Effects of low-concentration lidocaine on persistent sodium currents in hypoxic isolated rat CA1 hippocampal neurons / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of low-concentration lidocaine on the persistent sodium currents enhanced by hypoxia in isolated rat CA1 hippocampal neurons. Methods Brains were harvested from 10-14 day old SD rats of both sexes. Hippocampi were immediately isolated and cut into slices (400-500 ?m) which were incubated in artificial cerebral-spinal fluid (ACSF) at 31 ℃ for 1-1.5 h. CA1 regions were isolated and hippocampal neurons were prepared by enzymatical digestion. The experiment was performed in 7 groups ( n = 10 each) hypoxie control group (C) and lidocaine 1, 3, 6, 10, 20, 30 ?mol groups (L1-6). The isolated neurons were transferred to the recording chamber. The persistent sodium currents were recorded using whole-cell patch clamp technique first under normal condition. The normal perfusion solution was then replaced with hypoxie and glucose free perfusion solution within 20 seconds. The persistent sodium currents were recorded again after being perfused with hypoxie and glucose free solution with and without lidocaine. Results The persistent sodium current was greatly enhanced after 5 min hypoxia as compared to the baseline value before hypoxia. The persistent sodium current in group L1-6 was significantly lower than that in group C after 5 min hypoxia. The inhibitory effect of lidocaine on the persistent sodium current enhanced by hypoxia was dose-dependent. Conclusion Low concentration lidocaine can inhibit the persistent sodium current enhanced by hypoxia.