Analysis of beta-adrenoceptors mediating renin release produced by isoproterenol in conscious dogs

1980 ◽  
Vol 238 (5) ◽  
pp. F387-F393
Author(s):  
N. Himori ◽  
A. Izumi ◽  
T. Ishimori

Types of beta-adrenoceptors mediating renin release induced by isoproterenol were investigated in conscious dogs. The nonselective beta-adrenoceptor blocking drugs propranolol, D-32, and pindolol significantly inhibited increases in heart rate and plasma renin activity and a fall of blood pressure produced by intravenous infusion of isoproterenol (10 microgram . kg-1 . 20 min-1). d-Propranolol and d-D-32 did not inhibit these three responses to isoproterenol. The selective beta 1-adrenoceptor blocking drug atenolol, at the oral dose of 6 mg/kg, which selectively suppressed isoproterenol-induced tachycardia, significantly inhibited the renin release caused by isoproterenol. By contrast, the renin release induced by isoproterenol was not modified by the selective beta 2-adrenoceptor blocking drug IPS-339 at an oral dose of 3 mg/kg, which fully and selectively antagonized the fall of blood pressure in response to isoproterenol. There was good correlation between suppression of isoproterenol-induced renin release and that of isoproterenol-induced tachycardia after various beta-adrenoceptor blocking drugs. These results lead to the conclusion that in conscious dogs the beta-adrenoceptors mediating release are mainly of the beta 1 type.

1981 ◽  
Vol 139 (6) ◽  
pp. 545-549 ◽  
Author(s):  
Elizabeth A. Taylor ◽  
Paul Turner ◽  
Jean Harrison

SummaryThe influence of beta-adrenoceptor antagonism on the effects of a simple experimental stress was investigated in 12 healthy volunteers, using a double-blind protocol. A single oral dose of 80 mg propranolol reduced the stress-induced increase in heart rate and systolic blood pressure to 49.9 per cent and 8.3 per cent respectively compared to 61.0 per cent and 17.4 per cent with placebo. The rise in diastolic blood pressure was small and unaffected by beta-adrenoceptor blockade. The rise in temperature of the skin of the trunk was significantly reduced by propranolol. The self-rating of anxiety, alertness and concentration by the subjects was unaffected by propranolol.


1991 ◽  
Vol 260 (4) ◽  
pp. H1031-H1036 ◽  
Author(s):  
K. Hasunuma ◽  
K. Yamada ◽  
Y. Tamura ◽  
S. Yoshida

To investigate the involvement of prostacyclin and the sympathetic nervous system in cardiovascular responses to 1-desamino-8-D-arginine vasopressin (DDAVP), a selective V2-receptor agonist, in normal subjects, DDAVP (0.4 micrograms/kg) was infused with or without indomethacin, a cyclooxygenase inhibitor, or propranolol, a beta-adrenoceptor antagonist. A decrease in blood pressure and increases in pulse rate and plasma renin activity (PRA) were observed by DDAVP infusion. Indomethacin did not influence the DDAVP-induced changes in blood pressure and pulse rate but suppressed the increases in PRA and urinary 6-ketoprostaglandin F1 alpha excretion after DDAVP infusion. Even with propranolol administration, DDAVP produced a similar decrease in blood pressure with a reduction of the increased pulse rate. The DDAVP-induced increase in PRA was not affected either. Indomethacin or propranolol alone did not affect the basal levels of the parameters. DDAVP stimulated the in vitro renin release from rabbit renal cortical slices. The stimulation was inhibited by indomethacin or d(CH2)5[D-Ile2,Ile4]AVP, a selective V2-receptor antagonist. These findings suggest that DDAVP primarily elicits vasodilation, probably through the prostacyclin-independent endothelium-derived relaxation and DDAVP also causes an increase in renin release, which would be partly attributed to the increased synthesis of prostacyclin due to vasculoendothelial V2-like receptor activation but not mainly due to an increase in sympathetic nerve activity.


1995 ◽  
Vol 269 (4) ◽  
pp. R914-R922 ◽  
Author(s):  
K. Kamimura ◽  
H. Nishimura ◽  
J. R. Bailey

