Potassium Exchange in the Isolated Rat Diaphragm; Effect of Anoxia and Cold

Abstract

A method is descr. for measuring serially the K concn. of the isolated rat diaphragm, and the exchange rates, by means of radioactive K. The method involves successive, short-term incubation of the tissue in each of a series of tubes. Following a brief initial loss, the tissue K content remained steady for 4 hours. Deposition of glycogen in the tissue was accompanied by a net uptake of K in the avg. amt. of 4.5 [mu] [image]/mg. glycogen. During steady state, 1.5% of the tissue K was exchanged with the medium per minute. Both anoxia and cold were assiciated with a prompt fall in net tissue K content; the former was associated primarily with an increase in the rate of flow of K out of the tissue, the latter with a decrease in the rate of flow of K into the tissue.