected to DEP. Female rats in E and OVX+E(2) exhibited a significant decrease in induced sodium intake compared with females in D and OVX. This estrogen-dependent inhibition on induced sodium appetite (approximately 50% reduction) can be correlated with changes in Fos activation observed in the organum vasculosum of the lamina terminalis (OVLT) and DRN, in response to sodium depletion. Given our previous observations in males, the expected sodium depletion-induced activity of the OVLT was found to be absent in OVX+E(2) females, while the usual inhibitory tonic activity of serotonergic neurons of the DRN, instead of decreasing after sodium depletion, increases or remains unchanged in OVX+E(2)-DEP and E-DEP females, respectively. Regarding urinary water and sodium excretion 3h after furosemide treatment, E-DEP and OVX+E(2)-DEP animals excreted smaller volumes of more highly concentrated urine than depleted D and OVX rats. Twenty hours after sodium depletion, the same groups of animals also showed a significant increase in the number of Fos-AVP immunoreactive neurons within the supraoptic nucleus, compared with D-DEP. In summary, our results demonstrate an estrogen-dependent inhibition of induced sodium appetite in normally cycling rats and ovariectomized animals with estradiol replacement, which may involve an interaction between excitatory neurons of the OVLT and inhibitory serotonergic cells of the DRN. The main finding is thus serotonergic system involvement as a possible mechanism in the inhibitory action of estrogen on induced sodium appetite. PMID:21554894

Dalmasso, Carolina; Amigone, José Luis; Vivas, Laura

2011-09-01

233

Influence of ovarian hormones on development of ingestive responding to alterations in fatty acid oxidation in female rats.  

PubMed

Adult male rats have been demonstrated to increase food intake in response to administration of drugs that interfere with oxidation of fatty acids (e.g. methyl palmoxirate and mercaptoacetate [MA]), effects that are larger in animals maintained on a high-fat diet. In contrast, while administration of MA has been reported to stimulate food intake in pre-pubertal female rats, food intake is not stimulated by MA in adult female rats. Instead, administration of MA to adult females results in changes in reproductive behavior and physiology. The present experiments were designed to examine the effects of administration of MA on food intake in adult female rats. The results demonstrated that, as previously reported, food intake was stimulated by MA in adult male rats on low-fat and high-fat diets, but food intake was not stimulated by MA in gonadally-intact adult female rats on either low-fat or high-fat diet. Further, MA did not stimulate food intake in female rats ovariectomized as adults. However, when females were ovariectomized prior to the onset of puberty (postnatal day 25-28), food intake was stimulated by administration of MA in adulthood. Finally, cyclic injections of 17-beta-estradiol benzoate given to females ovariectomized prior to the onset of puberty abolished the stimulatory effects of MA on food intake in adult females. Taken together, the data suggest that exposure to estrogens during the time of puberty in female rats can persistently alter adult ingestive responding to signals related to changes in energy utilization. PMID:18586247

Swithers, Susan E; McCurley, Melissa; Hamilton, Erica; Doerflinger, Alicia

2008-08-01

234

Effect of six antiretroviral drugs (delavirdine, stavudine, lamivudine, nelfinavir, amprenavir and lopinavir/ritonavir in association) on albino pregnant rats (Rattus norvegicus Albinus, Rodentia, Mammalia): biological assay.  

PubMed

Objective: To compare the chronic effects of antiretrovirals (lamivudine, stavudine, delavirdine, nelfinavir, amprenavir and an association of lopinavir/ritonavir) on albino pregnant rats.Design: Review.Setting: Department of Obstetrics, Federal University of Săo Paulo (UNIFESP), Săo Paulo, SP, Brazil.Methods: This was a comparative retrospective study formed by 18 groups of 10 pregnant rats each, which were nearly three months of age and weighed 200 g. All of them were medicated every day using a stomach probe, while the control group was given 1 mL of distilled water. The study groups received lamivudine (at 5, 15 and 45 mg/kg/day); stavudine (at 1, 3 and 9 mg/kg/day); nelfinavir (at 40, 120 and 360 mg/kg/day); amprenavir (at 46, 138 and 414 mg/kg/day); lopinavir/ritonavir (at 12.8/3.2, 38.4/9.6 and 115/28.8 mg/kg/day) and delavirdine (at 20 and 60 mg/kg/day). These represented 1, 3 and 9 times the human therapeutic dose, except for the last drug, for which the 9-times dose was not used. Maternal, litter and placental weights, implantation and reabsorption numbers, major external fetal malformations and fetal and maternal deaths were evaluated. The Kruskal-Wallis test was used to compare quantitative variables and the chi-square test was used to compare qualitative variables.Results: At all three doses, stavudine increased the maternal weight (p=0.001), while lamivudine at 3- and 9-times doses reduced it (p<0.001). Amprenavir at all of the doses, and lopinavir/ritonavir at 3- and 9-times doses, caused higher rates of maternal death (p<0.001). Regarding the fetuses, none of the antiretroviral drugs studied were harmful with regard to implantation, reabsorption, teratogenity and mortality (p>0.05). Stavudine at all doses reduced the litter weights (p<0.001); however, lamivudine at the usual and 3-times doses, delavirdine at 3-times dose, and amprenavir at 3-times dose increased the litter weight (p<0.001).Conclusion: In the maternal compartment, we observed lethal toxicity in the pregnant rats that received amprenavir and ritonavir/lopinavir; and maternal weight change with lamivudine and stavudine. In the fetal compartment, adverse effects were observed in relation to litter weight from stavudine, lamivudine, delavirdine and amprenavir.Keywords: pregnant rats, antiretroviral drugs, teratology, biological assay. PMID:25398151

Nakamura, M U; Araujo, E Júnior; Simőes, J M; Oliveria, R M Filho; Kulay, L Júnior

2014-01-01

235

INHIBITION OF CHOLINESTERASE ENZYMES FOLLOWING A SINGLE DERMAL DOSE OF CHLORPYRIFOS AND METHYL PARATHION, ALONE AND IN COMBINATION, IN PREGNANT RATS  

Microsoft Academic Search

Pregnant Sprague-Dawley rats (14-18 d of gestation) were treated with either a single dermal subclinical dose of 30 mg\\/kg (15% of dermal LD50) chlorpyrifos (O,O-diethyl O-[3,5,6-trichloro-2-pyridinyl] phosphorothioate) or a single dermal subclinical dose of 10 mg\\/kg (15% of dermal LD50) methyl parathion (O,O-dimethyl O-4-nitrophenyl phosphorothioate) or the two in combination. Chlorpyrifos inhibited maternal and fetal brain acetylcholinesterase (AChE) activity within

Aqel W. Abu-Qare; Ali Abdel-Rahman; Ceciel Brownie; Amal M. Kishk; Mohamed B. Abou-Donia

2001-01-01

236

Enzymic basis of deranged foetal flavin-nucleotide metabolism consequent on immunoneutralization of maternal riboflavin carrier protein in the pregnant rat.  

PubMed Central

A comparison of the kinetic and other parameters of enzymes of flavin-nucleotide metabolism in the whole foetus vis-ŕ-vis the maternal liver in the pregnant rat revealed relatively lower activities of foetal flavokinase and FAD pyrophosphorylase. Passive immunoneutralization of the maternal riboflavin carrier protein suppresses foetal FAD pyrophosphorylase rather selectively. Additionally, although the activities of foetal nucleotide pyrophosphatase and FMN phosphatase were unchanged owing to immunoneutralization, higher activities of these enzymes in the whole foetus as compared with the maternal liver may be responsible for the drastic depletion of FAD levels that precipitates foetal degeneration. PMID:2996499

Surolia, N; Krishnamurthy, K; Adiga, P R

1985-01-01

237

Green tea polyphenols avert chronic inflammation-induced myocardial fibrosis of female rats  

Microsoft Academic Search

Objective  Green tea proposes anti-inflammatory properties which may attenuate chronic inflammation-induced fibrosis of vessels. This\\u000a study evaluated whether green tea polyphenols (GTP) can avert fibrosis or vascular disruption along with mechanisms in rats\\u000a with chronic inflammation.\\u000a \\u000a \\u000a \\u000a \\u000a Treatments  Forty 3-month-old female rats were assigned to a 2 (placebo vs. lipopolysaccharide, administration) × 2 (no GTP vs. 0.5% GTP\\u000a in drinking water) factorial design for 12 weeks.

Chwan-Li Shen; Christina Samathanam; Owatha L. Tatum; Suzanne Graham; Christine Tubb; Jay J. Cao; Dale M. Dunn; Jia-Sheng Wang

2011-01-01

238

Estradiol-sensitive projection neurons in the female rat preoptic area  

PubMed Central

Electrical stimulation of the preoptic area (POA) interrupts the lordosis reflex, a combined contraction of back muscles, in response to male mounts and the major receptive component of sexual behavior in female rat in estrus, without interfering with the proceptive component of this behavior or solicitation. Axon-sparing POA lesions with an excitotoxin, on the other hand, enhance lordosis and diminish proceptivity. The POA effect on the reflex is mediated by its estrogen-sensitive projection to the ventral tegmental area (VTA) as shown by the behavioral effect of VTA stimulation as well as by the demonstration of an increased threshold for antidromic activation of POA neurons from the VTA in ovariectomized females treated with estradiol benzoate (EB). EB administration increases the antidromic activation threshold in ovariectomized females and neonatally castrated males, but not in neonatally androgenized females; the EB effect is limited to those that show lordosis in the presence of EB. EB causes behavioral disinhibition of lordosis through an inhibition of POA neurons with axons to the VTA, which eventually innervate medullospinal neurons innervating spinal motoneurons of the back muscle. The EB-induced change in the threshold or the axonal excitability may be a result of EB-dependent induction of BK channels. Recordings from freely moving female rats engaging in sexual interactions revealed separate subpopulations of POA neurons for the receptive and proceptive behaviors. Those POA neurons engaging in the control of proceptivity are EB-sensitive and project to the midbrain locomotor region (MLR). EB thus enhances lordosis by reducing excitatory neural impulses from the POA to the VTA. An augmentation of the POA effect to the MLR may culminate in an increased locomotion that embodies behavioral estrus in the female rat. PMID:25852453

Sakuma, Yasuo

2015-01-01

239

Age-related changes in dorsal root ganglia, circulating and vascular calcitonin gene-related peptide (CGRP) concentrations in female rats: Effect of female sex steroid hormones  

PubMed Central

The aim of the present study is to investigate whether immunoreactive (I) calcitonin gene-related peptide (CGRP) content is decreased in plasma and mesenteric arteries (resistance arteries) in middle-aged rats and if so, whether sex steroid hormones enhance I-CGRP in middle-aged female rats. We also examined whether vascular CGRP receptor components, calcitonin receptor like receptor (CRLR) and receptor activity modifying protein 1 (RAMP1) are elevated by sex steroid hormones treatment in middle-aged female rats. Young adult (3 months old) and middle-aged (10–12 months old) ovariectomized rats were treated subcutaneously with estradiol-17? (E2; 2 mg), progesterone (P4; 5 mg), E2 +P4 (2 mg + 20 mg) or placebo (control). Radioimmunoassay and Western blot analysis were performed to measure I-CGRP content and CGRP receptor components in dorsal root ganglia (DRG), in resistance arteries and in plasma. Immunofluorescent staining methods were employed to determine cellular localization of CRLR, RAMP1 in resistance arteries. Our data demonstrated that I-CGRP content was significantly (p < 0.05) lower in the plasma and resistance arteries of middle-aged female rats compared to young controls. Both RAMP1 and CRLR were concentrated in vascular endothelium and the underlying smooth muscle cells. RAMP1 but not CRLR appeared to be decreased in middle-aged rat vasculature. Chronic perfusion of sex steroid hormones to ovariectomized rats: (1) significantly (p < 0.05) elevated I-CGRP in the DRG and in the plasma, and (2) significantly elevated RAMP1 (p < 0.05) but did not alter CRLR in resistance arteries. These data suggest that female sex steroid treatment enhances I-CGRP and its receptors, and thus regulate the blood pressure in aged female rats. PMID:19429067

Gangula, Pandu R.R.; Chauhan, Madhu; Reed, Luckey; Yallampalli, Chandra

2009-01-01

240

Pharmacological modulation of the endocannabinoid signalling alters binge-type eating behaviour in female rats  

PubMed Central

Background and Purpose Binge eating disorder (BED) is characterized by excessive food intake during short periods of time. Recent evidence suggests that alterations in the endocannabinoid signalling could be involved in the pathophysiology of BED. In this study, we investigated whether pharmacological manipulation of endocannabinoid transmission may be effective in modulating the aberrant eating behaviour present in a validated rat model of BED. Experimental Approach Binge-type eating was induced in female rats by providing limited access to an optional source of dietary fat (margarine). Rats were divided into three groups, all with ad libitum access to chow and water: control (C), with no access to margarine; low restriction (LR), with 2 h margarine access 7 days a week; high restriction (HR), with 2 h margarine access 3 days a week. Key Results Compared with the LR group, the HR group consumed more margarine and this was accompanied by an increase in body weight. The cannabinoid CB1/CB2 receptor agonist ?9-tetrahydrocannabinol significantly increased margarine intake selectively in LR rats, while the fatty acid amide hydrolase inhibitor URB597 showed no effect. The CB1 receptor inverse agonist/antagonist rimonabant dose-dependently reduced margarine intake in HR rats. Notably, in HR rats, chronic treatment with a low dose of rimonabant induced a selective long-lasting reduction in margarine intake that did not develop tolerance, and a significant and persistent reduction in body weight. Conclusions and Implications Chronic pharmacological blockade of CB1 receptors reduces binge eating behaviour in female rats and may prove effective in treating BED, with an associated significant reduction in body weight. Linked Articles This article is part of a themed section on Cannabinoids. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2013.169.issue-4 & http://dx.doi.org/10.1111/bph.2012.167.issue-8 PMID:23072421

Scherma, M; Fattore, L; Satta, V; Businco, F; Pigliacampo, B; Goldberg, SR; Dessi, C; Fratta, W; Fadda, P

2013-01-01

241

Dietary Soy May Not Confound Acute Experimental Stroke Infarct Volume Outcomes In Ovariectomized Female Rats  

PubMed Central

Estrogen administration can alter experimental stroke outcomes. Soy as a source of phytoestrogens may therefore modulate responses in “estrogen-sensitive” stroke models, thus potentially confounding results. We evaluated the effects of dietary soy on acute infarct volumes in a pilot study using a rat focal stroke model. We hypothesized that ovariectomized (OVX) rats fed a soy-rich diet would have smaller acute infarct volumes than rats fed a soy-free diet. OVX rats were randomly assigned to a soy-free (n=6) or a soy-rich (n=6) diet for 4 weeks and weighed weekly. Following the dietary trial, rats underwent 2 hours of middle cerebral artery occlusion (MCAO). Mean arterial blood pressure, rectal and temporalis muscle temperatures, arterial blood gases, and blood glucose were recorded peri-ischemia. Rats were euthanized 22 hours following 2 hours of MCAO. Brains were stained with 2,3,5-triphenyl tetrazolium chloride for acute infarct volume analysis. Uterine weight and histology were also evaluated as additional internal estrogen-sensitive controls. Rats on the soy-free diet had greater gains in body weight (259±6% baseline body weight) than rats on the soy-rich diet (238±4% baseline body weight). No differences were seen in uterine weight and histology, peri-ischemic physiological parameters, and infarct volumes between the treatment groups. Results of this pilot study suggest that the dietary soy level tested may not alter acute infarct volumes in ischemic female rat brain. More studies addressing the potential confounding effects of dietary soy in “estrogen-sensitive” stroke models are needed if investigators are to make informed choices regarding diets used in experimental stroke research. PMID:20147341

Prongay, Kamm D.; Lewis, Anne D.; Hurn, Patricia D.; Murphy, Stephanie J.

2009-01-01

242

Early maternal separation increases symptoms of activity-based anorexia in male and female rats.  

PubMed

Running activates the hypothalamic-pituitary-adrenal (HPA) axis, increasing the release of stress hormones known to exert anorexic effects. HPA axis reactivity is strongly influenced by early postnatal manipulations, including removal of pups from the dam for short (handling) or prolonged (maternal separation) durations during the preweaning period. The authors examined the effects of handling and maternal separation on food intake, body weight loss, and running rates of young adult male and female rats in the activity-based anorexia (ABA) paradigm. Postnatal treatment did not affect adaptation to a 1-hr restricted feeding schedule before the introduction of wheel running. During the ABA paradigm, maternally separated animals lost weight faster, ate less, ran more, and required fewer days to reach removal criterion compared with handled rats. Females were particularly vulnerable. These findings indicate that early postnatal treatment and sex influence ABA. PMID:19594284

Hancock, Stephanie; Grant, Virginia

2009-07-01

243

Internal Pudendal Artery from Type 2 Diabetic Female Rats Demonstrate Elevated Endothelin-1-Mediated Constriction  

PubMed Central

Introduction Diabetes is a risk factor for female sexual dysfunction (FSD). FSD has several etiologies, including a vasculogenic component that could be exacerbated in diabetes. The internal pudendal artery supplies blood to the vagina and clitoris and diabetes-associated functional abnormalities in this vascular bed may contribute to FSD. Aim The Goto-Kakizaki (GK) rat is a non-obese model of type 2 diabetes with elevated endothelin-1 (ET-1) activity. We hypothesize that female GK rats have diminished sexual responses and that the internal pudendal arteries demonstrate increased ET-1 constrictor sensitivity. Methods Female Wistar and GK rats were used. Apomorphine (APO)-mediated genital vasocongestive arousal (GVA) was measured. Functional contraction (ET-1 and phenylephrine) and relaxation (acetylcholine, ACh) in the presence or absence of the ETA receptor antagonist (ETAR; atrasentan) or Rho-kinase inhibitor (Y-27632) were assessed in the internal pudendal and mesenteric arteries. Protein expression of ET-1 and RhoA/Rho-kinase signaling pathway was determined in the internal pudendal and mesenteric arteries. Main Outcome Measure APO-mediated GVAs; contraction and relaxation of internal pudendal and mesenteric arteries; ET-1/RhoA/Rho-kinase protein expression. Results GK rats demonstrated no APO-induced GVAs. Internal pudendal arteries, but not mesenteric arteries, from GK rats exhibited greater contractile sensitivity to ET-1 compared with Wistar arteries. ETAR blockade reduced ET-1-mediated constriction in GK internal pudendal and mesenteric arteries. Rho-kinase inhibition reduced ET-1-mediated constriction of GK internal pudendal but not mesenteric arteries; however, it had no effect on arteries from Wistar rats. RhoA protein expression was elevated in GK internal pudendal arteries. At the highest concentrations, ACh-mediated relaxation was greater in the GK internal pudendal artery; however, no difference was observed in the mesenteric artery. Conclusions Female GK rats demonstrate decreased sexual responses that may be because of increased constrictor sensitivity to the ET-1/RhoA/Rho-kinase signaling in the internal pudendal artery. PMID:21718448

Allahdadi, Kyan J.; Hannan, Johanna L.; Ergul, Adviye; Tostes, Rita C.; Webb, R. Clinton

2014-01-01

244

Nicotine alters the usual reciprocity between meal size and meal number in female rat  

Microsoft Academic Search

Tobacco smoking reduces appetite and body weight (BW). Cessation of smoking leads to hyperphagia and weight gain. Daily food intake (FI) is a function of meal number (MN) and meal size (MZ), i.e., FI=MN×MZ. Under normal conditions, the female Fischer rat has a periodic reciprocal fluctuation between MZ and MN corresponding to phase of estrous cycle. Wide fluctuations between MZ

Go Miyata; Michael M Meguid; Madhu Varma; Serguei O Fetissov; Hyune-Ju Kim

2001-01-01

245

Birthdates of the Tyrosine Hydroxylase Immunoreactive Neurons in the Hypothalamus of Male and Female Rats  

Microsoft Academic Search

This study determined the birthdates of the tyrosine hydroxylase-(TH) immunoreactive (IR) neurons in the zona incerta (ZI), periventricular nucleus (PeVN) and arcuate nucleus (AN) of male and female rats. ‘Long-surviva? [3H]thymidine autoradiography combined with TH immunocytochemistry, the first enzyme of catecholamine synthesis, was used. In males, TH-IR neurons originate in the ZI between embryonic days (E) 12 and 13, while

Irina S. Balan; Michael V. Ugrumov; Nina A. Borisova; André Calas; Christof Pilgrim; Ingrid Reisert; Jean Thibault

1996-01-01

246

Oxytocin Causes a Long-Term Decrease of Blood Pressure in Female and Male Rats  

Microsoft Academic Search

The aim of the present study was to investigate the long-term effects of oxytocin (OXY) on blood pressure (BP) and heart rate (HR) in conscious female and male rats. For this purpose, subcutaneous (SC) (0.01, 0.1, and 1 mg\\/kg) or intracerebroventricular (ICV) (1 ?g\\/kg) injections of OXY were given during 5-day periods. BP and HR were measured daily. A significant

MARIA PETERSSON; PAWEL ALSTER; THOMAS LUNDEBERG; KERSTIN UVNÄS-MOBERG

1997-01-01

247

Maternal treatment of spontaneously hypertensive rats with pentaerythritol tetranitrate reduces blood pressure in female offspring.  

PubMed

Pentaerythritol tetranitrate is devoid of nitrate tolerance and shows no reproductive or developmental toxicity in animal studies. Recently, pentaerythritol tetranitrate has been demonstrated to reduce the risk of intrauterine growth restriction and the risk of preterm birth in women with abnormal placental perfusion. This study was conducted to test the perinatal programming effect of pentaerythritol tetranitrate in spontaneously hypertensive rats, a rat model of genetic hypertension. Parental spontaneously hypertensive rats were treated with pentaerythritol tetranitrate (50 mg/kg per day) during pregnancy and lactation periods; the offspring received standard chow without pentaerythritol tetranitrate after weaning. Maternal treatment with pentaerythritol tetranitrate had no effect on blood pressure in male offspring. In the female offspring, however, a persistent reduction in blood pressure was observed at 6 and 8 months. This long-lasting effect was accompanied by an upregulation of endothelial nitric oxide synthase, mitochondrial superoxide dismutase, glutathione peroxidase 1, and heme oxygenase 1 in the aorta of 8-month-old female offspring, which was likely to result from epigenetic changes (enhanced histone 3 lysine 27 acetylation and histone 3 lysine 4 trimethylation) and transcriptional activation (enhanced binding of DNA-directed RNA polymerase II to the transcription start site of the genes). In organ chamber experiments, the endothelium-dependent, nitric oxide-mediated vasodilation to acetylcholine was enhanced in aorta from female offspring of the pentaerythritol tetranitrate-treated parental spontaneously hypertensive rats. In conclusion, maternal pentaerythritol tetranitrate treatment leads to epigenetic modifications, gene expression changes, an improvement of endothelial function and a persistent blood pressure reduction in the female offspring. PMID:25385760

Wu, Zhixiong; Siuda, Daniel; Xia, Ning; Reifenberg, Gisela; Daiber, Andreas; Münzel, Thomas; Förstermann, Ulrich; Li, Huige

2015-01-01

248

Studies of tamoxifen as a promoter of hepatocarcinogenesis in female Fischer F344 rats  

Microsoft Academic Search

Tamoxifen, an antiestrogen used in the treatment of breast cancer, was assessed for carcinogenic potential in the two-stage model of experimental hepatocarcinogenesis. Groups of female Fischer F344 rats were initiated with a non-necrogenic, subcarcinogenic dose of diethylnitrosamine (DEN; 10 mg\\/kg, po) and fed tamoxifen at a concentration of 250 mg per kg of AIN-76A diet for 6 or 15 months.

