邻苯二酚氨羧酸螯合剂对钍内污染延缓给药的效果

Protective effects of chelating agents of catechols amino carboxylic acid type on radiation injury induced by radiothorium in mice Ⅱ.delayed administration

目的 进一步确证邻苯二酚氨羧酸螯合剂在体内的抗自由基作用 ,增进对核素内照射损伤的防护效果 ,及与促排效果之间的关系。方法 小鼠ip2 3 4 Th 0 6MBq 鼠 3d后im螯合剂 ,连续 3d ,并以DTPA和VitE作促排效果和抗自由基作用的阳性对照 ,第 8天处死动物检测整体和肝、骨中 2 3 4Th蓄积量 ,骨髓有核细胞计数 ,骨髓、血清、肝匀浆MDA含量 ,观察骨髓、肝脏组织的病理变化。结果 950 1、760 1、DTPA延缓给药均仍有明显的促排效果 ,使整体2 3 4 Th蓄积量比中毒组下降15%～ 16% ,肝、骨蓄积量下降分别为中毒组的 77%～ 79%和 72 %～ 75% ,三者的效果相比差异无显著性 ,但明显低于即刻用药的效果。 950 1和 760 1能明显减轻2 3 4 Th内污染小鼠的辐射损伤 ,骨髓有核细胞数 ,骨髓、肝脏MDA含量正常 ,未见明显的骨髓、肝脏的病理改变。而DTPA组的防护效果较差 ,出现较明显的骨髓组织损伤。VitE给药后第 8天对减轻2 3 4 Th所致骨髓、肝脏内照射损伤有一定的效果。结论 950 1和 760 1对核素内照射损伤有明显的防护效果 ,具有促排和抗自由基作用的双重功能 ,是 2个较理想的螯合剂 。

Objective To explore antioxidation efficacy of chelating agents (9501,7601) of catechols a m ino carboxylic acid type for radiothorium in vivo and relationship between t heir antioxidation and decorporation effects.To verify whether 9501 and 7601 could improve the protective effects for internal radiation injury. Methods The chelating agents were administered intramuscularly to ICR mice 3 days after intraperitoneal injection of 0 6 MBq 234 Th-ci trate for three consecutive days and the animals were sacrificed eight days late r.The 234 Th radioactivity in the whole body and its retention in the l iver and skeleton were determined.The malondialdehyde (MDA) production as an ind ex of 234 Th-induced lipid peroxidation in bone marrow and liver was a ssayed and the numbers of bone marrow nucleated cells (NBMNC) were counted.The p athological changes of bone marrow and liver tissue were observed. Results When 9501 and 7601 and DTPA were postponed to administer to 234 Th-inc orpo rated mice,the whole body radioactivity was only decreased by 15%-16% and the r etention of 234 Th in the liver, and skeleton was reduced to 77%-79% a n d 72%-75% as compared with the control group,respectively.They showed the simil ar removal effectiveness which was significantly lower than that when administed promptly.However,9501 and 7601 could inhibit 234 Th-induced lipid peroxid ation,causing significant reduction of MDA content in bone marrow and liver, and markedly ameliorate histopathological changes of bone marrow and liver tissue in 234 Th-treated mice.DTPA appeared to have a lower effectiveness.VitE hadn't decorporation activity and slightly alleviated internal radiation injury. Conclusion The chelating agents 9501 and 7601 of catechols amino c arboxylic acid type have double functions of more effective decorporation and an tioxidation and can improve the curative effects.They are worth further investig ation.;