Effect of Starvation on Exchangeable Potassium and Tissue K42 Content in Rabbits.

Abstract

Serial determinations of the exchangeable K content and of urinary K and creatinine excretion were made in one group of starved male animals. In 1 and 2 wks. the mean decreases in exchangeable K content were 29.8 and 54.6% of the base-line value, respectively. The corresponding mean decreases in body wt. were 15.6 and 31.7%. No significant changes in urinary creatinine excretion occurred. In a separate group of rabbits, tissue analyses for K42 and water concn. after 1 wk. of starvation revealed no significant differences from those in control animals on a constant diet. The decrease in total body K content, as measured by the exchange of K42 and the loss in the urine during starvation, could be accounted for by tissue catabolism, without postulating an intracellular deficiency of K in the remaining tissues. A functional abnormality in K metabolism may be detectable by the radio-isotope method prior to its manifestation by the external balance method.