scholarly journals Sex differences and central protective effect of 17β-estradiol in the development of aldosterone/NaCl-induced hypertension

2009 ◽  
Vol 296 (5) ◽  
pp. H1577-H1585 ◽  
Author(s):  
Baojian Xue ◽  
Daniel Badaue-Passos ◽  
Fang Guo ◽  
Celso E. Gomez-Sanchez ◽  
Meredith Hay ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Protective Effect ◽  
Protective Role ◽  
Female Rats ◽  
Sympathetic Outflow ◽  
Male And Female ◽  
Male And Female Rats ◽  
Induced Hypertension ◽  
Combined Administration ◽  
17Β Estradiol

The present study tested the hypotheses that male and female rats respond differently to subcutaneous infusions of aldosterone (Aldo; 1.8 μg·kg−1·h−1, 1% NaCl to drink; 28 days) and that central estrogen plays a protective role against the development of hypertension. In rats with blood pressure (BP) and heart rate (HR) measured by Data Sciences International telemetry, chronic Aldo/NaCl treatment induced a greater increase in BP in males (Δ25.4 ± 2.4 mmHg) than in females (Δ7.1 ± 2.2 mmHg). Gonadectomy augmented Aldo/NaCl-induced hypertension in females (Δ18.2 ± 2.0 mmHg) but had no effect in males (Δ23.1 ± 2.9 mmHg). Immunohistochemistry for Fra-like activity was higher in the paraventricular nucleus of intact males, castrated males, and ovariectomized (OVX) females compared with intact females after 28 days of Aldo/NaCl treatment. In intact males, central 17β-estradiol (E2) inhibited the Aldo/NaCl increase in BP (Δ10.5 ± 0.8) compared with that in central vehicle plus systemic Aldo/NaCl (Δ26.1 ± 2.5 mmHg) rats. Combined administration of E2 and estrogen receptor antagonist ICI182780 (ICI) blocked the protective effect of E2 (Δ23.2 ± 2.4 mmHg). In intact females central, but not peripheral, infusions of ICI augmented the Aldo/NaCl (Δ20.4 ± 1.8 mmHg) BP increase. Finally, ganglionic blockade after Aldo infusions resulted in a smaller reduction in BP in intact females (−23.9 ± 2.5 mmHg) and in central estrogen-treated males (−30.2 ± 1.0 mmHg) compared with other groups (intact males, −39.3 ± 3.4; castrated males, −41.8 ± 1.9; intact males with central E2 + ICI, −42.3 ± 2.1; OVX females, −40.3 ± 3.3; and intact females with central ICI, −39.1 ± 1.3 mmHg). Chronic Aldo infusion produced increases in NaCl intake and decreases in HR that were both similar in all groups. Taken together, the results indicate that central estrogen plays a protective role in the development of Aldo/NaCl-induced hypertension and that this may result from reduced sympathetic outflow.

Abstract 9: Endothelin B Receptors Protect Against Hypertension Induced by Chronic Angiotensin II in Female Rats

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Wararat Kittikulsuth ◽  
David M Pollock
Keyword(s):  
Blood Pressure ◽  
High Salt ◽  
Female Rats ◽  
Male Rats ◽  
Ang Ii ◽  
Hypertensive Rats ◽  
High Salt Diet ◽  
Male And Female ◽  
Male And Female Rats ◽  
Endothelin B

