Vasopressin Effects on Plasma Renin Activity in Male and Female Rats

1978 ◽  
Vol 55 (3) ◽  
pp. 301-307 ◽  
Author(s):  
I. W. Henderson ◽  
R. J. Balment ◽  
J. Ann Oliver

1. The influence of gonadal and pituitary factors on the plasma renin response to exogenous vasopressin was examined in anaesthetized rats. 2. Plasma renin activity (PRA) was measured in Brattleboro rats (with and without hypothalamic diabetes insipidus) and Long-Evans male and female rats, before and after single intravenous injection of antidiuretic hormone (ADH) or saline. 3. Control saline injections did not change PRA. ADH reduced PRA in male, but increased PRA in female rats. Rats with diabetes insipidus displayed the greatest changes and were used in subsequent experiments. Extrarenal renin activity (nephrectomized rats) gave qualitatively similar responses to ADH. Plasma renin concentration, which was also measured with PRA in intact and nephrectomized male and female rats with diabetes insipidus, increased in the females and decreased in the males after ADH. 4. Castration, 24 h before study, abolished the ADH-induced fall in PRA, and testosterone implanted before castration did not restore the response. Cyproterone acetate reversed the ADH effect in males, so that PRA then rose after ADH. Hypophysectomized male rats, with depressed basal plasma renin activities, also showed a reduced PRA after ADH. 5. Ovariectomy had little effect on the ADH-induced renin release and the response was similar at oestrus, metoestrus and dioestrus. In hypophysectomized female rats ADH reduced PRA; a male pattern of response was seen in hypophysectomized female rats. 6. In both sexes PRA responses to ADH were blunted but not abolished by β-adrenergic blockade (propranolol). α-Adrenergic blockade (phenoxybenzamine) had little influence on the male response but in females the typical increase disappeared so that ADH reduced PRA. 7. It is concluded that pituitary hormones, including gonadotrophins and gonadal factors as well as adrenal sex steroids, appear to affect significantly the interplay between antidiuretic hormone and the renin—angiotensin system.

2007 ◽  
Vol 293 (6) ◽  
pp. F1905-F1914 ◽  
Author(s):  
David L. Mattson ◽  
Melinda R. Dwinell ◽  
Andrew S. Greene ◽  
Anne E. Kwitek ◽  
Richard J. Roman ◽  
...  

This study examined the genetic basis for hypertension and renal disease phenotypes in Fawn Hooded hypertensive (FHH) rats using chromosome substitution strains (consomic rats) in which each of the 20 autosomes as well as the X and Y chromosomes were transferred from the normal Brown Norway (BN) rat onto the FHH genetic background. Male and female rats of each of the parental and consomic strains were maintained for 2 wk on high-salt (8.0% NaCl) chow with NG-nitro-l-arginine methyl ester (l-NAME) in the drinking water (12.5 mg/l) to induce hypertension and renal disease. Mean arterial blood pressure (MAP) was significantly higher (by over 60 mmHg) in the male FHH compared with BN rats. Urinary protein and albumin excretion rates were increased by 15- and 40-fold, respectively, in the male FHH compared with the BN. Plasma renin activity was 10-fold higher in the FHH than the BN. Similar significant differences were observed between the female FHH and BN, but the degree of hypertension and proteinuria was of a lesser magnitude. Substitution of chromosome 20 from the BN to the FHH attenuated the development of l-NAME-induced hypertension, normalized plasma renin activity, and decreased plasma creatinine in male rats. In female rats, substitution of chromosome 15 decreased MAP and urinary protein excretion. Urinary excretion of albumin in males was decreased by substitution of chromosomes 1, 15, 16, and 18 from the BN into the FHH genetic background. The present data indicate that genes that can modify l-NAME-induced hypertension and proteinuria are on chromosomes 1, 15, 16, 18, and 20.


2002 ◽  
Vol 92 (3) ◽  
pp. 935-940 ◽  
Author(s):  
M. Judith Radin ◽  
Bethany J. Holycross ◽  
Leslie C. Sharkey ◽  
Laura Shiry ◽  
Sylvia A. McCune

Sexual dimorphism may occur during the development of hypertension and congestive heart failure (CHF). Male and female spontaneous hypertension heart failure (SHHF) rats with established hypertension, but before CHF (age 5–8 mo) and during cardiac decompensation leading to CHF (age 18–20 mo in male rats and 22–24 mo in female rats), were studied. At 5–8 mo, male SHHF rats showed early activation of the renin-angiotensin system (RAS), as indicated by increased plasma renin activity (PRA) and higher serum angiotensin-converting enzyme activity compared with female rats. The increase in PRA in female rats was delayed compared with males rats, but it reached comparable levels just before CHF. Urinary endothelin excretion was significantly greater in 5- to 8-mo-old female rats compared with age-matched male rats. Urinary endothelin excretion increased in both male and female rats as CHF developed. Plasma atrial natriuretic peptide (ANP) was comparable at both time points, and both genders showed similar, marked increases as CHF developed. In conclusion, male rats show early activation of the RAS, whereas female rats show early activation of the endothelin vasopressor system. During cardiac decompensation, generalized activation of the RAS, endothelin, and ANP systems occurs and is similar in male and female SHHF rats.


