金属硫蛋白对培养神经细胞迟发性损伤的作用和一氧化氮的表达

本文以新生大鼠原代培养皮质神经元为实验材料，造成迟发性神经元损伤模型．在不同时程内，测试培养液中的细胞乳酸脱氢酶漏出量和用还原型尼克酰胺腺嘌呤二核着苷酸脱氢酶染色反应，观察培养细胞中一氧化氮合酶的表达水平．结果表明，缺血组在缺血与再灌流中，细胞乳酸脱氢酶漏出量明显高于对照组，差异显著（Ｐ＜０．００１）．一氧化氮合酶阳性神经元数量在缺血组的缺血时即明显高于对照组（Ｐ＜０．０１），再灌流后一氧化氮合酶表达仍然强烈，与对照组相比有显著差异（Ｐ＜０．０１）．当损伤细胞再灌流时，同时加入金属硫蛋白后，显示一氧化氮合酶表达减弱，和缺血组相比有显著差异（Ｐ＜０．０５～０．００１），细胞乳酸脱氢酶漏出量在再灌流后的早期近似于对照组．结合文献和本实验结果提示：在迟发性神经元损伤形成过程中一氧化氮起着重要作用；金属硫蛋白对脑缺血后迟发性神经元损伤有一定保护作用，是一种细胞保护剂，可望用于临床，控制缺血再灌流损伤。

THE PROTECTIVE EFFECT OF METALLOTHIONEIN ON DELAYED NEURONAL DAMAGE IN VITRO AND EXPRESSION OF NITRIC OXIDE SYNTHASE

The present paper reported that the neuronal primary culture of cerebral cortex from newborn rats was used to make delayed neuronal damage(DND) cellular model. We observed the expression levels of nitric oxide synthase(NOS) in culturedcells by using NADPH-diaphorase reaction and measured the effusion of lactate dehydrogenase (LDH) at different timecourses. The results showed that, during ischemia and reperfusion, the effusion of LDH in ischemia group was more thanthat of the normal control group, and showed significant differences (P<0. 001), the number of NOS positive neurons wasmore than that of the normal control group (P<0.01). during ischemia, after reper fusion, the expression levels of NOS werestill intense compared with normal control group (P<0.01). But, we used the metallothionein(MT) during reperfusion,the level of NOS in MT group decreased obviously as compared with ischemia group (P<0.05～0.001), the effusion ofLDH during early phase of the reperfusion was nearly equal to the normol control group. The results indicate that NO mayplay an important role in the mechanisms of DND, the MT is a cell protective drug and it is hopeful to be used to protectneurons against DND.