ROLE OF PHAGOCYTE IN HOST-PARASITE INTERACTIONS .19. LEUKOCYTIC GLUTATHIONE REDUCTASE AND ITS INVOLVEMENT IN PHAGOCYTOSIS

Glutathione reductase activity was found in guinea pig peritoneal polymorphonuclear leuckocytes. The cofactor requirement for the enzyme was found to be NADPH. This was determined by the requirement of GSSG for oxidation of the reduced cofactor and the stimulatory effect of KCN on GSH peroxidase which was also found in these cells. Enzyme activity was inhibited by the sulfhydryl antagonist N-ethyl maleimide. The addition of GSSG to the reaction mixture resulted in an increase in cellular GSH content. The activity of the enzyme was confined to the 20,000g supernatant fraction. Phagocytosis caused a significant increase in GSSG reductase activity within 15 sec after particle addition. The NADPH oxidase stimulation which has been associated with the phagocytic process did not occur until some minutes after the addition of latex particles. Since NADP+ is a limiting factor for the hexose monophosphate shunt and GSSG reductase can increase the NADP+ content of the cell, one can now postulate that increased activity of this enzyme is an early event involved in the phagocytosis-associated increase in this metabolic pathway. © 1969.