Several avian species show elevated blood pressure (BP) and spontaneous atherogenesis in the aorta and other large arteries. The BP appears to be influenced by age, sex (higher in males), environment, and diet in some species. We reported previously that mean aortic pressure and heart rate, but not plasma renin activity (PRA), of conscious female domestic fowl were markedly reduced by propranolol. In the present study, we aimed to determine in conscious roosters whether 1) hypotension evoked by atenolol or practolol, which selectively inhibit cardiac beta-receptors in mammals, is more potent than that evoked by propranolol, and 2) the renin-angiotensin (ANG) system and/or catecholamines are involved in beta-adrenoceptor antagonist-induced hypotension. Mean arterial pressure (171.2 +/- 3.5 mmHg) and heart rate (281 +/- 4 beats/min) of chronically cannulated roosters (n = 38) were markedly reduced by acute infusion or repeated injections (14 days) of propranolol, atenolol, or practolol, but not by SQ-14,225 (ANG-converting enzyme inhibitor) or [Sar1, Thr8]ANG II (nonselective ANG receptor antagonist). None of the beta-adrenoceptor blockers, however, showed cardioselectivity. The resting PRA of conscious roosters (1.27 +/- 0.09 ng.ml-1.h-1, n = 38) was low and did not change significantly after chronic or acute treatment with beta-adrenoceptor blockers except for a slight decrease induced by practolol. PRA increased after SQ-14,225. The plasma levels (pg/ml) of norepinephrine (701.9 +/- 76.0), epinephrine (337.2 +/- 57.1), and dopamine (299.1 +/- 39.0) of conscious roosters were further increased by propranolol. Practolol also increased dopamine significantly.(ABSTRACT TRUNCATED AT 250 WORDS)


1993 ◽  
Vol 264 (1) ◽  
pp. E11-E17 ◽  
Author(s):  
E. E. Blaak ◽  
M. A. van Baak ◽  
K. P. Kempen ◽  
W. H. Saris

This study was intended to investigate the role of alpha- and beta-adrenoceptor populations in the sympathetically mediated thermogenesis in healthy lean males. In the first study, the beta 1-, beta 2-, and beta 3-agonist isoprenaline was infused in increasing doses with and without simultaneous infusion of the beta 1-blocker atenolol (Iso and Iso+AT, respectively). There was an increase in whole body energy expenditure (EE) after infusing Iso+AT (P < 0.001) and an almost twofold higher increase after infusion of Iso only (P < 0.001). Stimulation of the beta 2-adrenoceptors by a specific agonist (salbutamol) resulted in a significant increase in EE (P < 0.001). The effect of stimulation of alpha 1-adrenoceptors on EE was measured by infusing increasing doses of the alpha 1-agonist phenylephrine. EE did not change, whereas blood pressure (BP) increased (P < 0.001) and heart rate decreased (P < 0.01). In addition to this study, the alpha 1-, alpha 2-, beta 1-, beta 2-, and beta 3-agonists norepinephrine and epinephrine were infused with simultaneous infusion of the beta 1- and beta 2-blocker propranolol. In both studies, there was no effect on EE, whereas BP increased (P < 0.01). In conclusion, in healthy male lean volunteers both beta 1- and beta 2-adrenoceptors are involved in the sympathetically mediated thermogenesis, whereas the alpha 1-, alpha 2-, and beta 3-adrenoceptors do not play a role.


1974 ◽  
Vol 48 (s2) ◽  
pp. 89s-91s
Author(s):  
M. A. Weber ◽  
Helen F. Oates ◽  
G. S. Stokes

1. Plasma renin activity (PRA) and mean blood pressure were studied in conscious rabbits infused with beta-adrenoreceptor antagonists. 2. Oxprenolol and dl-propranolol each significantly reduced PRA and blood pressure, but prindolol, which had a strong blood pressure-lowering effect, increased PRA. 3. When prindolol was given to animals in which PRA and blood pressure had been reduced by dl-propranolol, PRA returned to control values but blood pressure remained low. Thus the increase in PRA caused by prindolol is not mediated by hypotension. These findings, together with the observation that compound H35/25 reduced PRA without altering blood pressure, suggest that the effects of the beta-adrenoreceptor-blocking drugs on blood pressure are unrelated to their effects on renin release. 4. Studies with d-propranolol and with blocking agents with either beta-1 or beta-2 specificity indicated that the effects of beta-adrenoreceptor blockade on renin are directly dependent upon their action on beta-adrenergic receptors, probably of the beta-2 type.


1974 ◽  
Vol 48 (s2) ◽  
pp. 65s-67s ◽  
Author(s):  
C. F. George ◽  
P. J. Lewis ◽  
J. A. Steiner ◽  
C. T. Dollery

1. The effects of propranolol and R03-4787, a new beta-adrenoceptor antagonist with a partial agonist activity, have been studied in a blind, cross-over comparison with placebo. 2. In ten patients who completed the study, the two drugs produced a similar reduction in blood pressure; the reduction in heart rate with propranolol was significantly(P0.001)greater than that produced by R03-4787. 3. Plasma renin activity averaged 4.13 ± 1.37 ng h−1ml−1 on placebo, fell to 3.64 ± 1.47 ng h−1ml−1 on propranolol and to 2.50 ± 1.39 ngh−1ml−1 on R03-4787. 4. No correlation was demonstrable between the log plasma concentration of either propranolol or R03-4787 and change in blood pressure.