1973 ◽  
Vol 74 (1) ◽  
pp. 88-104 ◽  
Author(s):  
T. Jolín ◽  
M. J. Tarin ◽  
M. D. Garcia

ABSTRACT Male and female rats of varying ages were placad on a low iodine diet (LID) plus KClO4 or 6-propyl-2-thiouracil (PTU) or on the same diet supplemented with I (control rats). Goitrogenesis was also induced with LID plus PTU in gonadectomized animals of both sexes. The weight of the control and goitrogen treated animals, and the weight and iodine content of their thyroids were determined, as well as the plasma PBI, TSH, insulin and glucose levels. The pituitary GH-like protein content was assessed by disc electrophoresis on polyacrylamide gels. If goitrogenesis was induced in young rats of both sexes starting with rats of the same age, body weight (B.W.) and pituitary growth hormone (GH) content, it was found that both the males and females developed goitres of the same size. On the contrary, when goitrogenesis was induced in adult animals, it was found that male rats, that had larger B.W. and pituitary GH content than age-paired females, developed larger goitres. However, both male and female rats were in a hypothyroid condition of comparable degree as judged by the thyroidal iodine content and the plasma PBI and TSH levels. When all the data on the PTU or KClO4-treated male and female rats of varying age and B.W. were considered together, it was observed that the weights of the thyroids increased proportionally to B.W. However, a difference in the slope of the regression of the thyroid weight over B.W. was found between male and female rats, due to the fact that adult male rats develop larger goitres than female animals. In addition, in the male rats treated with PTU, gonadectomy decreased the B.W., pituitary content of GH-like protein and, concomitantly, the size of the goitre decreased; an opposite effect was induced by ovariectomy on the female animals. However, when goitrogenesis was induced in weight-paired adult rats of both sexes, the male animals still developed larger goitres than the females. Among all the parameters studied here, the only ones which appeared to bear a consistent relationship with the size of the goitres in rats of different sexes, treated with a given goitrogen, were the rate of body growth and the amount of a pituitary GH-like protein found before the onset of the goitrogen treatment. Moreover, though the pituitary content of the GH-like protein decreased as a consequence of goitrogen treatment, it was still somewhat higher in male that in female animals. The present results suggest that GH may somehow be involved in the mechanism by which male and female rats on goitrogens develop goitres of different sizes, despite equally high plasma TSH levels.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ming Song ◽  
Fang Yuan ◽  
Xiaohong Li ◽  
Xipeng Ma ◽  
Xinmin Yin ◽  
...  

Abstract Background Inadequate copper intake and increased fructose consumption represent two important nutritional problems in the USA. Dietary copper-fructose interactions alter gut microbial activity and contribute to the development of nonalcoholic fatty liver disease (NAFLD). The aim of this study is to determine whether dietary copper-fructose interactions alter gut microbial activity in a sex-differential manner and whether sex differences in gut microbial activity are associated with sex differences in hepatic steatosis. Methods Male and female weanling Sprague-Dawley (SD) rats were fed ad libitum with an AIN-93G purified rodent diet with defined copper content for 8 weeks. The copper content is 6 mg/kg and 1.5 mg/kg in adequate copper diet (CuA) and marginal copper diet (CuM), respectively. Animals had free access to either deionized water or deionized water containing 10% fructose (F) (w/v) as the only drink during the experiment. Body weight, calorie intake, plasma alanine aminotransferase, aspartate aminotransferase, and liver histology as well as liver triglyceride were evaluated. Fecal microbial contents were analyzed by 16S ribosomal RNA (16S rRNA) sequencing. Fecal and cecal short-chain fatty acids (SCFAs) were determined by gas chromatography-mass spectrometry (GC-MS). Results Male and female rats exhibit similar trends of changes in the body weight gain and calorie intake in response to dietary copper and fructose, with a generally higher level in male rats. Several female rats in the CuAF group developed mild steatosis, while no obvious steatosis was observed in male rats fed with CuAF or CuMF diets. Fecal 16S rRNA sequencing analysis revealed distinct alterations of the gut microbiome in male and female rats. Linear discriminant analysis (LDA) effect size (LEfSe) identified sex-specific abundant taxa in different groups. Further, total SCFAs, as well as, butyrate were decreased in a more pronounced manner in female CuMF rats than in male rats. Of note, the decreased SCFAs are concomitant with the reduced SCFA producers, but not correlated to hepatic steatosis. Conclusions Our data demonstrated sex differences in the alterations of gut microbial abundance, activities, and hepatic steatosis in response to dietary copper-fructose interaction in rats. The correlation between sex differences in metabolic phenotypes and alterations of gut microbial activities remains elusive.


