坐骨神经损伤对背根节细胞凋亡及细胞凋亡相关蛋白表达的影响

目的：观察大鼠坐骨神经条件性损伤后对背根节细胞凋亡及细胞凋亡相关蛋白表达的影响。方法：将45只成年Wistar大鼠，按手术的不同随机分为3组；正常对照组（A组，n=5）；坐骨神经压榨伤组（B组，n=20)；坐骨神经切断组（C组，n=20)。B、C两组又按术后3d，2周，1个月和2个月取材时间分为4个时间组，每组5只大鼠。各时间组取鼠的L5背根神经节后，以TUNEL法检测细胞的凋亡数，以免疫组化技术检测Bcl-2和Bax的表达。结果：正常组及B、C两组伤后3d时未检出凋亡细胞；B、C两组的细胞凋亡率在伤后2周达到高峰，以后随时间的推移而逐渐降低。C组的细胞凋亡率明显高于B组。背根节细胞凋亡相关蛋白Bcl-2及Bax的表达，伤后2周达到高峰。B组中Bcl-2和Bax的表达呈现从低到高而后逐渐恢复正常的规律；而C组的表达始终保持在高水平。结论：细胞凋亡相关蛋白Bcl-2和Bax参与外周神经损伤后背根节细胞凋亡的调节。外周神经的不同损伤方式对背根节细胞凋亡及细胞凋亡相关蛋白的表达影响不同。

Influence of sciatic nerve injury on the apoptosis of dorsal root ganglion and expression of apoptosis - related protein

Objective To observe the effect of sciatic nerve injury on apoptosis of dorsal root gargtien (DRG) and expression of apoptosis related protein in rats. Methods 45 adult wistar rats were divided into three groups randomly. Group A (n = 5) served as control. Group B (n = 20) was subjected to sciatic nerve crush. Sciatic nerve was transected in group C (n = 20). The latter of two groups were further subdivided into four groups according to different survival periods of 3 days, 2 weeks, 1 month and 2 months postoperatively, with 5 in each. L 5 dorsal root ganglion was harvested at above noted period. Th number of cell apoptosis was assessed by TUNEL. Immunohistochemical technique was used for detection of expression of Bcl 2/Bax. Results No apoptosis of DRG was detected in group A ,B and C at 3 days point. Apoptosis percentage in group B and C peaked at postinjury 2 weeks, declining gradually with time. Apoptosis percentage in group C is larger than that in group B. The expression of Bcl 2/Bax in DRG reached its peak at 2 postinjury weeks. The level of Bcl 2/Bax in group B was expressed from low to high and gradually restored to normal. But it persisted at high level in group C. Conclusions Apoptosis related protein Bcl 2 and Bax take part in the regulation of apoptosis in DRG after peripheral nerve injury. Different type of peripheral nerve injury has different effect on apoptosis of DRG and expression of apoptosis related protein.