大鼠坐骨神经节段不同剂量放射后再植的研究

目的　探索杀灭肿瘤细胞而最大程度保存神经干再生能力的放射剂量 ,为肿瘤侵犯神经干时保存肢体提供理论依据。方法　 35只大白鼠随机分 5组 ,切取大白鼠右侧坐骨神经中段约 10mm ,A组切断后原位再植 ;B、C、D、E组分别以 4 0 0 0、6 0 0 0、80 0 0、10 0 0 0cGy高能X线离体照射后原位再植。定期观察动物受试肢体功能恢复情况。12周后测定各组大白鼠坐骨神经指数、电生理指标 ,并在光镜电镜下观察实验坐骨神经节段形态学改变。结果　坐骨神经指数、神经传导速度及在光镜下轴索数均表明 :A组与C、D、E组之间有显著性差异 (P <0 .0 1) ;B组与C、D、E组之间有显著性差异 (P <0 .0 1) ;A组与B组之间无显著性差异 (P >0 .0 5 )。C、D、E组之间无显著性差异 (P>0 .0 5 )。结论　 4 0 0 0cGy高能X线照射可以作为杀灭肿瘤细胞而最大程度保存神经干再生能力的理想放射剂量

Experimental study on in situ replantation of the sciatic nerve segments of rats after different doses of radiation

Objective To measure the optimum radiation dose which was enough to inactivate tumor cells but could save the regenerative ability of rat sciatic nerves.Methods Thirty-five rats were divided into 5 groups randomly.10mm segments were cut from their right sciatic nerve.For Group A,replanted the segments in situ directly.For Groups B,C,D and e,replanted the segments in situ after 4 000,6 000,8 000 and 10 000cGy doses of radiation.Observed the functional recovery of these rats' limbs every day.12 weeks later,the functional recovery of the rats sciatic nerves were evaluated by sciatic functional index(SFI), eletrophysiological study,optical and electronic microscope studies.Results The results of SFI,eletrophysiological study,optical and electronic microscope study showed that Group A had significant difference with Groups C,D and E(P< 0.01);Group B had significant difference with Groups C,D and E(P< 0.01);There was no significant difference between Groups A and B (P>0.05).No difference had be found among Groups C,D and E(P> 0.05).Conclusion 4 000 cGy has been proved to be the suitable radiation dose for preserving the ability of sciatic nerve regeneration and killing tumor cells at the same time.