Name a peptide hormone which acts mainly on hepatocytes, adipocytes and enhances cellular glucose uptake and utilization :

Options

A. Insulin
B. Glucagon
C. Secretin
D. Gastrin

Answer

**Step-by-Step Solution:**

1. **Identify the Hormones**: The question asks for a peptide hormone that acts on hepatocytes (liver cells) and adipocytes (fat cells) to enhance glucose uptake and utilization. We need to consider the hormones that fit this description.

2. **Evaluate the Options**: The options provided include insulin, glucagon, secretin, and gastrin. We need to analyze each hormone to determine which one fits the criteria.

3. **Focus on Insulin**: Insulin is a peptide hormone secreted by the beta cells of the islets of Langerhans in the pancreas. Its primary function is to lower blood glucose levels by promoting the uptake of glucose by cells, particularly in the liver (hepatocytes) and fat (adipocytes).

4. **Role of Insulin**: When blood glucose levels rise, insulin is released, facilitating the uptake of glucose by hepatocytes and adipocytes. This process enhances cellular glucose utilization and storage, effectively controlling blood glucose levels.

5. **Consider Other Hormones**:
- **Glucagon**: Secreted by alpha cells of the islets of Langerhans, it has the opposite effect of insulin, increasing blood glucose levels by promoting the release of glucose from stored glycogen in the liver.
- **Secretin**: Secreted by the duodenum, it stimulates the secretion of digestive fluids but does not directly affect glucose uptake.
- **Gastrin**: Secreted by gastric glands, it stimulates gastric acid secretion and is not involved in glucose metabolism.

6. **Conclusion**: Based on the analysis, the peptide hormone that acts mainly on hepatocytes and adipocytes to enhance glucose uptake and utilization is **insulin**.

**Final Answer**: Insulin

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