Yvonne P. Dragan; Susan Fahey; Jennifer Vaughan; V. Craig Jordan; Henry C. Pitot

1994-01-01

249

Effects of ethanol ingestion and dietary fat levels on mitochondrial lipids in male and female rats  

Microsoft Academic Search

The effects of sex, dietary fat levels, and ethanol ingestion on rat liver mitochondrial lipids have been studied. Two groups\\u000a of male animals were fed either a low-fat diet for about 76 days or a high-fat diet for about 52 days, and two groups of female\\u000a animals were fed the same low-fat diet for about 50 days or the high-fat

John A. Thompson; Ronald C. Reitz

1978-01-01

250

Macrophagic and microglial responses after focal traumatic brain injury in the female rat  

PubMed Central

Background After central nervous system injury, inflammatory macrophages (M1) predominate over anti-inflammatory macrophages (M2). The temporal profile of M1/M2 phenotypes in macrophages and microglia after traumatic brain injury (TBI) in rats is unknown. We subjected female rats to severe controlled cortical impact (CCI) and examined the postinjury M1/M2 time course in their brains. Methods The motor cortex (2.5 mm left laterally and 1.0 mm anteriorly from the bregma) of anesthetized female Wistar rats (ages 8 to 10 weeks; N?=?72) underwent histologically moderate to severe CCI with a 5-mm impactor tip. Separate cohorts of rats had their brains dissociated into cells for flow cytometry, perfusion-fixed for immunohistochemistry (IHC) and ex vivo magnetic resonance imaging or flash-frozen for RNA and protein analysis. For each analytical method used, separate postinjury times were included for 24 hours; 3 or 5 days; or 1, 2, 4 or 8 weeks. Results By IHC, we found that the macrophagic and microglial responses peaked at 5 to 7 days post-TBI with characteristics of mixed populations of M1 and M2 phenotypes. Upon flow cytometry examination of immunological cells isolated from brain tissue, we observed that peak M2-associated staining occurred at 5 days post-TBI. Chemokine analysis by multiplex assay showed statistically significant increases in macrophage inflammatory protein 1? and keratinocyte chemoattractant/growth-related oncogene on the ipsilateral side within the first 24 hours after injury relative to controls and to the contralateral side. Quantitative RT-PCR analysis demonstrated expression of both M1- and M2-associated markers, which peaked at 5 days post-TBI. Conclusions The responses of macrophagic and microglial cells to histologically severe CCI in the female rat are maximal between days 3 and 7 postinjury. The response to injury is a mixture of M1 and M2 phenotypes. PMID:24761998

2014-01-01

251

Experimental gastritis leads to anxiety- and depression-like behaviors in female but not male rats  

PubMed Central

Human and animals studies support the idea that there is a gender-related co-morbidity of pain-related and inflammatory gastrointestinal (GI) diseases with psychological disorders. This co-morbidity is the evidence for the existence of GI-brain axis which consists of immune (cytokines), neural (vagus nerve) and neuroendocrine (HPA axis) pathways. Psychological stress causes disturbances in GI physiology, such as altered GI barrier function, changes in motility and secretion, development of visceral hypersensitivity, and dysfunction of inflammatory responses. Whether GI inflammation would exert impact on psychological behavior is not well established. We examined the effect of experimental gastritis on anxiety- and depression-like behaviors in male and female Sprague–Dawley rats, and evaluated potential mechanisms of action. Gastritis was induced by adding 0.1% (w/v) iodoacetamide (IAA) to the sterile drinking water for 7 days. Sucrose preference test assessed the depression-like behavior, open field test and elevated plus maze evaluated the anxiety-like behavior. IAA treatment induced gastric inflammation in rats of either gender. No behavioral abnormality or dysfunction of GI-brain axis was observed in male rats with IAA-induced gastritis. Anxiety- and depression-like behaviors were apparent and the HPA axis was hyperactive in female rats with IAA-induced gastritis. Our results show that gastric inflammation leads to anxiety- and depression-like behaviors in female but not male rats via the neuroendocrine (HPA axis) pathway, suggesting that the GI inflammation can impair normal brain function and induce changes in psychological behavior in a gender-related manner through the GI-to-brain signaling. PMID:24345032

2013-01-01

252

TITLE Disposition and kinetics of Tetrabromobisphenol A in female Wistar Han rats  

PubMed Central

Tetrabromobisphenol A (TBBPA) is the brominated flame retardant with the largest production volume worldwide. NTP 2-year bioassays found TBBPA dose-dependent increases in uterine tumors in female Wistar Han rats; evidence of reproductive tissues carcinogenicity was equivocal in male rats. To explain this apparent sex-dependence, the disposition and toxicokinetic profile of TBBPA were investigated using female Wistar Han rats, as no data were available for female rats. In these studies, the primary route of elimination following [14C]-TBBPA administration (25, 250 or 1,000 mg/kg) was in feces; recoveries in 72 h were 95.7±3.5%, 94.3±3.6% and 98.8±2.2%, respectively (urine: 0.2-2%; tissues: <0.1). TBBPA was conjugated to mono-glucuronide and —sulfate metabolites and eliminated in the bile. Plasma toxicokinetic parameters for a 250 mg/kg dose were estimated based on free TBBPA, as determined by UV/radiometric-HPLC analyses. Oral dosing by gavage (250 mg/kg) resulted in a rapid absorption of compound into the systemic circulation with an observed Cmax at 1.5 h post-dose followed by a prolonged terminal phase. TBBPA concentrations in plasma decreased rapidly after an IV dose (25 mg/kg) followed by a long elimination phase. These results indicate low systemic bioavailability (F<0.05), similar to previous reports using male rats. Elimination pathways appeared to become saturated leading to delayed excretion after a single oral administration of the highest dose (1,000 mg/kg); no such saturation or delay was detected at lower doses. Chronic high exposures to TBBPA may result in competition for metabolism with endogenous substrates in extrahepatic tissues (e.g., SULT1E1 estrogen sulfation) resulting in endocrine disruption. PMID:24977115

Knudsen, Gabriel A.; Sanders, J. Michael; Sadik, Abdella M.; Birnbaum, Linda S.

2014-01-01

253

Antispasmodic Effects of Aqueous and Hydroalcoholic Punica granatum Flower Extracts on the Uterus of Non-pregnant Rats  

PubMed Central

Background Punica granatum Linn. (PG) is native to the Mediterranean region. Its flower exhibited antioxidant activity. The present study attempt to investigate the effect of these extract on uterine contraction and its possible mechanism(s). Methods Thirty five female Wistar rats (200–300 g) at estrous phases of cycle was examined in this study; pieces of virgin adult rat uterus (1.5 cm) were suspended in an organ bath containing 10 ml of De Jalon solution at 29 °C. Tissue contractility was isometrically recorded. KCl (60 mM), BaCl2 (4 mM) and oxytocin (10 mU/ml) were applied to the tissue in the presence and absence of aqueous and hydroalcoholic extracts of the plant (0.05, 0.1, 0.2, 0.4 and 0.8 mg/ml). Propranolol (1 µM) and naloxane (1 µM) were added in KCl induced contractions. The results were analyzed by ANOVA and p < 0.05 were considered as significant. Results Cumulative concentration of extracts reduced uterine contractions induced by KCl dose-dependently (p < 0.01). Extracts in a dose dependent (p < 0.05) reduced uterine contractions decreased dose-dependently after of addition oxytocin. The extracts added cumulatively to the organ bath reduced contractions but they did not affect uterine contractions induced by BaCl2 except the last dose. Spasmolytic effects of the extracts were not affected by propranolol or naloxane in KCl induced contractions. Conclusion Extracts diminished K+-induced contraction in uterus, therefore it seems that substances that decrease K+-induced contraction can also block voltage dependent calcium channel. The extracts did not have any effect on ?-adrenoceptors or potassium channels. PMID:23926538

Ahangarpour, Akram; Heidari, Razieh; Abdolahzadeh, Mahsa; Oroojan, Ali Akbar

2012-01-01

254

Detecting Early Biomechanical Effects of Zoledronic Acid on Femurs of Osteoporotic Female Rats  

PubMed Central

Aim. To investigate the biomechanical effects of zoledronic acid (ZA) on femurs of female osteoporotic rats after follow-up periods of 9 and 12 months. Methods. Eighty female Wistar rats were prospectively assessed. At 60 days of age, the animals were randomly divided into two groups: bilateral oophorectomy (O) (n = 40) and sham surgery (S) (n = 40). At 90 days of age, groups O and S were randomly subdivided into four groups, according to whether 0.1?mg/kg of ZA or distilled water (DW) was intraperitoneally administered: OZA (n = 20), ODW (n = 20), SZA (n = 20), and SDW (n = 20). The animals were sacrificed at 9 and 12 months after the administration of the substances, and then their right femurs were removed and analyzed biomechanically. Axial compression tests that focused on determining the maximum load (N), yield point (N), and stiffness coefficient (N/mm) of the proximal femur were performed in the biomechanical study. Results. ZA significantly increased the maximum load and yield point, reducing the stiffness coefficient concerning the oophorectomy status and follow-up period. Conclusion. Zoledronic acid, at a dose of 0.1?mg/kg, significantly increased the maximum loads and yield points and reduced the stiffness coefficients in the femurs of female rats with osteoporosis caused by bilateral oophorectomy. PMID:23304634

Palacio, Evandro Pereira; Müller, Sérgio Swain; Sardenberg, Trajano; Mizobuchi, Roberto Ryuiti; Galbiatti, José Antônio; Durigan, Alcides; Savarese, Aniello; Ortolan, Érika Veruska Paiva

2012-01-01

255

Aloe vera Aqueous Extract Effect on Morphine Withdrawal Syndrome in Morphine-Dependent Female Rats  

PubMed Central

Background: Aloe vera is a medicinal herb used as an anti-inflammatory and sedative agent. Objectives: The current study aimed to evaluate the effect of Aloe vera aqueous extract on morphine withdrawal symptoms in morphine-dependent female rats. Patients and Methods: The current research was performed on 40 female Wista-Albino rats which were made dependent on morphine using Houshyar protocol and were randomly divided into five groups (A, B, C, D, and E). Group A did not receive any agent in the period of handling but other groups (B, C, D and E) received 5, 10, 20 and 40 mg/kg of Aloe vera aqueous extract by gavage, three times daily for a week, respectively. Withdrawal symptoms, stool form, agitation, disparity, floppy eyelids, and body mass variations were checked for 10 days. The obtained data were analyzed using SPSS v.11 software, and Friedman, Kruskal-Wallis, and Mann-Whitney statistical tests. Statistical difference was considered significant (P < 0.05). Results: The results of the present study showed that agitation, disparity, and floppy eyelids in group E were significantly higher than those of others groups; however, these symptoms in group C were significantly lower than those of the other groups. Conclusions: The results of the present study revealed that the Aloe vera aqueous extract had various effects on morphine withdrawal syndrome in morphine-dependent female rats . PMID:25593890

Shahraki, Mohammad Reza; Mirshekari, Hamideh; Sabri, Azame

2014-01-01

256

A soy supplement and tamoxifen inhibit sexual behavior in female rats.  

PubMed

In addition to displaying proceptive (hopping and darting) and receptive (lordosis) behaviors during a sexual encounter with a male, female rodents will regulate the timing of the encounter by engaging in a series of approaches and withdrawals from the male, a behavior termed paced mating behavior. Proceptive, receptive, and paced mating behaviors are all regulated by, and sensitive to, estrogen and progesterone, suggesting that compounds capable of disrupting these critical hormones may also perturb the display of female sexual behavior. The present experiments examined the impact of the selective estrogen receptor modulator (SERM) tamoxifen and a popular soy phytoestrogen dietary supplement on female sexual behavior in rats. Ovariectomized female rats were given either tamoxifen (TAMOX) by implant or the soy supplement through the diet then injected with estradiol benzoate (EB, 10 microg) or oil followed 48 h later with an injection of progesterone (P, 500 microg). Animals were then tested for sexual behavior 4 h after the P injection. Neither compound had any effect on sexual behavior when administered in conjunction with P alone; however, both significantly diminished receptive behavior, as measured by the lordosis quotient (LQ), in animals primed with both EB and P. Similarly, the hopping and darting rate was also significantly depressed in both the soy- and TAMOX-treated animals, compared to the EB- and P-treated controls, with the soy-treated animals showing significantly less proceptive behavior than the TAMOX-treated animals. Finally, soy but not TAMOX significantly attenuated paced mating behavior in animals compared to the EB- and P-treated controls. These results demonstrate that both the soy supplement and TAMOX act as estrogen antagonists on both proceptive and receptive behavior in female rats. PMID:15053943

Patisaul, Heather B; Luskin, Jordan R; Wilson, Mark E

2004-04-01

257

Dietary Quercetin Exacerbates the Development of Estrogen-Induced Breast Tumors in Female ACI Rats  

PubMed Central

Phytoestrogens are plant compounds that structurally mimic the endogenous estrogen 17?-estradiol (E2). Despite intense investigation, the net effect of phytoestrogen exposure on the breast remains unclear. The objective of the current study was to examine the effects of quercetin on E2-induced breast cancer in vivo. Female ACI rats were given quercetin (2.5 g/kg food) for 8 months. Animals were monitored weekly for palpable tumors, and at the end of the experiment, rats were euthanized, breast tumor and different tissues excised so that they could be examined for histopathologic changes, estrogen metabolic activity and oxidant stress. Quercetin alone did not induce mammary tumors in female ACI rats. However, in rats implanted with E2 pellets, co-exposure to quercetin did not protect rats from E2-induced breast tumor development with 100% of the animals developing breast tumors within 8 months of treatment. No changes in serum quercetin levels were observed in quercetin and quercetin + E2-treated groups at the end of the experiment. Tumor latency was significantly decreased among rats from the quercetin + E2 group relative to those in the E2 group. Catechol-O-methyltransferase (COMT) activity was significantly downregulated in quercetin exposed mammary tissue. Analysis of 8-isoprostane F2? (8-iso-PGF2?) levels as a marker of oxidant stress showed that quercetin did not decrease E2-induced oxidant stress. These results indicate that quercetin (2.5 g/kg food) does not confer protection against breast cancer, does not inhibit E2-induced oxidant stress and may exacerbate breast carcinogenesis in E2-treated ACI rats. Inhibition of COMT activity by quercetin may expose breast cells chronically to E2 and catechol estrogens. This would permit longer exposure times to the carcinogenic metabolites of E2 and chronic exposure to oxidant stress as a result of metabolic redox cycling to estrogen metabolites, and thus quercetin may exacerbate E2-induced breast tumors in female ACI rats. PMID:20600213

Singh, Bhupendra; Mense, Sarah M.; Bhat, Nimee K.; Putty, Sandeep; Guthiel, William A.; Remotti, Fabrizio; Bhat, Hari K.

2010-01-01

258

Dietary quercetin exacerbates the development of estrogen-induced breast tumors in female ACI rats  

SciTech Connect

Phytoestrogens are plant compounds that structurally mimic the endogenous estrogen 17{beta}-estradiol (E{sub 2}). Despite intense investigation, the net effect of phytoestrogen exposure on the breast remains unclear. The objective of the current study was to examine the effects of quercetin on E{sub 2}-induced breast cancer in vivo. Female ACI rats were given quercetin (2.5 g/kg food) for 8 months. Animals were monitored weekly for palpable tumors, and at the end of the experiment, rats were euthanized, breast tumor and different tissues excised so that they could be examined for histopathologic changes, estrogen metabolic activity and oxidant stress. Quercetin alone did not induce mammary tumors in female ACI rats. However, in rats implanted with E{sub 2} pellets, co-exposure to quercetin did not protect rats from E{sub 2}-induced breast tumor development with 100% of the animals developing breast tumors within 8 months of treatment. No changes in serum quercetin levels were observed in quercetin and quercetin + E{sub 2}-treated groups at the end of the experiment. Tumor latency was significantly decreased among rats from the quercetin + E{sub 2} group relative to those in the E{sub 2} group. Catechol-O-methyltransferase (COMT) activity was significantly downregulated in quercetin-exposed mammary tissue. Analysis of 8-isoprostane F{sub 2{alpha}} (8-iso-PGF{sub 2{alpha}}) levels as a marker of oxidant stress showed that quercetin did not decrease E{sub 2}-induced oxidant stress. These results indicate that quercetin (2.5 g/kg food) does not confer protection against breast cancer, does not inhibit E{sub 2}-induced oxidant stress and may exacerbate breast carcinogenesis in E{sub 2}-treated ACI rats. Inhibition of COMT activity by quercetin may expose breast cells chronically to E{sub 2} and catechol estrogens. This would permit longer exposure times to the carcinogenic metabolites of E{sub 2} and chronic exposure to oxidant stress as a result of metabolic redox cycling to estrogen metabolites, and thus quercetin may exacerbate E{sub 2}-induced breast tumors in female ACI rats.

Singh, Bhupendra [Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO 64108 (United States); Mense, Sarah M. [Department of Environmental Health Sciences, Columbia University, New York, NY 10032 (United States); Bhat, Nimee K. [Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO 64108 (United States); Putty, Sandeep; Guthiel, William A. [Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO 64108 (United States); Remotti, Fabrizio [Department of Pathology, Columbia University, New York, NY 10032 (United States); Bhat, Hari K., E-mail: bhath@umkc.ed [Division of Pharmacology and Toxicology, School of Pharmacy, University of Missouri-Kansas City, Kansas City, MO 64108 (United States)

2010-09-01

259

[Transference of cyclic monomeric acids into the milk of female rats eating thermopolymerised linseed oil].  

PubMed

Six month old female Wistar rats were fed a commercial diet until littering. Then they received a diet containing 10 p. 100 by weight of thermopolymerized linseed oil at 275 degrees C for 12 hours under nitrogen atmosphere. No mortality has been found among young rats during lactation but body growth is slower. In rats sacrificed at the age of 14 days stomach content (milk) and liver were analyzed for lipids. In milk and liver fatty acids respectively 2,7 and 3,0 p. 100 cyclic monomers (18 C) were detected. Consequently, the present study shows that these abnormal compounds formed during hearing of the oil are transmitted to the youngs before weaning through mother's milk. PMID:1037077

Potteau, B

1976-01-01

260

DIBROMOACETIC ACID-INDUCED ELEVATIONS IN CIRCULATING ESTRADIOL: EFFECTS IN BOTH CYCLING AND OVARIECTOMIZED/STEROID-PRIMED FEMALE RATS  

EPA Science Inventory

RTD-03-031 Goldman, JM and Murr, AS. Dibromoacetic Acid-induced Elevations in Circulating Estradiol: Effects in Both Cycling and Ovariectomized/Steroid-primed Female Rats. Reproductive Toxicology (in press). Abstract Oral exposures to high concentrations of th...

261

Hippocampal cell proliferation and spatial memory performance after social instability stress in adolescence in female rats.  

PubMed

We investigated the immediate and lasting effect of social instability stress in adolescence [SS: daily 1h isolation and change of cage partner postnatal days (P) 30-45] on cell proliferation in the hippocampus and on spatial memory using an object spatial location (SL) test. Female rats were treated with bromodeoxyuridine (BrdU) P43-45, and on P49, SS had reduced cell hippocampal cell proliferation/survival compared to controls as indicated by BrdU immunoreactive cell counts (p=0.009), and did not differ in Ki67 immunoreactive cell counts (p=0.15) from CTL. A separate group of SS and CTL rats were tested at P47 and P48, and again at P72 and P73 on the SL test using 1 and 8h retention intervals. SS and CTL females did not differ in adolescence, but CTL had better memory than SS as adults (p=0.03). The better memory performance of CTL rats is not due to differential investigation of objects during the familiarization pre-tests or by differential locomotor activity. The lasting memory reduction and reduced cell proliferation/survival in SS rats is consistent with the hypothesis that ongoing development of the hippocampus renders the adolescent particularly vulnerable to chronic social stress. PMID:19900485

McCormick, Cheryl M; Nixon, Feather; Thomas, Catherine; Lowie, Bobbi; Dyck, Joshua

2010-03-17

262

Effects of memantine on estrogen-dependent acute tolerance to the morphine analgesia in female rats.  

PubMed

Both human and animal studies suggest that there are sex differences in responding to noxious stimulation as well as in effects of opiate analgesic drugs. Development and/or expression of tolerance to opiate analgesia are also affected by the hormonal status of the experimental subjects. The present study aimed to compare acute tolerance to morphine in cycling and ovariectomized female rats and to evaluate the effects of N-methyl-D-aspartate (NMDA) receptor channel blocker memantine as well as 17-beta-estradiol on tolerance development using the tail-flick test. Acute tolerance to morphine analgesia was observed as a substantial reduction in the response to a test dose of morphine (10 mg/kg) given 6 h after the tolerance-inducing dose (10 mg/kg). Significant acute tolerance was observed in proestrous female rats and was prevented by memantine (3 or 10 mg/kg) treatment. Ovariectomized rats did not demonstrate tolerance to morphine analgesic effects but chronic estradiol administration (5 microg/day, 5 days) reinstated induction of tolerance. Both estrogen receptor modulator tamoxifen (5 mg/kg/day, 5 days) and memantine (3 mg/kg/day, 5 days) prevented estradiol-induced tolerance in ovariectomized rats. Thus, estrogens were found to play a key role in induction of acute tolerance to morphine antinociception. Estradiol-induced acute morphine tolerance may have NMDA receptor-dependent mechanisms. PMID:16546163

Shekunova, Elena V; Bespalov, Anton Y

2006-03-27

263

Effects of peripheral ? opioid receptor activation on inflammatory mechanical hyperalgesia in male and female rats  

PubMed Central

Activation of peripheral ? opioid receptors (KOR) effectively relieves pain and hyperalgesia in preclinical and clinical models of pain. Although centrally located KOR activation results in sexually dimorphic effects, it is unclear whether peripheral KOR also produces sex dependent effects in persistent inflammatory pain conditions. In this study, we investigated whether local administration of a specific KOR agonist, U50, 488 relieve mechanical hyperalgesia induced by the injection of complete Freund’s adjuvant (CFA) in the rat hindpaw, and whether there are sex differences. The effects of U50, 488 were assessed three days after the induction of CFA-induced inflammation, a time point at which mechanical hyperalgesia was most prominent. There were no sex differences in baseline and CFA-induced changes in mechanical thresholds between male and female rats. Local treatment of U50, 488 produced moderate, but significant, anti-hyperalgesia in both male and female rats. However, U50, 488 was significantly more effective in male rats at the highest dose of U50, 488. We confirmed that the highest dose of U50, 488 used in this study did not produce systemic effects, and that the drug effect is receptor specific. On the basis of these results, we suggest that local KOR agonists are effective in mitigating mechanical hyperalgesia under a persistent inflammatory pain condition and that sex differences in anti-hyperalgesic effects become more evident at high doses. PMID:22819973

Auh, Q-Schick; Ro, Jin Y.

2012-01-01

264

Immunotoxicity evaluation of jet a jet fuel in female rats after 28-day dermal exposure.  

PubMed

The potential for jet fuel to modulate immune functions has been reported in mice following dermal, inhalation, and oral routes of exposure; however, a functional evaluation of the immune system in rats following jet fuel exposure has not been conducted. In this study potential effects of commercial jet fuel (Jet A) on the rat immune system were assessed using a battery of functional assays developed to screen potential immunotoxic compounds. Jet A was applied to the unoccluded skin of 6- to 7-wk-old female Crl:CD (SD)IGS BR rats at doses of 165, 330, or 495 mg/kg/d for 28 d. Mineral oil was used as a vehicle to mitigate irritation resulting from repeated exposure to jet fuel. Cyclophosphamide and anti-asialo GM1 were used as positive controls for immunotoxic effects. In contrast to reported immunotoxic effects of jet fuel in mice, dermal exposure of rats to Jet A did not result in alterations in spleen or thymus weights, splenic lymphocyte subpopulations, immunoglobulin (Ig) M antibody-forming cell response to the T-dependent antigen, sheep red blood cells (sRBC), spleen cell proliferative response to anti-CD3 antibody, or natural killer (NK) cell activity. In each of the immunotoxicological assays conducted, the positive control produced the expected results, demonstrating the assay was capable of detecting an effect if one had occurred. Based on the immunological parameters evaluated under the experimental conditions of the study, Jet A did not adversely affect immune responses of female rats. It remains to be determined whether the observed difference between this study and some other studies reflects a difference in the immunological response of rats and mice or is the result of other factors. PMID:18338284

Mann, Cynthia M; Peachee, Vanessa L; Trimmer, Gary W; Lee, Ji-Eun; Twerdok, Lorraine E; White, Kimber L

2008-01-01

265

Protein malnutrition attenuates bone anabolic response to PTH in female rats.  

PubMed

PTH is indicated for the treatment of severe osteoporosis. Elderly osteoporotic patients frequently suffer from protein malnutrition, which may contribute to bone loss. It is unknown whether this malnutrition may affect the response to PTH. Therefore, the aim of the present study was to assess whether an isocaloric low-protein (LP) diet may influence the bone anabolic response to intermittent PTH in 6-month-old female rats. Six-month-old female rats were either pair fed an isocaloric LP diet (2.5% casein) or a normal-protein (NP) diet (15% casein) for 2 weeks. The rats continued on their respective diet while being treated with 5- or 40-?g/kg recombinant human PTH amino-terminal fragment 1-34 (PTH-[1-34]) daily, or with vehicle for 4 weeks. At the end of this period, areal bone mineral density, bone mineral content, microstructure, and bone strength in axial compression of proximal tibia or 3-point bending for midshaft tibia tests were measured. Blood was collected for the determination of IGF-I and osteocalcin. After 4 weeks of PTH-(1-34), the dose-dependent increase of proximal tibia bone mineral density, trabecular microstructure variables, and bone strength was attenuated in rats fed a LP diet as compared with rats on a NP intake. At the level of midshaft tibia cortical bone, PTH-(1-34) exerted an anabolic effect only in the NP but not in the LP diet group. Protein malnutrition was associated with lower IGF-I levels. Protein malnutrition attenuates the bone anabolic effects of PTH-(1-34) in rats. These results suggest that a sufficient protein intake should be recommended for osteoporotic patients undergoing PTH therapy. PMID:25396268

Ammann, P; Zacchetti, G; Gasser, J A; Lavet, C; Rizzoli, R

2015-02-01

266

The effects of prenatal PCBs on adult female paced mating reproductive behaviors in rats  

PubMed Central

Polychlorinated biphenyls (PCBs) are a family of toxicants that persist in measurable quantities in human and wildlife tissues, despite their ban in production in 1977. Some PCB mixtures can act as endocrine disrupting chemicals (EDCs) by mimicking or antagonizing the actions of hormones in the brain and periphery. When exposure to hormonally active substances such as PCBs occurs during vulnerable developmental periods, particularly prenatally or in early postnatal life, they can disrupt sex-specific patterning of the brain, inducing permanent changes that can later be manifested as improper sexual behaviors. Here, we investigated the effects of prenatal exposure to the PCB mixture Aroclor (A) 1221 on adult female reproductive behaviors in a dose-response model in the Sprague-Dawley rat. Using a paced mating paradigm that permits the female to set the timing of mating and control contact with the male during copulation, we were able to uncover significant differences in female-typical sexual activities in A1221-exposed females. Specifically, A1221 causes significant effects on mating trial pacing, vocalizations, ambulation and the female’s likelihood to mate. The results further demonstrate that the intermediate treatment group has the greatest number of disrupted endpoints, suggestive of non-linear dose responses to A1221. These data demonstrate that the behavioral phenotype in adulthood is disrupted by low, ecologically relevant exposures to PCBs, and the results have implications for reproductive success and health in wildlife and women. PMID:17274994

Steinberg, Rebecca M.; Juenger, Thomas E.; Gore, Andrea C.

2009-01-01

267

Female Rats Exposed to Stress and Alcohol Show Impaired Memory and Increased Depressive-like Behaviors  

PubMed Central

Exposure to daily life stressors is associated with increases in anxiety, depression, and overall negative affect. Alcohol or other psychoactive drugs are often used to alleviate stress effects. While females are more than twice as likely to develop mood disorders and are more susceptible to dependency than males, they are infrequently examined. In this study, female rats received no stress/no alcohol control (CON), alcohol alone (ALC), stress alone (STR), or stress plus alcohol (STR+ALC). Stress consisted of restraint for 6hr/day/7days, and alcohol was administered immediately following restraint via gastric gavage at a dose of 2.0 g/kg. Dependent measures included tests utilizing object recognition (OR), Y-maze, elevated plus maze (EPM), forced swim (FST), blood alcohol content, corticosterone levels, and body weights. ALC, STR+ALC, but not stress alone, impaired memory on OR. All treatments impaired spatial memory on the Y-maze. Anxiety was not affected on the EPM, but rats treated with alcohol or in combination with stress showed increased immobility on the FST, suggestive of alcohol-induced depression. Previously, we found alcohol reversed deleterious effects of stress on memory and mood in males, but current results show females reacted negatively when the two treatments were combined. Thus, responses to alcohol, stress and their combination suggest that sex specific treatments are needed for stress-induced behavioral changes and that self-medicating with alcohol to cope with stress maybe deleterious in females. PMID:24096191

Gomez, J.L.; Luine, V.N.

