腺苷对海马神经元高电压激活性钙通道电流的作用研究

Effects of Adenosine on the High Voltage-activated Calcium Channel Current of Cultured Rat Hippocampal Neurons

目的:在细胞水平研究腺苷(Ade)对海马神经元高电压激活性钙通道电流(IHVA)的影响。方法:条件培养基纯化法原代培养SD大鼠乳鼠的海马神经元,选取生长7～9d的细胞,应用全细胞膜片钳技术,以细胞外给予Ade的方法,比较Ade干预前后IHVA值及I-V曲线的变化,并观察硝苯地平预处理后,Ade对IHVA值影响的改变。结果:原代培养的SD大鼠乳鼠的海马神经元在7～9d发育基本成熟,采用膜片钳技术在预设的刺激程序下可以记录到IHVA,以细胞外干预的方式加入Ade后,观察到Ade可抑制IHVA的幅度,并呈浓度依赖性,可使I-V曲线上移,但对最大激活电位及峰值电位无明显影响;硝苯地平可部分减弱Ade对IHVA的影响。结论:Ade在一定浓度时可显著抑制体外培养海马神经元的IHVA,硝苯地平可部分减弱这种影响。

Objective： To study the effects of adenosine （Ade） on high voltage-activated calcium channel current （IHVA） of cultured rat hippocampal neurons. Methods： Primary culture of rat hippocampal neuronal cells was performed . Whole-cell patch clamp recording was used to in- vestigate the influence of Ade on IHva in the hippocampal neuronal cells at 7~9 days after culture. Ade was applied by extracellular bath and the amplitude of IHVA before and after Ade application was measured and compared. The effects of Ade on IHVA in the hippocampal neuronal cells pre- treated by nifedipine were observed. Results： Hippocampal neuronal cells were matured at 7~9 days after culture. Bath application of Ade at different concentrations could inhibit IHva dose-de- pendently, shift I-V curves upwardly without changing the reversal potential and the threshold potential for activating IHVA. Nifedipine, a kind of L-type calcium channel antagonists, could partly depress the reduction of IHvA by Ade. Conclusion： Ade could inhibit IHVA of cultured rat hippocampal neuronal cells and nifedipine could partly depress the reduction of IHVA by Ade.