放射性~(125)I粒子对家兔正常门静脉早期放射性损伤的实验研究

目的研究不同剂量放射性125I粒子植入不同时间对家兔正常门静脉的早期放射性损伤。方法将48只家兔随机分为对照组和实验组,实验组正常门静脉表面分别植入80、120、160Gy125I粒子,对照组正常门静脉表面植入空源粒子。于粒子植入30、60d观察家兔的一般情况、白细胞计数、大体、光镜及电镜的变化。结果实验组无溃疡、穿孔、出血、死亡等严重并发症。光镜下实验各组粒子植入后血管壁损伤主要为内皮改变及肌层水肿,损伤程度根据schmidt标准改进评分,实验组各组间粒子植入后30d和60d损伤程度评分差异有统计学意义(F=192.67,P=0.000;F=294.19,P=0.000);粒子植入后30d和60d实验组各组内Schmidt评分差异有统计学意义(P0.05)。电镜结果 :损伤主要表现为内膜层线粒体、粗面内质网及吞饮小泡改变,且随剂量的增加和时间的延长加重。粒子植入前后不同时间对照组和实验组白细胞计数差异均无统计学意义(P0.05)。结论 125I粒子植入门静脉,在剂量为80～160Gy门静脉损伤轻微,主要在内皮层和肌层,且随时间的延长和剂量的增加损伤程度加重,但损伤深度未见增加。

Early Radiation Injury to the Portal Vein Induced by Radioactive .125I seeds in Rabbits

Objective To study the early radiation injury to the portal vein induced by 125I seeds at different dose and duration in rabbits. Methods Totally 48 rabbits were randomly divided into treatment and control groups. 125I seeds were implanted into the portal vein of the rabbits in the treatment group at a dose of 80,120,or 160 Gy. While in the control group,seeds without activity was inserted. The general condition,WBC count,and gross,light and electronic microscopic changes of the portal vein of the rabbits were observed in 30 and 60 days after the implantation. Results No ulcer,perforation,hemorrhage or death occurred after the implantation in the treatment group. In the treatment group,light microscopy showed endothelial changes and muscular edema in the wall of the portal vein. According the modified Schmidt Standards,the severity of the injury to the portal vein was significantly different between 30 and 60 days （F=192.67,P=0.000; F=294.19,P=0.000）,such difference was also detected among different dose subgroups （P〈0.05）. Electronic microscopy showed change of the bioblast in the theca interna,rough endoplasmic reticulum and pinocytotic vesicles in the injured vessels. The level of the changes increased with dose and duration of the 125I seeds implantation. No significant difference was observed between the two groups at different time points. （P〈0.05）. Conclusions The ^125I seeds implanted into the portal vein can result in a slight injury to the endothelial and muscular layers at a dose of 80-160 Gy. The severity,but not the depth,of the injury increases with the duration and dose of the 125I seeds implanted.