pH gradient-stimulated transport of urate and p-aminohippurate in dog renal microvillus membrane vesicles

Abstract

The transport mechanism of urate and p-aminohippurate (PAH) was evaluated in microvillus membrane vesicles isolated from the renal cortex of the mongrel dog. Imposition of a transmembrane pH gradient (pH(o) < pH(i)) markedly accelerated the uptake of [14C]urate and [3H]PAH and caused the transient accumulation ('overshoot') of each anion above its final level of uptake. The transport of urate and PAH under both stimulated (pH(o)