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.

scholarly journals Splenectomy decreases blood pressure and abolishes sex differences in renal Tregs in spontaneously hypertensive rats

2021 ◽  
Author(s):  
Ellen E Gillis ◽  
Kasey Belanger ◽  
Mahmoud Abdelbary ◽  
Riyaz Mohamed ◽  
Jingping Sun ◽  
...  
Keyword(s):  
Blood Pressure ◽  
T Cells ◽  
Sex Differences ◽  
Spontaneously Hypertensive Rats ◽  
Flow Cytometric Analysis ◽  
Hypertensive Rats ◽  
Male And Female ◽  
Spontaneously Hypertensive ◽  
Flow Cytometric

Over the past decade there has been increasing support for a role of the immune system in the development of hypertension. Our lab has previously reported that female spontaneously hypertensive rats (SHR) have a blood pressure (BP)-dependent increase in anti-inflammatory renal regulatory T cells (Tregs), corresponding to lower BP compared to males. However, little is known regarding the mechanism for greater renal Tregs in females. The current study was designed to test the hypothesis that the greater relative abundance of renal Tregs in female SHR is due to greater Treg production. To test this hypothesis, T cell profiles were measured in the spleen by flow cytometry in male and female SHR at 5 weeks and 14 weeks of age.  Splenic Tregs did not differ between males and females, suggesting sex differences in renal Tregs is not due to differences in production. To assess the role of the spleen in sex differences in renal Tregs and BP control, rats were randomized to receive sham surgery (CON) or splenectomy (SPLNX, n=6) at 12 wks of age and implanted with telemeters to measure BP. After 2 weeks, kidneys were harvested for flow cytometric analysis of T cells. Splenectomy increased BP in both sexes after 2 weeks. Renal Tregs decreased in both sexes after splenectomy, abolishing the sex differences in renal Tregs. In conclusion, splenic Tregs were comparable in male and female SHR, suggesting that sex differences in renal Tregs is due to differences in renal Treg recruitment, not Treg production.

Antihypertensive actions of angiotensin-(1-7) in spontaneously hypertensive rats

1995 ◽  
Vol 269 (1) ◽  
pp. H313-H319 ◽  
Author(s):  
I. F. Benter ◽  
C. M. Ferrario ◽  
M. Morris ◽  
D. I. Diz
Keyword(s):  
Blood Pressure ◽  
Prostaglandin E2 ◽  
Spontaneously Hypertensive Rats ◽  
Systolic Pressure ◽  
Experimental Hypertension ◽  
Electrolyte Balance ◽  
Ang Ii ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Plasma Vasopressin

Observations that angiotensin-(1-7) [ANG-(1-7)] may oppose the vasoconstrictor actions of angiotensin II (ANG II) prompted an investigation of the effects of the heptapeptide on the maintenance of elevated blood pressure in spontaneously hypertensive rats (SHR). ANG-(1-7) (24 micrograms.kg-1.h-1) was infused into the jugular vein of 13-wk-old SHR (n = 64), Wistar-Kyoto (WKY, n = 50), and Sprague-Dawley (SD, n = 18) rats for 2 wk, with the use of osmotic minipumps. Blood pressure, fluid and electrolyte balance, plasma vasopressin, and urinary excretion of prostaglandin E2 and 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) were measured at days 2, 7, and 12 of the infusion. In SHR, ANG-(1-7) caused a sustained and significant reduction in plasma vasopressin concentration that was associated with an increase in urinary prostaglandin E2 and 6-keto-PGF1 alpha excretion at day 2 after the commencement of the infusion. These changes were accompanied by diuresis and natriuresis during the first 3 days of infusion in SHR but not in WKY or SD rats. Direct measurements of arterial pressure confirmed the lowering effect of ANG-(1-7) on systolic pressure of SHR on day 2 of treatment with a restoration of the pressure by days 7 and 12. These findings, along with our previous demonstration that ANG-(1-7) is an active depressor peptide in the intact animal, suggest that ANG-(1-7) may play a significant role as a vasodepressor system opposing the hemodynamic actions of ANG II in this genetic form of experimental hypertension.

