scholarly journals Central effects of prostaglandin E2 on blood pressure and plasma renin activity in rats. Role of the sympathoadrenal system and vasopressin.

Hypertension ◽  
1982 ◽  
Vol 4 (6) ◽  
pp. 809-816 ◽  
Author(s):  
T Okuno ◽  
M D Lindheimer ◽  
S Oparil
2010 ◽  
Vol 391 (12) ◽  
Author(s):  
M. David Percival ◽  
Sylvie Toulmond ◽  
Nathalie Coulombe ◽  
Wanda Cromlish ◽  
Sylvie Desmarais ◽  
...  

Abstract Renin is the first enzyme in the renin-angiotensin-aldosterone system which is the principal regulator of blood pressure and hydroelectrolyte balance. Previous studies suggest that cathepsin B is the activator of the prorenin zymogen. Here, we show no difference in plasma renin activity, or mean arterial blood pressure between wild-type and cathepsin B knockout mice. To account for potential gene compensation, a potent, selective, reversible cathepsin B inhibitor was developed to determine the role of cathepsin B on prorenin processing in rats. Pharmacological inhibition of cathepsin B in spontaneously hypertensive and double transgenic rats did not result in a reduction in renal mature renin protein levels or plasma renin activity. We conclude that cathepsin B does not play a significant role in this process in rodents.


1983 ◽  
Vol 244 (1) ◽  
pp. R74-R77 ◽  
Author(s):  
J. Schwartz ◽  
I. A. Reid

The role of vasopressin in the regulation of blood pressure during water deprivation was assessed in conscious dogs with two antagonists of the vasoconstrictor activity of vasopressin. In water-replete dogs, vasopressin blockade caused no significant changes in mean arterial pressure, heart rate, plasma renin activity (PRA), or plasma corticosteroid concentration. In the same dogs following 48-h water deprivation, vasopressin blockade increased heart rate from 85 +/- 6 to 134 +/- 15 beats/min (P less than 0.0001), increased cardiac output from 2.0 +/- 0.1 to 3.1 +/- 0.1 1/min (P less than 0.005), and decreased total peripheral resistance from 46.6 +/- 3.1 to 26.9 +/- 3.1 U (P less than 0.001). Plasma renin activity increased from 12.4 +/- 2.2 to 25.9 +/- 3.4 ng ANG I X ml-1 X 3 h-1 (P less than 0.0001) and plasma corticosteroid concentration increased from 3.2 +/- 0.7 to 4.9 +/- 1.2 micrograms/dl (P less than 0.05). Mean arterial pressure did not change significantly. When the same dogs were again deprived of water and pretreated with the beta-adrenoceptor antagonist propranolol, the heart rate and PRA responses to the antagonists were attenuated and mean arterial pressure decreased from 103 +/- 2 to 91 +/- 3 mmHg (P less than 0.001). These data demonstrate that vasopressin plays an important role in blood pressure regulation during water deprivation in conscious dogs.


1983 ◽  
Vol 65 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Michiko Handa ◽  
Kazuoki Kondo ◽  
Hiromichi Suzuki ◽  
Takao Saruta

1. Oral administration of dexamethasone (about 2.5 × 10-7 mol/day) caused hypertension in rats. The blood pressure rose from 108 ± 6 (mean ± sd) to 156 ± 17 mmHg on the seventh day. The urine volume and urinary excretion of sodium were increased. The plasma renin activity and plasma aldosterone were unchanged. However, the urinary excretions of prostaglandin E2 (UPGE2V) and kallikrein (Ukall.V) were markedly decreased throughout the experiment. 2. With concurrent administration of captopril, the elevation of blood pressure was partially prevented. in this group of rats, the plasma renin activity was elevated and the reductions in UPGE2V and Ukall.V were partially prevented. 3. Based on these results, it is suggested that suppression of the kallikrein—kinin and prostaglandin systems, in addition to involvement of the renin-angiotensin system, is one of the factors contributing to the hypertensive action of dexamethasone.


1978 ◽  
Vol 55 (s4) ◽  
pp. 307s-309s ◽  
Author(s):  
G. Leonetti ◽  
Laura Terzoli ◽  
Carla Sala ◽  
C. Bianchini ◽  
Laura Sernesi ◽  
...  

