Granulosa cells of the juxtaglomerular apparatus produce the enzyme renin. It proteolytically cleaves angiotensinogen into angiotensin I, which is hydrolyzed by the angiotensin-converting enzyme (ACE) to angiotensin (Ang) II. A rise in ANG II leads to the production of aldosterone in the cortex of the adrenal gland. The system serves to maintain blood pressure and can sense drops as small as 10-15mmHg. ACE is a target for ACE inhibitors, used for the treatment of elevated blood pressure.
Renal hormone production
In addition to renin, which is not a hormone in itself but affects hormone production, erythropoietin (EPO) is another important product of the kidney. It is a glycoprotein, which is formed in the endothelial cells of the capillaries. It affects the formation of red blood cells in the bone marrow and is released in case of hypoxia.