Reabsorpiton of `Na^(+)` is controlled by which one of the following hormones?

Options

A. Aldosterone
B. Estrogen
C. Glucocorticoids
D. Tstosterone

Explanation

To determine which hormone controls the reabsorption of sodium ions (Na⁺), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Hormones Listed**: The question provides four options: aldosterone, estrogen, glucocorticoid, and testosterone.

2. **Understand the Function of Each Hormone**:
- **Aldosterone**: This hormone is secreted by the adrenal glands, specifically the adrenal cortex. It plays a crucial role in regulating sodium and potassium levels in the body.
- **Estrogen**: This is a female sex hormone that is primarily involved in the regulation of the menstrual cycle and reproductive functions.
- **Glucocorticoid**: These hormones are involved in the metabolism of carbohydrates, proteins, and fats, and they help in reducing inflammation.
- **Testosterone**: This is a male sex hormone that is responsible for the development of male reproductive tissues and secondary sexual characteristics.

3. **Focus on Sodium Reabsorption**: Among the hormones listed, aldosterone is known for its specific role in the kidneys, where it stimulates the reabsorption of sodium ions (Na⁺) in the renal tubules. This process also leads to the retention of water and the excretion of potassium ions (K⁺).

4. **Eliminate Other Options**:
- Estrogen does not play a role in sodium reabsorption.
- Glucocorticoids are more focused on metabolic processes and inflammation rather than sodium regulation.
- Testosterone is primarily involved in male sexual characteristics and does not regulate sodium levels.

5. **Conclusion**: Based on the functions of these hormones, the correct answer is **aldosterone**, as it directly controls the reabsorption of sodium ions in the kidneys.

### Final Answer:
The reabsorption of `Na⁺` is controlled by **aldosterone**.

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