神经损伤后NGF对骨骼肌纤维琥珀酸脱氢酶活性的影响

用持针器夹持兔右侧坐骨神经制作神经损伤动物模型。实验组动物于损伤处喷布蛇毒神经生长因子（ＮＧＦ），对照组动物于同部位给予等量生理盐水，对胫骨前肌红肌、白肌和中间型肌纤维琥珀酸脱氢酶（ＳＤＨ）活性变化及分布进行定量、定位分析。结果显示，神经损伤１、２、３周，实验组和对照组各型肌纤维ＳＤＨ活性减弱，电镜下可见线粒体嵴断裂，酶阳性反应产物稀疏；神经损伤４周，实验组红肌、白肌和中间型肌纤维酶活性及分布恢复正常，对照组各型肌纤维酶活性仍较弱，电镜下酶阳性反应颗粒的分布也未恢复到正常水平。神经损伤３～６周，实验组各型肌纤维酶活性均强于对照组，组间差异显著（Ｐ＜００１）。本研究结果提示，坐骨神经损伤后，外源性的蛇毒ＮＧＦ对骨骼肌纤维酶活性和结构的恢复具有重要的促进作用

Effects of nerve growth factor (NGF) on SDH activity in skeletal muscle fiber after sciatic nerve injury

Sixty rabbits with right sciatic nerves crushing were used as the experimental models. Animals of the experimental group were locally sprayed with snake venom NGF (400BU/kg/day) and the control group with normal saline in the same position. The changes of the activity and distribution of succinic dehydrogenase (SDH) in every type muscle fibers of tibialis anterior muscle were observed under LM and TEM. The SDH activity on LM sections were measured quantitatively by a computer image analysis system and the data were analyzed statistically. Results: From the 1st to 3rd week after nerve crushing the SDH activity in every type muscle fibers decreased markedly in both experimental and control groups. The mitochondria cristae were broken and the distribution of SDH positive granules were sparse under TEM. At the end of the 4th week, the activity and distribution of SDH of red, intermediate and white fibers in experimental group all recovered to normal condition, but those in control group were still lower. The quantitative analysis results showed that the SDH activity was significant difference between experimental and control groups from 3rd to 6th week (P<0.01). These results suggest that the exogenous snake venom NGF may play an important role in promoting the structural and functional recovery of skeletal muscle fiber following peripheral nerve injury.