摘要
目的观察125Ⅰ粒子植入后不同时间家兔坐骨神经组织形态及功能的变化。方法选健康新西兰家兔30只，使用信封法分为2周、2个月及4个月3组，每组10只，直视下在兔的实验侧坐骨神经旁植入125Ⅰ粒子10粒，对照侧植入无放射活性空粒子10粒。按三维治疗计划系统（treatment plan system，TPS）计划设计布源，90％处方剂量集中在所研究的坐骨神经局部。术后2周、2个月及4个月行双侧坐骨神经神经电生理测定及大体观察、光镜观察和电镜观察。将同为4000放大倍数的电镜照片分为100（10×10）个方格，出现非特异性改变占1个方格则计数为1％。所测指标之间的比较采用t检验和秩和检验。结果2周、2个月、4个月组兔实验侧坐骨神经的近心端动作电位强度分别为（0．52±0．26）、（0．60±0．19）、（0．48±0．17）V，对照侧分别为（0．59±0．19）、（0．60±0．15）、（0．53±0．13）V，差异无统计学意义（t值分别为0．91、0．03、0．67，P值均〉0．05），2周、2个月、4个月组兔实验侧坐骨神经远心端动作电位强度分别为（0．51±0．15）、（0．52±0．11）、（0．53±0．15）V，对照侧分别为（0．52±0．10）、（0．56±0．12）、（0．54±0．10）V，差异无统计学意义（t值分别为0．25、0．74、0．17，P值均〉0．05）；2周、2个月、4个月组兔实验侧坐骨神经近心端动作电位最大振幅分别为（13．18±4．09）、（12．78±4．42）、（12．09±1．20）mV，对照侧分别为（10．55±4．21）、（10．31±4．22）、（12．88±3．54）mV，差异无统计学意义（t值分别为1．57、1．36、0．50，P值均〉0．05），2周、2个月、4个月组兔实验侧坐骨神经的远心端动作电位最大振幅分别为（11．18±3．38）、（11．68±3．21）、（12．52±3．09）mV，对照侧分别为（11．56±4．80）、（10．71±3．40）、（11．67±2．48）mV，差异无统计学意义（t值分别为0．29、1．01、0．55，P值均〉0．05）；2周、2个月、4个月组兔实验侧坐骨神经神经传导速度分别为（40．56±9．46）、（38．79±5．78）、（39．44±8．64）m／V，对照侧为（42．56±6．59）、（44．64±7．53）、（43．33±6．05）m／V，差异无统计学意义（t值分别为0．57、1．94、0．01，P值均〉0．05）。大体学观察和光镜观察实验侧坐骨神经病理学改变不明显；电镜观察可见到有髓神经鞘分层、塌陷、崩解等变性改变；神经鞘膜细胞和神经轴突内可见线粒体肿胀、空泡化。非特异性变化2周组为60％～70％，2个月组为50％左右，而4个月组下降到30％左右，3组比较差异有统计学意义（Z值均为-3．79，P〈0．05）。结论该实验剂量下放射性125Ⅰ粒子对家兔坐骨神经的组织影响以超微病理下的非特异性变化为主，对神经的生理功能影响微小。
Objective To study the effect of 125Ⅰodine seed on the rabbit ischiadic nerve at different time point after implantation. Methods Thirty healthy New-Zealand rabbits were randomly assigned into 3 groups（ 2-week group, 2-month group and 4-month group） using envelope method. During operation, 10 radioactive 125Ⅰ seeds were implanted randomly near one of the ischiadic nerve, while 10 non-radioactive seeds were implanted into the contralateral ischiadic nerve. According to treatment plan system（TPS） ,90%of the prescription dose （PD）was centered in the specific place, where the nerves were chosen to be studied. After 2 weeks, 2 months and 4 months respectively, nerve electro-physiology experiment was used to evaluate the bilateral ischiadic nerves, at the same time the morphology of the ischiadic nerve was examined by general observation, light microscope and electron microscope. The electron microscope photo with the same ×4000 amplification was divided into 100（10 × 10） cages and non-specific changes in one cage account for 1%. The t test and sum rank test were used for statistics. Results Potential leaking point of experimental ischiadic nerves near heart in 2-week group ,2-month group and 4-month group were （0. 52 ± 0. 26）, （0. 60 ±0. 19）, （0. 48 ±0. 17）V, while that of the control sides were （0. 59 ±0. 19）, （0. 60 ± 0. 15 ）, （0. 53± 0. 13 ）V, there was no statistical significance in the same group respectively （t = 0. 91, 0. 03,0.67, P 〉 0.05 ）. Potential leak point of experimental ischiadic nerves far from heart in 2-week group, 2-month group and 4-month group were （0. 51± 0. 15 ）, （0. 52 ± 0. 11 ）, （ 0. 53 ± 0. 15 ） V, the control sides were （0. 52 ±0. 10）, （0. 56 ± 0. 12）, （0. 54± 0. 10） V, there was no statistical significance in the same group respectively （ t = 0. 25,0. 74,0. 17, P 〉 0.05 ）. Action potential amplitude of experimental ischiadic nerves near heart in 2-week group, 2-month group and 4-month group were （ 13. 18±4.09 ）, （ 12. 78 ± 4. 42）, （ 12.09 ± 1.20） mV, while that of the control sides were （ 10. 55 ± 4. 21 ）, （ 10. 31 ±4. 22 ）, （12. 88 ± 3. 54）mV, there was no statistical significance in the same group respectively （t = 1.57,1.36, 0. 50,P 〉 0.05 ）. Action potential amplitude of experimental ischiadic nerves far from heart in 2-week group,2-month group and 4-month group were （ 11.18 ± 3.38 ）, （ 11.68 ± 3.21 ）, （ 12. 52± 3.09 ） mV, while that of the control sides were （11.56±4. 80）, （10.71 ±3.40）, （11.67±2.48） mV ,there was no statistical significance in the same group respectively （ t = 0. 29,1.01,0. 55, P 〉 0. 05 ）. Nerve conduction velocity of experimental ischiadic nerves in 2-week group,2-month group and 4-month group were （40. 56± 9. 46）, （38.79 ± 5. 78 ）, （ 39.44 ±8. 64 ） m/V, the control sides were （42. 56 ± 6. 59）, （44. 64 ± 7. 53 ）, （43. 33 ± 6. 05 ）m/V, there was no statistical significance in the same group respectively （t = 0. 57,1.94, 0.01 ,P 〉 0. 05）. There were some changes in general observation and light microscope, in electron microscope, many non-specificity changes were observed. All of these changes included delamination, collapse, disaggregation of the myelinated nerve, mitoehondria swelling and vacuolizafion of neurilemma cell and axon. The ratio of degenerative alterations in nerves was 60% -70% in 2-week group, 50% in 2-month group and 30% in 4-month group, and there was statistical significance among three groups（P 〈 0. 05）. Conclusion 125Ⅰ permanent plantation in our test dose has little effect on ischiadic nerve, all these non-specificity changes were observed in electron microscope, and it has no evident impacts on physiological functions.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2008年第8期888-892,共5页
Chinese Journal of Radiology
基金
广东省科委课题资助项目（2006B35802009）
关键词
辐射损伤
实验性
坐骨神经
放射学
介入性
放射性同位素
动物
实验
Radiation injuries, experimental
Sciatic nerve
Radiology, interventional
Radioisotopes
Animals,laboratory
