Volatile anesthetics inhibit the ion flux through Ca2+-activated K+ channels of rat glioma C6 cells

Ca2+-activated K+ channels in rat glioma C6 cells were investigated using monolayers of these cells in petri dishes. The ion flux through the channels was studied with 86Rb+ after addition of a Ca2+-ionophore to the incubation medium. Both the influx and efflux of 86Rb+ through these Ca2+-activated K+ channels were inhibited by the general anesthetic halothane (at clinical concentrations). Other volatile anesthetics such as isoflurane, enflurane and methoxyflurane also inhibited the Ca2+-activated K+ channels at clinical concentrations. Inhibition of these channels by general anesthetics could have profound effects on signal transmission in the brain.