title: Comparative study on effect of N-ethylmaleimide on the superoxide-generating system of guinea-pig eosinophils stimulated by soluble stimuli.
abstract: 1. The effect of N-ethylmaleimide (MalNEt) modification on O2- production by guinea-pig eosinophils mediated by different soluble stimuli was studied. 2. MalNEt pretreatment inhibited the O2- production stimulated by concanavalin A (Con A), cytochalasin E or digitonin, but not A23187 or sodium fluoride. 3. Particulate fractions from MalNEt-pretreated eosinophils before exposure to the stimulus showed the inhibition of the enhancement of NADPH-dependent O2- production induced by Con A, cytochalasin E or digitonin, but not A23187. 4. Treatment of eosinophils with MalNEt after stimulation had no effect on the NADPH oxidase activity. 5. These findings suggest that at least two pathways exist for the activation of the O2(-)-generating enzyme system, probably the NADPH oxidase system, in guinea-pig eosinophils.
authors.affiliation: Department of Physiological Chemistry, School of Medicine, Juntendo University, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamashita
authors.forename: A
authors.initials: A
authors.lastname: Someya
mesh_terms: D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D003208:Concanavalin A / Q000494:pharmacology; D003572:Cytochalasins / Q000494:pharmacology; D004072:Digitonin / Q000494:pharmacology; D004804:Eosinophils / Q000187:drug effects / Q000378:metabolism*; D005033:Ethylmaleimide / Q000494:pharmacology*; D006168:Guinea Pigs; D007700:Kinetics; D012969:Sodium Fluoride / Q000494:pharmacology; D013481:Superoxides / Q000097:blood*
chemical_list: D003572:Cytochalasins; D003208:Concanavalin A; D013481:Superoxides; C007215:cytochalasin E; D000001:Calcimycin; D012969:Sodium Fluoride; D004072:Digitonin; D005033:Ethylmaleimide