2013-01-01

268

Effects of Stimulation and Blockade of D2 Receptor on Depression-Like Behavior in Ovariectomized Female Rats  

PubMed Central

The aim of the present study was to explore the hedonic effects of D2 receptor agonist, quinpirole and D2 receptor antagonist, and sulpiride alone or in combination with a low dose of 17?-E2-estradiol (17?-E2) in the adult ovariectomized female rats (OVX). OVX rats of Wistar strain were used in all experiments. Two weeks after surgery rats were chronically treated with vehicle, a low dose of 17?-E2 (5.0??g/rat), quinpirole (0.1?mg/kg), sulpiride (10.0?mg/kg), quinpirole plus 17?-E2, or sulpiride plus 17?-E2 for 14 days before the forced swimming test. We found that sulpiride significantly decreased immobility time in the OVX females. A combination of sulpiride with a low dose of 17?-E2 induced more profound decrease of immobility time in the OVX rats compared to the rats treated with sulpiride alone. On the contrary, quinpirole failed to modify depression-like behavior in the OVX rats. In addition, quinpirole significantly blocked the antidepressant-like effect of 17?-E2 in OVX rats. Thus, the D2 receptor antagonist sulpiride alone or in combination with a low dose of 17?-E2 exerted antidepressant-like effect in OVX female rats, while the D2 receptor agonist quinpirole produced depressant-like profile on OVX rats. PMID:22530139

Fedotova, Julia

2012-01-01

269

Age-related alterations in prolactin binding sites in the female rat.  

PubMed

Aging is associated with various neuroendocrine alterations, including in the rat a hypersecretion of PRL with maintained ovulations (repetitive pseudo-pregnancy) and a reduced activity of the hypothalamic dopaminergic neurons with loss of the neuron responsiveness to PRL, suggestive of age-related alterations in PRL receptors. In this study we have investigated PRL binding sites in the hypothalamus as well as in the mammary glands, the ovaries and the liver of young and old nulliparous female rats. The old rats (26-28 months) displayed spontaneous repetitive pseudopregnancies and they were compared with young (4-6 months) pseudopregnant rats; the binding studies were performed by saturation analysis using 125I-oPRL as ligand and particulate membrane preparations. In the hypothalamus, a negligible binding of PRL was observed in all fragments studied, mediobasal hypothalamus, median eminence, in both young and old rats and no characterization of the binding sites could be achieved. In the mammary glands, the number of PRL binding sites was appreciable in spite of the nulliparity of the rats, but it was smaller in the old than in the young rats (9.0 +/- 1.4 vs 14.9 +/- 1.2 fmol/mg protein; mean +/- SEM; p less than 0.02). In the ovaries, the density of PRL binding sites was similar in the old and young rats (112.6 +/- 9.7 vs 115.0 +/- 8.9 fmol/mg protein), illustrative of a maintained luteotropic effect of PRL with age in the rat. In contrast, in the liver a greater number of binding sites was found in the old than in the young rats (261.9 +/- 36.6 vs 63.6 +/- 5.8 fmol/mg protein; p less than 0.001), supportive of the ability of PRL to induce its own receptors in that tissue. The affinity constant of PRL binding was not altered with age in the tissues studied. These results are illustrative of tissue-specific modifications in the number of PRL binding sites with age and they are suggestive of a sustained biological activity of PRL in the old rats. PMID:1901433

Schneiter, P; Reymond, M J; Lemarchand-Béraud, T

1991-03-01

270

The Serotonin Reuptake Inhibitor Fluoxetine Reduces Sex Steroid-Related Aggression in Female Rats: An Animal Model of Premenstrual Irritability?  

Microsoft Academic Search

The aggressive behavior displayed by some (but not all) female Wistar rats when an unfamiliar rat is being introduced into their home cage (the resident intruder paradigm) was found to be higher in non-receptive phases (metestrus, diestrus) than in the receptive phases (proestrus, estrus) of the estrus cycle, and effectively reduced by ovariectomy. When removal of the ovaries was followed

Hoi-Por Ho; Marie Olsson; M Pharm; Lars Westberg; Jonas Melke; Elias Eriksson

2001-01-01

271

Discrete Lesions Reveal Functional Heterogeneity of Suprachiasmatic Structures in Regulation of Gonadotropin Secretion in the Female Rat  

Microsoft Academic Search

The present study examines the function of several cytologically distinct suprachiasmatic structures in the regulation of ovulation and positive feedback effects of estrogen and progesterone on gonadotropin release in the rat. Small (0.6–0.8 mm dia.) electrolytic lesions were placed at four loci along the rostrocaudal extent of the suprachiasmatic region in regularly cycling female rats. Anovulatory persistent estrus occurred only

Stanley J. Wiegand; Ei Terasawa

1982-01-01

272

Marginal Growth Increase, Altered Bone Quality and Polycystic Ovaries in Female Prepubertal Rats after Treatment with the Aromatase Inhibitor Exemestane  

Microsoft Academic Search

Background: Aromatase inhibition has been proposed as a potential approach for growth enhancement in children with short stature, but detailed animal studies are lacking. Aim: To assess the effect and potential adverse effects of aromatase inhibition on growth in female rats. Methods: Prepubertal Wistar rats received intramuscular injections with placebo or the aromatase inhibitor exemestane at a dose of 10,

Sandy A. van Gool; Jan M. Wit; Tineke De Schutter; Nora De Clerck; Andreď A. Postnov; Sandra Kremer Hovinga; Jaap van Doorn; Sergio J. Veiga; Luis Miguel Garcia-Segura; Marcel Karperien

2010-01-01

273

Effects of different concentrations of sugarcane alcohol on food intake and nutritional status of male and female periadolescent rats  

Microsoft Academic Search

The present study evaluated the effects of food and alcohol intake on the nutritional and metabolic status of male and female periadolescent rats submitted to single (15%) and multiple (10%, 20%, 30%) concentrations of hydroalcoholic solutions of sugar-based alcohol associated with a feed mixture. Thirty-six periadolescent Wistar rats were used and randomly arranged into three groups: Group A (control; 0%

Luciana Gonçalves de Orange; Francisca Martins Bion; Cybelle Rolim de Lima

2009-01-01

274

Loss of ovarian estrogens causes only mild deterioration of glucose homeostasis in female ZDF rats preventable by voluntary running exercise.  

PubMed

Studies on normoglycemic ovariectomized Sprague-Dawley rats have provided insights about the effects of estrogen deficiency on insulin resistance in lean individuals. It is not completely clear if subjects with pre-established obesity and insulin resistance are at greater risk of developing type 2 diabetes when ovarian estrogens are no longer secreted, and if physical activity can protect against this susceptibility. Contrasting with their male counterparts, obese and insulin resistant female ZDF (Zucker diabetic fatty) rats do not become hyperglycemic when fed a standard diet. The aim of the study was to evaluate the hypothesis that withdrawal of ovarian estrogens in insulin resistant female ZDF rats would trigger overt hyperglycemia, provided they remain physically inactive. Female ZDF rats underwent either an ovariectomy (OVX) or a simulated surgery (SHAM). Thereafter, OVX rats engaged either in voluntary wheel cage running (OVX-Active), or like the Sham rats, remained sedentary (OVX-Sed) for 6 weeks. Fasting glycemia, insulinemia, and glucose tolerance were not altered in OVX-Sed as compared to SHAM-Sed rats. However, OVX-Sed rats showed altered liver triglyceride and glycogen contents, increased pancreatic insulin content and reduced insulin-stimulated muscle pAKT as compared to SHAM-Sed rats. Physical activity in OVX rats lowered fasting glucose and insulin levels, improved glucose tolerance and insulin-stimulated skeletal muscle glucose uptake as compared to OVX-Sed rats. OVX-induced alterations in pancreatic insulin content and liver glycogen and triglyceride contents were significantly improved by physical activity. Loss of ovarian estrogens did not cause overt hyperglycemia in insulin-resistant female ZDF rats. Physical activity improved glucose homeostasis despite estrogen deficiency. PMID:24983383

Bergeron, R; Mentor, J S; Côté, I; Ngo Sock, É T; Rabasa-Lhoret, R; Lavoie, J M

2014-10-01

275

Rapid and Acute Effects of Estrogen on Time Perception in Male and Female Rats  

PubMed Central

Sex differences in the rapid and acute effects of estradiol on time perception were investigated in adult male and female Sprague-Dawley rats. Because estradiol has been shown to increase striatal dopamine release, it may be able to modify time perception and timed performance by increasing the speed of an internal clock in a manner similar to indirect dopamine agonists such as amphetamine and cocaine. Two groups of females (neonatally estradiol-treated/adult ovariectomized and neonatally oil-treated/adult ovariectomized) and two groups of males (neonatally castrated and adult castrated) were trained in a 2 vs. 8-s duration bisection procedure and tested using intermediate signal durations. After obtaining oil-injected baseline psychometric functions over several days, rats were administered 5??g of estradiol for 4?days and behaviorally evaluated 30?min following each injection. This oil–estradiol administration cycle was subsequently repeated three times following the re-establishment of baseline training. Results revealed significant sex differences in the initial baseline functions that were not modifiable by organizational hormones, with males’ duration bisection functions shifted horizontally to the left of females’. Upon the first administration of estradiol, females, but not males, showed a significant, transient leftward shift in their bisection functions, indicative of an increase in clock speed. After extensive retraining in the duration bisection procedure, rats that were exposed to gonadal hormones during the first week of life showed a significant rightward shift in their bisection functions on the fourth day of estradiol administration during each cycle, suggesting a decrease in clock speed. Taken together, our results support the view that there are multiple mechanisms of estrogens’ action in the striatum that modulate dopaminergic activity and are differentially organized by gonadal steroids during early brain development. PMID:22016725

Pleil, Kristen E.; Cordes, Sara; Meck, Warren H.; Williams, Christina L.

2011-01-01

276

THE EFFECTS OF ATRAZINE ON FEMALE WISTAR RATS: AN EVALUATION OF THE PROTOCOL FOR ASSESSING PUBERTAL DEVELOPMENT AND THYROID FUNCTION  

EPA Science Inventory

Female rats were dosed by oral gavage from postnatal day (PND) 22 through PND 41 with 0, 12.5, 25, 50, 100 or 200 mg ATR /kg. Half of the females in each treatment group were killed on PND 41 and organ weights (e.g., liver, kidney, adrenal, ovary, uterus and pituitary) and serum ...

277

Long-term obesity levels in female OLETF rats following time-specific post-weaning food restriction  

Microsoft Academic Search

Obesity and the metabolic syndrome represent serious health threats affecting increasing numbers of individuals, with females being more affected than males and with growing incidence among children and adolescents. In the present study, we used the OLETF rat model of early-onset obesity to examine the influence of different timing of food restriction on long-term obesity levels in females. Food restriction

Mariana Schroeder; Vered Gelber; Timothy H. Moran; Aron Weller

2010-01-01

278

Liver iron overload induced by tamoxifen in diabetic and non-diabetic female Wistar rats.  

PubMed

Tamoxifen (TX), a drug used in the treatment of breast cancer, may cause hepatic changes in some patients. The consequences of its use on the liver tissues of rats with or without diabetes mellitus (DM) have not been fully explored. The purpose of this study was to evaluate the correlation between plasma hepatic enzyme levels and the presence of iron overload in the hepatic tissue of female Wistar rats with or without streptozotocin-induced DM and using TX. Female rats were studied in control groups: C-0 (non-drug users), C-V (sorbitol vehicle only) and C-TX (using TX). DM (diabetic non-drug users) and DM-TX (diabetics using TX) were the test groups. Sixty days after induced DM, blood samples were collected for glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST) alkaline phosphatase (ALP) and bilirubin measures. Hepatic fragments were processed and stained with hematoxylin and eosin, Masson's trichrome, Perls. The hepatic iron content was quantified by atomic absorption spectrometry. AST, ALT and ALP levels were significantly elevated in the DM and DM-TX groups, with unchanged bilirubin levels. Liver iron overload using Perls stain and atomic absorption spectrometry were observed exclusively in groups C-TX and DM-TX. There was positive correlation between AST, ALT and ALP levels and microscopic hepatic siderosis intensity in group DM-TX. In conclusion, TX administration is associated with liver siderosis in diabetic and non-diabetic rats. In addition, TX induced liver iron overload with unaltered hepatic function in non-diabetic rats and may be a useful tool for investigating the biological control of iron metabolism. PMID:17636394

Jatobá, Carlos André Nunes; de Rezende, Adriana Augusto; de Paiva Rodrigues, Sarah Jane; de Almeida Câmara, Maria Margareth; das Graças Almeida, Maria; Freire-Neto, Francisco; da Rocha, Luiz Reginaldo Menezes; da Medeiros, Aldo Cunha; Brandăo-Neto, José; de Carvalho Formiga, Maria Célia; de Azevedo, Italo Medeiros; de Oliveira Ramos, Ana Maria

2008-04-01

279

STRAIN COMPARISON IN PREGNANT RATS OF ENDOCRINE RESPONSE TO BROMODICHLOROMETHANE: A DRINKING WATER DISINFECTION BY-PRODUCT  

EPA Science Inventory

Bromodichloromethane (BDCM), a trihalomethane, is a by-product of the chlorination of drinking water. In an epidemiological study, consumption of drinking water with high levels of BDCM was associated with an increased risk of spontaneous abortion in pregnant women (Waller et al....

280

LH responses of female naked mole-rats, Heterocephalus glaber, to single and multiple doses of exogenous GnRH  

Microsoft Academic Search

Summary. To investigate possible differential pituitary secretion of LH in breeding and non-breeding female naked mole-rats, the LH responses to administration of exogenous GnRH were measured in 55 females from 20 captive colonies. Single doses of 0\\\\m=.\\\\1, 0\\\\m=.\\\\5or 1\\\\m=.\\\\0\\\\g=m\\\\gGnRH produced a significant rise in plasma LH concentrations 20 min after s.c. injection in breeding and non-breeding females at all doses

C. G. Faulkes; D. H. Abbott; J. U. M. Jarvis; F. E. Sherriff

1990-01-01

281

Single trial nicotine conditioned place preference in pre-adolescent male and female rats.  

PubMed

The mean age of first voluntary tobacco inhalation is 12.3 years (DiFranza et al., 2004). 60% of smokers start smoking before the age of 14 and 90% are dependent before reaching the age of 19. Females are typically more sensitive to nicotine than males yet few studies examine the effects of nicotine on the reward systems in pre-adolescent female subjects. This study utilized the single trial conditioned place preference (CPP) test in very young (postnatal day 25-27) rats of both sexes. Latent effects on anxiety and amphetamine response were determined 5 and 7 days following a second nicotine exposure. Results show that 0.05 mg/kg nicotine induced CPP in females following a single trial while both sexes showed CPP following the 0.5 mg/kg dose. Five days later, rats dosed with 0.05 mg/kg show increased time on the open arm of the elevated plus maze, an anxiolytic response. While baseline activity was increased in nicotine-exposed males 7 days following dosing, amphetamine response was not affected by the treatments in either sex. Therefore, our data suggest that young females are more sensitive to nicotine reward than males supporting a heightened sensitivity of the mesolimbic dopamine system in very young females. However, alterations in baseline activity were only seen in males suggesting that different components of the system are affected by nicotine in each sex. An anxiolytic response to nicotine 5 days after dosing may suggest that this very young age group is uniquely affected by this very low nicotine dose. Clearly, nicotine has substantial acute and lasting effects during pre-adolescence at doses substantially lower than seen at older ages as reported by others. These effects, which could potentially result from cigarette or e-cigarette smoking by 11-12 year old children , focus attention on the vulnerability of this age group to nicotine. PMID:25109273

Edwards, Alexander W; Konz, Nathan; Hirsch, Zahava; Weedon, Jeremy; Dow-Edwards, Diana L

2014-10-01

282

Oral administration of leaf extracts of Momordica charantia affect reproductive hormones of adult female Wistar rats  

PubMed Central

Objective To determine the effect of graded doses of aqueous leaf extracts of Momordica charantia on fertility hormones of female albino rats. Methods Twenty adult, healthy, female Wistar rats were divided into four groups: low dose (LD), moderate dose (MD) and high dose (HD) groups which received 12.5 g, 25.0 g, 50.0 g of the leaf extract respectively and control group that was given with water ad libatum. Result Estrogen levels reduced by 6.40 nmol/L, 10.80 nmol/L and 28.00 nmol/L in the LD, MD and HD groups respectively while plasma progesterone of rats in the LD, MD and HD groups reduced by 24.20 nmol/L, 40.8 nmol/L and 59.20 nmol/L respectively. Conclusion Our study has shown that the antifertility effect of Momordica charantia is achieved in a dose dependent manner. Hence, cautious use of such medication should be advocated especially when managing couples for infertility. PMID:25183143

Adewale, Osonuga Odusoga; Oduyemi, Osonuga Ifabunmi; Ayokunle, Osonuga

2014-01-01

283

Hindlimb unloading has a greater effect on cortical compared with cancellous bone in mature female rats  

NASA Technical Reports Server (NTRS)

This study was designed to determine the effects of 28 days of hindlimb unloading (HU) on the mature female rat skeleton. In vivo proximal tibia bone mineral density and geometry of HU and cage control (CC) rats were measured with peripheral quantitative computed tomography (pQCT) on days 0 and 28. Postmortem pQCT, histomorphometry, and mechanical testing were performed on tibiae and femora. After 28 days, HU animals had significantly higher daily food consumption (+39%) and lower serum estradiol levels (-49%, P = 0.079) compared with CC. Proximal tibia bone mineral content and cortical bone area significantly declined over 28 days in HU animals (-4.0 and 4.8%, respectively), whereas total and cancellous bone mineral densities were unchanged. HU animals had lower cortical bone formation rates and mineralizing surface at tibial midshaft, whereas differences in similar properties were not detected in cancellous bone of the distal femur. These results suggest that cortical bone, rather than cancellous bone, is more prominently affected by unloading in skeletally mature retired breeder female rats.

Allen, Matthew R.; Bloomfield, Susan A.

2003-01-01

284

Activation of estrogen receptor ? enhances bradykinin signaling in peripheral sensory neurons of female rats.  

PubMed

Numerous studies have demonstrated that females have a higher risk of experiencing several pain disorders with either greater frequency or severity than males. Although the mechanisms that underlie this sex disparity remain unclear, several studies have shown an important role for sex steroids, such as estrogen, in the modulation of nociception. Receptors for estrogen are present in primary afferent neurons in the trigeminal and dorsal root ganglia, and brief exposure to estrogen increases responses to the inflammatory mediator bradykinin (BK). However, the mechanism for estrogen-mediated enhancement of BK signaling is not fully understood. The aim of the present study was to evaluate the relative contributions of estrogen receptor ? (ER?), ER?, and G protein-coupled estrogen receptor 1 (GPER) to the enhanced signaling of the inflammatory mediator BK by 17?-estradiol (17?-E2) in primary sensory neurons from female rats in culture (ex vivo) and in behavioral assays of nociception in vivo. The effects of 17?-E2 on BK responses were mimicked by ER?-selective agonists and blocked by ER?-selective antagonists and by small interfering RNA knockdown of ER?. The data indicate that ER? is required for 17?-E2-mediated enhancement of BK signaling in peripheral sensory neurons in female rats. PMID:24706985

Rowan, Matthew P; Berg, Kelly A; Roberts, James L; Hargreaves, Kenneth M; Clarke, William P

2014-06-01

285

Administration of growth hormone or IGF-I to pregnant rats on a reduced diet throughout pregnancy does not prevent fetal intrauterine growth retardation and elevated blood pressure in adult offspring  

Microsoft Academic Search

Increasing evidence from human epidemiological studies suggests that poor growth before birth is associated with postnatal growth retardation and the development of cardiovascular disease in adulthood. We have shown previously that nutritional deprivation in the pregnant rat leads to intrauterine growth retardation (IUGR), postnatal growth failure, changes in the endocrine parameters of the somatotrophic axis, and to increased blood pressure

S M Woodall; B H Breier; B M Johnston; N S Bassett; R Barnard; P D Gluckman

1999-01-01

286

Enriched environment increases myelinated fiber volume and length in brain white matter of 18-month female rats.  

PubMed

Cognition and memory decline with normal aging, which could be partly attributed to the degeneration of brain white matter. Previous studies demonstrated that exposure to an enriched environment (EE) could protect cognition and memory from aging. However, if or how EE might affect the brain white matter has not been thoroughly investigated. In the current study, 24 middle-aged (14-month-old) female Sprague -Dawley (SD) rats were randomly assigned to EE or standard environment (SE) for 4 months. At the end of the environment intervention, the Morris water maze tests were performed. Then, 5 rats were randomly selected from each group for stereological assessment of the brain white matter and its myelinated fibers. The results revealed that middle-aged rats living in EE displayed better spatial learning than SE controls. The white matter volume was 124.6±7.8mm(3) in EE rats, which was significantly enlarged compared with 84.8±3.4mm(3) in SE rats. Likewise, the myelinated fiber volume was markedly increased from 56.6±1.7mm(3) in SE rats to 87.2±9.0mm(3) in EE rats; so was the myelinated fiber length from 83.5±6.6km in SE rats to 119.0±10.0km in EE rats. Our data suggested that EE could protect brain white matter and its myelinated fibers of female rats at middle age. PMID:25796176

Yang, Shu; Lu, Wei; Zhou, De-Shan; Tang, Yong

2015-04-23

287

The impact of social stress during adolescence or adulthood and coping strategy on cognitive function of female rats.  

PubMed

The age of stressor exposure can determine its neurobehavioral impact. For example, exposure of adolescent male rats to resident-intruder stress impairs cognitive flexibility in adulthood. The current study examined the impact of this stressor in female rats. Rats were exposed to resident-intruder stress during early adolescence (EA), mid-adolescence (MA) or adulthood (Adult). They were tested in an operant strategy-shifting task for side discrimination (SD), reversal learning (REV) and strategy set-shifting (SHIFT) the following week. Performance varied with age, stress and coping style. MA and EA rats performed SD and SHIFT better than other ages, respectively. Social stress impaired performance in rats depending on their coping strategy as determined by a short (SL) or long (LL) latency to become subordinate. SL rats were impaired in SD and REV, whereas EA-LL rats were impaired in SHIFT. These impairing effects of female adolescent stress did not endure into adulthood. Strategy set-shifting performance for female adolescents was positively correlated with medial prefrontal cortex (mPFC) activation as indicated by c-fos expression suggesting that this region is engaged during task performance. This contrasts with the inverse relationship between these indices reported for male adolescent rats. Together, the results demonstrate that social stress produces cognitive impairments for female rats that depend on age and coping style but unlike males, the impairing effects of female adolescent social stress are immediate and do not endure into adulthood. Sex differences in the impact of adolescent social stress on cognition may reflect differences in mPFC engagement during the task. PMID:25746514

Snyder, Kevin; Barry, Mark; Plona, Zachary; Ho, Andrew; Zhang, Xiao-Yan; Valentino, Rita J

2015-06-01

288

Interactions of "ultra-low" doses of naltrexone and morphine in mature and young male and female rats.  

PubMed

Sex and age influence morphine analgesia in humans and animals. Mature rats show greater morphine analgesia in males than in females. Ultra-low doses of naltrexone enhance morphine analgesia. In mature rats (18-22 weeks), naltrexone (0.002-2.0 mg/kg)-morphine (2 mg/kg) cotreatment enhanced morphine analgesia in females, an effect inversely related to naltrexone dose. Conversely, in mature male rats, naltrexone tended to decrease morphine analgesia with increasing dose. In young rats (8-10 weeks), morphine analgesia was unrelated to sex and in both sexes the naltrexone-morphine interaction was negligible. These data show that dose, age, and sex alter the naltrexone-morphine interaction in rats. PMID:15204037

Hamann, Scott R; Malik, Hammad; Sloan, Jewell W; Wala, Elzbieta P

2004-01-01

289

17?-Estradiol Attenuates Poststroke Depression and Increases Neurogenesis in Female Ovariectomized Rats  

PubMed Central

Studies have linked neurogenesis to the beneficial actions of specific antidepressants. However, whether 17?-estradiol (E2), an antidepressant, can ameliorate poststroke depression (PSD) and whether E2-mediated improvement of PSD is associated with neurogenesis are largely unexplored. In the present study, we found that depressive-like behaviors were observed at the first week after focal ischemic stroke in female ovariectomized (OVX) rats, as measured by sucrose preference and open field test, suggesting that focal cerebral ischemia could induce PSD. Three weeks after middle cerebral artery occlusion (MCAO), rats were treated with E2 for consecutive 14 days. We found that E2-treated rats had significantly improving ischemia-induced depression-like behaviors in the forced-swimming test and sucrose preference test, compared to vehicle-treated group. In addition, we also found that BrdU- and doublecortin (DCX)-positive cells in the dentate gyrus of the hippocampus and the subventricular zone (SVZ) were significantly increased in ischemic rats after E2 treatment, compared to vehicle-treated group. Our data suggest that focal cerebral ischemia can induce PSD, and E2 can ameliorate PSD. In addition, newborn neurons in the hippocampus may play an important role in E2-mediated antidepressant like effect after ischemic stroke. PMID:24307996

Cheng, Yifan; Su, Qiaoer; Shao, Bei; Cheng, Jianhua; Wang, Hong; Wang, Liuqing; Lin, Zhenzhen; Ruan, Linhui; ZhuGe, Qichuan; Jin, Kunlin

2013-01-01

290

Recombinant bovine somatotropin decreases hepatic amino acid catabolism in female rats.  

PubMed

The effect of recombinant bovine somatotropin (rbST) on hepatic amino acid catabolism in female rats was investigated. Daily injections of rbST for 5 d decreased liver homogenate lysine alpha-ketoglutarate reductase (EC 1.5.1.8) activity (P < 0.05) and liver homogenate lysine oxidation (P < 0.05) approximately 35%. Liver homogenate methionine and valine oxidation were depressed approximately 20 (P = 0.13) and 35% (P < 0.05), respectively. These data show a decrease in hepatic capacity to oxidize amino acids in rats administered rbST. Whether depressed liver amino acid degrading enzyme activity plays a role in amino acid oxidation in vivo remains to be evaluated. PMID:8648440

Blemings, K P; Gahl, M J; Crenshaw, T D; Benevenga, N J

1996-06-01

291

Immediate and residual effects of tamoxifen and ethynylestradiol in the female rat hypothalamus.  

