THE DISTRIBUTION OF ANGIOTENSIN-II TYPE-1 RECEPTORS, AND THE TISSUE RENIN-ANGIOTENSIN SYSTEMS

Since its discovery, the functions of the renin-angiotensin system (RA S) have attracted a great deal of attention, and the roles it plays un der normal conditions, and in disease, acquire a deepening significanc e with every year, In general, the RAS has been considered largely in terms of its roles in sodium and potassium homeostasis and the regulat ion of blood pressure, The continued acquisition of information on the distribution of angiotensin receptors, however, emphasizes that our i nterpretation needs to be widened, and it is now clear that angiotensi n II has an array of functions in the tissues, which are unrelated to its systemic roles. This paracrine function is brought about by the ex istence of complete, localized tissue RASs, which respond to physiolog ical demand independently from the systemic system.