Question

Mineralocorticoid receptor is not present in?

• A. Liver
• B. Colon
• C. Hippocampus
• D. Kidney

Hint:

Think of aldosterone targets: kidney, colon, heart, hippocampus, not the hepatocyte.

Answer 1

The Correct Option is A

Step 1: The mineralocorticoid receptor (MR, also called the aldosterone receptor or NR3C2) is a nuclear receptor encoded by the NR3C2 gene on chromosome 4q31.
Step 2: MR is expressed widely in aldosterone-responsive and other tissues: kidney, colon, heart, central nervous system (especially the hippocampus), brown adipose tissue and sweat glands.
Step 3: In epithelial tissues such as the renal tubule and colon, MR activation increases epithelial sodium channel (ENaC), the Na+/K+ pump and SGK1, driving sodium and water reabsorption and potassium excretion, which raises extracellular volume and blood pressure.
Step 4: Among the options, kidney, colon and hippocampus are all classic MR-expressing tissues. The liver is not a recognised mineralocorticoid target tissue and does not express the MR in this context.
Conclusion: Mineralocorticoid receptor is not present in the liver, so option A is correct.