虎纹捕鸟蛛毒素对脑缺血模型大鼠海马肿瘤坏死因子凋亡通路的影响

背景：虎纹捕鸟蛛毒素经离子通道分析技术证明是一种作用于突触前膜的N型钙离子通道阻断剂。目的：观察新型钙通道拮抗剂虎纹捕鸟蛛毒素对全脑缺血再灌注损伤模型大鼠海马组织肿瘤坏死因子凋亡通路中肿瘤坏死因子α、肿瘤坏死因子受体Ⅰ、肿瘤坏死因子受体相关死亡结构域、Fas相关死亡结构域蛋白、Caspase8表达的影响。方法：采用Pulsineli“四血管阻断法”构建全脑缺血结合蛛网膜下腔置管大鼠模型，通过留置的PE10管注入虎纹捕鸟蛛毒素或生理盐水。应用电镜、RT-PCR实验技术检测全脑缺血再灌注损伤大鼠海马CA1区锥体细胞超微结构和胞内线粒体形态变化及对海马组织中肿瘤坏死因子α、肿瘤坏死因子受体Ⅰ、肿瘤坏死因子受体相关死亡结构域、Fas相关死亡结构域蛋白、Caspase8等肿瘤坏死因子凋亡通路相关因子基因表达。结果与结论：虎纹捕鸟蛛毒素能维持全脑缺血再灌注脑损伤大鼠线粒体基本形态且能不同程度降低肿瘤坏死因子凋亡通路中促凋亡因子肿瘤坏死因子α、肿瘤坏死因子受体Ⅰ、肿瘤坏死因子受体相关死亡结构域、Fas相关死亡结构域蛋白、Caspase8mRNA表达。提示天然活性多肽虎纹捕鸟蛛毒素作为一种新型N-型电压依赖性钙通道阻断剂，能有效阻断胞外Ca2＋的大量内流，使细胞内游离钙降低，减少由于细胞内钙超载而引起的一系列病理损害，从而保护神经细胞，减轻缺血缺氧海马神经细胞的损伤。

Effects of huwentoxin on tumor necrosis factor apoptotic pathway in the hippocampus of a rat model of cerebral ischemia

BACKGROUND：Ion channel analytical technique has verified that huwentoxin is an N-type Ca2＋channel blocker affecting on presynaptic membrane. OBJECTIVE：To observe the effects of N-type Ca2＋channel blocker huwentoxin on expressions of tumor necrosis factorα, tumor necrosis factor receptor I, tumor necrosis factor receptor-related death domain, Fas-related death domain protein and Caspase 8 in the hippocampi of rat models of global cerebral ischemia reperfusion injury. METHODS：Rat models of global cerebral ischemia and subarachnoid catheter were established using Pulsinel i 4-vessel occlusion and then received infusion of huwentoxin or normal saline via a PE10 tube. Morphological changes in the mitochondria and ultrastructure of pyramidal neurons in the hippocampal CA1 region of rats with global cerebral ischemia reperfusion injury were observed using electron microscope. The expressions of tumor necrosis factorα, tumor necrosis factor receptor I, tumor necrosis factor receptor-related death domain, Fas-related death domain protein and Caspase 8 were measured using RT-PCR. RESULTS AND CONCLUSION：Huwentoxin could maintain the basic morphology of mitochondria of rats with global cerebral ischemia reperfusion injury and decrease the expressions of tumor necrosis factorα, tumor necrosis factor receptor I, tumor necrosis factor receptor-related death domain, Fas-related death domain protein and Caspase 8 mRNA. Results suggested that huwentoxin as a novel N-type Ca2＋channel blocker could block extracellular Ca2＋influx, reduce intracellular Ca2＋concentration, diminish a series of pathological lesion induced by intracellular Ca2＋overload, protect nerve cells, and lessen the injury to nerve cells of hippocampus after ischemia and hypoxia.