Open AccessSympathetic Nervous System in Essential Hypertension and Antihypertensive Response to α2-Adrenoceptor Stimulation
Author(s) -
Bühler Fr,
Peter Bolli,
Amann Wf,
Paul Erné,
Wolfgang Kiowski
Publication year - 1984
Publication title -
journal of cardiovascular pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.762
H-Index - 100
eISSN - 1533-4023
pISSN - 0160-2446
DOI - 10.1097/00005344-198400065-00005
Subject(s) - sympathetic nervous system , medicine , stimulation , essential hypertension , sympathetic activity , autonomic nervous system , pharmacology , neuroscience , blood pressure , psychology , heart rate
In patients with essential hypertension, the vasodilator response in the forearm circulation to postjunctional alpha 1-adrenoceptor blockade with prazosin is enhanced. Besides the effects at classical postjunctional alpha 1-adrenoceptor, postjunctional alpha 2-adrenoceptor-mediated effects contribute to vascular tone, and these may be comparable in magnitude to those observed with prazosin. Owing to the extrajunctional localization of alpha 2-adrenoceptors, they may be preferential targets for circulating catecholamines and adrenaline in particular. No evidence of autoinhibitory noradrenaline feedback system via prejunctional alpha 2-adrenoceptors was found by measuring noradrenaline release from the forearm. Therefore increased sympathetic nerve activity, as demonstrated by increased plasma adrenaline concentrations, plays an important role in the pathophysiology of essential hypertension by contributing to increased vascular resistance. Central prejunctional alpha 2-adrenoceptor-stimulating drugs lower sympathetic nerve activity and thereby peripheral resistance and blood pressure, and this effect seems to override peripheral (pre-) and postjunctional alpha 2-adrenoceptor-stimulating effects.