The rate of oxygen consumption and superoxide anion formation by stimulated human neutrophils. The effect of particle concentration and size.

The respiratory burst of neutrophils was measured as a function of the ratio of the opsonised beads to neutrophils. The rate of oxygen uptake was found to be linear up to a bead:neutrophil ratio of 25. The production of the superoxide anion, as measured by the rate of reduction of cytochrome c, was negligible until a certain 'critical' value of the bead:neutrophil ratio was reached. The rate of oxygen consumption and superoxide release above the critical value varies linearly with the bead:neutrophil ratio. Both the rate of oxygen consumption and of superoxide release vary with the square of the radius of the ingested particle. It is suggested that this depends on the surface area of neutrophil membrane, activated by contact with the antagonist.