2019 ◽  
Vol 22 (11) ◽  
pp. 710-723 ◽  
Author(s):  
Atul P Daiwile ◽  
Subramaniam Jayanthi ◽  
Bruce Ladenheim ◽  
Michael T McCoy ◽  
Christie Brannock ◽  
...  

Abstract Background Methamphetamine (METH) use disorder is prevalent worldwide. There are reports of sex differences in quantities of drug used and relapses to drug use among individuals with METH use disorder. However, the molecular neurobiology of these potential sex differences remains unknown. Methods We trained rats to self-administer METH (0. 1 mg/kg/infusion, i.v.) on an fixed-ratio-1 schedule for 20 days using two 3-hour daily METH sessions separated by 30-minute breaks. At the end of self-administration training, rats underwent tests of cue-induced METH seeking on withdrawal days 3 and 30. Twenty-four hours later, nucleus accumbens was dissected and then used to measure neuropeptide mRNA levels. Results Behavioral results show that male rats increased the number of METH infusions earlier during self-administration training and took more METH than females. Both male and female rats could be further divided into 2 phenotypes labeled high and low takers based on the degree of escalation that they exhibited during the course of the METH self-administration experiment. Both males and females exhibited incubation of METH seeking after 30 days of forced withdrawal. Females had higher basal mRNA levels of dynorphin and hypocretin/orexin receptors than males, whereas males expressed higher vasopressin mRNA levels than females under saline and METH conditions. Unexpectedly, only males showed increased expression of nucleus accumbens dynorphin after METH self-administration. Moreover, there were significant correlations between nucleus accumbens Hcrtr1, Hcrtr2, Crhr2, and Avpr1b mRNA levels and cue-induced METH seeking only in female rats. Conclusion Our results identify some behavioral and molecular differences between male and female rats that had self-administered METH. Sexual dimorphism in responses to METH exposure should be considered when developing potential therapeutic agents against METH use disorder.


1975 ◽  
Vol 48 (2) ◽  
pp. 147-151
Author(s):  
C. S. Sweet ◽  
M. Mandradjieff

1. Renal hypertensive dogs were treated with hydrochlorothiazide (8−2 μmol/kg or 33 μmol/kg daily for 7 days), or timolol (4.6 μmol/kg daily for 4 days), a potent β-adrenergic blocking agent, or combinations of these drugs). Changes in mean arterial blood pressure and plasma renin activity were measured over the treatment period. 2. Neither drug significantly lowered arterial blood pressure when administered alone. Plasma renin activity, which did not change during treatment with timolol, was substantially elevated during treatment with hydrochlorothiazide. 3. When timolol was administered concomitantly with hydrochlorothiazide, plasma renin activity was suppressed and blood pressure was significantly lowered. 4. These observations suggest that compensatory activation of the renin-angiotensin system limits the antihypertensive activity of hydrochlorothiazide in renal hypertensive dogs and suppression of diuretic-induced renin release by timolol unmasks the antihypertensive effect of the diuretic.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Maryam Malek ◽  
Mehdi Nematbakhsh

Background. Angiotensin-converting enzyme 2/angiotensin (1-7)/Mas receptor (ACE2/Ang-1-7/MasR) appears to counteract most of the deleterious actions of angiotensin-converting enzyme/angiotensin II/angiotensin II receptor 1 (ACE/Ang II/AT1R) in renal ischemia/reperfusion (I/R) injury but ACE2 activity and its levels are sexually dimorphic in the kidney. This study was designed to evaluate the effects of activation endogenous ACE2 using the diminazene aceturate (DIZE) in renal I/R injury in male and female rats.Methods. 36 Wistar rats were divided into two groups of male and female and each group distinct to three subgroups (n=6). I/R group was subjected to 45 min of bilateral ischemia and 24 h of reperfusion, while treatment group received DIZE (15 mg/kg/day) for three days before the induction of I/R. The other group was assigned as the sham-operated group.Results. DIZE treatment in male rats caused a significant decrease in blood urea nitrogen (BUN), creatinine, liver functional indices, serum malondialdehyde (MDA), and increase kidney nitrite levels (P<0.05), and in female rats a significant increase in creatinine and decrease serum nitrite levels compared to the I/R group (P<0.05).Conclusions. DIZE may protect the male kidney from renal I/RI through antioxidant activity and elevation of circulating nitrite level.


