Renin (None)

Renin is an aspartyl protease enzyme primarily produced and secreted by specialized juxtaglomerular cells in the kidneys. It plays a central role in regulating blood pressure, blood volume, and electrolyte balance through its involvement in the renin-angiotensin-aldosterone system (RAAS). Renin’s main function is to catalyze the conversion of angiotensinogen (a plasma protein produced by the liver) into angiotensin I. Angiotensin I is subsequently converted to angiotensin II by angiotensin-converting enzyme (ACE). Angiotensin II acts as a potent vasoconstrictor, increases aldosterone secretion from the adrenal cortex, stimulates antidiuretic hormone release, and activates thirst—all leading to increased blood pressure and restoration of kidney perfusion.

Renin cleaves angiotensinogen to form angiotensin I, initiating the renin-angiotensin-aldosterone system (RAAS) cascade, ultimately leading to increased blood pressure.