Involvement of Na+-K+-ATPase in p-aminohippurate transport by rabbit kidney tissue.
1. The relation between renal accumulation of p-aminohippurate (PAH), Na+-K+-ATPase activity, and the transmembranal Na+ gradient has been investigated by the use of cortex slices of rabbit kidney. 2. A moderate stimulation of PAH uptake rate was observed under anaerobic conditions in the presence of an extracellular-to-intracellular directed gradient of Na+. 3. Inhibition of aerobic accumulation of PAH by ouabain was related to a decrease in Na+-K+-ATPase activity, as evidenced by changes in tissue concentrations of Na+ and K+ and by measurements of high-affinity binding of ouabain to the slices. 4. Accumulation of PAH in media with various concentrations of Na+ and K+ resembled the effect of the cations on the ATPase activity of an isolated preparation of Na+-K+-ATPase. 5. Counteraction of the inhibitory effect of ouabain on PAH accumulation by a high concentration of K+ in the medium was related to retention of Na+-K+-ATPase activity, as evidenced by preservation of tissue--medium gradients of Na+ and K+. 6. The present data provide strong evidence for the involvement of Na+-K+-ATPase in the energization of renal PAH accumulation. However, it appears probable that a metabolic (Na+-gradient-independent) component, in addition to a Na+ gradient, is essential for the attainment of high accumulation ratios of PAH by intact renal cells.
D000332:Aerobiosis; D000618:Aminohippuric Acids / Q000378:metabolism*; D000693:Anaerobiosis; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D066298:In Vitro Techniques; D007672:Kidney Cortex / Q000201:enzymology / Q000378:metabolism*; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011817:Rabbits; D012964:Sodium / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D010130:p-Aminohippuric Acid / Q000378:metabolism*
D000618:Aminohippuric Acids; D010042:Ouabain; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium; D010130:p-Aminohippuric Acid