【摘要】 目的通过模型的构建,研究N-甲基-D-天氡氨酸激活的单通道动力学行为。方法分别采用3-态模型和4-态模型进行模拟,计算不同Mg²⁺浓度和电压下通道状态参数的分布,并同实验测定结果进行比较。结果当Mg²⁺＞20μmol/L时,通道的阻断速率同Mg²⁺浓度成线性关系:而当Mg²⁺＜20μmol/L时,通道的阻断速率同Mg²⁺的浓度无关。结论在Mg²⁺浓度很低的情况下,存在不依赖于镁的阻断机制,这可能是由于通道构象的改变所引起的。更多还原

【Abstract】 Objective To study N-methyl-D-aspartate activated single-channel kinetics behavior based on 3-and 4- state model.Methods The distribution of single-channel parameters were calculated in the different Mg ion concentration and holding potential based on 3-and 4-state model and compared it with data from experiment.Result The block rate depends linearly on Mg ion concentration when Mg ion concentration was greater than 20μmol/L,however,when Mg ion concentration was less than 20μmol/L,it is independent of Mg ion concentration.Conclusion There is a second blocking mechanism in addition to the Mg block at very low Mg ion concentrations.It may be because of the result of a voltage-dependent conformational change.更多还原