Inhibition of the Renal Tubular Transport of p-Aminohippurate (PAH) and Phenolsulfonphthalein (PSP) as Affected by Acetate

Abstract

The effects of acetate on the inhibition of the renal tubular transport of phenolsulfonphthalein (PSP) and PAH by 3 metabolic inhibitors, dehydroacetic acid (DHA), 2,4-dinitrophenol (DNP), and 4''-carboxyphenylmethane-sulfonanilide (carinamide), have been studied in vitro and in vivo. In the guinea pig kidney slice, by varying the concn., each inhibitor may produce partial or complete suppression of PSP concn. Similar results are obtained in relation to their effects on PAH accumulation by rabbit kidney slices. Addition of acetate to the suspending medium increases the uptake of PAH or PSP by the slice and partially or completely reverses the effects of all 3 inhibitors if suppression of transport of either compound is not complete. In the intact dog the intraven. infusion of acetate has been shown to increase the renal clearance of PSP. If the clearance of this compound or the tubular excretion of PAH has been markedly inhibited by DHA, DNP, or carinamide, admn. of acetate will completely or almost completely antagonize their action. The effect of these 3 inhibitors on the renal tubular transport of PAH is more readily reversed by acetate than is their inhibition of PSP clearance. The site of participation of acetate in the metabolic processes involved in the renal tubular excretion of PSP and PAH is discussed.