Influence of corticosteroids on human polymorphonuclear leukocyte function in vitro : Reduction of lysosomal enzyme...

In an experimental system in which phagocytosis or adherence of cells to surfaces were excluded as variables, we have investigated the possibility that corticosteroids may inhibit release of lysosomal constituents from viable human polymorphonuclear leukocytes into the extracellular environment. Release ofΒ-glucuronidase and lysozyme from cytochalasin B-treated cells exposed to serum-treated zymosan, heat-aggregated human IgG, and the complement component C5a was significantly reduced by pretreatment with hydrocortisone sodium succinate and methylprednisolone sodium succinate (5×10(-4) M). Both steroids also reduced superoxide production by these cells. These in vitro studies provide evidence that corticosteroids influence membrane-dependent responses of intact, viable polymorphonuclear leukocytes to immune reactants. Inhibition of these responses (lysosomal enzyme release, superoxide production) may explain, in part, both the antiinflammatory actions of steroids and their deleterious effects on host defenses.