裂变产物^(147)Pm的体内滞留诱发生殖细胞的放射遗传毒理效应

ACCUMULATION OF FISSION PRODUCT 147 Pm IN ORGANISM ON INDUCTION OF RADIOGENOTOXICOLOGICAL EFFECT OF GERM CELLS

实验研究观察了当机体摄入重核裂变产物^(147)Pm后在不同时间间隔的体内蓄积过程,尤其是在生殖系统睾丸中的滞留对生殖细胞染色体畸变和精子畸形的诱发效应。研究结果表明,^(147)Pm由静脉摄入机体后在持续50d的观察过程,拟合了在睾丸内的滞留方程为: R(t)=0.1872×e^(-0.0066t)可见随着受^(147)Pm内污染时间的延长,其在睾丸内的累积吸收剂量亦随之增升。而且发现^(147)Pm可诱发精原细胞染色体结构畸变:包括裂隙、染色单体断裂、染色体断片和易位;以及染色体数目畸变的多倍体精原细胞。并随着睾丸内累积吸收剂量的增高,染色体畸变率和多倍体细胞也有所增加。同时,^(147)Pm也可诱发初级精母细胞产生染色体断片和易位,形成多价体。染色体断片率可随^(147)Pm辐照时间的延长而升高,而多价体只在内污染10d后的实验组中出现。^(147)Pm所诱发的精子畸形主要是无钩精子,且畸形率亦随吸收剂量加大而增高。

The purpose of the present study is to ascertain ^(147)Pm retention inorganism and its radiogenotoxicological effect through varying intervals of internalexposure. Especially, accumulation of ^(147)Pm in testis on induction of chromosomeaberrations in germ cells and abnormalities in sperm. Results indicated that after iv^(147)Pm through 50d observation. The retention data in testis were well described byan exponential expression:R(t)=0. 1872×e^(-0.0056t)Studies indicated that the absorption dose in testis was increased when the internalexposure of ^(147)Pm was prolonged. Internal contamination of ^(147)Pm can be inducedchromosome aberrations in germ cells and abnormalities in sperm. Among the typeof chromosome aberrations of spermatogonium induced by ^(147)Pm including gap, chro-matid breakage, chromosome breakage and translocation, as well as polyploid sperma-togonium. The chromosome aberration rates and polyploid cells were elevated whenthe periods of contamination of ^(147)Pm were prolonged. At the same time chromosomefragment and translocations of primary spermatocyte also induced by ^(147)Pm. Studiesshowed that polyvalent of primary spermatocyte were enlarged only through 10 daysof ^(147)Pm contamination. Abnormalities in sperm induced by ^(147)Pm-non-hook spermswere predominant.