Changes in proton currents in murine microglia induced by cytoskeletal disruptive agents.
Voltage-gated proton currents (IPR) were investigated in cultured murine microglia using the whole-cell configuration of the patch clamp technique. At a gradient of 1.5 between intracellular (pHi = 6.0) and extracellular pH (pHo = 7.5) values, outward IPR were detected at depolarizing potentials, while the activation threshold of IPR was -40 mV. Time-dependent activation of IPR was fitted by a single exponential with a time constant of 661 ms at +40 mV. An increase in the activation time constant of IPR was seen after exposure of microglia to the cytoskeletal disruptive agents cytochalasin D or colchicine. Moreover, the current density of IPR was significantly reduced by 49% in cells treated with cytochalasin D and by 27% in cells treated with colchicine for 24 h. In contrast, voltage-dependence of steady-state activation of IPR was unchanged after disruption of the cytoskeleton. Exposure of microglia to the cytoskeletal stabilizers phalloidin and taxol did not affect IPR of microglia.
Klee
R
R
Department of Neurophysiology, Institute of Physiology, Humboldt University, Berlin, Germany.
Heinemann
U
U
Eder
C
C
D000200:Action Potentials; D000818:Animals; D002478:Cells, Cultured; D003078:Colchicine / Q000494:pharmacology*; D015638:Cytochalasin D / Q000494:pharmacology*; D003599:Cytoskeleton / Q000187:drug effects* / Q000502:physiology; D017136:Ion Transport / Q000187:drug effects; D051379:Mice; D017628:Microglia / Q000187:drug effects* / Q000378:metabolism; D008870:Microtubules / Q000187:drug effects / Q000502:physiology; D017239:Paclitaxel / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D010590:Phalloidine / Q000494:pharmacology; D011522:Protons
D011522:Protons; D010590:Phalloidine; D015638:Cytochalasin D; D017239:Paclitaxel; D003078:Colchicine