Effects of DOCA, K loading, and cations on K uptake by rabbit kidney cortex

In previous studies the nature of the substrate requirements, as well as the effects of metabolic inhibitors on potassium uptake by rabbit renal cortex slices, have been examined. In this study a variety of factors have been examined, some of which are known to influence the renal handling of potassium in the intact animal. Pretreatment with deoxycorticosterone acetate enhanced the ability of renal slices to take up potassium from a low external source. This was true even though the fresh-tissue levels of potassium were not markedly altered. Pretreatment with potassium chloride elevated the fresh-tissue potassium level but had no effect on potassium uptake by the slices. Two organic bases which have been reported to interact with the potassium secretory process in the dog were found to have no effect on potassium uptake in vitro. Ammonium chloride was found to depress potassium uptake when present in a concentration equimolar to that of potassium.