Which of the following pairs of hormones are not antagonistic (having opposite effects) to each other ?

Options

A. Relaxin - lnhibin
B. Parathormone - Calcitonin
C. lnsulin - Glucagon
D. Aldosterone - Atrial Natriuretic Factor

Answer

To determine which pair of hormones are not antagonistic (having opposite effects) to each other, we will analyze the options provided:

1. **Relaxin and Inhibin**
2. **Parathyroid hormone and Calcitonin**
3. **Insulin and Glucagon**
4. **Aldosterone and Anti-natriuretic factor**

### Step-by-Step Solution:

**Step 1: Understand the meaning of antagonistic hormones.**
Antagonistic hormones are those that have opposite effects on the same physiological function. For example, one hormone may increase a certain level (like blood glucose), while the other decreases it.

**Step 2: Analyze each hormone pair.**

- **Relaxin and Inhibin:**
- Relaxin is produced in the ovaries and helps in pregnancy by relaxing the pelvic ligaments and cervix.
- Inhibin is secreted by the granulosa cells in the ovaries and inhibits the secretion of Follicle Stimulating Hormone (FSH).
- Both hormones work synergistically during the menstrual cycle and pregnancy, meaning they complement each other rather than oppose.

- **Parathyroid hormone and Calcitonin:**
- Parathyroid hormone (PTH) increases blood calcium levels by promoting the release of calcium from bones.
- Calcitonin decreases blood calcium levels by promoting the storage of calcium in bones.
- These hormones have opposite effects, making them antagonistic.

- **Insulin and Glucagon:**
- Insulin lowers blood glucose levels by facilitating its uptake and storage as glycogen in the liver.
- Glucagon raises blood glucose levels by promoting the breakdown of glycogen into glucose.
- These hormones are also antagonistic.

- **Aldosterone and Anti-natriuretic factor:**
- Aldosterone increases blood pressure by promoting sodium and water retention in the kidneys.
- Anti-natriuretic factor decreases blood pressure by promoting the excretion of sodium and water.
- These hormones have opposite effects, making them antagonistic.

**Step 3: Conclusion**
The pair of hormones that are not antagonistic to each other is **Relaxin and Inhibin**.

### Final Answer:
**Relaxin and Inhibin** are the hormones that are not antagonistic to each other.

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