Endothelin B (ET B ) receptors mediate vasodilation, anti-inflammation and natriuresis, which ultimately contribute to blood pressure control. We previously showed that renal medullary ET B receptor function is maintained in female angiotensin (Ang) II hypertensive rats, while male Ang II hypertensive rats have blunted ET B -induced natriuretic responses. Because female rats are more resistance to blood pressure elevation induced by high salt intake and/or Ang II infusion, we hypothesized that ET B receptors protect female rats against the hypertensive response and renal injury induced by a high salt diet and chronic Ang II infusion compared to males. Male and female rats received Ang II infusion (150 ng/kg/min; sc.) with 4% NaCl for 4 weeks; blood pressure was measured by telemetry. After a week of Ang II infusion with a high salt diet, subsets of both male and female rats received the ET B antagonist, A-192621, at three doses on consecutive weeks (1, 3, and 10 mg/kg/d in food). Male rats had a significantly higher blood pressure compared to females after 4 weeks of Ang II (178±10 vs. 138±10 mmHg; p<0.05). A-192621 resulted in a dose-dependent increase in blood pressure in female Ang II hypertensive rats (167±8 mmHg at 10 mg/kg/d; p<0.05); the increase produced by A-192621 in male Ang II hypertensive rats was not statistically significant (193±10 mmHg). After 4 weeks of Ang II infusion, the level of proteinuria and nephrinuria was higher in male rats compared to female. A-192621 did not further increase urinary excretion of protein or nephrin in both male and female Ang II hypertensive rats. In conclusion, these results support the hypothesis that ET B receptors provide more protection against hypertension during chronic Ang II infusion in female rats compared to male.

scholarly journals Fetal Undernutrition Induces Resistance Artery Remodeling and Stiffness in Male and Female Rats Independent of Hypertension

Biomedicines ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 424
Author(s):  
Perla Y. Gutiérrez-Arzapalo ◽  
Pilar Rodríguez-Rodríguez ◽  
David Ramiro-Cortijo ◽  
Marta Gil-Ortega ◽  
Beatriz Somoza ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Pressure Level ◽  
Female Rats ◽  
Resistance Artery ◽  
Male And Female ◽  
Maternal Undernutrition ◽  
Male And Female Rats ◽  
Males And Females ◽  
Artery Remodeling ◽  
Tail Cuff

Fetal undernutrition programs hypertension and cardiovascular diseases, and resistance artery remodeling may be a contributing factor. We aimed to assess if fetal undernutrition induces resistance artery remodeling and the relationship with hypertension. Sprague–Dawley dams were fed ad libitum (Control) or with 50% of control intake between days 11 and 21 of gestation (maternal undernutrition, MUN). In six-month-old male and female offspring we assessed blood pressure (anesthetized and tail-cuff); mesenteric resistance artery (MRA) structure and mechanics (pressure myography), cellular and internal elastic lamina (IEL) organization (confocal microscopy) and plasma MMP-2 and MMP-9 activity (zymography). Systolic blood pressure (SBP, tail-cuff) and plasma MMP activity were assessed in 18-month-old rats. At the age of six months MUN males exhibited significantly higher blood pressure (anesthetized or tail-cuff) and plasma MMP-9 activity, while MUN females did not exhibit significant differences, compared to sex-matched controls. MRA from 6-month-old MUN males and females showed a smaller diameter, reduced adventitial, smooth muscle cell density and IEL fenestra area, and a leftward shift of stress-strain curves. At the age of eighteen months SBP and MMP-9 activity were higher in both MUN males and females, compared to sex-matched controls. These data suggest that fetal undernutrition induces MRA inward eutrophic remodeling and stiffness in both sexes, independent of blood pressure level. Resistance artery structural and mechanical alterations can participate in the development of hypertension in aged females and may contribute to adverse cardiovascular events associated with low birth weight in both sexes.

Substitution of chromosome 1 ameliorates l-NAME hypertension and renal disease in the fawn-hooded hypertensive rat

2005 ◽  
Vol 288 (5) ◽  
pp. F1015-F1022 ◽  
Author(s):  
David L. Mattson ◽  
Mary Pat Kunert ◽  
Richard J. Roman ◽  
Howard J. Jacob ◽  
Allen W. Cowley
Keyword(s):  
Renal Disease ◽  
Genetic Background ◽  
Female Rats ◽  
Chromosome 1 ◽  
Brown Norway ◽  
Male And Female ◽  
Arterial Blood ◽  
Male And Female Rats ◽  
Induced Hypertension ◽  
Excretion Rates