2012 ◽  
Vol 7 (6) ◽  
pp. 980-986 ◽  
Author(s):  
Milan Marounek ◽  
Zdeněk Volek ◽  
Eva Skřivanová ◽  
Marian Czauderna

AbstractMale and female rats were fed diets supplemented with cholesterol and palm fat at 10 and 50 g/kg, respectively; serum, hepatic tissue and faeces were analysed. Cholesterol supplementation significantly increased serum and hepatic cholesterol both in male and female rats. Male and female rats fed the cholesterol-containing diet differed significantly in serum cholesterol concentration (2.48 µmol/mL vs 2.92 µmol/mL), concentration of serum triacylglycerols, but not in hepatic cholesterol concentration. The serum and hepatic cholesterol concentrations correlated non-significantly in male rats (r=0.491; P=0.063) and significantly in female rats (r=0.818; P<0.001). Cholesterol supplementation non-significantly decreased relative expression of the hepatic LDL receptor gene and significantly increased relative expression of the hepatic cholesterol 7α-hydroxylase gene in rats of both genders. The faeces of control rats contained similar amounts of cholesterol and bile acids. Cholesterol supplementation increased cholesterol concentration 10 times in the faeces of male rats and 12 times in faeces of female rats. The corresponding increases of bile acid concentration were much lower (83% in male rats and 108% in female rats). It can be concluded that the effects of cholesterol supplementation were more pronounced in female than in male rats.


2002 ◽  
Vol 22 (2) ◽  
pp. 183-195 ◽  
Author(s):  
Aigang Lu ◽  
Rui-qiong Ran ◽  
Joseph Clark ◽  
Melinda Reilly ◽  
Alex Nee ◽  
...  

Estradiol reduces brain injury from many diseases, including stroke and trauma. To investigate the molecular mechanisms of this protection, the effects of 17-β-estradiol on heat shock protein (HSP) expression were studied in normal male and female rats and in male gerbils after global ischemia. 17-β-Estradiol was given intraperitoneally (46 or 460 ng/kg, or 4.6 μg/kg) and Western blots performed for HSPs. 17-β-Estradiol increased hemeoxygenase-1, HSP25/27, and HSP70 in the brain of male and female rats. Six hours after the administration of 17-β-estradiol, hemeoxygenase-1 increased 3.9-fold (460 ng/kg) and 5.4-fold (4.6 μg/kg), HSP25/27 increased 2.1-fold (4.6 μg/kg), and Hsp70 increased 2.3-fold (460 ng/kg). Immunocytochemistry showed that hemeoxygenase-1, HSP25/27,and HSP70 induction was localized to cerebral arteries in male rats, possibly in vascular smooth muscle cells. 17-β-Estradiol was injected intraperitoneally 20 minutes before transient occlusion of both carotids in adult gerbils. Six hours after global cerebral ischemia, 17-β-estradiol (460 ng/kg) increased levels of hemeoxygenase-1 protein 2.4-fold compared with ischemia alone, and HSP25/27 levels increased 1.8-fold compared with ischemia alone. Hemeoxygenase-1 was induced in striatal oligodendrocytes and hippocampal neurons, and HSP25/27 levels increased in striatal astrocytes and hippocampal neurons. Finally, Western blot analysis confirmed that estrogen induced heat shock factor-1, providing a possible mechanism by which estrogen induces HSPs in brain and other tissues. The induction of HSPs may be an important mechanism for estrogen protection against cerebral ischemia and other types of injury.


2012 ◽  
Vol 63 (4) ◽  
pp. 417-427 ◽  
Author(s):  
Mariana Tozlovanu ◽  
Delphine Canadas ◽  
Annie Pfohl-Leszkowicz ◽  
Christine Frenette ◽  
Robert J. Paugh ◽  
...  

AbstractIn the present study the photoreactivity of the fungal carcinogen ochratoxin A (OTA) has been utilised to generate authentic samples of reduced glutathione (GSH) and N-acetylcysteine (NAC) conjugates of the parent toxin. These conjugates, along with the nontoxic OTα, which is generated through hydrolysis of the amide bond of OTA by carboxypeptidase A, were utilised as biomarkers to study the metabolism of OTA in the liver and kidney of male and female Dark Agouti rats. Male rats are more susceptible than female rats to OTA carcinogenesis with the kidney being the target organ. Our studies show that the distribution of OTA in male and female rat kidney is not significantly different. However, the extent of OTA metabolism was greater in male than female rats. Much higher levels of OTα were detected in the liver compared to the kidney, and formation of OTα is a detoxification pathway for OTA. These findings suggest that differences in metabolism between male and female rats could provide an explanation for the higher sensitivity of male rats to OTA toxicity


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