Effect of water restriction on urinary concentrating ability of K-depleted rats

¹ Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, North Carolina

In order to test the possibility that the urinary concentrating defect associated with potassium depletion results from excessive water intake that accompanies potassium depletion, water intake was restricted in one half of a group of rats undergoing potassium depletion. The other one half of the group was allowed to drink ad libitum After 14 days, ability to concentrate the urine was tested in both groups as well as in two groups of control rats, one of which was allowed to drink ad libitum and the other having water intake restricted. Although both potassium-depleted groups concentrated urine less than the control groups, there was no difference in urine-concentrating ability between the two potassium-depleted groups. It is concluded that the urinary concentrating defect in potassium depletion is not due to excessive water intake.