Which of the following hormones is known to have calorigenic effect ?

Options

A. `T_(3) & T_(4)`
B. TCT
C. PTH
D. Calcitriol

Answer

To determine which hormone is known to have a calorigenic effect, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the term "calorigenic effect":**
- The calorigenic effect refers to the production of heat or energy in the body, which is primarily associated with the metabolism of carbohydrates, proteins, and fats.

2. **Identify the hormones listed in the question:**
- The question provides a list of hormones, among which we need to identify which one has a calorigenic effect.

3. **Examine the role of T3 and T4 hormones:**
- T3 (triiodothyronine) and T4 (thyroxine) are hormones secreted by the thyroid gland. They are crucial for regulating metabolism and maintaining the basal metabolic rate (BMR).
- These hormones promote the breakdown of carbohydrates, proteins, and fats, leading to the release of energy, which is indicative of a calorigenic effect.

4. **Consider other hormones mentioned:**
- TCT (calcitonin), PTH (parathyroid hormone), and calcitriol (active form of vitamin D3) are primarily involved in calcium metabolism rather than energy production.
- TCT lowers blood calcium levels, PTH raises blood calcium levels, and calcitriol aids in calcium absorption but does not have a direct calorigenic effect.

5. **Conclude which hormone has a calorigenic effect:**
- Since T3 and T4 are responsible for increasing metabolic activity and energy production, they are the hormones known for their calorigenic effect.

### Final Answer:
The hormone known to have a calorigenic effect is **T3 and T4 (thyroxine)**.

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