IN VITROSUPPRESSION OF POLYMORPHONUCLEAR LEUKOCYTE AND LYMPHOCYTE GLYCOLYSIS BY CORTISOL1

Abstract

In vitro metabolic studies are reported on leukocytes (PMN) and lymphocytes separated from human blood by differential sedimentation. Approximately 2 moles lactate are produced per mole glucose used by PMN (60–80% neutrophils). Glycolysis is maximal at an initial glucose concentration of .0045–.0056 M. Cortisol depresses glycolysis as a function of the log of the drug concentration. This suppressive effect also is maximal at an initial glucose concentration of .0045–.0056 M. Cortisol has no effect on oxygen consumption. The metabolism of lymphocytes differs somewhat from that of PMN. Their oxygen consumption is two-fold that of PMN although their glycolytic rate is lower. Cortisol inhibits lymphocyte glucose utilization at an initial glucose concentration of .0056–.0067 M without affecting lactate production or oxygen consumption. It is suggested that cortisol-induced involution of lymphoid tissue is due in part to a continued high rate of oxygen consumption and lactate production by lymphocytes despite a reduction in their glycolysis by this steroid.