Tuesday, May 31, 2011

What is angiotensin?

A protein-like hormone formed in the blood that raises blood pressure. Angiotensin contracts the muscles of CAPILLARIES and ARTERIES (vasopressor), which increases resistance for blood flow. Angiotensin is liberated by the action of RENIN, an ENZYME formed by the kidneys, on a serum PROTEIN (angiotensinogen) produced by the liver. The release of renin by the kidneys is triggered when they experience lowered blood flow, for example, due to dehydration. Angiotensin also plays an important role in the regulation of blood pressure by stimulating the ADRENAL GLANDS to secrete ALDOSTERONE. Aldosterone, in turn, promotes SODIUM retention and water retention by the kidneys, to help regulate water balance.

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