Evidence that the superoxide-generating system of human leukocytes is associated with the cell surface.

摘要: Superoxide anion (O-2-) generation by human peripheral blood polymorphonuclear leukocytes is enhanced when these cells encounter appropriate soluble or particulate stimuli. O-2- requires intact, viable and proceeds independently of phagocytosis. To investigate the possibility that O-2--generating system associated with outer surface leukocyte plasma membrane, we have examined effects upon production p-diazobenzenesulfonic acid, a reagent which can react predominantly proteins external cell membrane. When normal were preincubated cytochalasin B (to minimize endocytosis) then exposed to surface-active lectin, concanavalin A, stimulated generate in concentration- time-dependent fashion selectively discharge granule-associated enzyme, lysozyme, into surrounding medium. These responses, as well cellular binding [H] could be blocked alpha-methyl-D-mannoside. Brief treatment (less than 5 min at 4 degrees C) acid (1.0-5.0 mM) significantly interfered A-mediated but had no influence lysozyme release [3H] A. The diazonium salt did not alter viability specific activity cytoplasmic lactate dehydrogenase (inhibitable under conditions allowed entry this cytosol). p-Diazobenzenesulfonic therefore, very likely exerted its intact leukocyte, inhibiting (either directly indirectly) without influencing another response lectin-cell contact: lysozyme. results support ectoenzyme responsible for production.