A recombinant protein recommended to heart patients for dissolving blood clots in arteries is:

Options

A. TPA (Tissue plasminogen activator)
B. AAT
C. Calcitonin
D. Human growth hormone

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks for a recombinant protein that is recommended for heart patients to dissolve blood clots in arteries.

2. **Identifying the Options:**
The options provided are:
- tPA (tissue plasminogen activator)
- AAT (alpha-1 antitrypsin)
- Calcitonin
- Human growth hormone

3. **Analyzing Each Option:**
- **tPA (tissue plasminogen activator):** This is a clot-dissolving enzyme that is produced naturally by cells in the walls of blood vessels. It catalyzes the conversion of plasminogen to plasmin, which helps dissolve clots blocking coronary arteries during a heart attack and cranial arteries in certain strokes.

- **AAT (alpha-1 antitrypsin):** This protein is produced by the liver and primarily protects the lungs. It does not have a role in dissolving blood clots.

- **Calcitonin:** This is a hormone secreted by the thyroid gland that helps to reduce blood calcium levels. It is not involved in clot dissolution.

- **Human growth hormone:** This hormone regulates growth and metabolism in the body and is not related to blood clot dissolution.

4. **Conclusion:**
Based on the analysis, the recombinant protein that is recommended for heart patients to dissolve blood clots in arteries is **tPA (tissue plasminogen activator)**.

**Final Answer: tPA (tissue plasminogen activator)**

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