Transmembrane potential variations accompanying the PMA-triggered O −2 and H 2O 2 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 H 2O 2 release and rate of antimycin A insensitive O 2 uptake by Streptococci-elicited macrophages. The portion of O 2 uptake recovered as O − 2 was found to be 1 3 . The rate of O − 2 release was twice the rate of H 2O 2 production (1.1 nmol H 2O 2.min −.10 6 macrophages −1).