1. The pressor role of renin stimulated by chronic diuretic therapy has been assessed in 31 patients with essential hypertension by infusing the angiotensin II antagonist, saralasin, immediately before and at the end of 2 weeks' treatment with the diuretic, chlorthalidone. 2. Under diuretic therapy the change in blood pressure caused by saralasin was found to be correlated to plasma renin activity values, in such a way that small pressor responses were again observed in patients whose renin was mildly stimulated by the diuretic, whereas a marked depressor response occurred in patients whose renin was markedly increased. 3. On the other hand, the hypotensive effect of chlorthalidone was correlated to values of plasma renin activity under diuretic therapy in an opposite direction: indeed little or no decrease and sometimes an increase in blood pressure were observed in patients with marked renin activation by diuretic therapy. 4. It is concluded that stimulation of renin release by chronic diuretic therapy can be considered a factor limiting the hypotensive activity of diuretic drugs.


1988 ◽  
Vol 254 (3) ◽  
pp. H509-H516 ◽  
Author(s):  
M. Burnier ◽  
B. Waeber ◽  
J. F. Aubert ◽  
J. Nussberger ◽  
H. R. Brunner

A nonhypotensive dose of endotoxin was administered to normal conscious rats to evaluate the vascular and humoral effects of endotoxemia per se. Mean blood pressure and heart rate remained stable during the 45 min infusion of Escherichia coli endotoxin (0.01 mg/min). However, a marked increase in plasma renin activity (4.2 +/- 0.48 vs. 30.2 +/- 6 ng.ml-1.h-1, mean +/- SE, P less than 0.01), plasma epinephrine (0.112 +/- 0.04 vs. 1.71 +/- 0.5 ng/ml, P less than 0.01), and plasma norepinephrine (0.269 +/- 0.028 vs. 1.3 +/- 0.2 ng/ml, P less than 0.001) was observed during infusion in endotoxin-treated rats when compared with the vehicle-treated animals. In addition, the blood pressure response to exogenous norepinephrine was significantly reduced during nonhypotensive endotoxemia. Significant changes in regional blood flow distribution, as assessed by radiolabeled microspheres, were observed in endotoxemic rats; in particular a decrease in renal blood flow (7.39 +/- 0.43 vs. 5.97 +/- 0.4 ml.min-1.g-1, P less than 0.05) and an increase in coronary blood flow (5.01 +/- 0.38 vs. 6.44 +/- 0.33 ml.min-1.g-1, P less than 0.01) were found. The role of prostaglandins in the vascular and humoral alterations induced by nonhypotensive endotoxemia was also examined. Pretreatment with indomethacin (5 mg) prevented the increase in plasma renin activity as well as plasma catecholamine levels. On the contrary, the decreased vascular reactivity and the reduction in renal blood flow observed during endotoxemia were not affected by prostaglandin synthesis inhibition. Thus significant vascular and humoral changes have been found during endotoxemia even in absence of hypotension.(ABSTRACT TRUNCATED AT 250 WORDS)


1980 ◽  
Vol 59 (s6) ◽  
pp. 141s-144s ◽  
Author(s):  
Keishi Abe ◽  
Toru Ito ◽  
Makito Sato ◽  
Toshiaki Haruyama ◽  
KO Sato ◽  
...  

1. The role of endogenous prostaglandins in the antihypertensive mechanism of the angiotensin converting enzyme inhibitor, captopril, was investigated. 2. An unequivocal reduction in blood pressure and significant increase in plasma renin activity and urinary prostaglandin E excretion were found after the captopril administration. 3. The changes in blood pressure, plasma renin activity and urinary prostaglandin E excretion induced by captopril were reversed after the inhibition of endogenous prostaglandin synthesis by indomethacin. However, the responses in low renin hypertension were different from those in normal renin hypertension. 4. In low renin hypertensive patients who responded to captopril, the hypotensive effect was abolished after the addition of indomethacin, whereas no marked change in blood pressure was induced by indomethacin in normal renin hypertensive patients. In contrast, plasma renin activity was markedly increased after captopril administration in normal renin hypertension, and no significant change was found in low renin hypertension. 5. Potentiation of the prostaglandin system seems to be a principal factor in the antihypertensive mechanism of captopril in low renin hypertension, and inhibition of the renin-angiotensin system is important in normal renin hypertensives. 6. The increase in renin release after the administration of captopril was inhibited by indomethacin, suggesting that an endogenous prostaglandin system may contribute to the short feedback mechanism of renin release.


