Effect of a Single Intravenous Injection of Hydrocortisone on Erythrocyte Electrolyte Exchanges

¹ From the Medical Research Laboratory, Veterans Administration Hospital, Albany, New York

This investigation was undertaken to ascertain the rapidity with which electrolytc transfers could be induced in human erythrocytes. Two groups of experimental subjects were given, intravenously, 100 mg of hydrocortisone in 2 ml of saline. After a control specimen of venous blood was taken, blood was withdrawn at 30- to 60-minute intervals for 4 hours in the first group, and at 5- to 10-minute intervals for 1 hour in the second. Plasma ph and hematocrit was measured. Sodium, potassium, chloride and water content of whole blood and plasma were determined; intracellular concentrations of electrolyte and hydrogen ion were calculated using appropriate formulas. In the first group of experiments a slight rise in plasma ph and concentration of sodium in the erythrocytes was observed 30 minutes after injection. In the second group of experiments a rise in ph began 5–10 minutes after injection and the increase in concentration of sodium in the erythrocytes attained a peak 20–40 minutes after injection. Estimates of erythrocyte hydrogen ion concentration suggested a fall. In neither group was there a change in plasma or erythrocyte potassium or water. The results suggest that hydrocortisone may effect the transfer of sodium from distant sources to the red cell via the plasma. The transfer is rapid and short lived under these experimental conditions.