ACTIVITY OF SOME ENZYMES OF XENOBIOTIC METABOLISM IN HUMAN PERIPHERAL-BLOOD LYMPHOCYTES

The activity of NADPH-cytochrome c-reductase, benzpyrene hydroxylase, epoxyhydratase and glutathione-S-transferase in human peripheral blood lymphocytes was studied. In the presence of NADPH, native lymphocytes were unable to reduce cytochrome c. In order to improve the availability of substrates for enzymes, lymphocytes were degraded by single-stage freezing-melting. At the same time, the activities of NADPH-cytochrome c-reductase, epoxide hydratase, and glutathione-S-transferase were 1.7+/-0.6, 49.0+/-18.0, and 3-.0+/- +/-6.0 nmol/min per mg protein, respectively. The lymphocytic levels of cytochrome P-450 were approximately 0.1-0.2 nmol per mg microsomal protein, while those of cytochrome b5 were nearly 0.5 nmol/mg microsomal protein in the lymphocytes.