angiotensin [%PREMIUM_LINK%] (ān'jē-ō-těn'sĭn) Pronunciation Key |
Any of three polypeptide hormones that function in the body in controlling arterial pressure. The most important is known as angiotensin II, a powerful vasoconstrictor that stimulates steroid production by the adrenal glands, reduces fluid loss from the kidneys, and also functions as a neurotransmitter. Angiotensin II is formed from inactive angiotensin I by the action of angiotensin-converting enzyme (or ACE). See also ACE inhibitor, renin.