A Study of the Effects of Excessive Potassium Intake upon Body Potassium Stores1

Abstract

Rats subjected to loads of K which were increased stepwise from a normal intake level of 1.6 to as high as 368 meq/100 g body weight/day showed no signs of toxicity, ecg changes or elevation of plasma K concentration values until the intake exceeded 25.6 meq/100 g body weight/day. Of the animals taking more than this amount, one half died with signs of K intoxication within 3 days after attaining intake levels ranging between 28.8 and 38.4 meq/100 g body weight/day. Measurements carried out on the surviving half of the group disclosed pathologic elevation of plasma K concentration and characteristic ecg changes, but no significant change in total carcass K content or concentration values and a significant decrease in cardiac intracellular K concentration. These findings were in contrast to data obtained on animals on an ordinary dietary intake in which some intracellular "storage" of K may be observed transiently following the administration of an acute load. It is suggested that the restoration of cellular K values to normal levels following an acute load and the maintenance of these values at normal levels even in the presence of sustained hyperkalemia under conditions of chronic loading may be mediated by adrenocortical hormones. It is concluded that the occurrence of sustained hyperkalemia means that the individual has surpassed the upper limit of his individual tolerance for K and that he probably has very little capacity to store additional K within the body in innocuous form.