ARenin
BThymosin
CRelaxin
DSomatostatin
Answer:
A. Renin
Read Explanation:
The enzyme that initiates the degradation of angiotensinogen is renin.
The Renin-Angiotensin-Aldosterone System (RAAS)
Angiotensinogen is a large protein that is produced and released into the bloodstream by the liver. It is a precursor to the powerful hormone angiotensin II, which plays a central role in regulating blood pressure. The conversion of angiotensinogen to angiotensin II is a multi-step process known as the Renin-Angiotensin-Aldosterone System (RAAS).
The first and rate-limiting step of this process is the cleavage of angiotensinogen. When blood pressure or blood volume drops, the kidneys release the enzyme renin. Renin acts on the angiotensinogen, cleaving off a small peptide called angiotensin I. Angiotensin I is then converted into the active hormone angiotensin II by another enzyme, Angiotensin-Converting Enzyme (ACE).