TY - JOUR T1 - THE EFFECTS OF FUROSEMIDE ON THE OSMOLALITY OF THE URINE AND THE COMPOSITION OF RENAL TISSUE JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 475 LP - 486 VL - 158 IS - 3 AU - A. G. Fraser AU - J. F. Cowie AU - Anne T. Lambie AU - J. S. Robson Y1 - 1967/12/01 UR - http://jpet.aspetjournals.org/content/158/3/475.abstract N2 - In healthy human subjects furosemide is shown to reduce markedly the reabsorption of solute-free water (TcH2O) during hydropenia and inhibit the normal rise in free-water excretion (CH2O) during sustained maximal water diuresis. In order to determine the mechanism of the effect on TcH2O, mannitol and furosemide were given to hydropenic rats to produce similar rates of solute excretion. In contrast to the effect of mannitol, furosemide produces a marked reduction in TcH2O in the rat as in man. The concentrations of sodium and urea were measured in samples of papilla, inner medulla and cortex from rat kidneys during mannitol and furosemide diuresis. The renal medullary and papillary concentrations of sodium and urea were depressed by both diuretics to the same degree. The site of action of furosemide in the nephron is discussed in the light of these findings and it is suggested that part of its action is to reduce the permeability of the collecting ducts to water. © 1967 by The Williams & Wilkins Company ER -