The renin-angiotensin system and body function.

Angiotensin II, the biologically active component of the renin-angiotensin system, acts throughout the body to produce an impressive number of cardiovascular, endocrine, metabolic, and behavioral effects. Major actions include elevation of arterial pressure, stimulation of aldosterone secretion, and a variety of effects on the kidneys, brain, and pituitary. Investigation of the role of the renin-angiotensin system in physiological regulation has been greatly facilitated by the availability of specific inhibitors of the formation or actions of angiotensin II, most notably converting-enzyme inhibitors and angiotensin receptor antagonists. Studies with these agents have clearly shown that the renin-angiotensin system plays an important role in the defense of body balance and blood pressure in hypovolemic state, including sodium deficiency and hemorrhage. The inhibitors also lower blood pressure in some forms of hypertension, and converting-enzyme inhibitors are proving to be effective antihypertensive agents.