放射性125I对家兔正常神经组织损伤的实验研究

目的研究放射性125I对家兔正常神经组织的损伤。方法选择健康雄性家兔25只,体质量1.6～2.0kg,随机分为2组:实验组(n=15),植入放射性125I聚胺酯薄膜(放射活度12～14GBq,平均13GBq;吸收剂量25～30Gy,1～1.25cGy/h);对照组(n=10),植入无放射性聚胺酯薄膜。观察实验动物生存情况及组织病理改变。结果实验动物体质量增长无明显差异(P>0.05)。实验组动物细胞出现双层膜结构及染色质损伤,脱髓鞘改变,血管壁玻璃样变,脑组织水肿。在距离放射源2.3～2.5cm处,损伤明显减轻,与对照组动物无明显差异。结论放射性125I可对其有效放射半径以外正常神经组织造成损伤,但程度较轻,不会对实施内放射治疗造成影响。

Effect of implanted radioactive 125I on normal nerve tissue in rabbits

Objective To investigate the effects of implanted radioactive 125I on normal nerve tissue structure in rabbits. Methods Twenty-five healthy male rabbits weighing 1.6-2.0 kg were randomly divided into two groups: experiment group (n = 15),radioactive 125I-polyurethane membrane being implanted (radioactivity 12-14 GBq,median 13 GBq; absorbed dose 25-30 Gy,1.00-1.25 cGy/h) and control group (n = 10),in which the rabbits were implanted with non-radioactive membrane. Animals' living status and histopathological changes were observed to evaluate radiation effects. Results The increase in weight body was not significantly different between the two groups (P > 0.05). Chromatin and double membrane structure damages,demyelination,hyaline thickening of the vascular wall and brain tissue edema were observed in the experiment group. The radiation injuries were obviously relieved at the site which was about 2.3-2.5 cm from the radiation source,which was no significantly different between the experiment group and control group. Conclusion Radioactive 125I has a little harm on normal nerve tissue out of radio-radius,but does not influence on brachytherapy.