神经生长因子对一氧化氮介导的大鼠脑皮质神经元毒性的影响

Effects of Nerve Growth Factor on Nitric Oxide-mediated Neurotoxicity in Cultured Neurons of Cerebral Cortex

研究神经生长因子（ＮＧＦ）对一氧化氮（ＮＯ）介导的大鼠脑皮质神经无毒性的影响。方法：用原代培养的大鼠胎鼠脑皮质神经细胞，测定ＮＯ含量及原生型一氧化氮合酶（ｃＮＯＳ）基因表达，并研究ＮＧＦ对细胞缺氧／缺糖损伤的影响。结果：细胞缺氧／缺糖培养 ２４ ｈ后，细胞死亡率明显增高，ＮＯ大量释放。 ＮＧＦ １００ μｇ／Ｌ显著提高细胞生存力，降低ＮＯ释放，但其对硝普钠（ＳＮＰ）３００ μｍｏｌ／Ｌ引起的ＮＯ大量释放及细胞死亡率升高无明显影响。 ＮＧＦ５０、１００ μｇ／Ｌ显著降低细胞缺氧／缺糖引起的 ｃＮＯＳ ｍＲＮＡ的高表达。结论：ＮＯ介导了细胞缺氧／缺糖损伤，ＮＧＦ通过抑制ｃＮＯＳ活性，降低ＮＯ释放来保护神经元免受缺氧／缺糖损伤。

Purpose: Effects of nerve growth factor (NGF) on nitric oxide(NO)-mediated neurotoxicity in cultured neurons of cerebral cortex were studied. Methods: NO release and constitutive nitric oxide synthase (cNOS) mRNA level were measured in cultures of cerebral cortex from fetal rats, and the effects of NGF on NO-mediated neurotoxicity were studied. Results: There was a marked increase of neuronal death and NO release in oxygen/ glucose deprived cultures for 24 h. NGF 50, 100 μg/L significantly increased neuronal surviving and decreased NO release. However, it had no significantly effects on neurotoxicity induced by sodium nitroprusside (SNP) 300 umol/L in conical cultures. NGF significanlty attenuated cNOS gene expression. Conclusion: NO mediates the neurotoxicity of hypoxia/ hypoglycemia and NGF protects conical neurons against oxygen/glucose deprivation induced toxicity via inhibiting the activity of cNOS and the release of NO.