Potassium-sparing diuretics interfere with which pump?

Potassium-sparing diuretics interfere with which pump?

• A. Sodium-glucose transporter in proximal tubule
• B. Sodium-potassium pump controlled by aldosterone
• C. Chloride transporter in the loop of Henle
• D. Aquaporin channels in collecting ducts

Answer: (B)

Potassium-sparing diuretics work by blocking aldosterone’s effects in the collecting ducts, which reduces sodium reabsorption and, importantly, reduces potassium secretion. Aldosterone normally boosts activity and expression of the basolateral Na+/K+-ATPase pump as well as sodium channels, increasing Na+ reabsorption and driving K+ loss into the urine. When aldosterone action is blocked (or Na+ channels are directly inhibited), the Na+/K+-ATPase activity declines and the driving force for K+ secretion decreases, so potassium is retained. That’s why they interfere with the sodium-potassium pump regulated by aldosterone. The other targets listed aren’t the primary sites affected by these drugs.

Potassium-sparing diuretics work by blocking aldosterone’s effects in the collecting ducts, which reduces sodium reabsorption and, importantly, reduces potassium secretion. Aldosterone normally boosts activity and expression of the basolateral Na+/K+-ATPase pump as well as sodium channels, increasing Na+ reabsorption and driving K+ loss into the urine. When aldosterone action is blocked (or Na+ channels are directly inhibited), the Na+/K+-ATPase activity declines and the driving force for K+ secretion decreases, so potassium is retained. That’s why they interfere with the sodium-potassium pump regulated by aldosterone. The other targets listed aren’t the primary sites affected by these drugs.