The site of action of the loop diuretic furosemide is:: (A) Thick ascending limb of loop of Henle, (B) Descending limb of loop of Henle, (C) Proximal convoluted tubule, (D) Distal convoluted tubule
Answer is A. Ans. a. Thick ascending limb of loop of Henle (Ref: Goodman and Gilman : 12/e p678)The site of action of the loop diuretic furosemide is thick ascending limb of loop of Henle.DiureticSite of actionMechanism of actionCarbonic anbydrase inhibitorsProximal tubuleInhibit Na+ and HCO3 - absorption due to carbonic anhydraseQOsmotic diureticsLoop of HenleReduce renal medullary tonicityLoop diureticsThick ascending limb of loop of HenleInhibit Na+ - K+ 2CI- symporterQThiazidesEarly distal tubuleInhibit Na+ - Cl- symporterQAmilorideLate distal tubule, Collecting ductInhibit epithelial sodium channels (ENaC)QTrimaterenceLate distal tubule, Collecting ductInhibit epithelial sodium channels (ENaC)QAldosterone receptor antagonistsLate distal tubule, Collecting ductAntagonize the Na+ and H2O reabsorption due to aldosterone