The effect of ketamine on the large conductance Ca~(2+)-activated potassium channels / 中华麻醉学杂志

ABSTRACT

ObjecitveTo study the effects of ketamine on the large conductance Ca~(2+)-activated potassium (BK)channels in cultured newborn rat hippocampal neurons. Method:All experiments were carried out on 3-7 days old neurons. Single channel current signals were recorded in symmetrical high K~+ solution(140mM) under cell-attached patch and inside-out patch. Result:(1)In inside-out patch, with the unitary conductance being 176.5?16.5pS,the BK channel activity was markedly activated by internal Ca~(2+) but was blocked by potassium channel blocker (TEA). (2) In cellattached patch,when the concentration of ketamine was 0.01,0.05,0.20mmol/L and membrane potential kept at?60mV,the open probability (Po) decreased from 0.042?0.011 at baseline to 0.027?0.008,0.030?0.015,0.032?0.021 respectively(P0.05). Conclusion:Ketamine has dual effects on the BK channels,the inhibition may be related to its side effects,and the activation to the mechanism in anesthesia.