The renal enzyme that influences blood pressure is

• A. Renin
• B. Renal parenchyma
• C. Pelviectasis
• D. Uterocele

Answer: (A)

Renin is the kidney’s enzyme that links renal function to blood pressure through the renin-angiotensin-aldosterone system. It’s released by juxtaglomerular cells in response to reduced renal perfusion or lower sodium delivery to the distal tubule. Renin cleaves angiotensinogen (made by the liver) to angiotensin I, which is then converted to angiotensin II. Angiotensin II is a potent vasoconstrictor and stimulates aldosterone release, increasing sodium and water reabsorption and thereby raising blood pressure. This regulatory pathway is unique to renin as an enzymatic trigger; the other terms—renal parenchyma (kidney tissue), pelviectasis (dilation of the renal pelvis), and ureterocele (a ureteral cystic dilation)—are anatomical entities, not enzymes that influence blood pressure.