Effect of maleimide derivatives, sulfhydryl reagents, on stimulation of neutrophil superoxide anion generation with concanavalin A.
Using maleimide derivatives with relatively rare side reactions, their effect on stimulation of O-2 production by guinea-pig neutrophils with Con A was studied. Showdomycin, a very slowly penetrating agent, did not affect O-2 production whereas NEM, a rapidly penetrating agent, markedly inhibited O-2 production without interference with binding of Con A to cells. Particulate fractions from neutrophils stimulated with Con A showed markedly increased NADPH-dependent O-2 production compared with fractions from unstimulated cells. Treatment of neutrophils with NEM before exposure to Con A inhibited the enhancement of NADPH-dependent O-2 production of particulate fractions by Con A. However, particulate fractions from Con A-stimulated and unstimulated cells hardly exhibited reduced NADPH oxidase activity after direct exposure to NEM. Treatment of neutrophils with NEM after activation by Con A had no effect on NADPH-dependent O-2 production of particulate fractions. These results indicate that NEM inhibits the activation process of the O-2-generating enzyme, probably NADPH oxidase with Con A.
D000818:Animals; D003208:Concanavalin A / Q000494:pharmacology*; D005033:Ethylmaleimide / Q000494:pharmacology; D006168:Guinea Pigs; D008301:Maleimides / Q000494:pharmacology*; D009113:Muramidase / Q000097:blood; D009247:NADH, NADPH Oxidoreductases / Q000097:blood; D019255:NADPH Oxidases; D009504:Neutrophils / Q000187:drug effects*; D012787:Showdomycin / Q000494:pharmacology; D013439:Sulfhydryl Reagents / Q000494:pharmacology*; D013481:Superoxides / Q000097:blood*
D008301:Maleimides; D013439:Sulfhydryl Reagents; D003208:Concanavalin A; D013481:Superoxides; D012787:Showdomycin; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; D009113:Muramidase; D005033:Ethylmaleimide