Studies on the mechanism of renal transport depression caused by pretreatment with 2,4,5-trichlorophenoxyacetate.

Relatively low toxicity in the adult has been reported for the organic acid herbicides 2,4-dichlorophenoxyacetate and 2,4,5-trichlorophenoxyacetate (2,4,5-T). Although small doses of these herbicides are excreted rapidly, acute impairment of renal excretion has been reported when large doses of herbicide were administered. After the administration of 2,4,5-T in vitro analysis of renal proximal tubular function showed a decrease in the activity of the organic acid transport system which handles these herbicides. In addition, the pretreated animals show an impairment in the organic base transport system. To determine the nature of 2,4,5-T renal depression, renal cortical slices from herbicide-pretreated animals were studied. Alterations in the initial influx of organic ions, steady-state accumulation, and efflux were measured. Furthermore, a specific and reversible depression of tissue oxygen consumption was demonstrated. These changes do not appear to be the result of alterations in the gross morphology, electrolyte composition, or cell water content of the renal cortex.