PERMEABILITY OF ERYTHROCYTES TO RADIOACTIVE POTASSIUM

Abstract

The permeability of erythrocytes to K is confirmed by the use of radioactive K in cells of man, dog, rat, cat, guinea pig and frog. The results are calculated in millimols of K transferred simultaneously in both directions per hr. Allowance is made for differences in vol. and surface area of the various cells. Human erythrocytes show 40% penetration in 12 hrs. in vivo and this rate is unchanged in expts. in vitro. Dog erythrocytes are least permeable and frog cells the most permeable. Cat erythrocytes exchange 45% of their K per hr., frog cells only 1.4% while other cells exchange 4-10%. Cat and dog erythrocytes are shown to be permeable to radioactive Na. Erythrocytes are, therefore, undoubtedly permeable to cations although much less permeable to cations than to anions.