Competitive inhibition of renal transport of p-aminohippurate by analogues of chlorothiazide.

Abstract

Competitive inhibition of p-aminohippurate (PAH) transport by analogues of chlorothiazide has been demonstrated with slices of rabbit kidney cortex. Although analogues of low pK1 are better inhibitors of PAH transport than are analogues of higher pK1, no clear dependence of inhibitory capacity on degree of ionization at physiological values of pH was demonstrable. In contrast to earlier findings with phenolsulfonphthaleins and m- and p-substituted hippurates, no relation was noted between rate of transport and molecular weight or capacity to inhibit PAH transport. Similarly, no relation was noted between rate of transport and pK1. None of the analogues affected potassium content or uptake of K42.