In which organ is renin produced?

Renin is an enzyme that plays a crucial role in the regulation of blood pressure and fluid balance in the body. It is produced in the kidneys, specifically by specialized cells known as juxtaglomerular cells, which are located in the afferent arterioles. When blood pressure drops or when there is a decrease in sodium chloride concentration detected by the kidneys, these cells release renin into the bloodstream.

Renin initiates the renin-angiotensin-aldosterone system (RAAS), which ultimately increases blood pressure through a series of steps: renin converts angiotensinogen (produced by the liver) into angiotensin I, which is then converted to angiotensin II mainly in the lungs. Angiotensin II is a potent vasoconstrictor and stimulates the release of aldosterone from the adrenal glands, promoting sodium and water retention to increase blood volume and pressure.

Understanding this mechanism underscores the importance of the kidneys in regulating cardiovascular function and maintaining homeostasis in the body.