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

[摘要]

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 . The rate of O⁻ ₂ release was twice the rate of H₂O₂ production (1.1 nmol H₂O₂.min⁻.10⁶ macrophages⁻¹).

[学科分类] 生物化学/生物物理

[关键词] Macrophage;Transmembrane potential;Superoxide anion;Hydrogen peroxide;Extracellular Ca2+;di-I-C1-(5);3;3'-dimethylindodicarbocyanine iodide;DMSO;dimethylsulfoxide;EGTA;ethyleneglycol-bis (β-aminoethyl ether) N;N-tetraacetic acid;FCS;fetal calf serum;HBSS;Hanks' balanced salt solution;MEM;minimum essential medium;PDC;peritoneal exudate cells;PMA;phorbol myristate acetate;TPMP;triphenylmethyl phosphonium