PubMed

Very little is known about the impact of selective estrogen receptor modulators (SERMs) on the brain. We examined the effects of tamoxifen (TAMOX) and the synthetic estrogen 17alpha-ethynylestradiol (EE) on estrogen-dependent gene expression and receptor binding in the female rat brain. Both immediate and residual effects were examined in both the presence and absence of 17beta-estradiol. Two groups of adult, ovariectomized, female rats (n=30 per group) were injected with TAMOX (5 mg/kg), EE (0.1 mg/kg), or sesame oil daily for 14 days. Animals from the first group were implanted with blank or 17beta-estradiol Silastic capsules concurrently with the last three SERM injections (immediate, group 1). Animals from the second group received either blank or 17beta-estradiol implants 2 weeks after the last injection (residual, group 2). All animals were sacrificed 72 h after implantation. TAMOX increased uterine weight in the absence of estrogen, but inhibited uterine weight gain in the presence of estrogen in both groups 1 and 2. TAMOX and EE increased oxytocin receptor binding in the ventromedial nucleus of the hypothalamus (VMN) in the absence of estrogen in both groups 1 and 2. The estrogen-dependent induction of PR mRNA expression in the VMN was significantly attenuated by TAMOX in group 1. Finally, TAMOX and EE had opposite effects on ERbeta mRNA expression in the paraventricular nucleus in the absence of 17beta-estradiol in group 1. Neither had any effect in group 2 when 17beta-estradiol was present. These results suggest that TAMOX has mixed agonist/antagonist effects in the female rat brain, many of which persist at least 2 weeks after the administration ceases. PMID:12834913

Patisaul, Heather B; Aultman, Eleni A; Bielsky, Isadora F; Young, Larry J; Wilson, Mark E

2003-07-18

292

Estrous cycle affects the neurochemical and neurobehavioral profile of carvacrol-treated female rats  

SciTech Connect

Carvacrol is the major constituent of essential oils from aromatic plants. It showed antimicrobial, anticancer and antioxidant properties. Although it was approved for food use and included in the chemical flavorings list, no indication on its safety has been estimated. Since the use of plant extracts is relatively high among women, aim of this study was to evaluate carvacrol effects on female physiology and endocrine profiles by using female rats in proestrus and diestrus phases. Serotonin and metabolite tissue content in prefrontal cortex and nucleus accumbens, after carvacrol administration (0.15 and 0.45 g/kg p.o.), was measured. Drug effects in behavioral tests for alterations in motor activity, depression, anxiety-related behaviors and endocrine alterations were also investigated. While in proestrus carvacrol reduced serotonin and metabolite levels in both brain areas, no effects were observed in diestrus phase. Only in proestrus phase, carvacrol induced a depressive-like behavior in forced swimming test, without accompanying changes in ambulation. The improvement of performance in FST after subchronic treatment with fluoxetine (20 mg/kg) suggested a specific involvement of serotonergic system. No differences were found across the groups with regard to self-grooming behavior. Moreover, in proestrus phase, carvacrol reduced only estradiol levels without binding hypothalamic estradiol receptors. Our study showed an estrous-stage specific effect of carvacrol on depressive behaviors and endocrine parameters, involving serotonergic system. Given the wide carvacrol use not only as feed additive, but also as cosmetic essence and herbal remedy, our results suggest that an accurate investigation on the effects of its chronic exposure is warranted. - Highlights: > Carvacrol induced a depressive-like phenotype in rats, depending on ovarian cyclicity. > Carvacrol selectively reduced serotonin content in female rats in proestrus phase. > Carvacrol reduced serotonin levels in areas belonging to the emotional circuit. > Carvacrol reduced plasma estradiol levels only during the proestrus phase.

Trabace, L., E-mail: trabace@unifg.it [Department of Biomedical Sciences, University of Foggia, V. le Luigi Pinto 1, 71121 Foggia (Italy); Zotti, M.; Morgese, M.G.; Tucci, P.; Colaianna, M.; Schiavone, S. [Department of Biomedical Sciences, University of Foggia, V. le Luigi Pinto 1, 71121 Foggia (Italy); Avato, P. [Department of Pharmaco-Chemistry, University of Bari, 'A. Moro', Via Orabona 4, 70125, Bari (Italy); Cuomo, V. [Department of Human Physiology and Pharmacology, Vittorio Erspamer, University of Rome 'La Sapienza', P. le Aldo Moro 5, 00185, Rome (Italy)

2011-09-01

293

Low-dose effects of bisphenol A on early sexual development in male and female rats.  

PubMed

Bisphenol A (BPA) is widely detected in human urine and blood. BPA has been reported to impair many endpoints for reproductive and neurological development; however, it is controversial whether BPA has effects in the microgram per kilogram dose range. The aim of the current study was to examine the influence of BPA on early sexual development in male and female rats at dose levels covering both regulatory no observed adverse effect levels (NOAELs) (5 and 50?mg/kg bw per day) as well as doses in the microgram per kilogram dose range (0.025 and 0.25?mg/kg bw per day). Time-mated Wistar rats (n=22) were gavaged during pregnancy and lactation from gestation day 7 to pup day 22 with 0, 0.025, 0.25, 5 or 50?mg/kg bw per day BPA. From 0.250?mg/kg and above, male anogenital distance (AGD) was significantly decreased, whereas decreased female AGD was seen from 0.025?mg/kg bw per day and above. Moreover, the incidence of nipple retention in males appeared to increase dose relatedly and the increase was statistically significant at 50?mg/kg per day. No significant changes in reproductive organ weights in the 16-day-old males and females and no signs of maternal toxicity were seen. The decreased AGD at birth in both sexes indicates effects on prenatal sexual development and provides new evidence of low-dose adverse effects of BPA in rats in the microgram per kilogram dose range. The NOAEL in this study is clearly below 5?mg/kg for BPA, which is used as the basis for establishment of the current tolerable daily intake (TDI) by EFSA; thus a reconsideration of the current TDI of BPA appears warranted. PMID:24298045

Christiansen, Sofie; Axelstad, Marta; Boberg, Julie; Vinggaard, Anne Marie; Pedersen, Gitte Alsing; Hass, Ulla

2014-01-01

294

Serotonin and sexual behaviour in female rats. Effects of hallucinogenic indolealkylamines and phenylethylamines.  

PubMed

The effects of a number of hallucinogenic indolealkylamines and phenylethylamines on sexual receptivity in female rats have been studied. Preliminary experiments on extensor reflexes (which are highly dependent on serotonin (5-HT) receptor activity) indicated that the drugs possess marked 5-HT receptor agonist properties. All compounds increase sexual receptivity in low doses but inhibit this behaviour in high doses. 5-HT neurones are known to subserve inhibitory mechanisms in the control of receptivity. We suggest that the 5-HT agonists used enhance receptivity by preferentially stimulating presynaptic 5-HT receptors and inhibit receptivity by stimulating postsynaptic 5-HT receptors. Microiontophoretic and microelectrode recording data consistent with this hypothesis are discussed. PMID:19604947

Everitt, B J; Fuxe, K

1977-03-01

295

The effects of iridium on the renal function of female Wistar rats.  

PubMed

Despite the widespread use of iridium (Ir) in catalytic converters for improved capacity for reducing carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NO(x)) emissions, there is a lack of studies that have assessed possible toxicological hazards of exposure to Ir. The present investigation indicates that female Wistar rats exposed to Ir in the drinking water for 90 days displayed renal toxicity based on the elevated urinary retinol binding protein (RBP) and albumin. The RBP was more sensitive to albumin, showing significant increases at 0.01 mg/L. PMID:21764451

Iavicoli, Ivo; Fontana, Luca; Marinaccio, Alessandro; Alimonti, Alessandro; Pino, Anna; Bergamaschi, Antonio; Calabrese, Edward J

2011-10-01

296

Multi-Generational Drinking of Bottled Low Mineral Water Impairs Bone Quality in Female Rats  

PubMed Central

Background Because of reproductions and hormone changes, females are more sensitive to bone mineral loss during their lifetime. Bottled water has become more popular in recent years, and a large number of products are low mineral water. However, research on the effects of drinking bottled low mineral water on bone health is sparse. Objective To elucidate the skeletal effects of multi-generational bottled water drinking in female rats. Methods Rats continuously drank tap water (TW), bottled natural water (bNW), bottled mineralized water (bMW), or bottled purified water (bPW) for three generations. Results The maximum deflection, elastic deflection, and ultimate strain of the femoral diaphysis in the bNW, bMW, and bPW groups and the fracture strain in the bNW and bMW groups were significantly decreased. The tibiae calcium levels in both the bNW and bPW groups were significantly lower than that in the TW group. The tibiae and teeth magnesium levels in both the bNW and bPW groups were significantly lower than those in the TW group. The collagen turnover markers PICP (in both bNW and bPW groups) were significantly lower than that in the TW group. In all three low mineral water groups, the 1,25-dihydroxy-vitamin D levels were significantly lower than those in the TW group. Conclusion Long-term drinking of low mineral water may disturb bone metabolism and biochemical properties and therefore weaken biomechanical bone properties in females. Drinking tap water, which contains adequate minerals, was found to be better for bone health. To our knowledge, this is the first report on drinking bottled low mineral water and female bone quality on three generation model. PMID:25803851

Zeng, Hui; Wang, Lingqiao; Wang, Dahua; Luo, Jiaohua; Zhang, Liang; Huang, Yujing; Chen, Ji-an; Shu, Weiqun

2015-01-01

297

Overweight female rats selectively breed for low aerobic capacity exhibit increased myocardial fibrosis and diastolic dysfunction  

PubMed Central

The statistical association between endurance exercise capacity and cardiovascular disease suggests that impaired aerobic metabolism underlies the cardiovascular disease risk in men and women. To explore this connection, we applied divergent artificial selection in rats to develop low-capacity runner (LCR) and high-capacity runner (HCR) rats and found that disease risks segregated strongly with low running capacity. Here, we tested if inborn low aerobic capacity promotes differential sex-related cardiovascular effects. Compared with HCR males (HCR-M), LCR males (LCR-M) were overweight by 34% and had heavier retroperitoneal, epididymal, and omental fat pads; LCR females (LCR-F) were 20% heavier than HCR females (HCR-F), and their retroperitoneal, but not perireproductive or omental, fat pads were heavier as well. Unlike HCR-M, blood pressure was elevated in LCR-M, and this was accompanied by left ventricular (LV) hypertrophy. Like HCR-F, LCR-F exhibited normal blood pressure and LV weight as well as increased spontaneous cage activity compared with males. Despite normal blood pressures, LCR-F exhibited increased myocardial interstitial fibrosis and diastolic dysfunction, as indicated by increased LV stiffness, a decrease in the initial filling rate, and an increase in diastolic relaxation time. Although females exhibited increased arterial stiffness, ejection fraction was normal. Increased interstitial fibrosis and diastolic dysfunction in LCR-F was accompanied by the lowest protein levels of phosphorylated AMP-actived protein kinase [phospho-AMPK (Thr172)] and silent information regulator 1. Thus, the combination of risk factors, including female sex, intrinsic low aerobic capacity, and overweightness, promote myocardial stiffness/fibrosis sufficient to induce diastolic dysfunction in the absence of hypertension and LV hypertrophy. PMID:22345570

Johnson, Megan S.; Ma, Lixin; Pulakat, Lakshmi; Mugerfeld, Irina; Hayden, Melvin R.; Garro, Mona; Knight, William; Britton, Steven L.; Koch, Lauren G.; Sowers, James R.

2012-01-01

298

The effects of chronic restraint on the morphology of ventral CA1 neurons in female Long Evans rats.  

PubMed

Abstract Women are more likely than men to develop psychopathology as a result of stress, but there is little research regarding the effects of a stressful condition and its treatment in female non-human animals, perhaps because of inherent hormonal activity. Recent studies have demonstrated that there are structural and functional differences between the dorsal and ventral hippocampus, but the effects of stress on the morphology of CA1 and CA3 neurons have been studied primarily in the dorsal hippocampus. This study assessed the effects of stress induced by restricted movement on the morphology of ventral hippocampal CA1 neurons in male and female rats. Male and female Long Evans (LE) rats were subjected to restraint stress for 6?h every day for 25 days. One group of rats was used to study the dendritic morphology of CA1 ventral hippocampal neurons using the Golgi-Cox stain. A second group of rats was used to analyze learning and memory using the Morris water maze. Stressed female rats exhibited a decrease in the density of basilar dendritic spines, an increase in the number of apical dendritic intersections and deficits in spatial memory. There were no apparent effects of stress on male rats. Our data support previous findings of a dimorphic response to chronic stress and indicate that the ventral hippocampus is not particularly susceptible to the effects of stress. PMID:25287136

Morales Rico, Alexander; López Mendoza, Anayeli; Bravo Durán, Dolores Adriana; de la Luz Torres, Héctor; Arias Mendoza, Guadalupe; Silva Gómez, Adriana Berenice

2015-01-01

299

Preliminary assessment of the oral toxicity of 1,5-diazido-3-nitrazapentane, 2- and 6-week feeding study, male and female rats. Final report  

Microsoft Academic Search

A 2 and 6 week gavage feeding of DANPE caused testicular hypospermatogenesis in male rats and pneumonitis in female rats. A NOAEL was not achieved in male rats but was achieved in female rats at the 56.00 mg\\/kg\\/day dose level.... 1,5-Diazido-3-Nitrazapentane (DANPE), Gavage, Testicular hypospermatogenesis, Insterstitual Inflammation No-observed-Adverse-Effect-Level(NOAEL), Feeding study.

E. A. Haight; J. G. Harvey; P. A. Bell

1993-01-01

300

Preliminary assessment of the oral toxicity of 1,5-diazido-3-nitrazapentane, 2- and 6-week feeding study, male and female rats. Final report  

SciTech Connect

A 2 and 6 week gavage feeding of DANPE caused testicular hypospermatogenesis in male rats and pneumonitis in female rats. A NOAEL was not achieved in male rats but was achieved in female rats at the 56.00 mg/kg/day dose level.... 1,5-Diazido-3-Nitrazapentane (DANPE), Gavage, Testicular hypospermatogenesis, Insterstitual Inflammation No-observed-Adverse-Effect-Level(NOAEL), Feeding study.

Haight, E.A.; Harvey, J.G.; Bell, P.A.

1993-02-01

301

Mammary Gland Development as a Sensitive End Point after Acute Prenatal Exposure to an Atrazine Metabolite Mixture in Female Long-Evans Rats  

PubMed Central

Background Atrazine (ATR), a widely used chlorotriazine herbicide, inhibits a number of endocrine-dependent processes, including gonadotrophin surges and mammary gland development in rats. Chlorotriazine herbicides are rapidly metabolized in plants and animals to form a group of metabolites that are detected both in the environment and in exposed animals. The extent to which these metabolites are responsible directly for the observed health effects is not understood. Objectives Our goal was to determine if a mixture of ATR metabolites, in proportions found in the environment, might produce developmental effects in Long-Evans rats following exposure late in pregnancy. Methods We administered an ATR metabolite mixture (AMM) containing ATR, hydroxyatrazine, diaminochlorotriazine, deethylatrazine, and deisopropylatrazine orally to pregnant Long-Evans rats at 0.09, 0.87, or 8.73 mg/kg body weight (bw)/day, on gestation days 15–19, using 0 and 100 mg ATR/kg bw/day as negative and positive controls, respectively. Results We observed no significant effect of acute AMM exposure on body weight gain in dams during the dosing period, weight loss in pups on postnatal day (PND)4, or pubertal timing, as is seen with ATR alone. However, as with ATR, we detected delayed mammary gland development, evaluated by whole mount analysis, as early as PND4 in all treatment groups. Conclusions Our data suggest that acute exposure to AMM at levels as low as 0.09 mg/kg bw during late pregnancy causes persistent alterations in mammary gland development of female offspring, and that these effects do not appear to be related to bw or associated with pubertal timing. PMID:17450222

Enoch, Rolondo R.; Stanko, Jason P.; Greiner, Sara N.; Youngblood, Geri L.; Rayner, Jennifer L.; Fenton, Suzanne E.

2007-01-01

302

Renoprotective effect of hydroalcoholic extract of Rheum ribes root in diabetic female rats  

PubMed Central

Objective: Medical plants, as rich sources of natural antioxidants with antidiabetic effects, are used worldwide to diminish a variety of symptoms and many diseases. R. ribes L., which belongs to the family of polygonaceae, can provide symptomatic relief and assist in the prevention of the secondary complications of the diabetes. Material and Methods: 36 female adult rats were randomly divided into 6 groups of 6. Normal Control groups treated with normal saline. Positive control groups treated with hydroalcohlic extract of R. ribes root (150 mg/kg) daily by gavages for 4 consecutive weeks. Diabetes was inducedby injection of 120 mg/kg alloxan monohydrate intraperitoneally. Two diabetic groups were treated with different doses of R. ribes root extract. The sixth diabetic groups were treated with glibenclamide (0.6 mg/kg). At the end of 28 days, blood samples were collected and their kidney tissues were processed for light microscopy. Results: The results showed that hydro-alcoholic extract of R. ribes decreased the level of glucose, cholesterol, triglyceride, urea and creatinine in diabetic rats (p<0.05) in compared with diabetic rats, while the level of HDL increased at the same group (p<0.05). Histopathological changes of kidney samples were comparable with respective control. In diabetic rats, kidney sections showed atrophy of glomerular capillaries with increased Bowman's space and acute tubular necrosis. The groups that were treated with R. ribes root were improved towards normal condition. Conclusion: It is interesting to note that hydroalcohlic extract of R. ribes root improves renal dysfunction in alloxan-induced diabetic rats through controlling blood glucose and renal protective effects. PMID:25386403

Hamzeh, Shokri; Farokhi, Farah; Heydari, Reza; Manaffar, Ramin

2014-01-01

303

Adolescent pre-treatment with oxytocin protects against adult methamphetamine-seeking behavior in female rats.  

PubMed

The neuropeptide oxytocin (OT), given acutely, reduces self-administration of the psychostimulant drug methamphetamine (METH). Additionally, chronic OT administration to adolescent rats reduces levels of alcohol consumption in adulthood, suggesting developmental neuroplasticity in the OT system relevant to addiction-related behaviors. Here, we examined whether OT exposure during adolescence might subsequently inhibit METH self-administration in adulthood. Female Sprague-Dawley rats were administered vehicle or OT (1?mg/kg, i.p.) once daily from postnatal days (PND) 28 to 37 (adolescence). At PND 62 (adulthood), rats were trained to self-administer METH (intravenous, i.v.) in daily 2-hour sessions for 10 days under a fixed ratio 1 (FR1) reinforcement schedule, followed by determination of dose-response functions (0.01-0.3?mg/kg/infusion, i.v.) under both FR1 and progressive ratio (PR) schedules of reinforcement. Responding was then extinguished, and relapse to METH-seeking behavior assessed following priming doses of non-contingent METH (0.1-1?mg/kg, i.p.). Finally, plasma was collected to determine pre-treatment effects on OT and corticosterone levels. Results showed that OT pre-treatment did not significantly inhibit the acquisition of METH self-administration or FR1 responding. However, rats pre-treated with OT responded significantly less for METH under a PR reinforcement schedule, and showed reduced METH-primed reinstatement with the 1?mg/kg prime. Plasma OT levels were also significantly higher in OT pre-treated rats. These results confirm earlier observations that adolescent OT exposure can subtly, yet significantly, inhibit addiction-relevant behaviors in adulthood. PMID:25402719

Hicks, Callum; Cornish, Jennifer L; Baracz, Sarah J; Suraev, Anastasia; McGregor, Iain S

2014-11-17

304

Dietary Supplementation of Female Rats with Elk Velvet Antler Improves Physical and Neurological Development of Offspring  

PubMed Central

Elk velvet antler (EVA) has a traditional use for promotion of general health. However, evidence of EVA effects at different lifestages is generally lacking. This paper investigated the effects of long-term maternal dietary EVA supplementation on physical, reflexological and neurological development of rat offspring. Female Wistar rats were fed standard chow or chow containing 10% EVA for 90 days prior to mating and throughout pregnancy and lactation. In each dietary group, 56 male and 56 female pups were assessed for physical, neuromotor, and reflexologic development postnatally. Among the examined physical developmental parameters, incisor eruption occurred one day earlier in pups nursing dams receiving EVA. Among neuromotor developmental parameters, duration of supported and unsupported standing was longer for pups nursing EVA supplemented dams. Acquisition of neurological reflex parameters (righting reflex, negative geotaxis, cliff avoidance acoustic startle) occurred earlier in pups nursing dams receiving EVA. Longterm maternal EVA supplementation prior to and during pregnancy and lactation accelerated certain physical, reflexologic, and neuromotor developmental milestones and caused no discernible adverse effects on developing offspring. The potential benefits of maternal EVA supplementation on postnatal development warrants further investigation to determine whether EVA can be endorsed for the promotion of maternal and child health. PMID:22550542

Chen, Jiongran; Woodbury, Murray R.; Alcorn, Jane; Honaramooz, Ali

2012-01-01

305

Dietary supplementation of female rats with elk velvet antler improves physical and neurological development of offspring.  

PubMed

Elk velvet antler (EVA) has a traditional use for promotion of general health. However, evidence of EVA effects at different lifestages is generally lacking. This paper investigated the effects of long-term maternal dietary EVA supplementation on physical, reflexological and neurological development of rat offspring. Female Wistar rats were fed standard chow or chow containing 10% EVA for 90 days prior to mating and throughout pregnancy and lactation. In each dietary group, 56 male and 56 female pups were assessed for physical, neuromotor, and reflexologic development postnatally. Among the examined physical developmental parameters, incisor eruption occurred one day earlier in pups nursing dams receiving EVA. Among neuromotor developmental parameters, duration of supported and unsupported standing was longer for pups nursing EVA supplemented dams. Acquisition of neurological reflex parameters (righting reflex, negative geotaxis, cliff avoidance acoustic startle) occurred earlier in pups nursing dams receiving EVA. Longterm maternal EVA supplementation prior to and during pregnancy and lactation accelerated certain physical, reflexologic, and neuromotor developmental milestones and caused no discernible adverse effects on developing offspring. The potential benefits of maternal EVA supplementation on postnatal development warrants further investigation to determine whether EVA can be endorsed for the promotion of maternal and child health. PMID:22550542

Chen, Jiongran; Woodbury, Murray R; Alcorn, Jane; Honaramooz, Ali

2012-01-01

306

Comparison of Female Fischer and Sprague-Dawley Rats in the Response to Ketanserin  

PubMed Central

The effects of the 5-HT2A/2C receptor antagonist, ketanserin, on lordosis behavior were examined in hormonally primed, ovariectomized Fischer and Sprague-Dawley females. Rats were primed with 0.067 ?g/g body weight estradiol benzoate and 3.33 ?g/g body weight progesterone. After a pretest for sexual behavior, rats were injected with 0.416 to 10 mg/kg ketanserin. In both strains, lordosis behavior, lordosis quality, and proceptivity were significantly reduced by ketanserin. There was modest evidence of a strain difference with Sprague-Dawley females slightly more sensitive to ketanserin. In a second experiment, the effects of 10 mg/kg fluoxetine, 1 mg/kg ketanserin, and their combination were examined to determine if the two drugs would have additive effects on sexual behavior. There was no evidence that the drugs were additive in their effect and the strains did not differ in their response to the combined treatment. These findings are discussed in relation to prior evidence for strain differences in the sexual behavioral response to fluoxetine and to a receptor agonist acting preferentially at 5-HT1A receptors. PMID:24201045

Miryala, Chandra Suma Johnson; Hiegel, Cindy; Uphouse, Lynda

2014-01-01

307

Effects of Eucommia ulmoides extract on longitudinal bone growth rate in adolescent female rats.  

PubMed

Eucommia ulmoides is one of the popular tonic herbs for the treatment of low back pain and bone fracture and is used in Korean medicine to reinforce muscles and bones. This study was performed to investigate the effects of E.?ulmoides extract on longitudinal bone growth rate, growth plate height, and the expressions of bone morphogenetic protein 2 (BMP-2) and insulin-like growth factor 1 (IGF-1) in adolescent female rats. In two groups, we administered a twice-daily dosage of E.?ulmoides extract (at 30 and 100?mg/kg, respectively) per os over 4?days, and in a control group, we administered vehicle only under the same conditions. Longitudinal bone growth rate in newly synthesized bone was observed using tetracycline labeling. Chondrocyte proliferation in the growth plate was observed using cresyl violet dye. In addition, we analyzed the expressions of BMP-2 and IGF-1 using immunohistochemistry. Eucommia ulmoides extract significantly increased longitudinal bone growth rate and growth plate height in adolescent female rats. In the immunohistochemical study, E.?ulmoides markedly increased BMP-2 and IGF-1 expressions in the proliferative and hypertrophic zones. In conclusion, E.?ulmoides increased longitudinal bone growth rate by promoting chondrogenesis in the growth plate and the levels of BMP-2 and IGF-1. Eucommia ulmoides could be helpful for increasing bone growth in children who have growth retardation. PMID:25087723

Kim, Ji Young; Lee, Jeong-Il; Song, MiKyung; Lee, Donghun; Song, Jungbin; Kim, Soo Young; Park, Juyeon; Choi, Ho-Young; Kim, Hocheol

2015-01-01

308

Comparison of growth and pubertal progression in wild type female rats with different bedding types  

PubMed Central

Purpose Endocrine-disrupting chemicals interfere with the endocrine system and therefore affect growth and pubertal progression. The study aim was to compare the growth and pubertal progression in wild-type female rats with different bedding types. Methods Twenty 5-week-old female wild-type Sprague Dawley rats were randomly assigned to two groups with different bedding types: one group received wood shaving bedding, while a second group received corncob bedding. We determined crown-rump length and body weight as anthropometric measurements and assessed the serum growth hormone (GH) and estradiol levels. The gh1 mRNA expression levels were compared using quantitative real time transcription polymerase chain reaction. The estrous cycle was evaluated by vaginal smear. Results The anthropometric measurements were not significantly different between the two groups. The mean relative expression of the gh1 gene was lower in the corncob bedding group than that in the wood shaving group (P=0.768). Meanwhile serum GH and estradiol were increased in the wood shaving bedding group; however this difference was not statistically significant. The time to first estrus and the length of the estrous cycle were increased in the corncob bedding group; the proportion of normal estrous cycles was also decreased. These findings indicate irregularities in the estrous cycle. Conclusion Endocrine-disrupting chemicals in corncob bedding might be associated with time to first estrus and length of the estrous cycle. Therefore, the type of bedding should be considered as a factor affecting pubertal progression in rodents.