Linkage analysis studies previously identified genetic loci associated with proteinuria and hypertension on chromosome 1 of fawn-hooded hypertensive (FHH) rats. The present studies were performed on conscious male and female rats to evaluate the influence of transfer of chromosome 1 from the Brown Norway (BN) rat to the FHH genetic background (FHH-1BN). Rats were maintained for 2 wk on 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 accelerate the onset of renal disease. Mean arterial blood pressure (MAP) was significantly higher in the male FHH (188 ± 3 mmHg, n = 13) compared with the BN (121 ± 3 mmHg, n = 8); MAP in the FHH-1BN was midway between the two parental strains (167 ± 5 mmHg, n = 9). Urinary protein and albumin excretion rates in the male FHH-1BN (Uprot = 189 ± 36 mg/day, Ualb = 69 ± 16 mg/day, n = 10) were also midway between levels observed in the FHH (Uprot = 485 ± 54 mg/day; Ualb = 206 ± 25 mg/day, n = 13) and the BN (Uprot = 32 ± 5 mg/day, Ualb = 5 ± 1 mg/day, n = 8). Creatinine clearance was elevated, and the degree of glomerular damage was significantly reduced in the FHH-1BN compared with the FHH. Qualitatively similar results were obtained from female FHH, FHH-1BN, and BN rats. The present results indicate that genes contributing to l-NAME-induced hypertension and renal disease are found on chromosome 1 of the FHH rat.

Relationship among hyperinsulinemia, insulin resistance, and hypertension is dependent on sex

2002 ◽  
Vol 283 (2) ◽  
pp. H562-H567 ◽  
Author(s):  
Denise M. Galipeau ◽  
Linfu Yao ◽  
John H. McNeill
Keyword(s):  
Insulin Resistance ◽  
Blood Pressure ◽  
Insulin Sensitivity ◽  
Insulin Treatment ◽  
Tolerance Test ◽  
Female Rats ◽  
Male Rats ◽  
Oral Glucose ◽  
Male And Female ◽  
Male And Female Rats

Hyperinsulinemia and insulin resistance have been linked to hypertension; however, the influence of sex on this relationship has not been well studied. The purpose of this experiment was to compare the effects of chronic insulin treatment on insulin sensitivity and blood pressure in male and female rats. Male and female Wistar rats were treated with insulin (2 U/day) via subcutaneous sustained release implants for 5 wk. Systolic blood pressure was measured via the tail-cuff method before and after treatment, and insulin sensitivity was assessed with an oral glucose tolerance test. The insulin sensitivity of female rats was 4.5-fold greater than male rats. Chronic insulin treatment impaired insulin sensitivity in both sexes; however, this occurred to a greater degree in male rats. Blood pressure increased in male rats treated with insulin only. The results demonstrate that hyperinsulinemia and insulin resistance are associated with hypertension in male rats only. Therefore, the link between these conditions appears to depend on sex.

scholarly journals Oxytocin has sex-specific effects on social behaviour and hypothalamic oxytocin immunoreactive cells but not hippocampal neurogenesis in adult rats

2019 ◽  
Author(s):  
Paula Duarte-Guterman ◽  
Stephanie E. Lieblich ◽  
Wansu Qiu ◽  
Jared E.J. Splinter ◽  
Kimberly A. Go ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Body Mass ◽  
Hippocampal Neurogenesis ◽  
Female Rats ◽  
Brain Barrier ◽  
Social Investigation ◽  
Male And Female ◽  
Specific Effects ◽  
Male And Female Rats ◽  
17Β Estradiol