1978 ◽  
Vol 89 (1) ◽  
pp. 132-141 ◽  
Author(s):  
Ikuo Saito ◽  
Takao Saruta ◽  
Toyohisa Eguchi ◽  
Kazuoki Kondo ◽  
Ryuichi Nakamura ◽  
...  

ABSTRACT To evaluate the role of angiotensin III in the control of blood pressure, plasma aldosterone and plasma renin activity (PRA), the pressor, steroidogenic and PRA-suppressing effect of angiotensin III was studied in rabbits with or without simultaneous constant infusion of Ile7-angiotensin III, an analogue of angiotensin III, or Sar1Ala8-angiotensin II, an analogue of angiotensin II, and compared with the effect of angiotensin II. Infusion of 30 ng/kg/min of angiotensin III or angiotensin II produced a twofold increase in plasma aldosterone. Pressor response to angiotensin III was approximately one tenth of that of angiotensin II. Infusion of angiotensin II suppressed the PRA significantly, while infusion of angiotensin III did not suppress it. Angiotensin II or angiotensin III induced-increase in plasma aldosterone was attenuated by the pretreatment with either Ile7-angiotensin III or Sar1Ala8-angiotensin II. Pressor or PRA-suppressing action of angiotensin II was unaffected by the pre-treatment with Ile7-angiotensin III, while it was significantly inhibited by pre-treatment with Sar1Ala8-angiotensin II. This study indicates that angiotensin III or angiotensin III analogues affect the adrenal glands selectively and suggests that there are differences between the receptor sites for angiotensins in vascular smooth muscle, kidney and those in the adrenal cortex.


1986 ◽  
Vol 22 (3) ◽  
pp. 265-273
Author(s):  
V. Lahera ◽  
V. Cachofeiro ◽  
F.J. Cañizo ◽  
F. Durán ◽  
J. Parada ◽  
...  

1976 ◽  
Vol 51 (s3) ◽  
pp. 249s-251s
Author(s):  
C. G. Strong ◽  
J. C. Romero

1. Indomethacin inhibits prostaglandin synthesis and interferes with renin release; these effects were studied in rabbit renovascular hypertension. 2. Ten intravenous inject ons (3 mg day—1 kg—1 after two initial doses of 9 mg/kg) of indomethacin were given daily to ten normal rabbits, ten rabbits with two-kidney Goldblatt hypertension (2KH), and ten rabbits with one-kidney Goldblatt hypertension (1KH). Twelve appropriate control rabbits received diluent phosphate buffer without indomethacin. Plasma renin activity and plasma prostaglandin E2 were measured by radioimmunoassay. 3. In the normal group, indomethacin significantly decreased plasma prostaglandin E2 (1·15 to 0·2 ng/ml, sem 0·2; P < 0·01) and plasma renin activity (20 to 3 ng h—1 ml—1, sem 1, P < 0·01). Plasma creatinine increased slightly but the mean blood pressure was not significantly changed by indomethacin. 4. Six of ten rabbits with 2KH showed results similar to those in the normal rabbits. In four of ten rabbits in which development of 2KH was accompanied by increments in plasma renin activity (18 to 31·5 ng h—1 ml—1, sem 3 and 4 respectively; P < 0·01) and plasma prostaglandin E2 (1·2 to 3·4 ng/ml, sem 0·2 and 0·4 respectively; P < 0·05), treatment with indomethacin produced renal failure (plasma creatinine increasing to 7·6 mg/100 ml), oliguria, malignant hypertension (mean blood pressure, 168 mmHg, sem 7·7) and death within 5 days. 5. In 1KH, indomethacin decreased plasma renin activity and plasma prostaglandin E2, but caused increased mean blood pressure (102 to 121 mmHg, sem 4 and 6 respectively; P < 0·01) and decreased renal function (plasma creatinine 0·9 ± 0·04 to 3·5 ± 1 mg/100 ml, sem 0·04 and 1 respectively; P < 0·01). 6. Aggravation of hypertension was conditioned by pre-existing levels of renal function and, to a lesser extent, by plasma renin activities. 7. These results suggest that prostaglandins exert a protective effect on renal function in renovascular hypertension.


1975 ◽  
Vol 36 (6) ◽  
pp. 248-256 ◽  
Author(s):  
G G Geyskes ◽  
P Boer ◽  
J Vos ◽  
F H Leenen ◽  
E J Mees

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