renin-angiotensin system
(RAS), renin-angiotensin-aldosterone system (RAAS) the regulation of sodium balance, fluid volume, and blood pressure by renal secretions: in response to reduced perfusion, renin is secreted, which hydrolyzes a plasma globulin to release angiotensin I, which is rapidly hydrolyzed to angiotensin II; this in turn stimulates aldosterone secretion, which brings about sodium retention, increase in blood pressure, and restoration of renal perfusion, which shuts off the signal for renin release.
Medical dictionary.
2011.