THE SITE OF ACTION OF FUROSEMIDE

Abstract To establish whether furosemide (F) acts on the proximal tubule beside the thick ascending limb of Henleas loop, we reviewed the data from 55 rats studied before and during the i.v. infusion of 10 mg kg −1 of furosemide. These animals were the object of previously published studies. SNGFR was 42.6±1.1 nl min −1 during baseline conditions (B), 42.7 nl min −1 during F ( P >0.9). In 151 paired last proximal tubular samples, percentage reabsorption was 71.72 before and 71.72% after F ( P =1.0). In 64 paired early distal tubular samples, percent reabsorption fell from 86% in B to 78% during F ( P R =0.52, P