Peripheral Presynaptic Facilitatory Effect of Angiotensin II on Noradrenaline Release in Anesthetized Rabbits
- 1 June 1990
- journal article
- research article
- Published by Wolters Kluwer Health in Journal of Cardiovascular Pharmacology
- Vol. 15 (6), 968-975
- https://doi.org/10.1097/00005344-199006000-00015
Abstract
The function of presynaptic angiotensin II receptors at postganglionic sympathetic terminal axons under conditions of uninterrupted sympathetic impulse traffic was studied in anesthetized rabbits (alfadolone + alfaxalone). Mean arterial pressure, postganglionic renal sympathetic firing rate, the arterial plasma noradrenaline concentration, and heart rate were measured before (basal values) and at the end of 4-min infusions of sodium nitroprusside. Angiotensin II (20 or 100 ng kg-1 min-1) caused dose-dependent increases of basal mean arterial pressure and decreased of basal sympathetic nerve activity and heart rate, but did not change the basal plasma noradrenaline concentration. Moreover, it shifted the sympathetic nerve activity-plasma noradrenaline relationship in a manner indicating an increase of the average release of noradrenaline per action potential. Angiotensin II at 100 ng kg-1 had an additional effect, at any given blood pressure, sympathetic nerve activity and heart rate were lower than in the controls. Captopril (1 mg kg-1 followed by 1 mg kg-1) caused no change in any parameter. The results demonstrate that exogenous angiotensin II activates release-facilitating receptors at postganglionic sympathetic neurons in rabbits with ongoing sympathetic nerve activity. Endogenous angiotensin II, however, played no role in cardiovascular regulation under the present, acute experimental conditions. Vasopressin, which was studied for comparison, lacked a presynaptic effect on the release of noradrenaline but caused sympathoinhibition by an action on a central component of the baroreflex.This publication has 17 references indexed in Scilit:
- BETA-ADRENOCEPTOR FACILITATION OF NOREPINEPHRINE RELEASE IS NOT DEPENDENT ON LOCAL ANGIOTENSIN-II FORMATION IN THE RAT ISOLATED KIDNEY1987
- ACTH increases noradrenaline release in pithed rabbits with electrically stimulated sympathetic outflowEuropean Journal of Pharmacology, 1987
- Sensitization of aortic and cardiac baroreceptors by arginine vasopressin in mammals.The Journal of Physiology, 1986
- Influence of intravenous and intracerebroventricular vasopressin on baroreflex control of renal nerve traffic.Circulation Research, 1986
- The renal sympathetic baroreflex in the rabbit. Arterial and cardiac baroreceptor influences, resetting, and effect of anesthesia.Circulation Research, 1985
- Modulation of Noradrenaline Release in the Pithed RabbitJournal of Cardiovascular Pharmacology, 1984
- The noradrenaline release rate in the anaesthetized rabbit: Facilitation by adrenalineNaunyn-Schmiedebergs Archiv für experimentelle Pathologie und Pharmakologie, 1982
- The Effect of Angiotensin II Infusion on Plasma Catecholamines in the Conscious RabbitExperimental Biology and Medicine, 1981
- Inhibition by angiotensin II of baroreceptor‐evoked activity in cardiac vagal efferent nerves in the dog.The Journal of Physiology, 1979
- Presynaptic receptor systems on the noradrenergic neurones of the rabbit pulmonary arteryNaunyn-Schmiedebergs Archiv für experimentelle Pathologie und Pharmakologie, 1977