Diuretic activity of three primary fractions of total nondialyzable solids from human urine.

Abstract

SummaryThe total nondialyzable solids of normal human urine have been partially fractionated by ultrafiltration yielding an ultrafilterable fraction (UFO) and a residue, fraction RO. The latter has been fractionated further by extraction with barbital-sodium barbital buffer, pH 8.6, yielding a soluble fraction RSI and an insoluble residue fraction Rl. A significant increase in rate of urine flow in dogs was obtained by intravenous administration of fraction RSl in a dose range of 0.5–10 μg/kg. On a weight basis fraction RSl is much more potent than acetazolamide or chlorothiazide, under the conditions of the assay. Fraction UFO did not result in an increase in urine flow when given in a dose range of 0.5–2 μg/kg. Fraction Rl could not be assayed in the dog because of toxicity, but when administered as a suspension intraperitoneally in doses of 20–25 μg/100 g to the rat it resulted in appreciable increases in rate of urine flow and electrolyte excretion.