Modulation of macrophage superoxide release by purine metabolism.

Metabolic flux through the purine salvage pathway appears to modulate superoxide secretion by elicited macrophages. Exogenous adenosine, the first substrate of this pathway, stimulates superoxide secretion, and Allopurinol, a specific inhibitor of xanthine oxidase, inhibits superoxide secretion. The effects of these agents are additive since it was possible for each to neutralize the effects of the other when given in combination. In these experiments, the purine salvage pathway was responsible for over ten times the superoxide production attributable to the NADPH oxidase system.