Effects of midazolam on delayed rectifier potassium channels from acutely isolated pyramidal neurons of rats / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of midazolam on the delayed rectifier outward potassium channel current (Ik) using the whole-cell patch clamp technique. Methods Pyramidal neurons were isolated acutely from 5-15 d SD rat hippocampus. We measured amplitudes of the delayed outward rectifier potassium currents by activating depolarizing pulse from - 50mV to 30mV. Different concentrations of midazolam were added and potassium channel currents were measured. Results Delayed outward rectifier potassium channel currents were inhibited by midazolam in a dose-dependent manner. EC50 was (8.31 ?2.78) ? 10-8 mol/L and Hill constant was 0.90? 0.16.Conclusions Our results suggest that block of the outward rectifier potassium channel current by midazolam may contribute to the mechanism of midazolam anesthesia action.