Hormone secreted by Leydig cells of testes is :

Options

A. Thyroxine
B. Testosterone
C. Growth hormone
D. Estrogen

Answer

**Step-by-Step Solution:**

1. **Understanding Leydig Cells**: Leydig cells, also known as interstitial cells, are located in the testes and are responsible for the production of hormones.

2. **Identifying the Hormone**: The primary hormone secreted by Leydig cells is testosterone. This hormone plays a crucial role in male reproductive functions, including the development of male secondary sexual characteristics and the regulation of spermatogenesis.

3. **Role of Luteinizing Hormone (LH)**: The secretion of testosterone from Leydig cells is stimulated by luteinizing hormone (LH), which is produced by the anterior pituitary gland.

4. **Analyzing the Options**:
- **Thyroxine**: This hormone is produced by the thyroid gland and is not related to Leydig cells. Therefore, this option is incorrect.
- **Testosterone**: This is the correct answer as it is the hormone secreted by Leydig cells.
- **Growth Hormone**: This hormone is secreted by the anterior pituitary and is involved in growth and metabolism, not related to Leydig cells. Hence, this option is incorrect.
- **Estrogen**: This hormone is primarily associated with female reproductive functions and is not secreted by Leydig cells. Therefore, this option is also incorrect.

5. **Conclusion**: Based on the analysis of the options, the hormone secreted by Leydig cells of the testes is testosterone.

**Final Answer**: Testosterone

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