Dietary sodium stimulates ouabainlike activity in adrenalectomized spontaneously hypertensive rats

1993 ◽  
Vol 265 (1) ◽  
pp. H421-H424 ◽  
Author(s):  
F. H. Leenen ◽  
E. Harmsen ◽  
H. Yu ◽  
B. Yuan
Keyword(s):  
Blood Pressure ◽  
Central Nervous System ◽  
Nervous System ◽  
Spontaneously Hypertensive Rats ◽  
Adrenal Glands ◽  
Dietary Sodium ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
The Central Nervous System

Both the adrenal glands and the hypothalamus have been proposed to produce compound(s) with ouabainlike activity (OLA). To evaluate the contribution of the adrenal glands, 4-wk-old spontaneously hypertensive rats (SHR) were sham operated or adrenalectomized. The adrenalectomized SHR were given daily injections of corticosterone and aldosterone. Subsequently, rats were randomized to control or high (8%) dietary Na+, and after 2.5 wk, blood pressure and OLA in plasma, hypothalamus, and pituitary were evaluated. Hypertension developed somewhat less in adrenalectomized vs. sham-operated SHR. On control Na+ intake, adrenalectomy caused only minor decreases in circulating and central OLA. Adrenalectomy did not prevent the 50-90% increases in plasma, hypothalamus, and pituitary OLA caused by high Na+ intake for 2.5 wk. These findings are consistent with the concept that, at least in SHR, the central nervous system may represent the major source of both central and peripheral OLA.

Contribution of the Kidneys but not Adrenal Glands to the Acute Antihypertensive Effects of Captopril in Spontaneously Hypertensive Rats

1979 ◽  
Vol 57 (s5) ◽  
pp. 127s-130s ◽  
Author(s):  
M. J. Antonaccio ◽  
J. P. High ◽  
B. Rubin ◽  
T. Schaeffer
Keyword(s):  
Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Adrenal Glands ◽  
Antihypertensive Effect ◽  
Bilateral Adrenalectomy ◽  
Bilateral Nephrectomy ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Subsequent Dose

1. Captopril (100 mg/kg, orally) decreased blood pressure in spontaneously hypertensive (SH) rats. 2. Bilateral adrenalectomy either before or after captopril administration did not alter the antihypertensive effect of captopril. 3. Bilateral nephrectomy reversed the established antihypertensive effect of captopril and prevented any change in blood pressure to a subsequent dose of captopril. 4. It is concluded that kidneys but not adrenal glands are essential to the antihypertensive actions of captopril in SH rats.

Effect of potassium supplementation on blood pressure and vasodilator mechanisms in spontaneously hypertensive rats

1988 ◽  
Vol 75 (5) ◽  
pp. 527-534 ◽  
Author(s):  
Anne Barden ◽  
Lawrence J. Beilin ◽  
Robert Vandongen
Keyword(s):  
Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Hydrolysis Product ◽  
Pressure Rise ◽  
Plasma Renin ◽  
Renin Activity ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Potassium Supplementation ◽  
Blood Pressure Rise

1. Supplementation with 1% (w/v) KCl solution significantly attenuated the blood pressure rise with age normally observed in spontaneously hypertensive rats, resulting in a difference in blood pressure of 18 mmHg after 5 weeks. 2. Urinary 6-keto-prostaglandin F1α (the stable hydrolysis product of prostacyclin) and kallikrein excretion were significantly elevated in rats receiving potassium. 3. No difference was observed in sodium excretion during the initial days of potassium supplementation; however, the potassium-supplemented animals excreted relatively more sodium over the 5 week period. 4. Plasma renin activity was significantly reduced in those animals receiving potassium after 5 weeks. 5. It is proposed that a combination of increased systemic and/or renal prostacyclin and kallikrein synthesis may, in combination with reduced renin activity, contribute to the attenuation of blood pressure in potassium-supplemented spontaneously hypertensive rats.

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