scholarly journals Ontogenesis of sympathetic responsiveness in spontaneously hypertensive rats. II. Renal G proteins in male and female rats.

Hypertension ◽  
1994 ◽  
Vol 23 (5) ◽  
pp. 653-658 ◽  
Author(s):  
M C Michel ◽  
W Farke ◽  
W Erdbrügger ◽  
T Philipp ◽  
O E Brodde
Keyword(s):  
G Proteins ◽  
Spontaneously Hypertensive Rats ◽  
Female Rats ◽  
Hypertensive Rats ◽  
Male And Female ◽  
Spontaneously Hypertensive ◽  
Male And Female Rats

Exercise training and incidence of cerebrovascular lesions in stroke-prone spontaneously hypertensive rats

1990 ◽  
Vol 68 (3) ◽  
pp. 1080-1085 ◽  
Author(s):  
C. M. Tipton ◽  
S. McMahon ◽  
J. R. Leininger ◽  
E. L. Pauli ◽  
C. Lauber
Keyword(s):  
Exercise Training ◽  
Spontaneously Hypertensive Rats ◽  
Female Rats ◽  
Moderate Exercise ◽  
Hypertensive Rats ◽  
Cerebrovascular Lesions ◽  
Spontaneously Hypertensive ◽  
Male And Female Rats ◽  
Blood Pressures ◽  
Subjective Evidence

To assess the effects of moderate exercise [40-70% maximal oxygen uptake (VO2max)] on resting blood pressures, the presence of cerebrovascular lesions, and the life spans of stroke-prone hypertensive rats, nontrained and trained male and female rats were assigned to two experimental groups. The first (n = 48) were exercise trained after 38 days of age, whereas the second (n = 44) initiated exercise training when the animals were 134 days of age. To facilitate cerebrovascular lesions, the sodium concentrations in the rat chow and in the drinking solutions were increased. Symptoms utilized to denote the presence of cerebrovascular lesions were irritability, hyperresponsiveness, ataxia, lethargy, unwillingness to run, and combinations thereof. All brains were removed immediately after death, fixed, and evaluated grossly and microscopically for lesions. In the study with the younger animals, training was associated with a 7-9% increase in VO2max that was statistically significant only in animals with no histological evidence of cerebrovascular lesions. For the older animals, a significant 5-8% increase in VO2max was noted for animals with or without lesions. After 42 days of training for both groups, resting blood pressures for the trained groups with histological lesions were significantly lower. However, this trend did not continue, and the older trained rats appeared to have strokes earlier and to die sooner than their nontrained controls. Although 83% of the older animals had subjective evidence for a stroke before they died, the percentage of animals with lesions ranged from 42 to 58%, with the trained groups having higher percentages.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Effects of L-arginine oral supplements in pregnant spontaneously hypertensive rats

2006 ◽  
Vol 21 (4) ◽  
pp. 192-196 ◽  
Author(s):  
José Ricardo Sousa Ayres de Moura ◽  
Nelson Sass ◽  
Sérgio Botelho Guimarães ◽  
Paulo Roberto Leitão de Vasconcelos ◽  
Rosiane Mattar ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Statistical Significance ◽  
Virgin Female ◽  
Female Rats ◽  
Vaginal Smear ◽  
Shr Rats ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Oral Supplementation