Kang, Byung Ho; Kim, Shin-Hee; Jung, Kyung A; Kim, So Youn; Chung, Sung-Hoon; Park, Young Shil; Yoon, Kyung Lim

2015-01-01

309

Adolescent exposure to THC in female rats disrupts developmental changes in the prefrontal cortex.  

PubMed

Current concepts suggest that exposure to THC during adolescence may act as a risk factor for the development of psychiatric disorders later in life. However, the molecular underpinnings of this vulnerability are still poorly understood. To analyze this, we investigated whether and how THC exposure in female rats interferes with different maturational events occurring in the prefrontal cortex during adolescence through biochemical, pharmacological and electrophysiological means. We found that the endocannabinoid system undergoes maturational processes during adolescence and that THC exposure disrupts them, leading to impairment of both endocannabinoid signaling and endocannabinoid-mediated LTD in the adult prefrontal cortex. THC also altered the maturational fluctuations of NMDA subunits, leading to larger amounts of gluN2B at adulthood. Adult animals exposed to THC during adolescence also showed increased AMPA gluA1 with no changes in gluA2 subunits. Finally, adolescent THC exposure altered cognition at adulthood. All these effects seem to be triggered by the disruption of the physiological role played by the endocannabinoid system during adolescence. Indeed, blockade of CB1 receptors from early to late adolescence seems to prevent the occurrence of pruning at glutamatergic synapses. These results suggest that vulnerability of adolescent female rats to long-lasting THC adverse effects might partly reside in disruption of the pivotal role played by the endocannabinoid system in the prefrontal cortex maturation. PMID:25281318

Rubino, Tiziana; Prini, Pamela; Piscitelli, Fabiana; Zamberletti, Erica; Trusel, Massimo; Melis, Miriam; Sagheddu, Claudia; Ligresti, Alessia; Tonini, Raffaella; Di Marzo, Vincenzo; Parolaro, Daniela

2015-01-01

310

Maternal Programming of Reproductive Function and Behavior in the Female Rat  

PubMed Central

Parental investment can be used as a forecast for the environmental conditions in which offspring will develop to adulthood. In the rat, maternal behavior is transmitted to the next generation through epigenetic modifications such as methylation and histone acetylation, resulting in variations in estrogen receptor alpha expression. Natural variations in maternal care also influence the sexual strategy adult females will adopt later in life. Lower levels of maternal care are associated with early onset of puberty as well as increased motivation to mate and greater receptivity toward males during mating. Lower levels of maternal care are also correlated with greater activity of the hypothalamus–pituitary–gonadal axis, responsible for the expression of these behaviors. Contrary to the transition of maternal care, sexual behavior cannot simply be explained by maternal attention, since adoption studies changed the sexual phenotypes of offspring born to low caring mothers but not those from high caring dams. Indeed, mothers showing higher levels of licking/grooming have embryos that are exposed to high testosterone levels during development, and adoption studies suggest that this androgen exposure may protect their offspring from lower levels of maternal care. We propose that in the rat, maternal care and the in utero environment interact to influence the reproductive strategy female offspring display in adulthood and that this favors the species by allowing it to thrive under different environmental conditions. PMID:22203802

Cameron, Nicole M.

2011-01-01

311

Nonproliferative and Proliferative Lesions of the Rat and Mouse Female Reproductive System  

PubMed Central

The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions in Rats and Mice) Project (www.toxpath.org/inhand.asp) is a joint initiative of the Societies of Toxicological Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally accepted nomenclature for proliferative and nonproliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in the female reproductive tract of laboratory rats and mice, with color photomicrographs illustrating examples of some lesions. The standardized nomenclature presented in this document is also available electronically on the internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous and aging lesions as well as lesions induced by exposure to test materials. There is also a section on normal cyclical changes observed in the ovary, uterus, cervix and vagina to compare normal physiological changes with pathological lesions. A widely accepted and utilized international harmonization of nomenclature for female reproductive tract lesions in laboratory animals will decrease confusion among regulatory and scientific research organizations in different countries and provide a common language to increase and enrich international exchanges of information among toxicologists and pathologists. PMID:25516636

Dixon, Darlene; Alison, Roger; Bach, Ute; Colman, Karyn; Foley, George L.; Harleman, Johannes H.; Haworth, Richard; Herbert, Ronald; Heuser, Anke; Long, Gerald; Mirsky, Michael; Regan, Karen; Van Esch, Eric; Westwood, F. Russell; Vidal, Justin; Yoshida, Midori

2014-01-01

312

The Physiological Role of Arcuate Kisspeptin Neurons in the Control of Reproductive Function in Female Rats  

PubMed Central

Kisspeptin plays a pivotal role in pubertal onset and reproductive function. In rodents, kisspeptin perikarya are located in 2 major populations: the anteroventral periventricular nucleus and the hypothalamic arcuate nucleus (ARC). These nuclei are believed to play functionally distinct roles in the control of reproduction. The anteroventral periventricular nucleus population is thought to be critical in the generation of the LH surge. However, the physiological role played by the ARC kisspeptin neurons remains to be fully elucidated. We used bilateral stereotactic injection of recombinant adeno-associated virus encoding kisspeptin antisense into the ARC of adult female rats to investigate the physiological role of kisspeptin neurons in this nucleus. Female rats with kisspeptin knockdown in the ARC displayed a significantly reduced number of both regular and complete oestrous cycles and significantly longer cycles over the 100-day period of the study. Further, kisspeptin knockdown in the ARC resulted in a decrease in LH pulse frequency. These data suggest that maintenance of ARC-kisspeptin levels is essential for normal pulsatile LH release and oestrous cyclicity. PMID:24424033

Beale, K.E.; Kinsey-Jones, J.S.; Gardiner, J.V.; Harrison, E.K.; Thompson, E.L.; Hu, M.H.; Sleeth, M.L.; Sam, A.H.; Greenwood, H.C.; McGavigan, A.K.; Dhillo, W.S.; Mora, J.M.; Li, X.F.; Franks, S.; Bloom, S.R.; O'Byrne, K.T.

2014-01-01

313

Excess genistein suppresses the synthesis of extracellular matrix in female rat mandibular condylar cartilage  

PubMed Central

Aim: To investigate the effect of excess genistein on the extracellular matrix in mandibular condylar cartilage of female rats in vivo. Methods: Female SD rats were administered through oral gavage with genistein (50 mg/kg) or placebo daily for 6 weeks. The morphological changes of temporomandibular joints were studied with HE staining. The expression of cartilage matrix compounds (aggrecan and collagen type II), estrogen-related molecules (aromatase, estradiol, ER? and ER?) and proliferating cell nuclear antigen (PCNA) in mandibular condylar cartilage was detected using immunohistochemistry, ELISA and real-time PCR. Results: The genistein treatment significantly reduced the thickness of the posterior and middle regions of mandibular condylar cartilage, and decreased the expression of collagen type II, aggrecan and PCNA. Compared with the control group, the estradiol content and expression levels of the key estradiol-synthesizing enzyme aromatase in the genistein-treatment group were significantly decreased. The genistein treatment significantly increased the expression of ER?, but decreased the expression of ER?. Conclusion: Excess genistein suppresses extracellular matrix synthesis and chondrocytes proliferation, resulting in thinner mandibular condylar cartilage. These effects may be detrimental to the ability of mandibular condylar cartilage to adapt to mechanical loads. PMID:22705728

Yu, Shi-bin; Xing, Xiang-hui; Dong, Guang-ying; Weng, Xi-li; Wang, Mei-qing

2012-01-01

314

The effect of piroctone olamine on reproduction of male and female rats.  

PubMed

The purpose of this study was to determine the effect of piroctone olamine, an antidandruff active, on reproductive performance, fertility, parturition, and neonatal viability and growth. Piroctone olamine was administered orally by gavage to three groups of 35 male Sprague-Dawley rats each beginning 64 days prior to mating and continuing until euthanized and to three groups of 35 female Sprague-Dawley rats each beginning 14 days prior to mating and continuing until euthanized. Animals in the treated groups received piroctone olamine in a combination of 1.0% methylcellulose and polyethylene glycol 400 as a single daily dose at levels of 0, 10, 100, and 250 mg/kg/day, at a volume of 2.5 ml/kg. The control group received the vehicle only. Ten randomly selected females/group were mated and underwent a uterine examination on Gestation Day 13; the remaining females were allowed to deliver. Because earlier studies reported hematological effects, blood samples were collected from all parental animals during acclimation and prior to euthanasia for hematological and blood chemistry (Gestation Day 13 females) characterization. The parental animals were necropsied and tissues were grossly examined. Systemic effects induced by the test article were seen at the mid- and high-dose levels but only among the male rats. These effects were reduced body weight and decreased liver weights. Hematological findings representative of anemia occurred at the high-dose level, as did rales in several animals. Offspring growth was inhibited for the high-dose group as evidenced by significantly reduced mean weight values throughout lactation. The remaining parameters assessed, including mating ability and reproductive performance, were not affected by treatment at any dosage level tested. In summary, the no observable effect level of piroctone olamine with respect to systemic toxicity was considered to be 10 mg/kg/day. Neonatal growth was not affected at 100 mg/kg/day or less, and the no observable effect level with respect to reproductive parameters, including fertility, was 250 mg/kg/day. PMID:2019350

Allgood, G S; Miller, J M; Schardein, J L

1991-01-01

315

Restoring and maintaining bone in osteopenic female rat skeleton: I. Changes in bone mass and structure  

NASA Technical Reports Server (NTRS)

This experiment contains the crucial data for the lose, restore, and maintain (LRM) concept, a practical approach for reversing existing osteoporosis. The LRM concept uses anabolic agents to restore bone mass and architecture (+ phase) and then switches to an agent with the established ability to maintain bone mass, to keep the new bone (+/- phase). The purpose of this study was to learn whether switching to an agent known chiefly for its ability to maintain existing bone mass preserves new bone induced by PGE2 in osteopenic, estrogen-depleted rats. The current study had three phases, the bone loss (-), restore (+), and maintain (+/-) phases. We ovariectomized (OX) or sham ovariectomized (sham-OX) 5.5-month-old female rats (- phase). The OX rats were treated 5 months postovariectomy with 1-6 mg PGE2 per kg/day for 75 days to restore lost cancellous bone mass (+ phase), and then PGE2 treatment was stopped and treatment began with 1 or 5 micrograms/kg of risedronate, a bisphosphonate, twice a week for 60 days (+/- phase). During the loss (-) phase, the cancellous bone volume of the proximal tibial metaphysis in the OX rat fell to 19% of initial and 30% of age-matched control levels. During the restore (+) phase, the cancellous bone volume in OX rats doubled. When PGE2 treatment was stopped, however, and no special maintenance efforts were made during the maintain (+/-) phase, the PGE2-induced cancellous bone disappeared. In contrast, the PGE2-induced cancellous bone persisted when the PGE2 treatment was followed by either a 1 or 5 micrograms treatment of risedronate per kg given twice a week for 60 days during the maintain (+/-) phase. The tibial shaft demonstrated very little cortical bone loss during the loss (-) phase in OX rats. The tibial shaft cortical bone fell some 8%. During the restore (+) phase, new cortical bone in OX rats increased by 22%. When PGE2 treatment was stopped and nothing was given during the maintain (+/-) phase, however, all but the PGE2-induced subperiosteal bone disappeared. In contrast, when PGE2 treatment was stopped and 1 micron risedronate per kg twice a week for 60 days was administered during the maintenance (+/-) phase, the PGE2-induced subperiosteal bone and some of the subendocortical bone and marrow trabeculae persisted.(ABSTRACT TRUNCATED AT 400 WORDS).

Tang, L. Y.; Jee, W. S.; Ke, H. Z.; Kimmel, D. B.

1992-01-01

316

Metabolism of n-butyl benzyl phthalate in the female Wistar rat. Identification of new metabolites.  

PubMed

n-Butyl benzyl phthalate (BBP), a plasticizer used in polyvinylchloride (PVC) and other polymers, has been orally administered to female Wistar rats with four doses (150, 475, 780 and 1500 mg/kg body weight/day) for 3 consecutive days. Metabolites recovered in urines were analysed by gas chromatography-mass spectrometry (GC-MS) after 24, 48 and 72 hours. Six metabolites were identified. Mono-n-butyl phthalate (MBuP) and mono-n-benzyl phthalate (MBeP) represented respectively 29-34% and 7-12% of the total recovered metabolites. Hippuric acid, the main metabolite of benzoic acid, represented the second major metabolite (51-56%). Phthalic acid, benzoic acid and an omega-oxidized metabolite of MBuP were also recovered in urine but in small quantities. BBP was never identified in urines. Total urinary metabolites recovery represented 56% of the dose administered in the first 24 hours. However, total recovery decreased when the dose increases (43% at 780 mg/kg body weight/day, only 30% at 1500 mg/kg body weight/day). Whatever the time was, BBP metabolites recovered in urines were all present and in the same proportions for the two lowest doses. Discrepancy in metabolites quantities expressed as percentages of the dose observed in urine of rat treated with the highest BBP dose disappeared with time as MBuP, MBeP and hippuric acid recovery has significantly increased at day 3. Metabolic profile of BBP in female rats has been established. The aim of the present study is to identify further the active(s) agent(s) involved in the BBP malformations and teratogenic effects. PMID:10506015

Nativelle, C; Picard, K; Valentin, I; Lhuguenot, J C; Chagnon, M C

1999-08-01

317

Antidepressant effects of Soyo-san on Immobilization stress in ovariectomized female rats.  

PubMed

Soyo-san is a traditional oriental medicinal formula, a mixture of 9 crude drugs, and it has been clinically used for treating mild depressive disorders. The purpose of the study was to examine the effect of Soyo-san on repeated stress-induced alterations of learning and memory on a Morris water maze (MWM) task and also the anxiety-related behavior on the elevated pulse maze (EPM) in ovariectomized female rats. We assessed the changes in the reactivity of the cholinergic system by measuring the immunoreactive neurons of choline acetyltransferase (ChAT) and reactivity of acetylcholinesterase (AChE) in the hippocampus, and the serum levels of corticosterone were assessed after behavioral testing. The female rats were randomly divided into three groups: the nonoperated and nonstressed group (normal), the ovariectomized and stressed group (control), and the ovariectomized, stressed and Soyo-san treated group (SOY). The rats were exposed to immobilization stress (IMO) for 14 d (2 h/d), and Soyo-san (400 mg/kg, i.p.) was administered 30 min before IMO stress. Treatments with SOY caused significant reversals of the stress-induced deficits in learning and memory on a spatial memory task, and it also produced an anxiolytic-like effect on the EPM, and increased the ChAT and AChE reactivities (p<0.05, respectively). The serum level of corticosterone in the SOY group was significantly lower than that in the control group (p<0.05). These results suggest that Soyo-san might prove to be an effective antidepressant agent. PMID:17666797

Oh, Jin Kyung; Kim, Yoon-Sang; Park, Hyun-Jung; Lim, Eun-Mee; Pyun, Kwang-Ho; Shim, Insop

2007-08-01

318

Role of dehydroepiandrosterone in management of glucocorticoid-induced secondary osteoporosis in female rats.  

PubMed

The current study aimed to evaluate the potential role of dehydroepiandrosterone (DHEA) in the protection and intervention of glucocorticoid-induced secondary osteoporosis in female rats. For this purpose this study was conducted on five groups of female Sprague Dawley rats which were classified into: (1) negative control group received saline as vehicle, (2) osteoporotic group orally administered with prednisolone (5 mg/kg b.wt.) daily for six months, (3) positive control group orally administered with DHEA (250 mg/kg b.wt.) three times weekly for six months, (4) protective group orally administered with prednisolone daily with simultaneous oral administration of DHEA three times weekly for six months and (5) therapeutic group orally administered with prednisolone daily for six months then orally administered with DHEA three times weekly for other six months. The obtained data revealed that prednisolone administration resulted in significant decrease in serum osteocalcin (OC), 1,25-dihydroxyvitamin D(3) (1,25-(OH)(2) D(3)) and osteoprotegerin (OPG) levels accompanied with significant increase in serum parathyroid hormone (PTH) and receptor activator nuclear factor kappa B ligand (RANKL) levels. Histopathological investigation of left femur bone showed that prednisolone administration produced compression of the reduced articular surface and atrophy of the epiphyseal bone. On the other hand, DHEA supplementation to osteoporotic rats increased serum OC, 1,25-(OH)(2) D(3) and OPG levels while decreased serum PTH and RANKL levels. Moreover, DHEA administration resulted in restoration of intact epiphyseal bony structure and articular surface. In conclusion, DHEA via its control on glucocorticoid activity and androgenic action provided potent effect on bone. PMID:21310600

Ahmed, Hanaa H; Morcos, Nadia Y S; Eskander, Emad F; Seoudi, Dina M S; Shalby, Aziza B

2012-09-01

319

Acute and chronic psychostimulant treatment modulates the diurnal rhythm activity pattern of WKY female adolescent rats.  

PubMed

The psychostimulants considered the gold standard in the treatment of attention deficit hyperactivity disorder, one of the most common childhood disorders, are also finding their way into the hands of healthy young adults as brain augmentation to improve cognitive performance. The possible long-term effects of psychostimulant exposure in adolescence are considered controversial, and thus, the objective of this study was to investigate whether the chronic exposure to the psychostimulant amphetamine affects the behavioral diurnal rhythm activity patterns of female adolescent Wistar-Kyoto (WKY) rat. The hypothesis of this study is that change in diurnal rhythm activity pattern is an indicator for the long-term effect of the treatment. Twenty-four rats were divided into two groups, control (N = 12) and experimental (N = 12), and kept in a 12:12-h light/dark cycle in an open-field cage. After 5-7 days of acclimation, 11 days of consecutive non-stop behavioral recordings began. On experimental day 1 (ED1), all groups were given an injection of saline. On ED2 to ED7, the experimental group was injected with 0.6 mg/kg amphetamine followed by 3 days of washout from ED8 to ED10, and amphetamine re-challenge on ED11 similar to ED2. The locomotor movements were counted by the computerized animal activity monitoring system, and the cosinor statistical test analysis was used to fit a 24-h curve of the control recording to the activity pattern after treatment. The horizontal activity, total distance, number of stereotypy, vertical activity, and stereotypical movements were analyzed to find out whether the diurnal rhythm activity patterns were altered. Data obtained using these locomotor indices of diurnal rhythm activity pattern suggest that amphetamine treatment significantly modulates the locomotor diurnal rhythm activity pattern of female WKY adolescent rats. PMID:24482155

Jones, Cathleen G; Yang, Pamela B; Wilcox, Victor T; Burau, Keith D; Dafny, Nachum

2014-05-01

320

Exercise Training and Calorie Restriction Influence the Metabolic Parameters in Ovariectomized Female Rats  

PubMed Central

The estrogen deficiency after menopause leads to overweight or obesity, and physical exercise is one of the important modulators of this body weight gain. Female Wistar rats underwent ovariectomy surgery (OVX) or sham operation (SO). OVX and SO groups were randomized into new groups based on the voluntary physical activity (with or without running) and the type of diet for 12 weeks. Rats were fed standard chow (CTRL), high triglyceride diet (HT), or restricted diet (CR). The metabolic syndrome was assessed by measuring the body weight gain, the glucose sensitivity, and the levels of insulin, triglyceride, leptin, and aspartate aminotransferase transaminase (AST) and alanine aminotransferase (ALT). The exercise training combined with the CR resulted in improvements in the glucose tolerance and the insulin sensitivity. Plasma TG, AST, and ALT levels were significantly higher in OVX rats fed with HT but these high values were suppressed by exercise and CR. Compared to SO animals, estrogen deprivation with HT caused a significant increase in leptin level. Our data provide evidence that CR combined with voluntary physical exercise can be a very effective strategy to prevent the development of a metabolic syndrome induced by high calorie diet. PMID:25874022

Pósa, Anikó; Kupai, Krisztina; Szalai, Zita; Veszelka, Médea; Török, Szilvia; Varga, Csaba

2015-01-01

321

Swimming exercise enhances the hippocampal antioxidant status of female Wistar rats.  

PubMed

Objectives Moderate exercise is known to have health benefits, while both sedentarism and strenuous exercise have pro-oxidant effects. In this study, we assessed the effect of moderate exercise on the antioxidant homeostasis of rats' hippocampi. Methods Female Wistar rats were submitted to a 30-minute swimming protocol on 5 days a week, for 4 weeks. Control rats were immersed in water and carefully dried. Production of hippocampal reactive species, activity of antioxidant enzymes, and glutathione levels in these animals were determined up to 30 days after completion of the 4-week protocol. Results Production of reactive species and hippocampal glutathione levels were increased 1 day after completion of the 4-week protocol, and returned to control levels after 7 days. Antioxidant enzyme activities were increased both 1 day (catalase) and 7 days (superoxide dismutase and glutathione peroxidase) after completion of the protocol. Thirty days after completion of the protocol, none of the antioxidant parameters evaluated differed from those of controls. Discussion Our results reinforce the benefits of aerobic exercise, which include positive modulation of antioxidant homeostasis in the hippocampi. The effects of exercise are not permanent; rather, an exercise regimen must be continued in order to maintain the neurometabolic adaptations. PMID:25387101

Stone, Vinícius; Kudo, Karen Yurika; Marcelino, Thiago Beltram; August, Pauline Maciel; Matté, Cristiane

2015-05-01

322

Amelioration of Collagen-Induced Arthritis in Female Dark Agouti Rats by Glucosamine Treatment  

PubMed Central

The present study assessed the therapeutic efficacy of glucosamine hydrochloride against collagen-induced arthritis in female Dark Agouti rats (DA). Arthritis was induced by intradermaly injecting a collagen and complete Freund's adjuvant suspension at multiple sites in the rat at a dose of 4?mg/kg of body weight and thereafter followed by two more boosters of the same dose, after the 1st week and 2nd week of primary immunization. After 21 days from the day of primary immunization, the arthritic group rats were given oral supplementation of glucosamine hydrochloride at a dose of 300?mg/kg of body weight until day 45. The arthritic group treated with glucosamine hydrochloride from day 21 to day 45 showed significant reduction in arthritic histopathological changes of the joints, reduction in paw thickness and also a significant decrease in C-reactive protein and TNF-alpha in the serum. Treatment with 300?mg/kg of glucosamine hydrochloride was able to reverse the arthritic changes, hence suggesting that glucosamine has a therapeutic effect against collagen-induced arthritis. PMID:23476804

Haleagrahara, Nagaraja; Tudawe, Dulanthi; Chakravarthi, Srikumar; Kutty Radhakrishnan, Ammu

2013-01-01

323

Action potential configuration in heart papillary muscles from female rats in different thyroid states.  

PubMed

We have studied the effects of thyroidectomy and the in vivo administration of different triiodothyronine (T3) doses in thyroidectomized female rats on electrophysiological properties, measured in vitro, of the anterior and posterior papillary muscle fibers from the right ventricle. In each thyroid state, the action potential duration (APD) measured by stimulating at 1 Hz was shorter for the posterior papillary muscle. APD from both preparations was found significantly lengthened in thyroidectomized animals in comparison to euthyroid controls. APD was shortened owing to treatment of thyroidectomized rats with T3 doses up to 10 micrograms/100 g body weight every second day. Treatment with larger doses of T3 tended to restore the values of APD found for ventricular fibres from both controls and thyroidectomized animals treated with substitutive T3 doses (5 micrograms/100 g body weight every second day). As the stimulation rate was increased from 1 to 5 Hz, APD increased in both preparations of all groups. The changes were of different amounts but the APD difference between the rat groups, which were significant at 1 Hz, remained significant at 5 Hz, while the differences between anterior and posterior preparations were cancelled in animals treated with 50 micrograms of T3 and reversed in those treated with 100 micrograms. PMID:9224547

Di Meo, S; de Martino Rosaroll, P; Venditti, P; Balestrieri, M; De Leo, T

1997-02-01

324

Effect of Hypericum perforatum Extract in an Experimental Model of Binge Eating in Female Rats  

PubMed Central

Purpose. The present study evaluated the effect of Hypericum perforatum dry extract in an experimental model of binge eating (BE). Methods. BE for highly palatable food (HPF) was evoked in female rats by three 8-day cycles of food restriction/re-feeding and acute stress on the test day (day 25). Stress was induced by preventing access to HPF for 15?min, while rats were able to see and smell it. Hypericum perforatum dry extract was given by gavage. Results. Only rats exposed to both food restrictions and stress exhibited BE. The doses of 250 and 500?mg/kg of Hypericum perforatum extract significantly reduced the BE episode, while 125?mg/kg was ineffective. The same doses did not affect HPF intake in the absence of BE. The dose of 250?mg/kg did not significantly modify stress-induced increase in serum corticosterone levels, suggesting that the effect on BE is not due to suppression of the stress response The combined administration of 125?mg/kg of Hypericum perforatum together with Salidroside, active principle of Rhodiola rosea, produced a synergic effect on BE. Conclusions. The present results indicate for the first time that Hypericum perforatum extracts may have therapeutic properties in bingeing-related eating disorders. PMID:22997570

Micioni Di Bonaventura, Maria Vittoria; Vitale, Giovanni; Massi, Maurizio; Cifani, Carlo

2012-01-01

325

Molecular Mechanisms Underlying the Rapid Arrhythmogenic Action of Bisphenol A in Female Rat Hearts  

PubMed Central

Previously we showed that bisphenol A (BPA), an environmental estrogenic endocrine disruptor, rapidly altered Ca2+ handling and promoted arrhythmias in female rat hearts. The underlying molecular mechanism was not known. Here we examined the cardiac-specific signaling mechanism mediating the rapid impact of low-dose BPA in female rat ventricular myocytes. We showed that protein kinase A (PKA) and Ca2+/CaM-dependent protein kinase II (CAMKII) signaling pathways are the two major pathways activated by BPA. Exposure to 1 nM BPA rapidly increased production of cAMP and rapidly but transiently increased the phosphorylation of the ryanodine receptors by PKA but not by CAMKII. BPA also rapidly increased the phosphorylation of phospholamban (PLN), a key regulator protein of sarcoplasmic reticulum Ca2+ reuptake, by CAMKII but not PKA. The increase in CAMKII phosphorylation of PLN was mediated by phospholipase C and inositol trisphosphate receptor-mediated Ca2+ release, likely from the endoplasmic reticulum Ca2+ storage. These two pathways are likely localized, impacting only their respective target proteins. The rapid impacts of BPA on ryanodine receptors and PLN phosphorylation were mediated by estrogen receptor-? but not estrogen receptor-?. BPA's rapid signaling in cardiac myocytes did not involve activation of ERK1/2. Functional analysis showed that PKA but not CAMKII activation contributed to BPA-induced sarcoplasmic reticulum Ca2+ leak, and both PKA and CAMKII were necessary contributors to the stimulatory effect of BPA on arrhythmogenesis. These results provide mechanistic insight into BPA's rapid proarrhythmic actions in female cardiac myocytes and contribute to the assessment of the consequence and potential cardiac toxicity of BPA exposure. PMID:24140712

Gao, Xiaoqian; Liang, Qian; Chen, Yamei

2013-01-01

326

Effects of developmental methylphenidate (MPH) treatment on monoamine neurochemistry of male and female rats.  

