Effect of hydrocortisone on the synthesis of 2,3-diphosphoglycerate in human erythrocytes.

Studies were carried out on the mechanism of action of glucocorticoids on erythrocyte glycolysis. Inosine increased the levels of 2,3-DPG, lactate, and ATP in red blood cell samples with very low glucose concentrations in which the glycolytic system was unable to utilize glucose. With inosine and hydrocortisone added to red blood cells, 2,3-DPG and lactate increased more than in red blood cells supplemented with inosine alone. There was no significant increase in the level of ATP when glucose and inosine were added compared to the addition of inosine only. There were no changes in the activity of enzymes such as PFK and PGK. From these findings, it is suggested that glucocorticoids increase the level of red blood cell 2,3-DPG, by activating the conversion of 1,3-DPG to 2,3-DPG during glycolysis, probably by stimulating 2,3-DPG mutase.