PURPOSE: To evaluate the effects of L-arginine oral supplementation in spontaneously hypertensive pregnant rats (SHR). METHODS: Thirty SHR and ten Wistar-EPM-1 virgin female rats were used in the study. Before randomization, females were caged with males of the same strain (3:1). Pregnancy was confirmed by sperm-positive vaginal smear (Day 0). Wistar-EPM-1 rats served as counterpart control (C-1). SHR rats were randomized in 4 groups (n=10): Group Control 2, non-treated rats; Group L-Arginine treated with L-arginine 2%; Group Alpha-methyldopa treated with Alpha-methyldopa 33mg/Kg; Group L-Arginine+Alpha-methyldopa treated with L-arginine 2%+Alpha-methyldopa 33mg/Kg. L-arginine 2% solution was offered ad libitum in drinking water and Alpha-methyldopa was administered by gavage twice a day during the length of pregnancy (20 days). Blood pressure was measured by tailcuff plethysmography on days 0 and 20. Body weight was measured on days 0, 10 and 20. Results were expressed as mean ± SD (Standard Deviation). One-Way ANOVA/Tukey (or Kruskal-Wallis/Dunn, as appropriate) was used for group comparisons. Statistical significance was accepted as p<0.05. RESULTS: There was no significant weight gain in isolated L-arginine treated SHR. Mean blood pressure decreased in L-arginine-treated SLR compared with untreated-SHR rats. CONCLUSION: L-arginine oral supplementation reduces blood pressure in spontaneously hypertensive rats during pregnancy.

scholarly journals Aortic depressor nerve morphometry in male and female adult spontaneously hypertensive rats.

2013 ◽  
Vol 27 (S1) ◽  
Author(s):  
Milena Menezes Amorim ◽  
Jaci Airton Castania ◽  
Helio Cesar Salgado ◽  
Valéria Paula Sassoli Fazan
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
Female Adult ◽  
Male And Female ◽  
Spontaneously Hypertensive ◽  
Aortic Depressor Nerve ◽  
Nerve Morphometry

scholarly journals STIM1/Orai1 contributes to sex differences in vascular responses to calcium in spontaneously hypertensive rats

2011 ◽  
Vol 122 (5) ◽  
pp. 215-226 ◽  
Author(s):  
Fernanda R. C. Giachini ◽  
Victor V. Lima ◽  
Fernando P. Filgueira ◽  
Anne M. Dorrance ◽  
Maria Helena C. Carvalho ◽  
...  
Keyword(s):  
Sex Differences ◽  
Neutralizing Antibodies ◽  
Spontaneously Hypertensive Rats ◽  
Female Rats ◽  
Hypertensive Rats ◽  
Vascular Protection ◽  
Spontaneously Hypertensive ◽  
Female Sex Hormones ◽  
Impaired Control ◽  
Wistar Kyoto

Sex differences in Ca2+-dependent signalling and homoeostasis in the vasculature of hypertensive rats are well characterized. However, sex-related differences in SOCE (store-operated Ca2+ entry) have been minimally investigated. We hypothesized that vascular protection in females, compared with males, reflects decreased Ca2+ mobilization due to diminished activation of Orai1/STIM1 (stromal interaction molecule 1). In addition, we investigated whether ovariectomy in females affects the activation of the Orai1/STIM1 pathway. Endothelium-denuded aortic rings from male and female SHRSP (stroke-prone spontaneously hypertensive rats) and WKY (Wistar–Kyoto) rats and from OVX (ovariectomized) or sham female SHRSP and WKY rats were used to functionally evaluate Ca2+ influx-induced contractions. Compared with females, aorta from male SHRSP displayed: (i) increased contraction during the Ca2+-loading period; (ii) similar transient contraction during Ca2+ release from the intracellular stores; (iii) increased activation of STIM1 and Orai1, as shown by the blockade of STIM1 and Orai1 with neutralizing antibodies, which reversed the sex differences in contraction during the Ca2+-loading period; and (iv) increased expression of STIM1 and Orai1. Additionally, we found that aortas from OVX-SHRSP showed increased contraction during the Ca2+-loading period and increased Orai1 expression, but no changes in the SR (sarcoplasmic reticulum)-buffering capacity or STIM1 expression. These findings suggest that augmented activation of STIM1/Orai1 in aortas from male SHRSP represents a mechanism that contributes to sex-related impaired control of intracellular Ca2+ levels. Furthermore, female sex hormones may negatively modulate the STIM/Orai1 pathway, contributing to vascular protection observed in female rats.

scholarly journals Oxidative stress induces BH4 deficiency in male, but not female, SHR

