Studies on the mechanism of metabolic stimulation in polymorphonuclear leukocytes during phagocytosis. Activators and inhibitors of the granule bound NADPH oxidase.
The effects of several known inhibitors and activators of peroxidase-catalyzed reactions have been studied on the NADPH oxidase activity of granules isolated from polymorphonuclear leukocytes at rest or during phagocytosis. Redogenic substances, such as ascorbate or hydroquinone, and superoxide dismutase, which are known to inhibit peroxidase-catalyzed reactions, also inhibited the NADPH oxidase activity of granules. Oxidogenic substances, such as guaiacol or resorcinol, and manganese, which are known to stimulate peroxidase-catalyzed reactions, also activated the NADPH oxidase activity of granules. Cyanide, an inhibitor of peroxidase-catalyzed reactions, inhibited the NADPH oxidase activity of granules isolated from resting leukocytes but only slightly affected that of granules isolated from phagocytosing cells, as previously reported. A list of the properties of the NADPH oxidase activity of granules and of peroxidase oxidase activity is given. The arguments in favor of and those against a possible identity of the two activities are discussed.
D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D001665:Binding Sites; D003486:Cyanides / Q000494:pharmacology; D003594:Cytoplasmic Granules / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D006168:Guinea Pigs; D006873:Hydroquinones / Q000494:pharmacology; D007700:Kinetics; D008345:Manganese / Q000494:pharmacology; D009247:NADH, NADPH Oxidoreductases / Q000097:blood*; D009504:Neutrophils / Q000201:enzymology*; D010587:Phagocytosis; D011485:Protein Binding; D012118:Resorcinols / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000494:pharmacology
D003486:Cyanides; D006873:Hydroquinones; D012118:Resorcinols; D008345:Manganese; D013482:Superoxide Dismutase; D009247:NADH, NADPH Oxidoreductases; D001205:Ascorbic Acid