Question

Match List-I with List-II

List-I (Target)	List-II (Agent)
(A) Na, K -2Cl symporter	(I) Frusemide
(B) Na-Cl symporter	(II) Triamterene
(C) Renal epithelial Na channel	(III) Acetazolamide
(D) Carbonic anhydrase	(IV) Chlorothiazide

• (A) - (I), (B) - (III), (C) - (II), (D) - (IV)
• (A) - (I), (B) - (IV), (C) - (II), (D) - (III)
• (A) - (II), (B) - (IV), (C) - (III), (D) - (I)
• (A) - (II), (B) - (IV), (C) - (I), (D) - (III)

Hint:

- Loop Diuretic (Frusemide) = Loop of Henle co-transporter ($Na^+-K^+-2Cl^-$) (A-I).
- Thiazide (Chlorothiazide) = Distal tubule co-transporter ($Na^+-Cl^-$) (B-IV).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Diuretics act on different segments of the renal nephron by targeting specific transport proteins or enzymes to increase urine production.
Detailed Explanation:
Let us match each drug with its molecular target in the nephron:
- (A) $Na^+-K^+-2Cl^-$ symporter: This cotransporter is located in the thick ascending limb of the loop of Henle. It is targeted by loop diuretics like (I) Frusemide (Furosemide).
- (B) $Na^+-Cl^-$ symporter: Located in the distal convoluted tubule. It is targeted by thiazide diuretics like (IV) Chlorothiazide.
- (C) Renal epithelial $Na^+$ channel (ENaC): Located in the collecting duct. It is blocked by potassium-sparing diuretics like (II) Triamterene.
- (D) Carbonic anhydrase: An enzyme present primarily in the proximal convoluted tubule. It is inhibited by (III) Acetazolamide.
This yields the matched sequence:
\[ \text{(A) - (I), (B) - (IV), (C) - (II), (D) - (III)} \]

Step 2: Final Answer:
The correct matching sequence corresponds to Option (B).