What hormone produced by the kidneys helps regulate blood pressure?

The hormone produced by the kidneys that plays a crucial role in regulating blood pressure is renin. Renin is an enzyme that is secreted by the juxtaglomerular cells of the kidneys in response to low blood pressure, low sodium chloride concentration, or sympathetic nervous system stimulation. Once released into the bloodstream, renin converts angiotensinogen, a protein produced by the liver, into angiotensin I. Angiotensin I is then converted to angiotensin II through the action of the angiotensin-converting enzyme (ACE) primarily in the lungs. Angiotensin II is a potent vasoconstrictor that raises blood pressure and stimulates the release of aldosterone, which promotes sodium and water reabsorption in the kidneys, further increasing blood volume and pressure.

Understanding this mechanism is vital as it highlights how the kidneys actively participate in the regulation of blood pressure through the renin-angiotensin-aldosterone system (RAAS). This intricate process underscores the importance of renal function and hormonal signaling in maintaining cardiovascular health.

The other hormones listed do not serve the primary role of blood pressure regulation as renin does. Aldosterone, while involved in the RAAS, is not produced by the kidneys but rather secreted by