Renin

Renin is an enzyme that is produced and secreted by the juxtaglomerular cells of the kidney. The stimulus for its secretion is a drop in blood pressure. Renin catalyzes the conversion of angiotensinogen (or renin substrate) to angiotensin I, which is also enzymatically converted to angiotensin II. The conversion of angiotensin I to angiotensin II is catalyzed by angiotensin-converting enzyme (ACE), which is mainly found in the endothelial cells of the pulmonary vessels.

Angiotensin II increases blood pressure by two main mechanisms – vasoconstriction and renal water and salt retention.

Angiotensin I has only a mild vasoconstrictive effect and renin has no vasoactive effects.

Related articles

 * The renin-angiotensin-aldosterone system
 * Angiotensin converting enzyme inhibitors
 * Vylučovací soustava
 * ADH