Question

Renin is released from:

• A. \( \text{Hepatocytes of liver} \)
• B. \( \text{Beta-cells of pancreas} \)
• C. \( \text{Microglial cells} \)
• D. \( \text{Juxtaglomerular cells (JGCs) of kidney} \)

Hint:

The juxtaglomerular cells of the kidney release renin in response to: 1. Low blood pressure. 2. Low sodium concentration in the distal tubule. 3. Activation of the sympathetic nervous system. This is a key component of the renin-angiotensin-aldosterone system (RAAS).

Answer 1

The Correct Option is D

Step 1: Understanding the renin-angiotensin system. Renin is an enzyme secreted by the juxtaglomerular cells (JGCs) of the kidney in response to decreased blood pressure, reduced sodium levels, or sympathetic nervous system activation. It plays a vital role in regulating blood pressure and fluid balance. Step 2: Mechanism of renin release. Renin converts angiotensinogen (produced by the liver) into angiotensin I, which is then converted into angiotensin II by angiotensin-converting enzyme (ACE). Angiotensin II causes vasoconstriction and stimulates aldosterone secretion, increasing blood pressure. Step 3: Comparison with other options. - Option \( (A) \): Hepatocytes of the liver produce angiotensinogen, not renin. - Option \( (B) \): Beta-cells of the pancreas secrete insulin, not renin. - Option \( (C) \): Microglial cells are involved in immune functions in the central nervous system. Conclusion: Renin is specifically released by the juxtaglomerular cells (JGCs) of the kidney, making \( (D) \) the correct answer.