Inhibition of p-aminohippurate transport by cholegraphic agents.

Abstract

Summary and DiscussionThese data show that under proper conditions, and at an appropriate dose, the cholecystography agents can inhibit the transport of PAH both in vitro and in vivo. By inference, this suggests that these agents, or their glucuronide conjugates, may participate in the organic acid transport mechanism of the proximal tubule. This has been demonstrated for iophenoxic acid in a separate study (unpublished observations). Definitive experiments on the other oral agents are not available. In the case of iodipamide, its modest inhibition of PAH secretion in the dog can probably not be attributed to its own participation in proximal transort, since Berndt and Mudge (7) could find no evidence for iodipamide secretion in the dog, although it was demonstrable in the rabbit. Using far larger doses, Lindgren (8) has found marked renal hemodynamic responses to this agent.A major problem posed by these studies is the evaluation of in vivo inhibitory potency. Presumably, either total plasma concentratio...