大鼠坐骨神经损害c-fos基因表达及Ca2+阻滞剂的保护作用

目的：探讨周同神经嵌压性损害早期c—fos基凶的表达及Ca^2＋通道阻滞剂（CCB）对周同神经嵌压性损害保护作用的机制。方法：将80只SD大鼠按体重随机分层分组制作坐骨神经嵌压性损害的动物模型，取嵌压后第1、4周的大鼠坐骨神经，采用免疫组织化学结合电生理学的方法测定c-fos基凶的表达及坐骨神经传导速度，并将两者结果进行对比，运用正常对照组、模型组、CCB高剂量和CCB低剂量组进行对照统计。结果：嵌压大鼠坐骨神经后，大鼠坐骨神经c—fos基因的表达第1周时显著增加（P〈0．01），第4周时趋于正常：CCB可减少1周时大鼠背根神经节细胞c—fos基因的表达，高剂量组尤为显著（P〈0．01）；第4周时CCB组坐骨神经的传导速度虽较正常对照组及假手术组慢（P〈0．01），但较模型组快，高剂量组显著（P〈0．05）：结论：周同神经嵌压性损害早期c—fos基因表达增加，并使神经功能受损；CCB则可通过阻断Ca^2＋内流过程而减少早期神经细胞c—fos基因的表达．从而对周围神经嵌压性损害具有保护作用。

Expression of c-fos gene in crush lesion of sciatic nerve and protection of Calcium channel blocker

Objective:To investigate the expression of c-fos gene in crush lesion of peripheral nerve in early stage, and the protective mechanism of calcium channel blocker (CCB). Methods:Sciatic nerve was crushed by pincers to establish the model of sciatic nerve crush lesion in rats. The expression of c-fos gene and conductive rate of sciatic nerve were quantitated by immunohistochemistrical and electrophysiological techniques. SD rats were divided into normal group,pseudo-operation group, placebo control group, CCB (high-dose or low-dose Flunarizine) group at random. Results:The expression of c-fos gene in sciatic nerve was increased significantly on the first week after sciatic nerve crush lesion(P < 0.01),and it was decreased by CCB significantly in the high-dose group(P < 0.01). Conductive rate of sciatic nerve on the fourth week after sciatic nerve crush lesion was slower in CCB groups than that in normal group and pseudo-operation group, but higher than that in placebo control group(P < 0.05). It was decreased by CCB in a dose-dependent manner(P < 0.01). Conclusion: The expression of c-fos gene is increased significantly, which causes injury of nerve function in early stage of peripheral nerve crush lesion. CCB could decrease c-fos gene enpression by blocking Ca2 internal flow. It shows that CCB has the protective action against peripheral nerve crush lesion.