一氧化氮合成酶在培养海马神经细胞上的分布及其激活对细胞兴奋性的影响

目的：观察一氧化氮合成酶（NOS）在培养海马神经细胞上的分布情况和酶激活时对细胞兴奋性的影响。方法：NOS的分布情况采用免疫荧光标记方法，细胞兴奋性的变化采用膜片钳全细胞的模式来记录膜电位的变化。结果：发现两种结构型NOS包括nNOS和eNOS均分布在神经元上。另外，eNOS还分布在胶质细胞上。当给予NOS的底物L-精氨酸时，海马神经元的膜电位出现去极化，并产生动作电位。结论：以上结果显示NOS广泛分布在海马神经细胞中，当其激活时对海马神经元有兴奋作用。

Distribution and excitable effects of NOS in rat hippocampal neurons cultured in vitro

Objective: To define the distribution and excitable effects of nitric oxide synthase (NOS) in rat hippocampal cells cultured in vitro. Methods: The distribution of nitric oxide synthase was detected by immunofluorescent labeling. Membrane potentials were recorded by whole-cell patch clamp. Results: Both nNOS and eNOS were found to express in the hippocampal neurons. For the glial cells, only eNOS but not nNOS was found in their processes. When L-arginine, a non-selective substrate of NOS was applied, the membrane potential of hippocampal neurons depolarized and the cells became firing with action potentials. Conclusions: These results indicate that NOS is extensively distributed in hippocampal cells and its activation leads to an increase of the neuronal excitability.