PubMed

Attention Deficit Hyperactivity Disorder (ADHD) is estimated to affect 4-5% of the adult human population (Kessler et al., 2006; Willcutt, 2012). Often prescribed to attenuate ADHD symptoms (Nair and Moss, 2009), methylphenidate hydrochloride (MPH) can have substantial positive effects. However, there is a paucity of literature regarding its use during pregnancy. Thus, adult women with ADHD face a difficult decision when contemplating pregnancy. In this study, pregnant Sprague-Dawley rats were orally treated a total of 0 (water), 6 (low), 18 (medium), or 42 (high) mg MPH/kg body weight/day (divided into three doses) on gestational days 6-21 (i.e., the low dose received 2 mg MPH/kg body weight 3×/day). Offspring were orally treated with the same daily dose as their dam (divided into two doses) on postnatal days (PNDs) 1-21. One offspring/sex/litter was sacrificed at PND 22 or PND 104 (n=6-7/age/sex/treatment group) and the striatum was quickly dissected and frozen. High Performance Liquid Chromatography (HPLC) coupled to a Photo Diode Array detector (PDA) was used to analyze monoamine content in the striatum of one side while a sandwich ELISA was used to analyze tyrosine hydroxylase (TH) from the other side. Age significantly affected monoamine and metabolite content as well as turnover ratios (i.e., DA, DOPAC, HVA, DOPAC/DA, HVA/DA, 5-HT and 5-HIAA); however, there were no significant effects of sex. Adult rats of the low MPH group had higher DA levels than control adults (p<0.05). At both ages, subjects of the low MPH group had higher TH levels than controls (p<0.05), although neither effect (i.e., higher DA or TH levels) exhibited an apparent dose-response. PND 22 subjects of the high MPH treatment group had higher ratios of HVA/DA and DOPAC/DA than same-age control subjects (p<0.05). The increased TH levels of the low MPH group may be related to the increased DA levels of adult rats. While developmental MPH treatment appears to have some effects on monoamine system development, further studies are required to determine if these alterations manifest as functional changes in behavior. PMID:25132048

Panos, John J; O'Callaghan, James P; Miller, Diane B; Ferguson, Sherry A

2014-01-01

327

Distribution of the neuronal inputs to the ventral premammillary nucleus of male and female rats?  

PubMed Central

The ventral premammillary nucleus (PMV) expresses dense collections of sex steroid receptors and receptors for metabolic cues, including leptin, insulin and ghrelin. The PMV responds to opposite sex odor stimulation and projects to areas involved in reproductive control, including direct innervation of gonadotropin releasing hormone neurons. Thus, the PMV is well positioned to integrate metabolic and reproductive cues, and control downstream targets that mediate reproductive function. In fact, lesions of PMV neurons blunt female reproductive function and maternal aggression. However, although the projections of PMV neurons have been well documented, little is known about the neuronal inputs received by PMV neurons. To fill this gap, we performed a systematic evaluation of the brain sites innervating the PMV neurons of male and female rats using the retrograde tracer subunit B of the cholera toxin (CTb). In general, we observed that males and females show a similar pattern of afferents. We also noticed that the PMV is preferentially innervated by neurons located in the forebrain, with very few projections coming from brainstem nuclei. The majority of inputs originated from the medial nucleus of the amygdala, the bed nucleus of the stria terminalis and the medial preoptic nucleus. A moderate to high density of afferents was also observed in the ventral subiculum, the arcuate nucleus and the ventrolateral subdivision of the ventromedial nucleus of the hypothalamus. Our findings strengthen the concept that the PMV is part of the vomeronasal system and integrates the brain circuitry controlling reproductive functions. PMID:25084037

Cavalcante, Judney Cley; Bittencourt, Jackson Cioni; Elias, Carol Fuzeti

2014-01-01

328

Plastic changes induced by neonatal handling in the hypothalamus of female rats.  

PubMed

Early-life events can exert profound long-lasting effects on several behaviors such as fear/anxiety, sexual activity, stress responses and reproductive functions. Present study aimed to examine the effects of neonatal handling on the volume and number of cells in the hypothalamic paraventricular nucleus (pPVN, parvocellular and mPVN, magnocellular regions) and the supraoptic nucleus (SON) in female rats at 11 and 90 days of age. Moreover, in the same areas, immunohistochemistry for oxytocin (OT) and glial fibrillary acidic protein (GFAP) were analyzed in the adult animals. Daily handling during the first 10 postnatal days reduced the number of cells in the pPVN and SON at both the 11 and 90 days. Handling decreased the number of OT-positive parvocellular cells in the PVN in adult females. No significant differences were detected on the optical density (OD) of GFAP-positive cells between the handled and nonhandled adult females. The effect of handling on cell loss was observed 24 h after the 10-day handling period and persisted into adulthood, indicating a stable morphological trace. Results suggest that neonatal handling can induce plastic changes in the central nervous system. PMID:17692831

Winkelmann-Duarte, Elisa C; Todeschin, Anelise S; Fernandes, Marilda C; Bittencourt, Lisandra C; Pereira, Gabriela A M; Samios, Vinicius N; Schuh, Artur F S; Achaval, Matilde E; Xavier, Leder L; Sanvitto, Gilberto L; Mandarim-de-Lacerda, Carlos A; Lucion, Aldo B

2007-09-19

329

Adult Consequences of Post-weaning High Fat Feeding on the Limbic–HPA Axis of Female Rats  

Microsoft Academic Search

The peripubertal period is critical for the final maturation of circuits controlling energy homeostasis and stress response.\\u000a However, the consequence of juvenile fat consumption on adult physiology is not clear. This study analyzed the adult consequences\\u000a of post-weaning fat feeding on limbic–hypothalamic–pituitary–adrenal (HPA) axis components and on metabolic regulators of\\u000a female rats. Wistar rats were fed either a high fat

George Boukouvalas; Kyriaki Gerozissis; Efthimia Kitraki

2010-01-01

330

Female rats are susceptible to cardiac hypertrophy induced by copper deficiency: The lack of influence of estrogen and testosterone  

SciTech Connect

In contrast to a previous report female rats were shown to be susceptible to copper (Cu) deficiency giving rise to restriction of growth, cardiac hypertrophy, and anemia. The severity of these effects was, however, found to be less marked than in the male rats which had similar liver Cu levels. Castration or ovariectomy of Cu-deficient rats had little effect on CH or the other parameters associated with Cu deficiency, and supplementation of the neutered animals with estrogen or testosterone was similarly without effect. The ultrastructural appearance of the hypertrophied Cu-deficient female heart was similar to that previously found in males and was characterized by a large increase in mitochondrial area with disrupted cristae. The results also indicated that in contrast to Cu-deficient males iron (Fe) was not accumulated in the liver of the Cu-deficient female rats. It may be concluded that the limited protection of female rats to the effects of Cu deficiency observed in this study unconnected with the sex steroids.

Farquharson, C.; Robins, S.P. (Rowett Research Institute, Aberdeen (Scotland))

1988-07-01

331

Neonatal Bladder Inflammation Produces Functional Changes and Alters Neuropeptide Content in Bladders of Adult Female Rats  

PubMed Central

Neonatal bladder inflammation has been demonstrated to produce hypersensitivity to bladder re-inflammation as an adult. The purpose of this study was to investigate the effects of neonatal urinary bladder inflammation on adult bladder function and structure. Female Sprague-Dawley rats were treated on postnatal days 14-16 with intravesical zymosan or anesthesia alone. At 12-16 weeks of age, micturition frequency and cystometrograms were measured. Similarly treated rats had their bladders removed for measurement of plasma extravasation following intravesical mustard oil, for neuropeptide analysis (CGRP or SubP), or for detailed histological examination. Rats treated with zymosan as neonates exhibited increased micturition frequency, reduced micturition volume thresholds, greater extravasation of Evan's Blue following intravesical mustard oil administration, and greater total bladder content of CGRP and SubP. In contrast, there were no quantitative histological changes in the thickness, fibrosis or mast cells of bladder tissue due to neonatal zymosan treatments. Functional changes in urologic systems observed in adulthood, coupled with the increased neuropeptide content and neurogenic plasma extravasation in adult bladders, suggest that the neonatal bladder inflammation treatment enhanced the number, function and/or neurochemical content of primary afferent neurons. These data support the hypothesis that insults to the urologic system in infancy may contribute to the development of adult bladder hypersensitivity. Perspective Inflammation of the bladder early in life in the rat has multiple sequelae including laboratory measures that suggest an alteration of the neurophysiological substrates related to the bladder. Some painful bladder syndromes in humans have similar characteristics and so may be due to similar mechanisms. PMID:19945355

DeBerry, Jennifer; Randich, Alan; Shaffer, Amber D.; Robbins, Meredith T.; Ness, Timothy J.

2009-01-01

332

Transplacental Action of Diethylstilbestrol on Mammary Carcinogenesis in Female Rats Given One or Two Doses of 7,12-Dimethylbenz(a)anthracene1  

Microsoft Academic Search

Aspects of the development, morphology, and estrogen bind ing capacity of mammary tumors in rats exposed prenatally to the synthetic estrogen, diethylstilbestrol (DES), and treated post- natally with 7,12-dimethylbenz(s)anthracene (DMBA) were ana lyzed as part of a project aimed at understanding the effects of transplacental exposure to DES on estrogen-sensitive tissues. Pregnant Sprague-Dawley rats were given injections of DES (total

Elizabeth S. Boylan; Robert E. Calhoon

333

An enriched rearing environment calms adult male rat sexual activity: implication for distinct serotonergic and hormonal responses to females.  

PubMed

Early life events induce alterations in neural function in adulthood. Although rearing in an enriched environment (EE) has a great impact on behavioral development, the effects of enriched rearing on sociosexual behavior remain unclear. In this study, we investigated the effects of rearing in an EE on male copulatory behavior and its underlying neurobiological mechanisms in Wistar-Imamichi rats. Three-week-old, recently weaned rats were continuously subjected to a standard environment (SE) or an EE comprised of a large cage with several objects, such as toys, tunnels, ladders, and a running wheel. After 6 weeks, rats reared in an EE (EE rats) showed decreased sexual activity compared with rats reared in a SE (SE rats). This included a lower number of ejaculations and longer latencies in three consecutive copulatory tests. In addition, EE rats showed decreased emotional responsiveness and less locomotor behavior in an open field. In a runway test, on the other hand, sexual motivation toward receptive females in EE males was comparable to that of SE males. Furthermore, following exposure to a female, increases in serotonin levels in the nucleus accumbens and the striatum were significantly suppressed in EE males, whereas dopaminergic responses were similar between the groups. Female-exposure-induced increases in the levels of plasma corticosterone and testosterone were also suppressed in EE rats compared to SE rats. These data suggest that rearing in an EE decreases male copulatory behavior, and serotonin and hormonal regulating systems may regulate the differences in sociosexual interactions that result from distinct rearing environments. PMID:24505330

Urakawa, Susumu; Mitsushima, Dai; Shimozuru, Michito; Sakuma, Yasuo; Kondo, Yasuhiko

2014-01-01

334

An Enriched Rearing Environment Calms Adult Male Rat Sexual Activity: Implication for Distinct Serotonergic and Hormonal Responses to Females  

PubMed Central

Early life events induce alterations in neural function in adulthood. Although rearing in an enriched environment (EE) has a great impact on behavioral development, the effects of enriched rearing on sociosexual behavior remain unclear. In this study, we investigated the effects of rearing in an EE on male copulatory behavior and its underlying neurobiological mechanisms in Wistar-Imamichi rats. Three-week-old, recently weaned rats were continuously subjected to a standard environment (SE) or an EE comprised of a large cage with several objects, such as toys, tunnels, ladders, and a running wheel. After 6 weeks, rats reared in an EE (EE rats) showed decreased sexual activity compared with rats reared in a SE (SE rats). This included a lower number of ejaculations and longer latencies in three consecutive copulatory tests. In addition, EE rats showed decreased emotional responsiveness and less locomotor behavior in an open field. In a runway test, on the other hand, sexual motivation toward receptive females in EE males was comparable to that of SE males. Furthermore, following exposure to a female, increases in serotonin levels in the nucleus accumbens and the striatum were significantly suppressed in EE males, whereas dopaminergic responses were similar between the groups. Female-exposure-induced increases in the levels of plasma corticosterone and testosterone were also suppressed in EE rats compared to SE rats. These data suggest that rearing in an EE decreases male copulatory behavior, and serotonin and hormonal regulating systems may regulate the differences in sociosexual interactions that result from distinct rearing environments. PMID:24505330

Urakawa, Susumu; Mitsushima, Dai; Shimozuru, Michito; Sakuma, Yasuo; Kondo, Yasuhiko

2014-01-01

335

Maternal Omega-3 Supplementation Increases Fat Mass in Male and Female Rat Offspring  

PubMed Central

Adipogenesis and lipogenesis are highly sensitive to the nutritional environment in utero and in early postnatal life. Omega-3 long chain polyunsaturated fatty acids (LCPUFA) inhibit adipogenesis and lipogenesis in adult rats, however it is not known whether supplementing the maternal diet with omega-3 LCPUFA results in reduced fat deposition in the offspring. Female Albino Wistar rats were fed either a standard chow (Control, n?=?10) or chow designed to provide ?15?mg/kg/day of omega-3 LCPUFA, chiefly as docosahexaenoic acid (DHA), throughout pregnancy and lactation (Omega-3, n?=?11) and all pups were weaned onto a commercial rat chow. Blood and tissues were collected from pups at 3 and 6?weeks of age and weights of visceral and subcutaneous fat depots recorded. The expression of adipogenic and lipogenic genes in the subcutaneous and visceral fat depots were determined using quantitative real time reverse transcription-PCR. Birth weight and postnatal growth were not different between groups. At 6?weeks of age, total percentage body fat was significantly increased in both male (5.09?±?0.32% vs. 4.56?±?0.2%, P?female (5.15?±?0.37% vs. 3.89?±?0.36%, P?female offspring, particularly in subcutaneous depots, but that this effect is not mediated via upregulation adipogenic/lipogenic gene transcription. These data suggest that maternal n?3 LCPUFA supplementation during pregnancy/lactation may not be an effective strategy for reducing fat deposition in the offspring. PMID:22303344

Muhlhausler, Beverly Sara; Miljkovic, Dijana; Fong, Laura; Xian, Cory J.; Duthoit, Emmanuelle; Gibson, Robert A.

2011-01-01

336

Late-onset exercise in female rat offspring ameliorates the detrimental metabolic impact of maternal obesity.  

PubMed

Rising rates of maternal obesity/overweight bring the need for effective interventions in offspring. We observed beneficial effects of postweaning exercise, but the question of whether late-onset exercise might benefit offspring exposed to maternal obesity is unanswered. Thus we examined effects of voluntary exercise implemented in adulthood on adiposity, hormone profiles, and genes involved in regulating appetite and metabolism in female offspring. Female Sprague Dawley rats were fed either normal chow or high-fat diet (HFD) ad libitum for 5 weeks before mating and throughout gestation/lactation. At weaning, female littermates received either chow or HFD and, after 7 weeks, half were exercised (running wheels) for 5 weeks. Tissues were collected at 15 weeks. Maternal obesity was associated with increased hypothalamic inflammatory markers, including suppressor of cytokine signaling 3, TNF-?, IL-1?, and IL-6 expression in the arcuate nucleus. In the paraventricular nucleus (PVN), Y1 receptor, melanocortin 4 receptor, and TNF-? mRNA were elevated. In the hippocampus, maternal obesity was associated with up-regulated fat mass and obesity-associated gene and TNF-? mRNA. We observed significant hypophagia across all exercise groups. In female offspring of lean dams, the reduction in food intake by exercise could be related to altered signaling at the PVN melanocortin 4 receptor whereas in offspring of obese dams, this may be related to up-regulated TNF-?. Late-onset exercise ameliorated the effects of maternal obesity and postweaning HFD in reducing body weight, adiposity, plasma leptin, insulin, triglycerides, and glucose intolerance, with greater beneficial effects in offspring of obese dams. Overall, hypothalamic inflammation was increased by maternal obesity or current HFD, and the effect of exercise was dependent on maternal diet. In conclusion, even after a significant sedentary period, many of the negative impacts of maternal obesity could be improved by voluntary exercise and healthy diet. PMID:23928377

Bahari, Hasnah; Caruso, Vanni; Morris, Margaret J

2013-10-01

337

Soyo-san reduces depressive-like behavior and proinflammatory cytokines in ovariectomized female rats  

PubMed Central

Background Soyo-san is a traditional oriental medicinal formula, a mixture of 9 crude drugs, and it has been clinically used for treating mild depressive disorders. The role of pro- and anti-inflammatory cytokines in psychiatric disorders has been the focus of great research attention in recent years. In the present study, we detected the antidepressant effect of soyo-san in the ovariectomized and repeated stressed female rats. Methods This study was designed to evaluate the antidepressant-like effect of soyo-san on the forced swimming test (FST). The rats were randomly divided into the following groups: the nonoperated and nonstressed group (non-op), the nonoperated and stressed group (non-op?+?ST), the ovariectomized and stress group (OVX) and sham operated and stressed group (sham), the ovariectomized and stressed group (OVX?+?ST), the ovariectomized, stressed and soyo-san 100 mg/kg treated group (SOY100) and the ovariectomized, stressed and soyo-san 400 mg/kg treated group (SOY400). The rats were exposed to immobilization stress (IMO) for 14day (2 h/14day), and soyo-san (100 mg/kg and 400 mg/kg) was administrated during the same time. In the same animals, the levels of corticosterone and interleukin-1-beta (IL-1?) were examined in the serum. Also, the change of IL-1? expression in brain regions was examined after behavior test. Results In the FST, the lower dose (100 mg/kg) of extract was effective in reducing immobility, along with an increase in swimming time. The serum levels of corticosterone and IL-1? in the SOY groups were significantly lower than those in the control group. In the brain, the expression of IL-1? positive neurons in the control group were significantly increased in the paraventricular nucleus (PVN) and hippocampus compared to the non-op. However, soyo-san groups significantly reduced the IL-1?-ir neurons in the PVN and hippocampal regions compared to the control. Conclusion The present results demonstrated that soyo-san effectively reduced behavioral and patho-physiological depression-like responses. Trial registration: Our results suggest that soyo-san may be useful for immune regulator in repeated stress-induced ovariectomized female rats. PMID:24444307

2014-01-01

338

Teasing apart socially-induced infertility in non-reproductive female Damaraland mole-rats, Fukomys damarensis (Rodentia: Bathyergidae).  

PubMed

The Damaraland mole-rat is a subterranean mammal exhibiting extreme reproductive skew with a single reproductive female in each colony responsible for procreation. Non-reproductive female colony members are physiologically suppressed while in the colony, exhibiting reduced concentrations of plasma luteinizing hormone (LH) and a decreased response of the pituitary, as measured by the release of bioactive LH, to an exogenous dose of gonadotrophin releasing hormone (GnRH). Removal of the reproductive female from the colony results in an elevation of LH and an enhanced response of the pituitary to a GnRH challenge in non-reproductive females comparable to reproductive females, implying control of reproduction in these individuals by the reproductive female. The Damaraland mole-rat is an ideal model for investigating the physiological and behavioral mechanisms that regulate the hypothalamo-pituitary-gonadal axis. In contrast, we know less about the control of reproduction at the level of the hypothalamus. The immunohistochemistry of the GnRH system of both reproductive and non-reproductive female Damaraland mole-rats has revealed no significant differences with respect to morphology, distribution or numbers of immunoreactive GnRH perikarya. We examined whether the endogenous opioid peptide beta-endorphin was responsible for the inhibition of the release of the GnRH from the neurons indirectly by measuring LH concentrations in these non-reproductive females following single, hourly and 8 hourly injections of the opioid antagonist naloxone. The results imply that the endogenous opioid peptide, beta-endorphin, is not responsible for the inhibition of GnRH release from the perikarya in non-reproductive females. Preliminary data examining the circulating levels of cortisol also do not support a role for circulating glucocorticoids. The possible role of kisspeptin is discussed. PMID:22182323

Bennett, Nigel C

2011-12-01

339

Comparison of the validity of the use of the spontaneously hypertensive rat as a model of attention deficit hyperactivity disorder in males and females.  

PubMed

The spontaneously hypertensive rat (SHR) is a commonly used and well-studied rodent model of attention deficit hyperactivity disorder (ADHD). Sex differences in the cognitive symptoms of ADHD are reported. However, the female SHR rat is much less studied than its male counterpart. The goal of the current study was to assess the validity of the SHR rodent model of ADHD by examining attentional performance, inhibitory control, and hyperactivity in both male and female SHR rats. Adult SHR and control Wistar-Kyoto rats were trained on the 5-choice serial reaction time task, a self-paced test of attention and inhibitory control. This task requires animals to identify the location of a brief light stimulus among five possible locations under several challenging conditions. Analyses of percent correct revealed that attentional performance in SHR females was not significantly different from control females, whereas attentional performance in SHR males was significantly different from control males. Analyses of the number of premature responses revealed that SHR rats made more inhibitory control errors than did control rats and that this decrease in inhibitory control was present in both SHR males and females. Analyses of activity in the open field revealed that SHR rats were more hyperactive than were control rats and that this increased hyperactivity was present in both SHR males and females. The current findings have implications for the study of sex differences in ADHD and for the use of SHR rats as a model of ADHD in females. PMID:25724583

Bayless, Daniel W; Perez, Maria C; Daniel, Jill M

2015-06-01

340

7,12-DIMETHYLBENZ(A)ANTHRACENE-DNA ADDUCTS IN SPRAGUE-DAWLEY AND LONG-EVANS FEMALE RATS: THE RELATIONSHIP OF DNA ADDUCTS TO MAMMARY CANCER  

EPA Science Inventory

7,12-dimethylbenz(a)anthracene (DMBA) is a powerful carcinogen to the mammary gland of the pubescent female Sprague-Dawley (S.D.) rat but is a much less potent inducer of mammary adenocarcinoma in the female Long-Evans (L.E.) rat of the same age. The livers of both strains are re...

341

Activation of amygdalar metabotropic glutamate receptors modulates anxiety, and risk assessment behaviors in ovariectomized estradiol-treated female rats  

PubMed Central

Anxiety disorders are more prevalent in females than males. The underlying reasons for this gender difference are unknown. Metabotropic glutamate receptors (mGluRs) have been linked to anxiety and it has been shown that interaction between estrogen receptors and mGluRs modulate sexual receptivity in rats. We investigated the role of mGluRs in anxiety-related behaviors in ovariectomized (OVX) female rats with (OVX+EB) or without (OVX) estradiol implants. We centrally infused (s)-3,5-dihydroxyphenylglycine (DHPG), a group I mGluR agonist, into the basolateral amygdala (BLA) of OVX+EB and OVX rats at 0.1 and 1.0 ?M. Male rats that normally have low estradiol levels were used to compare with OVX rats. Generalized anxiety, explorative activity and detection and analysis of threat were analyzed in the elevated plus maze (EPM) and risk assessment behaviors (RABs). DHPG (1.0 ?M) increased the percentage of time spent in- and entries into- the open arms in OVX+EB, but not in OVX females or male rats. Flat-back approaches and stretch-attend postures, two RABs, were significantly reduced by DHPG (0.1 and 1.0 ?M) in OVX+EB female rats only. DHPG did not modulate rearing- and freezing, behaviors related to exploration and fear-like behavior, respectively. However, DHPG (1.0 ?M) increased head dipping and decreased grooming behaviors in OVX female rats, suggesting a weak explorative modulation. The effects of DHPG observed in OVX+EB, were blocked by 50 ?M of (RS)-1-Aminoindan-1,5-dicarboxylic acid (AIDA), a mGluR1 antagonist. AIDA and/or estradiol did not modulate anxiety and or RABs. Our results show that intra-BLA infusion of DHPG exerts an anxiolytic-like effect in OVX+EB, but not in OVX or male rats. This effect seems to depend upon mGluR1 subtype activation. Our findings led us to suggest that the effects observed in OVX+EB rats might be due to an interaction at the membrane level of estrogen receptors with mGlu1 within the BLA. PMID:22326382

De Jesús-Burgos, María; Torres-Llenza, Vanessa; Pérez-Acevedo, Nivia L.

2014-01-01

342

The effects of aerobic exercise on cocaine self-administration in male and female rats  

Microsoft Academic Search

Rationale  In drug self-administration procedures, extended-access test sessions allow researchers to model maladaptive patterns of excessive\\u000a and escalating drug intake that are characteristic of human substance-abusing populations.\\u000a \\u000a \\u000a \\u000a \\u000a Objectives  The purpose of the present study was to examine the ability of aerobic exercise to decrease excessive and escalating patterns\\u000a of drug intake in male and female rats responding under extended-access conditions.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Male and

Mark A. Smith; Katherine L. Walker; Kathryn T. Cole; Kimberly C. Lang

343

Adult Female Rats Altered Diurnal Locomotor Activity Pattern Following Chronic Methylphenidate Treatment  

PubMed Central

Methylphenidate (MPD) is one of the most prescribed pharmacological agents and also used as cognitive enhancement and for recreational purposes. The objective of this study was to investigate the repetitive dose-response effects of MPD on rhythm locomotor activity pattern of female WKY rats and compare to prior study done on male. The hypothesis is that change in the circadian activity pattern indicates a long-lasting effect of the drug. Four animal groups (saline control, 0.6, 2.5, and 10.0 mg/kg MPD dose groups) were housed in a sound-controlled room at 12:12 light/dark cycle. All received saline injections on experimental day 1 (ED 1). On EDs 2-7, the control group received saline injection; the other groups received 0.6, 2.5, or 10.0 mg/kg MPD, respectively. On ED 8-10, injections were withheld. On ED 11, each group received the same dose as EDs 2-7. Hourly histograms and cosine statistical analyses calculating the acrophase (?), amplitude (A), and MESOR (M) were applied to assess the 24-hour circadian activity pattern. The 0.6 and 2.5 mg/kg MPD groups exhibited significant (p<0.05) change in their circadian activity pattern on ED 11. The 10.0 mg/kg MPD group exhibited tolerance on ED 11 and also a significant change in activity pattern on ED 8 compared to ED 1, consistent with withdrawal behavior (p<0.007). In conclusion, chronic MPD administration alters circadian locomotor activity of adult female WKY rats and confirms that chronic MPD use elicits long lasting effects PMID:23893293

Trinh, T.; Kohllepin, S; Yang, P.B.; Burau, K.D.; Dafny, N.

