Abstract
Studies are presented on the effect of potassium depletion on the permeability of the collecting duct of the rat kidney to water and on the ability of the rat kidney to accumulate urea. The data show that the collecting duct of the potassium-depleted rat has essentially the same permeability characteristics for urea and thiourea-C14 as that of the normal rat. These data are discussed in relation to the effect of potassium depletion on the renal concentrating mechanism.