Glucose Metabolism in Normal Erythrocytes. I. Kinetics of the Hexokinase Reaction in Intact Cells

A method has been developed for determination of erythrocyte glucose consumption at a wide range of glucose concentrations. The method is based on paper chromatographic separation and quantitation of C14‐glucose and its labelled metabolites after incubation of intact cells. The glucose consumption was maximal at glucose concentrations above 0.4 mM. The inhibitory effect of inosine was investigated and found to be delayed, indicating an indirect action of this compound. The presence of EDTA in the medium increased the glucose consumption markedly, three to four times at 5–10 mM, whereas magnesium and calcium had no effect. EDTA removed easily exchangeable erythrocyte calcium during these conditions, but did not significantly penetrate the red cell membrane. Mercaptoethanol increased the glucose consumption, indicating the presence of potentially active SH‐groups on hexokinase in the intact cell.