The role of reactive oxygen species in membrane potential changes in macrophages and astrocytes.
Involvement of reactive oxygen species (ROS) in changes of the plasma membrane potential of mouse peritoneal macrophages and astrocytes (U118 cell line) under the action of different agents has been studied. Membrane potential was measured using the voltage-dependent fluorescent oxonol dye DiBAC4(3). Agonists which stimulate macrophages to release ROS (the fMLP peptide and platelet activating factor) caused prolonged hyperpolarization. Experiments with the fluorescent probe 2',7'-dichlorofluorescein diacetate have shown that astrocytes release ROS upon the action of C5a complement anaphylatoxin (but not C3a). The effect of C5a was accompanied with hyperpolarization of the astrocyte plasma membrane. Treatment of the cells with agents which do not induce ROS generation (C3a, lipopolysaccharide, interferon-gamma) depolarized the plasma membrane. Hyperpolarization of both cell types was significantly decreased in the presence of superoxide dismutase (but not catalase). Moreover, the O2- -generating system caused a marked hyperpolarization of both cell types. The data obtained suggest that O2- is involved in the macrophage and astrocyte hyperpolarization response.
Institute of Cytology, Russian Academy of Sciences, St. Petersburg.
I V
IV
Klyubin
K M
KM
Kirpichnikova
A M
AM
Ischenko
A V
AV
Zhakhov
I A
IA
Gamaley
D000706:Anaphylatoxins / Q000494:pharmacology; D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D002374:Catalase / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D005456:Fluorescent Dyes / Q000494:pharmacology; D005909:Glioblastoma; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000031:analogs & derivatives* / Q000494:pharmacology; D010972:Platelet Activating Factor / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D000706:Anaphylatoxins; D005456:Fluorescent Dyes; D008070:Lipopolysaccharides; D010972:Platelet Activating Factor; D017382:Reactive Oxygen Species; D009240:N-Formylmethionine Leucyl-Phenylalanine; C049813:N-formylmethionyl-leucyl-phenylalanyl-lysine; D007371:Interferon-gamma; D002374:Catalase; D013482:Superoxide Dismutase