Improved chelation therapy of intramuscularly deposited thorium by CaDTPA in the rat.
Comparative studies on the translocation and retention of intramuscularly (i.m.) injected thorium nitrate (234Th 46 ng + 232Th 5 microg per rat) in solutions of citrate, CaDTPA or citrate + CaDTPA in rats have been conducted. Results showed that only thorium in mixed-ligand solution was entirely translocated from the muscle, with the greatest part being excreted from the body. In this case, the whole-body retention of thorium decreased to 16% of the injected radioactivity within 2 d, 13% being retained in the skeleton. Studies on the decorporation of 234Th + 232Th nitrates from a rat wound simulated with i.m. injection have also been carried out. The greatest translocation of thorium and its excretion was achieved with a single local injection of the mixed-ligand (citrate + CaDTPA) solution when compared with those of citrate or CaDTPA alone. The efficiency of mixed-ligand treatment decreased with its delay. On day 2 post-therapy, the whole-body content of thorium decreased to 30, 37 and 55% of injected radioactivity when the local treatment started immediately, postponed to 1 h or 24 h, after i.m. injection of thorium, respectively. In control rats without treatment, there was only a slight decrease in the content of thorium in the whole body.
Rencová
J
J
National Institute of Public Health, Centre of Industrial Hygiene and Occupational Diseases, 100 42 Praha, Czech Republic. renc@szu.cz
Vlková
A
A
Veselá
G
G
D000818:Animals; D002614:Chelating Agents / Q000008:administration & dosage; D015913:Chelation Therapy / Q000379:methods*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D007273:Injections, Intramuscular; D004369:Pentetic Acid / Q000008:administration & dosage*; D011786:Quality Control; D011832:Radiation Injuries / Q000209:etiology / Q000517:prevention & control*; D051381:Rats; D017208:Rats, Wistar; D013910:Thorium / Q000008:administration & dosage* / Q000493:pharmacokinetics* / Q000633:toxicity; D014018:Tissue Distribution; D016896:Treatment Outcome; D014915:Whole-Body Counting
D002614:Chelating Agents; D013910:Thorium; D004369:Pentetic Acid