Present data concerning the renin-angiotensin system of extrarenal origin

After a brief historical incursion regarding RAS of renal origin, we present the main extrarenal angiotensin-forming enzymes, starting with isorenin, tonin, D and G cathepsin and ending with the conversion enzyme and chymase. This is followed by a short presentation of data concerning tissue RAS in the heart and vessels, brain and neurocranial accessory glands, cortico-suprarenal and gonadal glandular territory. In the end we refer to the relations between circulating RAS of renal origin and the extrarenal RAS specific to tissue underlying the fact that the two RAS components cooperate and constitute a unitary hormonal system, regulating the major functions of the organism and maintaining the main homeostatic equilibria. While the circulating RAS of renal origin is acutely activated to contribute to the accomplishment of short term homeostatic reactions, tissue RAS, in paracrine or autocrine ways, exerts local-regional adaptive actions of long duration.