AbstractOxytocin regulates social behaviours, pair bonding and hippocampal neurogenesis but most studies have used adult males. Our study investigated the effects of oxytocin on social investigation and adult hippocampal neurogenesis in male and female rats. Oxytocin has poor penetration of the blood-brain barrier, therefore we tested a nanoparticle drug, TRIOZANTM (Ovensa Inc.), which permits greater blood-brain-barrier penetration. Adult male and female rats were injected daily (i.p.) for 10 days with either: oxytocin in PBS (0.5 or 1.0 mg/kg), oxytocin in TRIOZANTM (0.5 or 1.0 mg/kg), or vehicle (PBS) and tested for social investigation. Oxytocin decreased body mass and increased social investigation and number of oxytocin-immunoreactive cells in the supraoptic nucleus (SON) of the hypothalamus in male rats only. In both sexes, oxytocin decreased the number of immature neurons (doublecortin+ cells) in the ventral hippocampus and reduced plasma 17β-estradiol levels in a dose- and delivery-dependent way. Oxytocin in TRIOZANTM reduced sedation observed post-injection and increased some central effects (oxytocin levels in the hypothalamus and ventral hippocampus neurogenesis) relative to oxytocin in PBS indicating that the nanoparticle may be used as an alternative brain delivery system. We showed that oxytocin has sex-specific effects on social investigation, body mass, sedation, and the oxytocin system. In contrast, similar effects were observed in both sexes in neurogenesis and plasma 17β-estradiol. Our work suggests that sex differences in oxytocin regulation of brain endpoints is region-specific (hypothalamus versus hippocampus) and that oxytocin does not promote social investigation in females.

scholarly journals Dextrose Hydration May Promote Cisplatin-induced Nephrotoxicity in Rats: Gender-related Difference

2019 ◽  
Vol 11 (2) ◽  
pp. 136-44
Author(s):  
Farzaneh Karimi ◽  
Sayyedehnikta Kasaei ◽  
Azar Baradaran ◽  
Farzaneh Ashrafi ◽  
Ardeshir Talebi ◽  
...  
Keyword(s):  
Kidney Tissue ◽  
Serum Levels ◽  
Protective Role ◽  
Female Rats ◽  
Male And Female ◽  
Cisplatin Nephrotoxicity ◽  
Male And Female Rats ◽  
Before And After ◽  
Different Doses

BACKGROUNDS: Cisplatin (CP) as an anticancer drug may affect the plasma glucose level while diabetic subjects are protected against CP-induced nephrotoxicity. In the current study, the role of dextrose hydration during CP therapy on CP-induced nephrotoxicity was evaluated.METHODS: Sixty-nine male and female rats were divided into 12 groups. The rats were hydrated with 15 mL/kg vehicle or different doses of 2%, 10% and 20% dextrose before and after 7.5 mg/kg CP administration. One week later, the biochemical and kidney function markers, and histology finding were determined.RESULTS: All the animals co-treated with CP and 20% dextrose, were dead during one week of the experiment. Administration of CP alone increased kidney tissue damage score (KTDS) and kidney weight (KW). It also elevated the blood urea nitrogen (BUN) and BUN-creatineine ratio (BUN/Cr) levels in the serum. In addition, CP decreased body weight and creatinine (Cr) clearance (ClCr) significantly in both male and female rats (p<0.05). However, 2% and 10% dextrose did not alter the mentioned parameters in male, but 10% dextrose supplement increased the serum levels of BUN, Cr and BUN/Cr ratio, KW and KTDS significantly in female rats (p<0.05).CONCLUSION: Our data suggest that not only do not support the nephro-protective role of dextrose hydration during CP therapy, the dextrose hydration can act as risk factor to promote CP-induced nephrotoxicity in female rats. Prohibition of high carbohydrate (glucose) diet during CP therapy is recommended.KEYWORDS: cisplatin, nephrotoxicity, dextrose, rat, gender

Protective Effect of PACAP on Ischemia/Reperfusion-Induced Kidney Injury of Male and Female Rats: Gender Differences

2018 ◽  
Vol 68 (3) ◽  
pp. 408-419 ◽  
Author(s):  
Eszter Laszlo ◽  
Tamas Juhasz ◽  
Adam Varga ◽  
Bernadett Czibere ◽  
Krisztina Kovacs ◽  
...  
Keyword(s):  
Gender Differences ◽  
Protective Effect ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Female Rats ◽  
Male And Female ◽  
Male And Female Rats
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