Transmembrane potential variations accompanying the PMA-triggered O-2 and H2O2 release by mouse peritoneal macrophages.

ABSTRACT

Stimulation by PMA of Streptococci-elicited macrophages induced a transient membrane depolarization preceding the onset of detectable O-2 production. Mice-resident peritoneal macrophages were unresponsive to PMA for both activities. The PMA-triggered membrane depolarization seemed to be independent from O-2 production because inhibition of membrane depolarization by EGTA had no effect on rates of O-2 or H2O2 release and rate of antimycin A insensitive O2 uptake by Streptococci-elicited macrophages. The portion of O2 uptake recovered as O-2 was found to be 1/3. The rate of O-2 release was twice the rate of H2O2 production (1.1 nmol H2O2.min-1 X 10(6) macrophages-1).