INTERACTIONS BETWEEN THE SYMPATHETIC AND RENIN-ANGIOTENSIN SYSTEMS

The renin-angiotensin system is involved in the control of sodium and water balance, mitogenesis and the regulation of vascular tone as well as of the activity of the sympathetic nervous system. Many of these e ffects may be regulated at a local level by independent tissue renin-a ngiotensin systems. The renin-angiotensin and adrenergic nervous syste ms are cross-regulated by interactive compensatory mechanisms. Therefo re, the activation of one of these systems induces the activation or i nduction of the other leading to a co-amplification of cellular mechan isms, for instance resulting in the facilitation of sympathetic neurot ransmission. This paper describes the interactions between these syste ms in the central nervous system and at pre- and postsynaptic sites of the nerve endings in cardiovascular tissues. Since these systems are cross-regulated, the inhibition of one would attenuate the activity of the other. The drugs that inhibit specifically the various components of the renin-angiotensin system have proved powerful tools for studie s of the physiology of this system as well as for the treatment of hyp ertension and heart failure.