不同年龄神经再生组织特异性差异的实验研究

目的　比较不同年龄大鼠坐骨神经切断后神经再生趋化性在组织特异性水平上的差异。方法　SD大鼠40只,按年龄分成幼年组和成年组,每组20只，建立组织特异性模型。右侧坐骨神经切断后，将神经近端接于Y形硅胶管入口端，神经远端和肌腱分别接于Y形管两出口端。术后3、6周采用神经电图和组织学方法检测神经再生情况。结果　术后3、6周,幼年组实验侧运动神经传导速度的恢复率分别为(27.21±6.06)%和(39.33±10.41)%,成年组分别为(38.23±11.46)%和(52.36±8.12)%;两组的差异有显著性和非常显著性意义（F=6.49、10.73，P＜0.05、P<0.01）。幼年组复合肌肉动作电位（CMAP）波幅的恢复率分别为(30.21±17.43)%和(30.42±18.43)%，成年组分别为(35.43±32.13)%和(37.18±16.12)%;两组的差异无显著性意义（F=0.23、0.92,P>0.05）。幼年组神经纤维再生准确率分别为(59.31±13.21)%和(59.39±24.16)%，成年组分别为(78.26±12.41)%和(84.28±9.01)%;两组的差异有非常显著性意义（F=10.75、8.36，P<0.01）。结论　周围神经损伤后，远端神经组织对再生轴索有诱导作用，但幼年大鼠神经再生趋化的组织特异性较成年大鼠差。

Comparison of tissue specificity in peripheral nerve regeneration at different ages: an experimental study

Objective　To investigate the difference of tissue specificity in peripheral nerve regeneration through Y - shaped silicone tube following resection of the sciatic nerve in rats of different ages. Methods　Forty SD rats were divided into young group and adult group, with 20 each. The tissue specificity model was set up. The proximal end of Y - shaped conduit was sutured to the proximal stump of severed sciatic nerve. The two distal ends of the conduit were sutured to the distal nerve stump and a tendon respectively. Electroneuromyography and morphological evaluation was conducted at 3 and 6 weeks postoperatively. Results　3 weeks and 6 weeks postoperatively, the recovery rate of nerve conduction velocity was (27.21 ± 6.06)% and (39.33 ± 10.41)% in young group, (38.23 ± 11.46)% and (52.36 ± 8.12)% in adult group respectively. There were significant differences between the groups at each assessment point. The recovery rate of compound muscle action potential (CMAP) amplitude was (30.21 ± 17.43)% and (30.42 ± 18.43)% in young group, (35.43 ± 32.13)% and (37.18 ± 16.12)% in adult group respectively. The difference however was not statistically significant. The accuracy rate of nerve regeneration was (59.31 ± 13.21)% and (59.39 ± 24.16)% in young group，(78.26 ± 12.41)% and (84.28 ± 9.01)% in adult group respectively. There were significant differences between the groups at each assessment point. Conclusions　Substances from the distal stumps of transected peripheral nerves exert a neurotrophic effect on regenerating nerve fibers. The tissue specificity in young rats was inferior to that in adult rats.