2014-01-01

344

Direct stimulatory effects of oxytocin in female rat gonadotrophs and somatotrophs in vitro: comparison with lactotrophs.  

PubMed

The peptide oxytocin (OT) is secreted by hypothalamic neurons and exerts numerous actions related to reproduction. OT stimulation of prolactin secretion in female rats is important during the estrous cycle, pregnancy, and lactation. Here we report that OT also stimulates transients of intracellular Ca(2+) concentration in somatotrophs and gonadotrophs as well as the release of GH and LH in a dose-dependent manner with EC50 values that closely correspond to the ligand affinity of the OT receptor (OTR). Remarkably, the hormone-releasing effect of OT in these two cell types is 2 orders of magnitude more sensitive than that in lactotrophs. The specific OTR agonist [Thr(4),Gly(7)]-oxytocin acutely stimulated the release of LH, GH, and prolactin from female rat pituitary cells in primary culture and increased intracellular Ca(2+) concentration in gonadotrophs, somatotrophs, and lactotrophs. In these three cell types, the effects on hormone release and intracellular Ca(2+) of both OT and [Thr(4),Gly(7)]oxytocin were abolished by the specific OT receptor antagonist desGly-NH2-d(CH2)5[D-Tyr(2),Thr(4)]OVT but not by the highly selective vasopressin V1a receptor antagonist, d(CH2)5[Tyr(Me)(2),Dab(5)]AVP. Furthermore, 10 nM arginine vasopressin stimulated LH and GH release comparably with a dose of OT that was at least 10 times lower. Finally, the presence of the OTR-like immunoreactivity could be observed in all three cell types. Taken together, these results show that OT directly stimulates gonadotrophs, somatotrophs, and lactotrophs through OT receptors and suggest that OT signaling may serve to coordinate the release of different pituitary hormones during specific physiological conditions. PMID:25406939

Gonzalez-Iglesias, Arturo E; Fletcher, Patrick A; Arias-Cristancho, José A; Cristancho-Gordo, Ruth; Helena, Cleyde V; Bertram, Richard; Tabak, Joël

2015-02-01

345

Lack of efficacy of blueberry in nutritional prevention of azoxymethane-initiated cancers of rat small intenstions and colon  

Technology Transfer Automated Retrieval System (TEKTRAN)

We examined the efficacy of freeze-dried blueberry (BB) in inhibition of formation of azoxymethane (AOM)-induced colon aberrant crypt foci (ACF) and intestine tumors in male and female Sprague-Dawley rats. Pregnant rats were fed a control diet with or without 10% BB; progeny were weaned to the same...

346

Assessment of attention in male and female Brattleboro rats using a self-paced five-choice serial reaction time task.  

PubMed

The Brattleboro rat is a mutant variation of the Long-Evans strain that exhibits negligible central nervous system levels of vasopressin, a neuropeptide that may influence behavioral and cognitive processes. Compared to Long-Evans rats, Brattleboro rats exhibit diminished fear conditioning and have impairments in spatial memory and sensory gating. The present study sought to further evaluate the cognitive profile of vasopressin-deficient rats by studying attention in male and female Brattleboro and heterozygous rats using a self-paced version of the five-choice serial reaction time task. Male Brattleboro rats required significantly more sessions to meet the training criteria than those by heterozygotic and Long-Evans (wild type) rats. Female Brattleboro rats displayed significantly poorer attention accuracy compared to heterozygotic and Long-Evans rats. Taken together, the present findings add further evidence that vasopressin deficiency diminishes cognitive functioning. PMID:24055104

Berquist Ii, Michael D; Mooney-Leber, Sean M; Feifel, David; Prus, Adam J

2013-11-01

347

Lipid-Lowering Effects of Tetradecylthioacetic Acid in Antipsychotic-Exposed, Female Rats: Challenges with Long-Term Treatment  

PubMed Central

Background Psychiatric patients often require chronic treatment with antipsychotic drugs, and while rats are frequently used to study antipsychotic-induced metabolic adverse effects, long-term exposure has only partially mimicked the appetite-stimulating and weight-inducing effects found in the clinical setting. Antipsychotic-induced effects on serum lipids are also inconsistent in rats, but in a recent study we demonstrated that subchronic treatment with the orexigenic antipsychotic olanzapine resulted in weight-independent increase in serum triglycerides and activation of lipogenic gene expression in female rats. In addition, a recent long-term study in male rats showed that chronic treatment with antipsychotic drugs induced dyslipidemic effects, despite the lack of weight gain. Aims In the current study, we sought to examine long-term effects of antipsychotic drugs on weight gain, lipid levels and lipid composition after twice-daily administration of antipsychotics to female rats, and to investigate potential beneficial effects of the lipid-lowering agent tetradecylthioacetic acid (TTA), a modified fatty acid. Methods Female rats were exposed to orexigenic antipsychotics (olanzapine or clozapine), metabolically neutral antipsychotics (aripiprazole or ziprasidone), or TTA for 8 weeks. Separate groups received a combination of clozapine and TTA or olanzapine and TTA. The effects of TTA and the combination of olanzapine and TTA after 2 weeks were also investigated. Results The antipsychotic-induced weight gain and serum triglyceride increase observed in the subchronic setting was not present after 8 weeks of treatment with antipsychotics, while lipid-lowering effect of TTA was much more pronounced in the chronic than in the subchronic setting, with concomitant upregulation of key oxidative enzymes in the liver. Unexpectedly, TTA potentiated weight gain in rats treated with antipsychotics. Conclusion TTA is a promising candidate for prophylactic treatment of antipsychotic-induced dyslipidemic effects, but a more valid long-term rat model for antipsychotic-induced metabolic adverse effects is required. PMID:23226405

Skrede, Silje; Fernř, Johan; Bjřrndal, Bodil; Brede, Wenche Rřdseth; Bohov, Pavol; Berge, Rolf Kristian; Steen, Vidar Martin

2012-01-01

348

[Immunochemical determination of placenta-specific and interorganic antigens in placental extract and blood serum in pregnant rats].  

PubMed

It has been demonstrated that placenta extract of rats contains up to 14 antigens. Moreover, 11 of them are interorgan proteins of wide and limited specificity, two antigens (alpha 1- and alpha 2-globulins) are attributed to acute-phase proteins typical for pregnancy. beta 1-Globulin is a specific protein of rat placenta. The content of these antigens in blood serum increases with pregnancy and reaches a maximum toward the delivery; 3-4 days after delivery beta 1-globulin disappears completely from maternal blood, whereas the concentration of acute-phase proteins drops to the initial level. PMID:2580577

Kan, M F; Krivonosov, S K; Tatarinova, Iu S

1985-04-01

349

Developmental effects of perinatal exposure to PBDE and PCB on gene expression in sexually dimorphic rat brain regions and female sexual behavior.  

PubMed

The developing nervous system is a potential target of environmental contaminants such as polybrominated diphenylethers (PBDE), which accumulate in the biosphere. We compared effects of 2,2',4,4',5-pentabromo-BDE (PBDE99), a PBDE congener present in environmental samples, and PCB on brain development. Time-pregnant rats were subcutaneously injected with PBDE99 (1 or 10mg/kg), the PCB mixture Aroclor 1254 (10mg/kg), or vehicle from gestational day 10-18. mRNA levels of genes involved in central control of reproductive functions and sexual behavior were analyzed by real time RT PCR in two sexually dimorphic brain regions, medial preoptic area (MPO) and ventromedial hypothalamus (VMH) of adult offspring of both sexes. Exposure to PBDE99 or the PCB mixture during pre- and postnatal development affected mRNA expression levels in a treatment-, region- and sex-specific manner, and changed the sensitivity of target genes to estradiol. The sex difference in progesterone receptor mRNA levels of VMH normally seen in untreated controls was abolished by both, PBDE99 and PCB. Estrous cycles were significantly affected, and preliminary experiments suggest an impairment of female sexual behavior. Our data indicate that developmental exposure to PBDE99 at doses below signs of general toxicity affects the regulation of estrogen target genes in rat brain. Since PBDE99 was detected in blood and adipose tissue of adult offspring, these effects may result from interactions with developmental processes, with adult functions, or a combination of both. PMID:23619185

Faass, Oliver; Ceccatelli, Raffaella; Schlumpf, Margret; Lichtensteiger, Walter

2013-07-01

350

The effect of dihydrotestosterone exposure during or prior to the masculinization programming window on reproductive development in male and female rats.  

PubMed

Masculinization is programmed by androgen exposure during a masculinization programming window (MPW). Deficiency in MPW androgen action results in reduced size of all reproductive organs and anogenital distance (AGD) and reproductive disorders. Although timing of MPW closing has been defined, what determines 'opening' and 'closing' of the MPW remains unknown. To test whether initiation of testosterone production/action defines the opening of the window, we first demonstrated that androgen receptor mRNA and protein are expressed prior to the MPW, and then investigated whether masculinization could be advanced or enhanced by treating pregnant rats with either 1 or 10 mg/kg/day dihydrotestosterone (DHT) prior to (early window, EW; e11.5-e14.5) or during the MPW (e15.5-e18.5), and then evaluating offspring in foetal life (e18.5, e21.5), early puberty (day 25) or adulthood (?day 75). DHT treatment did not affect pregnancy duration, birth, litter or pup size. DHT exposure in either time window did not advance foetal male development (Wolffian duct coiling) and had no effect on AGD, testis, penis and ventral prostate (VP) size at any age when measured; there was a tendency towards smaller penis size. In contrast, exposure of females to 10 mg DHT in either time window induced varying degrees of masculinization, including stabilization of the Wolffian duct and increased AGD (e21.5, Pnd25), VP formation, more male-like phallus structure, absence of nipples and vaginal opening and, in some adult females, gross fluid distension of the uterus (hydrometrocolpos); these effects were generally more pronounced after exposure in the MPW than in the EW. In conclusion, exposure of the male rat foetus to additional androgens prior to or during the MPW does not advance or enhance any measured parameter of reproductive development. Therefore, androgen availability plays no role in determining timing of the MPW. Susceptibility of the female reproductive system to androgens may precede the MPW. PMID:22248293

Dean, A; Smith, L B; Macpherson, S; Sharpe, R M

2012-06-01

351

EFFECTS OF PRENATAL TESTOSTERONE PROPIONATE AND VINCLOZOLIN ON PERINATAL AND INFANTILE DEVELOPMENT OF MALE AND FEMALE RATS  

EPA Science Inventory

Effects of Prenatal Testosterone Propionate and Vinclozolin on Perinatal and Infantile Development of Male and Female Rats Cynthia Wolf1,2, Jonathan Furr1, Gerald A. LeBlanc2, and L. Earl Gray, Jr.1 1USEPA, NHEERL, RTD, EB, RTP, NC 27711, 2Dept. of Environmental and Molecu...

352

EFFECTS OF PRENATAL TESTOSTERONE PROPIONATE ON THE SEXUAL DEVELOPMENT OF MALE AND FEMALE RATS: A DOSE-RESPONSE STUDY  

EPA Science Inventory

Effects of Prenatal Testosterone Propionate on the Sexual Development of Male and Female Rats: A Dose-Response Study Cynthia J. Wolf1,2, Andrew Hotchkiss3, Joseph S. Ostby1, Gerald A. LeBlanc2 and L. Earl Gray1,4, Jr. ABSTRACT Testosterone plays a major role in ...

353

EFFECTS OF PRENATAL TESTOSTERONE PROPIONATE ON SEXUAL DEVELOPMENT OF MALE AND FEMALE RATS: A DOSE-RESPONSE STUDY  

EPA Science Inventory

Effects of Prenatal Testosterone Propionate on Sexual Development of Male and Female Rats: A Dose-Response Study Cynthia Wolf1,2, Joe Ostby1*, Andrew Hotchkiss3, Gerald LeBlanc2, and L. Earl Gray, Jr.1 1USEPA, NHEERL, Reproductive Toxicology Division, RTP, NC; 2Dept. of To...

354

Investigation into the influence of a high fat diet on antipsychotic-induced weight gain in female rats.  

PubMed

Atypical antipsychotic drug therapy may result in substantial weight gain, increased adiposity and the promotion of metabolic abnormalities. The mechanism(s) which underlie such effects remain unclear. Previous studies in our laboratory have demonstrated significant weight gain in female rats maintained on a standard laboratory diet after sub-chronic administration of olanzapine and risperidone, but not ziprasidone. The aim of this paper is to investigate the effect of antipsychotic drugs on body weight, ingestive behaviour and adiposity in female rats with access to a high fat diet. Adult female rats given free access to a high fat diet received either olanzapine (2 mg/kg), risperidone (0.5 mg/kg), ziprasidone (2.5 mg/kg) or vehicle for 28 days. Body weight, food and water intake in addition to intra-abdominal fat deposition were assessed. Olanzapine initially increased body weight but by the end of the study olanzapine animals appeared to have lost weight compared to the vehicle-treated group. Olanzapine-induced reductions in body weight were accompanied by a significant hypophagia during weeks 3 and 4. Risperidone increased body weight during week 1 only and reduced intake of a high fat diet during weeks 3 and 4. Ziprasidone was without effect on indices of body weight and ingestive behaviour. There were no effects of antipsychotic drugs on intra-abdominal fat deposition. Access to a diet high in fat attenuated weight gain induced by olanzapine and risperidone in female rats. PMID:18308803

Fell, M J; Neill, J C; Anjum, N; Peltola, L M; Marshall, K M

2008-03-01

355

Additive Effects of Atrial Natriuretic Peptide and Angiotensin II on Luteinizing Hormone and Prolactin Release in Female Rats  

Microsoft Academic Search

The present experiments were designed to assess the effects of central administration of atrial natriuretic peptide (ANP), alone or in conjunction with angiotensin II (All), on luteinizing hormone (LH) and prolactin release in ovarian steroid-primed female rats. Intracerebroventricular injection of ANP (200 ng\\/2 ?l over 1 min) induced an increase in plasma LH levels without significantly affecting prolactin release. Injection

M. K. Steele

1990-01-01

356

DIBROMOACETIC ACID-INDUCED ELEVATIONS OF ESTRADIOL IN THE CYCLING AND OVARIECTOMOZED/ESTRADIOL-IMPLANTED FEMALE RAT  

EPA Science Inventory

Goldman, JM and Murr, AS. Dibromoacetic Acid-induced Elevations of Estradiol in Both Cycling and Ovariectomized / Estradiol-implanted Female Rats ABSTRACT Haloacetic acids are one of the principal classes of disinfection by-products generated by the chlorination of mun...

357

IN UTERO EXPOSURE TO ATRAZINE INDUCES DELAYED PUBERTY OF LONG EVANS RATS: DAM-MEDIATED EFFECTS IN FEMALES  

EPA Science Inventory

IN UTERO EXPOSURE TO ATRAZINE INDUCES DELAYED PUBERTY OF LONG EVANS RATS: DAM-MEDIATED EFFECTS IN FEMALES. J L Rayner1 and S E Fenton2. 1 University of North Carolina at Chapel Hill, School of Public Health, Chapel Hill, NC, and 2 Reproductive Toxicology Divisio...

358

Soy protein isolate and estradiol differ in their effects on the mammary gland of weanling male and female rats  

Technology Transfer Automated Retrieval System (TEKTRAN)

Isoflavones are phytochemical components of soy diets that bind weakly to estrogen receptors (ERs). To study potential estrogen-like actions of soy in the mammary gland, we fed weanling male and female Sprague-Dawley rats a casein diet from PND21 to PND33, the same diet substituting soy protein isol...

359

METHOXYCHLOR AFFECTS THE DECIDUAL CELL RESPONSE OF THE UTERUS BUT NOT OTHER PROGESTATIONAL PARAMETERS IN FEMALE RATS (JOURNAL VERSION)  

EPA Science Inventory

The pesticide methoxychlor (MXC) is a proestrogen which is metabolized to a compound that has been shown to exhibit estrogenic activity in vivo and in vitro. Following long-term exposure of female rats to MXC, fertility is reduced and fetotoxicity is evident. However, the effects...

360

Sorghum Bran in the Diet Dose Dependently Increased Excretion of Catechins and Microbial Derived Phenolic Acids in Female Rats  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sorghum bran is concentrated with procyanidins (predominately polymers), which may be beneficial for health in humans; however, the bioavailability of procyanidins is not well understood. Female Sprague-Dawley rats were fed an AIN93G diet containing 0, 5, 10, 20, or 40% Hi-tannin sorghum bran (n=5-7...

361

PERINATAL EXPOSURE TO ATRAZINE SUPPRESSES JUVENILE IMMUNE FUNCTION IN MALE, BUT NOT FEMALE SPRAGUE-DAWLEY RATS  

EPA Science Inventory

PERINATAL EXPOSURE TO ATRAZINE SUPPRESSES JUVENILE IMMUNE FUNCTION IN MALE, BUT NOT FEMALE SPRAGUE-DAWLEY RATS. AA Rooney1 and RW Luebke2. 1NCSU/USEPA CVM, Department of Anatomy, Physiological Sciences, and Radiology, Raleigh, NC;2USEPA, NHEERL, RTP, NC. The ability of the ...

362

Response of ER -IR and ER -IR cells in the forebrain of female rats to mating stimuli  

E-print Network

Response of ER -IR and ER -IR cells in the forebrain of female rats to mating stimuli Be´atrice Gre -, and mating-induced Fos-immunoreactivity (Fos-ir) in neurons in which mating stimulation reliably increases, or received 15 intromissions. In the rostral medial preoptic area, Fos-ir was induced by mounts alone

Blaustein, Jeffrey D.

363

EFFECTS OF 2,2',4,4'-TETRABROMODIPHENYL ETHER ON CAR AND PXR REGULATED GENE EXPRESSION IN WEANLING FEMALE RATS  

EPA Science Inventory

EFFECTS OF 2,2',4,4,'-TETRABROMODIPHENYL ETHER ON CAR AND PXR REGULATED GENE EXPRESSION IN WEANLING FEMALE RATS. V M RICHARDSON1, K M CROFTON2, AND M J DEVITO1. USEPA, ORD/NHEERL/ETD1/NTD2,RTP, NC, USA. The polybrominated diphenyl ether (PBDEs) mixture DE-71 (PBDEs) cause endo...

364

Estrogen effects on angiotensin receptors are modulated by pituitary in female rats  

SciTech Connect

The present studies were designed to test the hypothesis that changes in angiotensin II (ANG II) receptors might modulate the layered target tissue responsiveness accompanying estradiol administration. Estradiol was infused continuously in oophorectomized female rats. Aldosterone was also infused in control and experimental animals to avoid estrogen-induced changes in renin and ANG II. ANG II binding constants were determined in radioreceptor assays. Estradiol increased binding site concentration in adrenal glomerulosa by 76% and decreased binding sites of uterine myometrium and glomeruli by 45 and 24%, respectively. There was an accompanying increase in the affinity of ANG II binding to adrenal glomerulosa and uterine myometrium. Because estrogen is a potent stimulus of prolactin release from the pituitary of rodents, studies were also designed to test the hypothesis that prolactin may mediate some or all of the estrogen-induced effects observed. Hypophysectomy abolished estradiol stimulation of prolactin release and most ANG II receptor changes. Prolactin administration to pituitary intact rats was associated with a 50% increase in receptor density of adrenal glomerulosa simulating estradiol administration. However, the changes in glomeruli and uterine myometrium were opposite in that both tissues also increased receptor density, suggesting that prolactin was not the sole mediator of the estrogen-induced receptor changes. In conclusion, regulation of ANG II receptors in a number of diverse target tissues by estradiol is complex with contributions from estrogens and pituitary factors, which include but do not exclusively involve prolactin.

Douglas, J.G.

1987-01-01

365

The effects of chronic photoperiod shifting on the physiology of female Long-Evans rats.  

PubMed

As the prevalence of shift work is increasing, it is important to elucidate the impact that shift work has on health. Because of the alternating work schedules present in rotating shift work and working at night, shift workers are in a chronic state of circadian disruption. Animal models of circadian disruption are useful because they offer more experimental control than the largely correlational human shift work studies. The effects of chronic circadian disruption on food preference, glucose tolerance, corticosterone secretion, and performance in a stress-inducing task were investigated in female Long-Evans rats. A 64-day photoperiod shifting paradigm was used to induce circadian disruption. Surprisingly, neither the photoperiod shifted animals, nor the control animals demonstrated a preference for either an unhealthy or healthy diet. Nor was there a difference between the groups in weight gained during photoperiod shifting. However, the photoperiod shifted rats gained significantly more weight than control animals, without eating more food during discriminative fear conditioning to context (DFCTC). Surprisingly, chronic photoperiod shifting appeared to facilitate retention in the DFCTC task. The photoperiod shifted animals also had increased serum glucose values during fasting and after a glucose challenge test. The photoperiod shifted animals only had elevated corticosterone during the final two phases of photoperiod shifting. This study demonstrates that chronic photoperiod shifting elicits weight gain when exposed to a stressful event and impairs glucose tolerance in the same individual. PMID:24631903

Deibel, Scott H; Hong, Nancy S; Himmler, Stephanie M; McDonald, Robert J

2014-04-01

366

Assessment of Genotoxic Potential of Arsenic in Female Albino Rats at Permissible Dose Levels  

PubMed Central

Background: Arsenic is a wide spread environmental contaminant and has been recognized as a genotoxic element which is of major public health concern. Aim: The present study evaluates the genotoxic potential of arsenic at low permissible dose levels. Materials and Methods: Forty-eight mature female rats were divided into four groups of 12 animals each. Group I animals received distilled water and served as control. Group II-IV animals received sodium arsenite dissolved in distilled water continuously for a period of 60 days at the dose of 10, 30 and 50 ?g/L (ppb) respectively. Six rats from each group were sacrificed after 30 days of arsenic exposure and the remaining animals were sacrificed after 60 days. Liver was excised from the sacrificed animals to study the probable advent signs of carcinogenicity measured through microsomal degranulation test. Assessment of mutagenic potential of arsenic was evaluated through chromosomal aberrations observed in the bone marrow cells. Results: The levels of RNA and proteins decreased significantly (P ? 0.01) in all the three doses administered along with an increase in % microsomal degranulation in hepatic fraction when compared to control at both 30 and 60 days time period. A dose-dependent increase in chromosome aberrations like fragmentation, breakage has been observed in all the treated animals. Conclusion: The results of present study revealed that chronic exposure of arsenic even at its low permissible dose limits results in carcinogenic and mutagenic effects which emphasize its genotoxic possibility. PMID:24748731

Mehta, Madhuri; Hundal, Swarndeep Singh

2014-01-01

367

Gestational and lactational exposure to TCDD or coplanar PCBs alters adult expression of saccharin preference behavior in female rats.  

PubMed

Previous studies have shown that maternal doses of 1 microg/kg or less of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in late gestation can demasculinize and feminize reproductive behavior in male rats. However, it was not known whether coplanar polychlorinated biphenyls (PCBs) had similar effects, or whether non-reproductive sexually dimorphic behaviors such as saccharin preference behavior were also altered. We determined the effects of TCDD or coplanar PCBs on saccharin consumption and saccharin preference in male and female rats. Sprague-Dawley rats were dosed with 3,3',4, 4'-tetrachlorobiphenyl (PCB 77; 2 or 8 mg/kg/day), 3,3',4,4', 5-pentachlorobiphenyl (PCB 126; 0.25 or 1.0 microg/kg/day), TCDD (0. 025 or 0.10 microg/kg/day), or corn oil vehicle on days 10-16 of gestation. Maternal exposure to TCDD or coplanar PCBs did not change saccharin consumption or saccharin preference in male rats. However, TCDD and coplanar PCB-exposed females showed decreased saccharin consumption and saccharin preference. The results indicate that saccharin consumption is masculinized in female rats exposed to TCDD or coplanar PCBs during perinatal development. This effect could be related to the anti-estrogenic actions of these chemicals. PMID:11106860

Amin, S; Moore, R W; Peterson, R E; Schantz, S L

2000-01-01

368

Effect of hydroalcoholic extract of ginger on the liver of epileptic female rats treated with lamotrigine  

PubMed Central

Objective: Lamotrigine is an antiepileptic drug, widely used in the treatment of epilepsy; long-term use of this drug can cause hepatotoxicity. Zingiber officinale Roscoe (ginger) possesses antioxidant properties. In present research, the effect ofhydroalcoholic extract of ginger (HEG) on the liver of lamotrigine-treated epileptic rats was investigated Material and Methods: Forty-eight female Wistar rats were selected and allocated to 8 groups of 6 each. Group 1: Negative controls were treated with normal saline. Group 2: Positive controls were treated with lamotrigine (LTG) (10 mg/kg) daily by gavages for 4 consecutive weeks. Epilepsy was induced in treatment groups by i.p. injection of pentylenetetrazol (PTZ) (40 mg/kg). Group 3: Epileptic group received normal saline (10 ml/kg). Group 4: Epileptic group was treated with LTG (10 mg/kg). Groups 5 and 6: Epileptic groups received HEG (50 and 100 mg/kg). Groups 7 and 8: Epileptic groups received LTG and HEG (50 and 100 mg/kg). At the end of 28 days, blood samples were drawn and their livers were processed for light microscopy. Results: The mean values of TG, CHOL, AST, and ALT activity significantly rose (p<0.01) in groups 2, 3, and 4, while in rats treated with HEG (groups 5, 6, 7, and 8), the levels of liver enzymes significantly decreased (p<0.05) compared with epileptic group treated with lamotrigine (group 4). Histopathological changes of liver samples were comparable with respective control. Conclusion: These results suggest that hydroalcoholic extract of ginger improves liver function in lamotrigine-induced hepatotoxicity. PMID:25068142

Poorrostami, Ameneh; Farokhi, Farah; Heidari, Reza

2014-01-01

369

Cumulative dietary energy intake determines the onset of puberty in female rats.  

