Renal Secretion of Thiosulfate in the Dog

Abstract

Trained female dogs normally show CS2O3/Ccr ratios of unity. In such animals a large net secretory transport of thiosulfate can be induced by the chronic administration of cortisone or testosterone. This is believed to be due to the renotrophic action of androgenic steroids. Renal tubular transport of thiosulfate is markedly depressed by carinamide. Under these circumstances tubular reabsorption can be demonstrated. Tubular secretory transport is not reduced by benemid, dehydroacetate, 2,4-dinitrophenol, mercupurin or by the simultaneous renal tubular transport of organic anions. Thiosulfate secretion is enhanced by sodium acetate and bicarbonate. The distinction between the actions of benemid and carinamide indicates that these inhibitors may act at different sites in the sequence of events leading to the tubular secretions of other anions. Under most circumstances the net tubular re-absorption or secretion of thiosulfate is so small that thiosulfate clearances closely approximate filtration rate. However, the fact that tubular transport of the ion can occur interdicts its employment for a precise and reliable measurement of the rate of glomerular filtration.