`alpha`-cells of pancreas secrete

Options

A. Insulin
B. Glucagon
C. Trypsinogen
D. Amylase

Answer

To answer the question regarding what the alpha cells of the pancreas secrete, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Function of the Pancreas**:
- The pancreas is a composite gland that has both exocrine (digestive enzymes) and endocrine (hormones) functions.

2. **Understand the Islets of Langerhans**:
- The pancreas contains clusters of cells known as the Islets of Langerhans, which are responsible for its endocrine functions. These islets contain different types of cells, primarily alpha and beta cells.

3. **Determine the Role of Alpha Cells**:
- Alpha cells are one type of cell found in the Islets of Langerhans. Their primary function is to secrete hormones.

4. **Identify the Hormone Secreted by Alpha Cells**:
- Alpha cells specifically secrete glucagon, which is a peptide hormone.

5. **Understand the Function of Glucagon**:
- Glucagon plays a crucial role in regulating blood glucose levels. It primarily acts on liver cells to promote glycogenolysis, the process of breaking down glycogen into glucose, which increases blood sugar levels.

6. **Eliminate Other Options**:
- The other options provided (insulin, truxinogen, and amylase) do not correspond to the secretion of alpha cells:
- Insulin is secreted by beta cells.
- Truxinogen is not a recognized hormone related to pancreatic function.
- Amylase is an enzyme secreted by the exocrine part of the pancreas, not by the alpha cells.

7. **Conclusion**:
- Based on the information above, the correct answer to the question is that alpha cells of the pancreas secrete **B. Glucagon**.

### Final Answer:
**B. Glucagon**

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