1989 ◽  
Vol 256 (6) ◽  
pp. R1299-R1307
Author(s):  
A. J. Gorman ◽  
J. S. Chen

The purpose of the present study was to determine the effects of left ventricular (LV) outflow obstruction on plasma renin activity (PRA) and the contribution from afferent receptors located in the LV myocardium. In chronically instrumented, conscious dogs (n = 12), changes in PRA during a 15- to 20-mmHg decrease in arterial blood pressure were assessed during 1) intravenous infusions of nitroprusside (NP) alone and 2) infusions of NP while peak systolic LV pressure was elevated by acute ascending aortic occlusion (AAO + NP). Infusions of NP alone elicited significant increases in heart rate (24.9 +/- 5.1 beats/min; P less than 0.01) and in PRA [3.31 +/- 0.53 ng angiotensin I (ANG I).ml-1.h-1; P less than 0.01]. These were accompanied by decreases in both LV pressure (-13.8 +/- 3.6 mmHg; P less than 0.05) and left atrial pressure (-3.0 +/- 0.7 mmHg; P less than 0.05). During AAO + NP, LV pressure was elevated to an absolute level of 169.2 +/- 4.6 mmHg (+53.3 +/- 4.2 mmHg; P less than 0.001), whereas left atrial pressure was not changed. Both the hypotension-induced rise in PRA and tachycardia were significantly inhibited during AAO + NP (+0.59 +/- 0.29 ng ANG I.ml-1.h-1 and +6.3 +/- 4.6 beats/min, respectively; NS). The topical application of a local anesthetic in the region of the main coronary artery, sufficient to block the heart rate and arterial blood pressure responses to selective LV receptor stimulation by intracoronary veratridine (0.1-0.4 microgram/kg), resulted in significant increases in PRA and heart rate during AAO + NP.(ABSTRACT TRUNCATED AT 250 WORDS)


1991 ◽  
Vol 260 (6) ◽  
pp. E910-E919 ◽  
Author(s):  
M. L. Blair ◽  
H. Hisa ◽  
C. D. Sladek ◽  
K. J. Radke ◽  
F. M. Gengo

These experiments evaluated the contribution of renal alpha-adrenoceptors, renal beta-adrenoceptors, and extrarenal beta-adrenoceptors to increased plasma renin activity (PRA) during nonhypotensive hemorrhage in conscious dogs. Blood withdrawal at a rate of 16 g/kg body wt over 20 min increased PRA to nearly threefold control levels without decreasing mean arterial pressure. The PRA response to hemorrhage was reduced to a greater extent by simultaneous direct renal arterial (ira) infusion of phenoxybenzamine and propranolol than by propranolol alone. Phenoxybenzamine infusion ira did not block alpha-adrenoceptors located outside of the kidney. The PRA and heart rate responses to hemorrhage were both significantly reduced when propranolol was infused either ira or intravenously (iv) at a rate of 2 micrograms.kg-1.min-1 for 20 min followed by 0.5 microgram.kg-1.min-1 continuous infusion. Propranolol infusion at a lower rate (0.5 microgram.kg-1.min-1 for 20 min followed by 0.12 microgram.kg-1.min-1) had little effect on the magnitude of increase in PRA when infused either iv or ira. The calculated renal arterial plasma propranolol concentration was at least fivefold higher or more during ira than during iv propranolol infusion at each rate and was approximately the same during ira infusion at the lower rate (17.5 +/- 0.7 ng/ml) as during iv infusion at the higher rate (16.7 +/- 2.4 ng/ml). These data indicate that the hemorrhage-induced increase in PRA is mediated by renal alpha-adrenoceptors and extrarenal beta-adrenoceptors, whereas renal beta-adrenoceptors appear to play little or no role.


1998 ◽  
Vol 9 (7) ◽  
pp. 1318-1320
Author(s):  
C Baylis ◽  
K Engels ◽  
W H Beierwaltes

Plasma renin activity (PRA) was similar in young versus old male Sprague Dawley rats under unstressed conditions (1.3 +/- 0.2 versus 1.8 +/- 0.3 ng angiotensin I/ml per min). Airjet stress increases PRA in young but not old rats (13.9 +/- 3.8 versus 2.9 +/- 0.8 ng angiotensin I/ml per min), respectively. This response is ablated in young rats by beta-adrenoceptor blockade, suggesting that the increased PRA is mediated by beta-adrenoceptors, and this response was blunted in old rats.


Sign in / Sign up

Export Citation Format

Share Document