Tumor necrosis factor provokes superoxide anion generation from neutrophils

We report that tumor necrosis factor (TNF) provokes superoxide anion generation from human neutrophils. Superoxide anion generation was provoked at TNF concentration of 1 X 10(-11) M and maximal generation was attained at TNF concentration of 1 X 10(-9) M. We also show that movements of intracellular calcium may mediate the TNF-stimulated superoxide anion generation because 8-(diethylamino) octyl 3,4,5-trimethoxybenzoate hydrochloride--but not extracellular EGTA--inhibited the generation of superoxide anion. These results suggest that TNF may mediate some mechanisms of host defense by provoking superoxide anion generation from neutrophils.