THE MECHANISM OF GLYCOSURIC DIURESIS IN DIABETIC MAN 1

Abstract

Large doses of glucose, urea, or mannitol were admd. to 3 diabetic subjects, previously dehydrated by food and water deprivation for 16 hrs., who had reached urine flows of 0.33-1.02 cc./min. and solute concns. of 1000-1100 milliosmoles per liter. Loading with glucose or mannitol increased the urine flow to as high as 20 cc./min. Urea had a smaller effect. A reproducible relationship between urine flow and concn. or total solute load excreted was found independent of the chemical or metabolic properties of the loading solute. Calculated osmotic work of the kidney increased to a max. value of 4 gram-calories/min. and was not potentiated by further increases in urine flow, load, or plasma level of the loading solute. Loss of Na and chloride increased during diuresis to as much as 1.5 milliequivalents per min. in almost direct proportionality to the rate of urine flow. K and phosphate losses increased only slightly. Glucose diuresis in the diabetic subject is a non-specific phenomenon depending only on the total number of osmotically active particles claiming excretion and not on a specific effect of glucose.