Which of the following enzyme is produced in the kidneys ?

Options

A. Rennin
B. Renin
C. Uricase
D. Arginase

Answer

To determine which enzyme is produced in the kidneys, follow these steps:

### Step-by-Step Solution:

1. **Identify the Function of the Kidneys**: The kidneys play a crucial role in various bodily functions, including the regulation of blood pressure, electrolyte balance, and waste elimination.

2. **Focus on Enzyme Production**: Among the various functions of the kidneys, one significant aspect is the production of specific enzymes that aid in physiological processes.

3. **Recognize the Enzyme Renin**: The primary enzyme produced in the kidneys is called renin. It is secreted by specialized cells known as juxtaglomerular cells.

4. **Locate the Juxtaglomerular Apparatus**: The juxtaglomerular apparatus is located near the Bowman's capsule, adjacent to the glomerulus in the nephron of the kidney.

5. **Understand the Role of Renin**: Renin plays a vital role in the regulation of blood pressure. It is involved in the renin-angiotensin-aldosterone system (RAAS), which helps to maintain blood pressure and fluid balance in the body.

6. **Explain the Mechanism**: When blood pressure drops, renin is released into the bloodstream. It acts on a protein called angiotensinogen (produced by the liver) and converts it into angiotensin I. Angiotensin I is then converted into angiotensin II, which stimulates the adrenal glands to release aldosterone, leading to increased sodium and water reabsorption in the kidneys, thus raising blood pressure.

7. **Conclude the Answer**: Therefore, the correct answer to the question "Which of the following enzyme is produced in the kidneys?" is **renin**.

### Final Answer:
The enzyme produced in the kidneys is **renin**.

---