PubMed

Laboratory animal diets for studies to determine the endocrine-disrupting potential of chemicals are under scrutiny because they can affect both assay control values and assay sensitivity. Although phytoestrogen content is important, we have previously shown that a phytoestrogen-rich diet and a phytoestrogen-free diet were equally uterotrophic to rats and advanced vaginal opening (VO) when compared with the standard diet RM1. Abolition of the effects by the gonadotrophin-releasing hormone antagonist Antarelix indicated that these effects were mediated through the hypothalamus-pituitary-reproductive organ axis. In the present study, we investigated the relationship between cumulative energy intake and sexual maturation in female rats. Infant formula (IF) at different concentrations and synthetic diets, with a wide range of metabolizable energy (ME) values, were used to modulate energy intake. Increasing energy intake was associated with an increase in uterine weight (absolute and adjusted for body weight) for both IF and the synthetic diets. In both cases, the increased uterine weight was directly proportional to energy intake. Body weight was unaffected by IF consumption but, in the case of the diets, was increased proportionally with energy consumption. Antarelix abolished the uterine weight increases with both formula and the diets, whereas body weight was unaffected. The mean day of VO was also advanced by high-ME diets and IF, whereas body weight at VO was unaffected. VO occurred at an energy intake of approximately 2,300 kJ/rat determined by measuring total food intake from weaning to VO, indicating that this cumulative energy intake was the trigger for puberty. ME is therefore a critical factor in the choice of diets for endocrine disruption studies. PMID:15531430

Odum, Jenny; Tinwell, Helen; Tobin, Graham; Ashby, John

2004-11-01

370

Ultrasounds emitted by female rats during agonistic interactions: effects of morphine and naltrexone.  

PubMed

Ultrasonic vocalizations may be an expression of the affective pain response in laboratory rodents. The present experiment compared morphine's effects on high (33-60 kHz) and low (20-32 kHz) frequency ultrasonic vocalizations to its effects on a range of unconditioned behavioral responses to aversive stimuli; the influence of estrous cyclicity on morphine sensitivity was also investigated. In experiment 1, naive female Long-Evans rats, selected during estrus or diestrus, received cumulative morphine (1, 3, 6, 10 mg/kg SC) or saline, and in experiment 2, rats were pretreated with naltrexone (0.1 mg/kg IP) 5 min before morphine (17, 30, 60, 100 mg/kg SC). The following endopoints were measured 20-25 min post-injection: (1) tail flick latency; (2) ultrasonic and audible vocalizations; (3) the behavioral response to aggressive attack; and (4) locomotor activity. Following a brief exposure to an attack, rats were threatened by an aggressor but protected from further attack by a wire mesh cage (30 x 21.5 x 20 cm), thereby allowing for continued behavioral and vocal measurement without the risk of physical injury; video and audio recordings were made of the attack encounter and a subset of the protected encounter (1 min). The endpoint most potently and specifically modulated by morphine was high frequency ultrasounds. The rate of high frequency calling varied as a function of the estrous cycle, supporting gonadal hormone modulation of ultrasonic vocalizations. Low frequency ultrasounds, by contrast, were relatively insensitive to opiate manipulation and were less influenced by estrous cyclicity. High frequency vocalizations may be a more sensitive indication of the affective response to an attacking conspecific that low frequency calls.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7855202

Haney, M; Miczek, K A

1994-04-01

371

Combined Olfactory Contact with the Parent Colony and Direct Contact with Nonbreeding Animals Does Not Maintain Suppression of Ovulation in Female Naked Mole-Rats ( Heterocephalus glaber)  

Microsoft Academic Search

The study investigated the role of odor cues from two naked mole-rat colonies, in conjunction with behavioral cues from nonbreeding colony members, in maintaining suppression of ovulation in subordinate female naked mole-rats isolated from the two parent colonies. Four high ranking nonbreeding female naked mole-rats were removed from their respective parent colonies and singly housed in separate burrow systems. For

T. E. Smith; C. G. Faulkes; D. H. Abbott

1997-01-01

372

Identification of neural cells activated by mating stimulus in the periaqueductal gray in female rats  

PubMed Central

Induction of lordosis as typical female sexual behavior in rodents is dependent on a mount stimulus from males and blood levels of estrogen. Periaqueductal gray (PAG) efferent neurons have been suggested to be important for lordosis behavior; however, the neurochemical basis remains to be understood. In this study, we neuroanatomically examined (1) whether PAG neurons activated by mating stimulus project to the medullary reticular formation (MRF), which is also a required area for lordosis; and (2) whether these neurons are glutamatergic. Mating stimulus significantly increased the number of cFos-immunoreactive (ir) neurons in the PAG, particularly in its lateral region. Half of cFos-ir neurons in the lateral PAG were positive for a retrograde tracer (FluoroGold; FG) injected into the MRF. cFos-ir neurons also colocalized with mRNA of vesicular glutamate transporter 2 (vGLUT2), a molecular marker for glutamatergic neurons. Using retrograde tracing and in situ hybridization in conjunction with fluorescent microscopy, we also found FG and vGLUT2 mRNA double-positive neurons in the lateral PAG. These results suggest that glutamatergic neurons in the lateral PAG project to the MRF and are involved in lordosis behavior in female rats. PMID:25565950

Yamada, Shunji; Kawata, Mitsuhiro

2014-01-01

373

Estradiol affects liver mitochondrial function in ovariectomized and tamoxifen-treated ovariectomized female rats  

SciTech Connect

Given the tremendous importance of mitochondria to basic cellular functions as well as the critical role of mitochondrial impairment in a vast number of disorders, a compelling question is whether 17{beta}-estradiol (E2) modulates mitochondrial function. To answer this question we exposed isolated liver mitochondria to E2. Three groups of rat females were used: control, ovariectomized and ovariectomized treated with tamoxifen. Tamoxifen has antiestrogenic effects in the breast tissue and is the standard endocrine treatment for women with breast cancer. However, under certain circumstances and in certain tissues, tamoxifen can also exert estrogenic agonist properties. We observed that at basal conditions, ovariectomy and tamoxifen treatment do not induce any statistical alteration in oxidative phosphorylation system and respiratory chain parameters. Furthermore, tamoxifen treatment increases the capacity of mitochondria to accumulate Ca{sup 2+} delaying the opening of the permeability transition pore. The presence of 25 {mu}M E2 impairs respiration and oxidative phosphorylation system these effects being similar in all groups of animals studied. Curiously, E2 protects against lipid peroxidation and increases the production of H{sub 2}O{sub 2} in energized mitochondria of control females. Our results indicate that E2 has in general deleterious effects that lead to mitochondrial impairment. Since mitochondrial dysfunction is a triggering event of cell degeneration and death, the use of exogenous E2 must be carefully considered.

Moreira, Paula I. [Center for Neuroscience and Cell Biology, University of Coimbra, 3005-504 Coimbra (Portugal); Institute of Physiology, Faculty of Medicine, University of Coimbra, 3005-504 Coimbra (Portugal); Custodio, Jose B.A. [Center for Neuroscience and Cell Biology, University of Coimbra, 3005-504 Coimbra (Portugal); Institute of Biochemistry, Faculty of Pharmacy, University of Coimbra, 3005-504 Coimbra (Portugal); Nunes, Elsa [Center for Neuroscience and Cell Biology, University of Coimbra, 3005-504 Coimbra (Portugal); Institute of Physiology, Faculty of Medicine, University of Coimbra, 3005-504 Coimbra (Portugal); Moreno, Antonio [Center for Neuroscience and Cell Biology, University of Coimbra, 3005-504 Coimbra (Portugal); Department of Zoology, Faculty of Sciences and Technology, University of Coimbra, 3005-504 Coimbra (Portugal); Institute of Marine Research, University of Coimbra, 3005-504 Coimbra (Portugal); Seica, Raquel [Center for Neuroscience and Cell Biology, University of Coimbra, 3005-504 Coimbra (Portugal); Institute of Physiology, Faculty of Medicine, University of Coimbra, 3005-504 Coimbra (Portugal); Oliveira, Catarina R. [Center for Neuroscience and Cell Biology, University of Coimbra, 3005-504 Coimbra (Portugal); Institute of Biochemistry, Faculty of Medicine, University of Coimbra, 3005-504 Coimbra (Portugal); Santos, Maria S. [Center for Neuroscience and Cell Biology, University of Coimbra, 3005-504 Coimbra (Portugal) and Department of Zoology, Faculty of Sciences and Technology, University of Coimbra, 3005-504 Coimbra (Portugal)]. E-mail: mssantos@ci.uc.pt

2007-05-15

374

Hypothalamo-Pituitary-Adrenal Axis-Regulated Stress Response and Negative Feedback Sensitivity Is Altered by Prenatal Morphine Exposure in Adult Female Rats  

Microsoft Academic Search

It has been shown that adult female rats react to stressors more intensely than adult male rats. Our previous work demonstrated that the adrenocorticotropic hormone (ACTH) but not corticosterone (CORT) response to stress is altered by prenatal morphine exposure in adult male rats. Response of the hypothalamo-pituitary-adrenal (HPA) axis to stress is known to be sex specific and dependent on

Romana Šlamberová; Ágnes Rimanóczy; Michelle A. Riley; Ilona Vathy

2004-01-01

375

Female spontaneously hypertensive rats have a compensatory increase in renal regulatory T cells in response to elevations in blood pressure.  

PubMed

Female spontaneously hypertensive rats (SHR) have more regulatory T cells (Tregs) in their kidneys than males. The goal of this study was to determine the impact of blood pressure (BP) on the renal immune profile. We hypothesize that increases in BP promote a proinflammatory renal T cell and cytokine profile in SHR, although females will have greater hormone-dependent increases in Tregs and males will have greater increases in Th17 cells. Renal T cell and cytokine profiles were assessed in male and female Wistar-Kyoto rats and male and female SHR treated with vehicle or hydrochlorothiazide and reserpine (HCTZ) from 6 to 12 (6-HCTZ) or 11 to 13 weeks of age (2-HCTZ). Regardless of sex, SHR had a more proinflammatory renal immune profile than Wistar-Kyoto rats. 6-HCTZ attenuated age-related increases in BP and 2-HCTZ reversed hypertension compared with vehicle-treated SHR. Neither 6-HCTZ nor 2-HCTZ altered CD3(+), CD4(+), or CD8(+) T cells in either sex. Both treatments decreased Tregs only in female SHR abolishing sex differences in Tregs. 6-HCTZ has no impact on Th17 cells in either sex and 2-HCTZ had a minimal impact on renal Th17 cells. To further assess mechanisms mediating sex differences in the renal immune profile, male and female SHR were gonadectomized to determine the impact of sex hormones. Gonadectomy increased proinflammatory markers in both sexes, suggesting that both male and female sex hormones are anti-inflammatory. In conclusion, BP contributes to sex differences in the renal T-cell profile of SHR; female SHR increase renal Tregs in response to increases in BP. PMID:24914200

Tipton, Ashlee J; Baban, Babak; Sullivan, Jennifer C

2014-09-01

376

Differential effects of leptin receptor mutation on male and female BBDR Gimap5-/Gimap5- spontaneously diabetic rats.  

PubMed

Rodents homozygous for autosomal leptin receptor gene mutations not only become obese, insulin resistant, and hyperleptinemic but also develop a dysregulated immune system. Using marker-assisted breeding to introgress the Koletsky rat leptin receptor mutant (lepr-/lepr-), we developed a novel congenic BBDR.(lepr-/lepr-) rat line to study the development of obesity and type 2 diabetes (T2D) in the BioBreeding (BB) diabetes-resistant (DR) rat. While heterozygous lepr (-/+) or homozygous (+/+) BBDR rats remained lean and metabolically normal, at 3 wk of age all BBDR.(lepr-/lepr-) rats were obese without hyperglycemia. Between 45 and 70 days of age, male but not female obese rats developed T2D. We had previously developed congenic BBDR.(Gimap5-/Gimap5-) rats, which carry an autosomal frameshift mutation in the Gimap5 gene linked to lymphopenia and spontaneous development of type 1 diabetes (T1D) without sex differences. Because the autoimmune-mediated destruction of pancreatic islet beta-cells may be affected not only by obesity but also by the absence of leptin receptor signaling, we next generated BBDR.(lepr-/lepr-,Gimap5-/Gimap5-) double congenic rats carrying the mutation for Gimap5 and T1D as well as the Lepr mutation for obesity and T2D. The hyperleptinemia rescued end-stage islets in BBDR.(lepr-/lepr-,Gimap5-/Gimap5-) congenic rats and induced an increase in islet size in both sexes, while T1D development was delayed and reduced only in females. These results demonstrate that obesity and T2D induced by introgression of the Koletsky leptin receptor mutation in the BBDR rat result in islet expansion associated with protection from T1D in female but not male BBDR.(lepr-/lepr-,Gimap5-/Gimap5-) congenic rats. BBDR.(lepr-/lepr-,Gimap5-/Gimap5-) congenic rats should prove valuable to study interactions between lack of leptin receptor signaling, obesity, and sex-specific T2D and T1D. PMID:19996157

Moralejo, Daniel H; Hansen, Carl T; Treuting, Piper; Hessner, Martin J; Fuller, Jessica M; Van Yserloo, Brian; Jensen, Richard; Osborne, William; Kwitek, Anne E; Lernmark, Ake

2010-03-01

377

Differential effects of leptin receptor mutation on male and female BBDR.Gimap5?/Gimap5? spontaneously diabetic rats  

PubMed Central

Rodents homozygous for autosomal leptin receptor gene mutations not only become obese, insulin resistant, and hyperleptinemic but also develop a dysregulated immune system. Using marker-assisted breeding to introgress the Koletsky rat leptin receptor mutant (lepr?/lepr?), we developed a novel congenic BBDR.lepr?/lepr? rat line to study the development of obesity and type 2 diabetes (T2D) in the BioBreeding (BB) diabetes-resistant (DR) rat. While heterozygous lepr (?/+) or homozygous (+/+) BBDR rats remained lean and metabolically normal, at 3 wk of age all BBDR.lepr?/lepr? rats were obese without hyperglycemia. Between 45 and 70 days of age, male but not female obese rats developed T2D. We had previously developed congenic BBDR.Gimap5?/Gimap5? rats, which carry an autosomal frameshift mutation in the Gimap5 gene linked to lymphopenia and spontaneous development of type 1 diabetes (T1D) without sex differences. Because the autoimmune-mediated destruction of pancreatic islet ?-cells may be affected not only by obesity but also by the absence of leptin receptor signaling, we next generated BBDR.lepr?/lepr?,Gimap5?/Gimap5? double congenic rats carrying the mutation for Gimap5 and T1D as well as the Lepr mutation for obesity and T2D. The hyperleptinemia rescued end-stage islets in BBDR.lepr?/lepr?,Gimap5?/Gimap5? congenic rats and induced an increase in islet size in both sexes, while T1D development was delayed and reduced only in females. These results demonstrate that obesity and T2D induced by introgression of the Koletsky leptin receptor mutation in the BBDR rat result in islet expansion associated with protection from T1D in female but not male BBDR.lepr?/lepr?,Gimap5?/Gimap5? congenic rats. BBDR.lepr?/lepr?,Gimap5?/Gimap5? congenic rats should prove valuable to study interactions between lack of leptin receptor signaling, obesity, and sex-specific T2D and T1D. PMID:19996157

Hansen, Carl T.; Treuting, Piper; Hessner, Martin J.; Fuller, Jessica M.; Van Yserloo, Brian; Jensen, Richard; Osborne, William; Kwitek, Anne E.; Lernmark, Ĺke

2010-01-01

378

Single acute stress-induced progesterone and ovariectomy alter cardiomyocyte contractile function in female rats  

PubMed Central

Aim To assess how ovarian-derived sex hormones (in particular progesterone) modify the effects of single acute stress on the mechanical and biochemical properties of left ventricular cardiomyocytes in the rat. Methods Non-ovariectomized (control, n?=?8) and ovariectomized (OVX, n?=?8) female rats were kept under normal conditions or were exposed to stress (control-S, n?=?8 and OVX-S, n?=?8). Serum progesterone levels were measured using a chemiluminescent immunoassay. Left ventricular myocardial samples were used for isometric force measurements and protein analysis. Ca2+-dependent active force (Factive), Ca2+-independent passive force (Fpassive), and Ca2+-sensitivity of force production were determined in single, mechanically isolated, permeabilized cardiomyocytes. Stress- and ovariectomy-induced alterations in myofilament proteins (myosin-binding protein C [MyBP-C], troponin I [TnI], and titin) were analyzed by sodium dodecyl sulfate gel electrophoresis using protein and phosphoprotein stainings. Results Serum progesterone levels were significantly increased in stressed rats (control-S, 35.6?±?4.8 ng/mL and OVX-S, 21.9?±?4.0 ng/mL) compared to control (10?±?2.9 ng/mL) and OVX (2.8?±?0.5 ng/mL) groups. Factive was higher in the OVX groups (OVX, 25.9?±?3.4 kN/m2 and OVX-S, 26.3?±?3.0 kN/m2) than in control groups (control, 16.4?±?1.2 kN/m2 and control-S, 14.4?±?0.9 kN/m2). Regarding the potential molecular mechanisms, Factive correlated with MyBP-C phosphorylation, while myofilament Ca2+-sensitivity inversely correlated with serum progesterone levels when the mean values were plotted for all animal groups. Fpassive was unaffected by any treatment. Conclusion Stress increases ovary-independent synthesis and release of progesterone, which may regulate Ca2+-sensitivity of force production in left ventricular cardiomyocytes. Stress and female hormones differently alter Ca2+-dependent cardiomyocyte contractile force production, which may have pathophysiological importance during stress conditions affecting postmenopausal women. PMID:24891282

Kalász, Judit; Tóth, Enik? Pásztor; Bódi, Beáta; Fagyas, Miklós; Tóth, Attila; Pal, Bhattoa Harjit; Vári, Sándor G.; Balog, Marta; Blažeti?, Senka; Heffer, Marija; Papp, Zoltán; Borbély, Attila

2014-01-01

379

Chronic alcohol consumption disrupts myocardial protein balance and function in aged, but not adult, female F344 rats.  

PubMed

The purpose of this study was to assess whether the deleterious effect of chronic alcohol consumption differs in adult and aged female rats. To address this aim, adult (4 mo) and aged (18 mo) F344 rats were fed a nutritionally complete liquid diet containing alcohol (36% total calories) or an isocaloric isonitrogenous control diet for 20 wk. Cardiac structure and function, assessed by echocardiography, as well as myocardial protein synthesis and proteolysis did not differ in either alcohol- versus control-fed adult rats or in adult versus aged control-fed rats. In contrast, cardiac function was impaired in alcohol-fed aged rats compared with age-matched control rats. Additionally, alcohol feeding decreased cardiac protein synthesis that was associated with decreased phosphorylation of 4E-BP1 and S6K1. This reduction in mammalian target of rapamycin (mTOR) kinase activity was associated with reduced eIF3f and binding of both Raptor and eIF4G to eIF3. Proteasome activity was increased in alcohol-fed aged rats with a coordinate elevation in the E3 ligases atrogin-1 and muscle RING-finger protein-1 (MuRF1). These changes were associated with increased regulated in development and DNA damage response 1 (REDD1) and phosphorylation of AMP-activated protein kinase (AMPK) but no increase in AKT or forkhead transcription factor (FOXO)3 phosphorylation. Finally, markers of autophagy (e.g., LC3B, Atg7, Atg12) and TNF-? were increased to a greater extent in alcohol-fed aged rats. These data demonstrate that aged female rats exhibit an enhanced sensitivity to alcohol compared with adult animals. Our data are consistent with a model whereby alcohol increases proteolysis via FOXO-independent increase in atrogin-1, which degrades eIF3f and therefore impairs formation of a functional preinitiation complex and protein synthesis. PMID:24226028

Lang, Charles H; Korzick, Donna H

2014-01-01

380

Effect of the aqueous extract of Foeniculum vulgare (fennel) on the kidney in experimental PCOS female rats  

PubMed Central

Objective: Foeniculum vulgare seed (F. vulgare) is an herbal plant which is used with phytoestrogene compounds for polycystic ovary syndrome (PCOS) treatment. In this research, renoprotective effect of the aqueous extract of Foeniculum vulgare (AEF) in experimental PCOS female rats is studied. Materials and Methods: Forty female rats were randomly divided into five groups. The first group served as control, was injected with an equivalent volume (0.2 ml) of normal saline, and received normal diet. Animals in the second group were non poly cystic ovary syndrome (PCOS) rats which were treated with intragastric administration of aqueous extract of F. vulgare (150 mg/kg b.w.). In the third group, the rats were treated with intraperitoneal injection of estradiolvalerate (EV) (4 mg in 0.2 ml of sesame oil). The fourth groups were treated with EV and AEF (150mg/kg bw) with the same route. The fifth groups were treated with EV and AEF (100mg/kg bw). After 4 weeks of study, all of the rats were sacrificed, their kidneys tissues were processed for light microscopy, and some biochemical parameters of serum were measured. Results: The mean values of blood urea nitrogen in PCOS rats treated with low dose of AEF and EV and non-treated, was significantly (p<0.05) increased compared with non-PCOS and PCOS rats treated with high dose of AEF. Moreover, histopathological changes of kidney samples were comparable in PCOS rats with respect to treated groups with AEF. Conclusion: Aqueous extract of fennel seed showed the beneficial effect (especially at dose of 150 mg/kg b.w.) on renal function in PCOS rats. PMID:25050308

Sadrefozalayi, Somayyeh; Farokhi, Farah

2014-01-01

381

Nuclear receptor coactivators function in estrogen receptor- and progestin receptor-dependent aspects of sexual behavior in female rats  

PubMed Central

The ovarian hormones, estradiol (E) and progesterone (P) facilitate the expression of sexual behavior in female rats. E and P mediate many of these behavioral effects by binding to their respective intracellular receptors in specific brain regions. Nuclear receptor coactivators, including Steroid Receptor Coactivator-1 (SRC-1) and CREB Binding Protein (CBP), dramatically enhance ligand-dependent steroid receptor transcriptional activity in vitro. Previously, our lab has shown that SRC-1 and CBP modulate estrogen receptor (ER)-mediated induction of progestin receptor (PR) gene expression in the ventromedial nucleus of the hypothalamus (VMN) and hormone-dependent sexual receptivity in female rats. Female sexual behaviors can be activated by high doses of E alone in ovariectomized rats, and thus are believed to be ER-dependent. However, the full repertoire of female sexual behavior, in particular, proceptive behaviors such as hopping, darting and ear wiggling, are considered to be PR-dependent. In the present experiments, the function of SRC-1 and CBP in distinct ER- (Exp. 1) and PR- (Exp. 2) dependent aspects of female sexual behavior was investigated. In Exp. 1, infusion of antisense oligodeoxynucleotides to SRC-1 and CBP mRNA into the VMN decreased lordosis intensity in rats treated with E alone, suggesting that these coactivators modulate ER-mediated female sexual behavior. In Exp. 2, antisense to SRC-1 and CBP mRNA around the time of P administration reduced PR-dependent ear wiggling and hopping and darting. Taken together, these data suggest that SRC-1 and CBP modulate ER and PR action in brain and influence distinct aspects of hormone-dependent sexual behaviors. These findings support our previous studies and provide further evidence that SRC-1 and CBP function together to regulate ovarian hormone action in behaviorally-relevant brain regions. PMID:16769066

Molenda-Figueira, Heather A.; Williams, Casey A.; Griffin, Andreana L.; Rutledge, Eric M.; Blaustein, Jeffrey D.; Tetel, Marc J.

2008-01-01

382

Hypobaric Hypoxia Induces Depression-like Behavior in Female Sprague-Dawley Rats, but not in Males.  

PubMed

Kanekar, Shami, Olena V. Bogdanova, Paul R. Olson, Young-Hoon Sung, Kristen E. D'Anci, and Perry F. Renshaw. Hypobaric hypoxia induces depression-like behavior in female Sprague-Dawley rats, but not males. High Alt Med Biol 16:52-60, 2015-Rates of depression and suicide are higher in people living at altitude, and in those with chronic hypoxic disorders like asthma, chronic obstructive pulmonary disorder (COPD), and smoking. Living at altitude exposes people to hypobaric hypoxia, which can lower rat brain serotonin levels, and impair brain bioenergetics in both humans and rats. We therefore examined the effect of hypobaric hypoxia on depression-like behavior in rats. After a week of housing at simulated altitudes of 20,000?ft, 10,000?ft, or sea level, or at local conditions of 4500?ft (Salt Lake City, UT), Sprague Dawley rats were tested for depression-like behavior in the forced swim test (FST). Time spent swimming, climbing, or immobile, and latency to immobility were measured. Female rats housed at altitude display more depression-like behavior in the FST, with significantly more immobility, less swimming, and lower latency to immobility than those at sea level. In contrast, males in all four altitude groups were similar in their FST behavior. Locomotor behavior in the open field test did not change with altitude, thus validating immobility in the FST as depression-like behavior. Hypobaric hypoxia exposure therefore induces depression-like behavior in female rats, but not in males. PMID:25803141

Kanekar, Shami; Bogdanova, Olena V; Olson, Paul R; Sung, Young-Hoon; D'Anci, Kristen E; Renshaw, Perry F

2015-03-01

383

Female temperament, tumor development and life span: relation to glucocorticoid and tumor necrosis factor alpha levels in rats.  

PubMed

Behavioral characteristics closely associated with specific physiological profiles present an important area of research in understanding health disparities. In particular, glucocorticoid overproduction may be an important factor moderating disease progression; natural variance in production of this steroid has been proposed as one mechanism underlying individual differences in health and disease. In the current paper, we examined immune parameters in female rats of two different behavioral types previously shown to have differential glucocorticoid production and life spans. We categorized young female rats according to their behavioral response to novelty (high- or low-locomotion), and compared their glucocorticoid production, adrenal size, thymus size, tumor necrosis factor-alpha (TNF-alpha) production, tumor development and life span. As expected, high-locomotion females produced more glucocorticoids and had larger adrenal glands during young adulthood than did low-locomotion females. High-locomotion females had significantly smaller thymuses and reduced TNF-alpha levels compared to low-locomotion, suggesting altered immune function in young adulthood. Finally, high-locomotion females had shorter life spans than did low-locomotion females, and this was particularly true in females that developed pituitary tumors, but n