Glycolysis of red cells suspended in solutions of impermeable solutes. Intracellular pH and glycolysis.

The glycolytic rate human red cells suspended in a sucrose medium of low or physiological pH was higher than that of the cells suspended in Ringer's medium of the same. pH. The medium pHP-glycolytic rate curve of red cells suspended in soucrose media shifted to the acidic side by about one unit compared with that of cells suspended in Ringer's medium. Similarly, the pattern of glycolytic intermediates in red cells suspended in a sucrose medium resembled that in cells suspended in Ringer's solution of about one unit higher pH. These phenomena could be ascribed to the change of intracellular pH, which was measured by the 5,5'-dimethyl-oxazolidine-2,4-dione method. A similar stimulation of glycolysis was observed when sodium citrate was added to red cells suspended in Ringer's solution at constant pH. These observations indicate that membrane-impermeable non-electrolytes or anions stimulate glycolysis of red cells by elevation ofthe intracellular pH. Red cell glycolysis is influenced mainly by the intracellular pH rather than by the pH of the suspending medium.