Question

What activates angiotensin?

Answer 1

Renin-angiotensin system:

1. It is a physiological hormone system that is involved in the regulation of arterial blood pressure & plasma sodium concentration.
2. When the renin is liberated in blood, it acts on the angiotensinogen (a circulating layer) which goes by proteolytic cleavage to make the decapeptide angiotensin I.
3. Vascular endothelium also has an enzyme called angiotensin transforming the enzyme which separates 2 amino acids & forms angiotensin II (AII) and the other tissues in the body, including the brain & heart also form an angiotensin II (AII).
4. The members of the renin-angiotensin system are:
   1. Renin
   2. Angiotensin I
   3. Angiotensin II
   4. Angiotensin-Converting Enzyme (ACE) Functions of Renin-Angiotensin System
5. The important functions of the Renin-angiotensin system.
   1. Build resistance vessels, hence its increasing arterial pressure and systemic vascular resistance.
   2. Stimulates delivery of the sodium at different renal tubular sites & increasing the body’s water retention.
   3. Stimulates liberation of the vasopressin from the posterior pituitary & increases liquid retention by the kidneys.