| The electrophysiological property of etomidate (ET)-induced current (Iet) and the effect of etomidate at clinically relevant concentration (1-10 μM) on synaptic and extrasynaptic GABAa receptor and glycine receptor function were investigated by using the whole-cell patch-clamp technique in freshly dissociated rat dorsal horn neurons. These results suggested that the anesthetics-induced changes at the level of the spinal cord could contribute significantly to the general anesthesia.The electrophysiological property of IETApplication of etomidate evoked inward current (Iet) in all rat dorsal horn neurons at a holding potential of -40 mV. The current became detectable at the concentration of 10-5 M and, within the range of ET concentrations from 10-5 to 10-3 M, the amplitude of Iet increased in a concentration-dependent manner with a conductance increase. The application of ET over 10-3 M, however, suppressed the peak current components, as leading to a bell-shaped concentration-response curve. When ET over 3×10-4 M was applied, a transient inward current (tail current) was elicited immediately after wash out and increased in a concentration-dependent manner.For characterizing the etomidate-induced current (Iet), the kinetics were analysed. The time constants for activation (Tact), desensitization and deactivation (τdeact) of Iet were compared in the experiment... |
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