[Mechanisms of hyperpolarization of plasma membrane of macrophages and astrocytes during activation].
The hyperpolarization response of macrophages and glial cells (astrocytes, U118 cell line) to the action of inducers of reactive oxygen species (ROS) has been studied. Macrophages were stimulated with chemotactic peptide fMLP and platelet activation factor (PAF). Astrocytes were affected by complement component--anaphylatoxin C5a. The hyperpolarization response of both cell types depends on intracellular Ca2+ concentration and extracellular K+ concentration. Depletion of K+ concentration in the medium (1 mM KCl) or chelation of intracellular Ca2+ with Quin-2 (50 microM) significantly decreased the hyperpolarization response or caused depolarization of plasma membrane. Moreover, inhibition of Ca(2+)-dependent K(+)-channels with quinidine (50 microM) induced only a prolonged depolarization of both cell types. The data obtained permit a suggestion that macrophage and astrocyte hyperpolarization response to stimulation with ROS inducers involves O2.- mediated activation of Ca(2+)-dependent K(+)-channels.
Gamaleĭ
I A
IA
Institute of Cytology, Russian Academy of Sciences, St. Petersburg.
Kirpichnikova
K M
KM
Ishchenko
A M
AM
Zhakhov
A V
AV
Kliubin
I V
IV
D000818:Animals; D001253:Astrocytes / Q000187:drug effects*; D002460:Cell Line; D015936:Complement C5a / Q000494:pharmacology*; D008262:Macrophage Activation; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D008815:Mice, Inbred Strains; D017382:Reactive Oxygen Species / Q000378:metabolism
D017382:Reactive Oxygen Species; D015936:Complement C5a
Mekhanizm giperpoliarizatsii plazmaticheskoĭ membrany makrofagov i astrotsitov pri aktivatsii.