低浓度利多卡因对大鼠海马CA1区缺氧神经元持续钠电流的影响  

Effects of low-concentration lidocaine on persistent sodium currents in hypoxic isolated rat CA1 hippocampal neurons

作　　者：张一[1] 杨伊林[1] 焦志华[2] 王士雷[2] 周岱[3] 庄心良[2] 

机构地区：[1]苏州大学附属第三医院神经外科,常州市213003 [2]上海市第一人民医院麻醉科 [3]苏州大学附属第一医院神经外科

出　　处：《中华麻醉学杂志》2005年第8期576-578,共3页Chinese Journal of Anesthesiology

摘　　要：目的观察低浓度利多卡因对大鼠海马CA1区缺氧神经元持续钠电流的影响,探讨其对缺血脑损伤保护作用的机制。方法酶消化法急性分离SD大鼠海马CA1区锥体细胞,随机分为7 组(n=10):缺氧组(C组)、利多卡因1μmol·L-1组(L1组)、3μmol·L-1组(L2组)、6μmol·L-1组(L3组)、10 μmol·L-1组(L4组)、20μmol·L-1组(L5组)、30μmol·L-1组(L6组)。以全细胞膜片钳技术记录各组缺氧前持续钠电流的基础值后,C组以无糖缺氧灌流液、L1-6组以含有不同浓度利多卡因的无糖缺氧灌流液在20 s内快速置换灌流液,建立体外神经元缺氧模型。记录缺氧5 min时各组神经元的持续钠电流。结果与基础值比较,各组神经元在缺氧5 min时持续钠电流均增大(P<0.01)。在缺氧5 min 时,L1-6组持续钠电流均低于C组,L2-6组均低于L1组,L3-6组均低于L2组,L4-6组均低于L3组(P< 0.01)。结论低浓度利多卡因能抑制大鼠海马CA1区神经元缺氧引起的持续钠电流增加,该作用在10 μmol·L-1时达到最大。Objective To investigate the effects of low-concentration lidocaine on the persistent sodium currents enhanced by hypexia in isolated rat CAI hippecampal neurons.Methods Brains were harvested from 10- 14 day old SD rats of both sexes. Hippecampi were immediately isolated and cut into slices （400-500 μm） 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）： hypexic control group （C） and lidocaine 1, 3, 6, 10, 20, 30 μmol groups （L1-6 ）. The isolated neurons were transferred to the recording chamber. The persistent sodium currents were recorded using whole-cell patch clamp technique fast under normal condition. The normal perfusion solution was then replaced with hypoxic and glucose free perfusion solution within 20 seconds. The persistent sodium currents were recorded again after being perfused with hypexic and glucose free solution with and without lidocaine. Results The persistent sodium current was greatly enhanced after 5 min hypexia as compared to the baseline value before hypexia. 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 hypexia was dose-dependent. Conclusion Low concentration lidocaine can inhibit the persistent sodium current enhanced by hypexia.

关 键 词：利多卡因 钠通道 海马 神经元 细胞低氧 海马CA1区锥体细胞 低浓度利多卡因 持续钠电流 神经元缺氧 缺氧模型 

分 类 号：R614[医药卫生—麻醉学]