Juxta Glomerular cells of kidneys secrete hormone :

Options

A. Angiotensinogen
B. Angiotensin –II
C. Coherin
D. Renin

Answer

**Step-by-Step Solution:**

1. **Identify the Location of Juxtaglomerular Cells:**
- Juxtaglomerular (JG) cells are located in the kidneys, specifically between the distal convoluted tubule and the efferent arteriole of the nephron.

2. **Understand the Function of Juxtaglomerular Cells:**
- The primary function of JG cells is to regulate blood pressure. They play a crucial role in the body's ability to maintain homeostasis regarding blood pressure levels.

3. **Identify the Hormone Secreted by Juxtaglomerular Cells:**
- The main hormone secreted by the Juxtaglomerular cells is Renin.

4. **Explain the Role of Renin:**
- Renin is released when there is a significant drop in blood pressure. It initiates a cascade of reactions that ultimately lead to the reabsorption of sodium and water in the body, which helps to increase blood volume and restore blood pressure to normal levels.

5. **Discuss the Interaction with Other Hormones:**
- Renin acts on a substrate called Angiotensinogen (produced by the liver) to form Angiotensin I, which is then converted to Angiotensin II in the lungs by the enzyme ACE (Angiotensin-Converting Enzyme). Angiotensin II is a potent vasoconstrictor and also stimulates the secretion of aldosterone, which promotes sodium and water reabsorption.

6. **Conclude with the Correct Answer:**
- Therefore, the hormone secreted by the Juxtaglomerular cells of the kidneys is Renin.

**Final Answer: Renin**

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