邻苯二酚氨羧酸螯合剂对钍内污染早期给药效果

目的 研究邻苯二酚氨羧酸螯合剂的促排^234Th的效果和抗自由基作用在防护核素内照射损伤中的作用关系。方法 首先确定小鼠ip中毒^234Th致内照射损伤的剂量和时间，选择0.6MBq／鼠的中毒剂量ip后，立即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4天处死动物，观察整体和肝、骨中^234Th蓄积量，骨髓有核细胞数(BMNC)，骨髓、肝脏和血清脂质过氧化产物丙二醛(MDA)含量及骨髓和肝脏的病理变化。结果 小鼠ip^234Th0.6MBq／鼠第4～8天，骨髓和肝脏出现明显的内照射损伤。给予螯合剂9501、7601和DTPA后，均有明显的促排作用，使整体中^234Th蓄积量比中毒组分别下降81％、86％和72％，以第一次用药效果最为明显；肝、骨中总的^234Th蓄积量分别仅为中毒组的22％、21％和58％，其中9501、7601的效果明显优于DT—PA，骨中蓄积量仅为DTPA的1／3～1／5。9501和7601立即给药未观察到^234Th急性中毒后的内照射损伤，BMNC数、骨髓MDA含量正常，骨髓、肝脏未见明显的病理改变。DTPA组可见骨髓组织轻度受损。给予VitE未能减轻骨髓、肝组织的内照射损伤，可能由于在短时间内核素大量蓄积于组织中所致。VitE和DTPA合并用药，显示DTPA的促排活性和VitE的抗氧化作用。结论 9501和7601立即给药对核素内照射损伤有明显的防护作用，主要是由于其显著的促排作用。

Protective effect of chelating agents of catechols amino carboxylic acid on radiation injury induced by radiothorium in mice:prompt administration

Objective To study decorporation and antioxidation efficacy of chelating agents (9501 and 7601) of the substituted catechols amino carboxylic acid for radiothorium in vivo . Methods The experiment was first designed to find out the dose and time of radiation injury by incorporated 234 Th-citrate in ICR mice.The malondialdehyde (MDA) production serving as an index of 234 Th-induced lipid peroxidation in bone marrow,serum and liver of mice was assayed and the numbers of bone marrow nucleated cells (NBMNC) were counted.The pathological changes of bone marrow and liver tissue were observed.The chelating agents were promptly administered im to mice for three consecutive days after ip injection of 0.6 MBq 234 Th-citrate.The animals were sacrificed 4 days later and the 234 Th retention in the whole body,liver and skeleton and the above indexes were determined. Results The mice showed significantly internal radiation injury of bone marrow and liver at 4th to 8th after ip injection of 0.6 MBq 234 Th-citrate.The prompt administration of 9501,7601 and DTPA decreased the whole body radioactivity by 81%,86% and 72%,respectively,as compared with those of the control group.The sum of retention of 234 Th in liver and skeleton was reduced to 22%,21% and 58% of controls,respectively.The removal efficacy of 9501 and 7601 was better than that of DTPA.The NBMNC,contents of MDA in bone marrow and the structure of bone marrow and liver tissue didn't show any abnormality in 9501 and 7601 groups.DTPA appeared to have a lower protective effectiveness on radiation injury of bone marrow.VitE had no decorporation activity and didn't alleviate radiotoxicity.The combined use of DTPA and VitE showed both decorporation effect of DTPA and antioxidation effect of VitE. Conclusion The prompt administration of 9501 and 7601 has remarkable protective effects on internal radiation injury,which resulting from decorporation activity and conceal their antioxidation. ;