The function of renin is

Options

A. degradation of angiotensinogen
B. stimulation of corpus luteum
C. to reduce blood pressure
D. vasodilation

Answer

### Step-by-Step Solution:

1. **Understanding Renin**: Renin is an enzyme secreted by the juxtaglomerular apparatus of the kidneys. It plays a crucial role in the regulation of blood pressure and fluid balance in the body.

2. **Function of Renin**: The primary function of renin is to convert angiotensinogen, an inactive protein produced by the liver, into angiotensin I. This conversion occurs when there is a decrease in blood pressure or body fluid volume.

3. **Conversion Process**:
- Renin acts on angiotensinogen to produce angiotensin I.
- Angiotensin I is then converted into angiotensin II by the action of the enzyme angiotensin-converting enzyme (ACE) primarily in the lungs.

4. **Effects of Angiotensin II**:
- Angiotensin II has two main effects:
a. It stimulates the adrenal cortex to release aldosterone, which promotes sodium reabsorption in the kidneys, leading to increased water retention and blood volume.
b. It causes vasoconstriction of blood vessels, which increases blood pressure.

5. **Evaluating the Options**:
- **Option 1**: Degradation of angiotensinogen - This is correct as renin initiates the conversion of angiotensinogen.
- **Option 2**: Stimulation of corpus luteum - This is incorrect; corpus luteum is related to the reproductive system and not the function of renin.
- **Option 3**: To reduce blood pressure - This is incorrect; renin actually contributes to increasing blood pressure.
- **Option 4**: Vasodilation - This is incorrect; renin causes vasoconstriction, not vasodilation.

6. **Conclusion**: The correct answer is that the function of renin is the degradation of angiotensinogen.