At the entrance of the glomeruli of the kidney, there are certain sets of specialized cells that encircle the arterioles which secrete an enzyme called Renin into the blood. Renin secreting cells composing of juxtaglomerular apparatus are sensitive to change in blood pressure. When the blood flow to the kidneys reduce the secretion of renin is high. This may lead from loss of sodium and water or by narrowing of the renal artery. During this process renin acts as a catalyst in the formation of a plasma protein called angiotensinogen into a decapeptide (consisting of 10 amino acids) called as Angiotensin I. Another enzyme in the serum converts this decapeptide enzyme into an octapeptide enzyme called Angiotensin II that stimulates the secretion of Aldosterone that in turn stimulates salt and water reabsorption by the kidneys and also constricts the small arteries. ACE inhibitors which block the formation of Angiotensin II are used for the treatment of high blood pressure.
- Track 1-1 Activation
- Track 2-2 Cardiovascular Effects
- Track 3-3 Local Renin-angiotensin System
- Track 4-4 Fetal Renin-angiotensin System
- Track 5-5 Clinical Significance