摘要
目的观察大剂量分割放疗对大鼠脊髓损伤的影响及其凋亡基因的表达。方法6MeV电子线照射,每次照射剂量为5Gy,隔日1次,总照射剂量为40Gy。照射结束后20周,取脊髓组织行HE染色与透射电镜观察脊髓损伤的形态学变化,免疫组化检测凋亡基因caspase-3与bax在脊髓组织中的表达。结果HE染色见受照的脊髓白质内神经纤维排列松散紊乱,部分灰质出现细胞肿胀、破坏、炎细胞浸润,部分神经元尼氏体消失,神经胶质细胞固缩。透射电镜表现为髓鞘的板层结构水肿明显、膨大、粘连,模糊不清,细胞器空泡变性改变,神经胶质细胞有核固缩现象。免疫组化结果显示正常大鼠脊髓神经细胞中很少有凋亡基因caspase-3与bax的表达,放疗组脊髓损伤后caspase-3与bax表达的阳性细胞明显增加(P<0.05)。结论大剂量分割放疗可引起大鼠放射性脊髓损伤,且caspase-3与bax凋亡基因在脊髓损伤中呈过表达。
Objective To observe the effect of high-dose partition radiotherapy on spinal cord and the expression of caspase-3 and bax in the injuried spinal cord. Methods 6MeV electron beam was adopted, the dose of single irradiation was 5Gy, and total dose was 40Gy. The spinal cord was taken out 20 weeks after irradiation, HE was used ,the morphological changes were observed under transmission electron microscope（TEM） and expression of caspase-3 and bax was determined by immunohistochemistry. Results The disorder of incompact nerve fibre array was found in white matter, cell tumidness, destruction, inflammatory cells infiltration, disappearance of Nissl body and neuroglia cell pycnosis were observed in the grey matter of irradiated spinal cord. The slab structure of myelin sheaths appeared obvious hydroncus, intumescentia, conglutination, blurring; cellular organ vacuole appeared the change of denaturation, and the neuroglia cell nucleus was pycnosis in the grey matter of irradiated spinal cord by TEM . The results of immunohistochemistry showed that the expressions of caspase-3 and bax were rare in the normal spinal cord, but overexpressions of caspase-3 and bax were seen in the masculine cells of radiotherapy group（P〈0.05）. Conclusion The high-dose partition radiotherapy can cause the spinal cord injury, and the caspase-3 and bax were overexpressed.
出处
《解剖科学进展》
CAS
2008年第4期361-364,368,共5页
Progress of Anatomical Sciences
基金
辽宁省科技公关资助项目(2005225003-12)
