Effects of alpha-adrenoceptor blockers on renal function and blood pressure adjustment in human hypertension

In this paper the different aspects of the role played by alpha-adrenoceptors in the control of renin secretion from the juxtaglomerular apparatus and renal sodium and water reabsorption, and the effects of alpha-adrenoceptor antagonists on systemic haemodynamics, will be investigated. Animal experiments suggest that the renal alpha-adrenoceptors exert a restraining action on renin secretion while increasing tubular reabsorption of sodium and water. A recent study in man has confirmed the alpha-adrenoceptor-mediated inhibition of renin secretion. Previously available ganglion blocking and antiadrenergic agents, while causing a significant supine blood pressure reduction, can cause at the same time clinically relevant side effects such as orthostatic hypotension, sedation, drowsiness etc. The advent of selective alpha 1-adrenoceptor blockers, such as prazosin and urapidil, allow a significant blood pressure reduction without significant interference on haemodynamic adjustments and only induce a limited incidence of side effects.