Cation Transport in Erythrocytes of Normal and Porphyric Cows: Transmembrane Fluxes of Sodium and Potassium

Abstract

Congenital erythropoieticporphyria in cattle is characterized by a haemolytic anaemia of varying severity and shortened red cell median survival times. The shortened survival of the porphyric erythrocytes is thought to be due to an intracorpuscular defect. Unidirectional fluxes of sodium and potassium ions across the membranes of erythrocytes from normal and porphyric cows were measured utilizing the radioisotopes 42K and 24Na to determine if marked differences in cation pumping rates or passive leaks existed. Total potassium influxes and potassium pump influxes of the porphyric cells were found to be significantly elevated (P Therefore, with regard to cation permeability, the porphyric cells were essentially normal and the increased potassium pump fluxes were considered to be due to the presence of a young cell population. Thus, any changes in cation metabolism would seem to be the result rather than the cause of the haemolysis.