Effect of hyperoxia on the carbohydrate metabolism of human lymphocytes

Lymphocytes incubated under high oxygen tensions have impaired lymphoblastic transformation to nonspecific mitogens. Since carbohydrate metabolism may be essential for an optimal proliferation of these cells following an antigenic stimulus, we have characterized the effect of hyperoxia on the glucose metabolism of human lymphocytes in vitro. The mean rates of glucose utilization, Krebs cycle activity, and hexose monophosphate shunt activity were determined for unstimulated and phytohemagglutinin (PHA)-stimulated cultures incubated for 3 days. In unstimulated cultures, hyperoxia stimulated glucose utilization and markedly impaired Krebs cycle activity but did not alter HMPS activity. These observations suggest that hyperoxia impairs the mitochondrial activity of lymphocytes and that increased glycolysis compensates for the loss of cellular energy normally produced by this organelle. Under high oxygen tension PHA-stimulated cultures failed to show the burst in HMPS activity and increased Krebs cycle activity characteristic of cultures incubated under physiological oxygen tensions and consumed less glucose. Our results indicate that hyperoxia alters the glucose metabolism of lymphocytes. This metabolic alteration may be related to the impaired function of the cells under hyperoxic conditions.