With increasing age, secretion of which of the following is reduced to half

Options

A. HGH
B. Estrogen
C. GTH
D. Melatonin.

Answer

To answer the question, "With increasing age, secretion of which of the following is reduced to half?", we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Hormones**: The question presents several hormones. We need to analyze each one to determine which hormone's secretion decreases significantly with age.

2. **Analyze Human Growth Hormone (HGH)**:
- Human Growth Hormone is primarily secreted during childhood and puberty.
- While its levels do decrease with age, it does not reduce to half; hence, it is not the correct answer.

3. **Examine Estrogen**:
- Estrogen is a principal feminizing hormone responsible for the development of secondary sexual characteristics in females.
- Its levels are high during puberty but decline significantly after menopause, which typically occurs between the ages of 45 to 55.
- The reduction in estrogen levels can be substantial, often reducing to half or more during and after menopause due to the atresia of ovarian follicles.

4. **Consider Other Hormones**:
- If there are additional options (not provided in the transcript), they should be analyzed similarly. However, based on the information given, estrogen is the most relevant hormone regarding significant reduction with age.

5. **Conclusion**: Based on the analysis, the hormone whose secretion is reduced to half with increasing age is **Estrogen**.

### Final Answer:
The secretion that is reduced to half with increasing age is **Estrogen**.

---