Effect of glucose, NADH and NADPH on cortisol metabolism by mononuclear cells

Mononuclear cell preparations are capable of metabolizing cortisol to three metabolites which lack the immunosuppressive effect of their precursor. In the present study we noted a linear correlation, up to a point, between glucose concentration and the rate of human mononuclear cell cortisol metabolism in vitro. The mechanism by which glucose exerts its effect was investigated further. We observed that: (1) the effect of glucose on mononuclear cell cortisol metabolism was not influenced by insulin; (2) NADPH and NADH enhanced cortisol metabolism by disrupted cells, irrespective of whether the homogenates were dialysed or not; (3) lactate and ATP inhibited mononuclear cell cortisol metabolism and (4) almost all the glucose used was converted to lactate. It is concluded that mononuclear cell cortisol metabolism can depend on both nucleotides.