Roles of sodium and potassium ions on p-aminohippurate transport in rabbit kidney slices.
This investigation was principally undertaken to test the ionic gradient hypothesis as applied to active p-aminohippurate uptake in the rabbit kidney cortical slice preparation. Efflux of p-aminohippurate from the slice was shown to be independent of external Na+ concentration. Transferring slices from a low sodium preincubation to a high sodium incubation medium containing p-aminohippurate increased intracellular concentrations of both Na+ and K+, and p-aminohippurate accumulation occurred. Transferring slices from a low sodium preincubation to a high sodium incubation medium containing ouabain and p-aminohippurate resulted in a net increase in intracellular Na+ concentration but no p-aminohippurate accumulation occurred. Different combinations of preincubation and incubation media gave a high to low array of intracellular Na+ concentrations and these directly reflected their respective p-aminohippurate uptake. These results suggest that the Na+ gradient hypothesis does not adequately explain the transport of organic acids in rabbit kidney. These results also suggest that Na+ possibly has an intracellular role through its stimulation of (Na+ + K+)-ATPase channeled to energizing the p-aminohippurate accumulative mechanism.
D000085:Acetates / Q000494:pharmacology; D000618:Aminohippuric Acids / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active; D066298:In Vitro Techniques; D007461:Iodoacetates / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology*; D011817:Rabbits; D012964:Sodium / Q000494:pharmacology*
D000085:Acetates; D000618:Aminohippuric Acids; D007461:Iodoacetates; D010042:Ouabain; D012964:Sodium; D011188:Potassium