PTH is a

Options

A. Hypocalcemic hormone
B. Hypercalcemic hormone
C. Antiosteoclastic hormone
D. A hormone which stimulates excretion of `Ca^(+2)` in urine

Answer

**Step-by-Step Solution:**

1. **Identify PTH**: PTH stands for Parathyroid Hormone. It is a hormone secreted by the parathyroid glands, which are small glands located near the thyroid gland in the neck.

2. **Function of PTH**: The primary function of PTH is to regulate calcium levels in the blood. It increases the concentration of calcium in the blood when levels are low.

3. **Mechanism of Action**: PTH increases blood calcium levels by:
- Stimulating the release of calcium from bones (osteoclast activity).
- Increasing the reabsorption of calcium in the kidneys, which reduces calcium excretion in urine.
- Enhancing the absorption of calcium from the intestine by activating vitamin D.

4. **Classification of PTH**: Due to its role in increasing blood calcium levels, PTH is also referred to as a hypercalcemic hormone. This is in contrast to calcitonin (TCT), which is secreted by the thyroid gland and lowers blood calcium levels.

5. **Conclusion**: Therefore, PTH is classified as a hypercalcemic hormone that plays a crucial role in maintaining calcium homeostasis in the body.