The renin-angiotensin system is intimately involved in the control of
sodium and water balance, the activity of the sympathetic nervous syst
em, mitogenesis and the regulation of vascular tone. There is evidence
that many of these effects may be controlled at a local,level by inde
pendent tissue renin-angiotensin systems. Drugs that are specific inhi
bitors of the cascade have proved powerful tools for dissecting the ph
ysiology of the renin-angiotensin system, and are of major benefit in
the treatment of hypertension and chronic heart failure. Recent eviden
ce suggests that variations in the genes coding for components of the
system may affect the risk of developing hypertension and ischaemic he
art disease.