Metabolic Site and Time Course of Cortisol Action on Glucose Uptake, Lactic Acid Output, and Glucose 6-Phosphate Levels of Rat Thymus Cells in Vitro

In rat thymus cells exposed under aerobic conditions to a glucose pulse, cortisol at 10-6 m reduces the rates of glucose uptake and lactic acid output, and reduces the magnitude of the glucose-induced increase in glucose 6-phosphate. Effects are discernible by 15 to 20 min of exposure to cortisol. These results are interpreted as showing that cortisol produces a block at the level of glucose transport or phosphorylation, or both. Under anaerobic conditions a marked Pasteur effect is observed, and all the above effects of cortisol are abolished.