[Interaction between the sympathetic and renin-angiotensin system]

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 effects may be regulated at a local level by independent tissue renin-angiotensin systems. The renin-angiotensin and adrenergic nervous systems are cross-regulated by interactive compensatory mechanisms. Therefore, the activation of one of these systems induces the activation or induction of the other leading to a co-amplification of cellular mechanisms, for instance resulting in the facilitation of sympathetic neurotransmission. This paper describes the interactions between these systems 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 studies of the physiology of this system as well as for the treatment of hypertension and heart failure.