Q. Which of the following is correct w.r.t. the function of renin?
Solution:
Renin or angiotensinogenase is an aspartate protease that plays an important role in the renin-angiotensin-aldosterone system (RAAS), which is responsible for the body's water balance and blood pressure level. Renin is produced and secreted by the JG cells of JGA (Juxta-glomerular apparatus) present in kidneys.
In Renin-Angiotensin-Aldosterone System (RAAS), renin enzyme (secreted from JG cells) converts Angiotensinogen (453 amino acids) into angiotensin - I (10 amino acids).
This angiotensin - I is converted into angiotensin - II (8 amino acids) in the presence of enzyme Angiotensin-Converting Enzyme (ACE), secreted from lungs.
This Angiotensin - II is a vasoconstrictor and stimulates the adrenal cortex for the secretion of the hormone aldosterone, which promotes the absorption of Na+ ions from nephric filtrate, resultantly blood pressure is increased.
This angiotensin - I is converted into angiotensin - II (8 amino acids) in the presence of enzyme Angiotensin-Converting Enzyme (ACE), secreted from lungs.
This Angiotensin - II is a vasoconstrictor and stimulates the adrenal cortex for the secretion of the hormone aldosterone, which promotes the absorption of Na+ ions from nephric filtrate, resultantly blood pressure is increased.