ACTIVITY OF SOME ENZYMES OF XENOBIOTIC ME TABOLISM 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 availabil ity of substrates for enzymes, lymphocytes were degraded by single-sta ge freezing-melting. At the same time, the activities of NADPH-cytochr ome 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, r espectively. The lymphocytic levels of cytochrome P-450 were approxima tely 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.