2018 ◽  
Vol 38 (4) ◽  
Author(s):  
Ellen E. Gillis ◽  
Krystal N. Brinson ◽  
Olga Rafikova ◽  
Wei Chen ◽  
Jacqueline B. Musall ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Spontaneously Hypertensive Rats ◽  
No Synthase ◽  
Hypertensive Rats ◽  
Male And Female ◽  
Spontaneously Hypertensive ◽  
No Bioavailability ◽  
Renal Inner Medulla ◽  
Relative Deficiency ◽  
To Receive

We previously published that female spontaneously hypertensive rats (SHR) have significantly greater nitric oxide (NO) bioavailability and NO synthase (NOS) enzymatic activity in the renal inner medulla (IM) compared with age-matched males, although the mechanism responsible remains unknown. Tetrahydrobiopterin (BH4) is a critical cofactor required for NO generation, and decreases in BH4 as a result of increases in oxidative stress have been implicated in the pathogenesis of hypertension. As male SHR are known to have higher levels of oxidative stress compared with female SHR, we hypothesized that relative BH4 deficiency induced by oxidative stress in male SHR results in lower levels of NOS activity in renal IM compared with females. Twelve-week-old male and female SHR were randomized to receive tempol (30 mg/kg/day via drinking water) or vehicle for 2 weeks. Tempol treatment did not affect blood pressure (BP) in either sex, but reduced peroxynitrite levels only in males. Females had more total biopterin, dihydrobiopterin (BH2), and BH4 levels in renal IMs than males, and tempol treatment eliminated these sex differences. Females had greater total NOS activity in the renal IM than males, and adding exogenous BH4 to the assay increased NOS activity in both sexes. This sex difference in total NOS and the effect of exogenous BH4 were abolished with tempol treatment. We conclude that higher oxidative stress in male SHR results in a relative deficiency of BH4 compared with females, resulting in diminished renal NOS activity in the male.

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.

Gonadectomy-induced reduction of blood pressure in adult spontaneously hypertensive rats

1982 ◽  
Vol 101 (1) ◽  
pp. 154-160 ◽  
Author(s):  
Yoshiko Masubuchi ◽  
Toshio Kumai ◽  
Akiyo Uematsu ◽  
Kenji Komoriyama ◽  
Masanao Hirai
Keyword(s):  
Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Adrenal Glands ◽  
Systolic Pressure ◽  
Pressure Rise ◽  
Progressive Increase ◽  
Hormonal Changes ◽  
Hypertensive Rats ◽  
Male And Female ◽  
Spontaneously Hypertensive

Abstract. Adult male and female spontaneously hypertensive rats (SHR-Okamoto, Kyoto) were gonadectomized when they were 17 weeks old. Intact SHR showed a progressive increase of their blood pressure with growth, attaining systolic pressure levels of 194–208 in males and 163–173 mmHg in females when they were 29–30 weeks old. During this same period, the gonadectomized animals showed a significant reduction in blood pressure ranging from 168–175 in males and from 158–163 mmHg in females. These studies indicate that male and female SHR gonadectomized at 17 weeks of age do not show the progressive blood pressure rise that occurs in intact SHR. There was no change in heart rate in either sex. Corticosterone (B) levels in plasma were increased in the orchidectomized males, and 18-OH-DOC levels in plasma were increased in the adrenal glands of ovariectomized females indicating that these hormonal changes probably do not play a role in SHR hypertension. It appears that gonadal and other hormones are involved in the pathogenesis of SHR hypertension.

Mortality and histological findings of the brain during and after cerebral ischemia in male and female spontaneously hypertensive rats

1988 ◽  
Vol 454 (1-2) ◽  
pp. 238-243 ◽  
Author(s):  
Seizo Sadoshima ◽  
Yasuo Nakatomi ◽  
Kenichiro Fujii ◽  
Hiroaki Ooboshi ◽  
Takao Ishitsuka ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Spontaneously Hypertensive Rats ◽  
Histological Findings ◽  
Hypertensive Rats ◽  
Male And Female ◽  
Spontaneously Hypertensive ◽  
The Brain
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