EFFECTIVENESS OF SODIUM 4,5-DIHYDROXYBENZENE-1,3-DISULFONATE (TIRON) IN PROTECTING AGAINST URANIUM-INDUCED DEVELOPMENTAL TOXICITY IN MICE

The effect of Tiron (sodium 4,5-dihydroxybenzene-1,3-disulfonate), a c helating agent used in the treatment of experimental poisoning by a nu mber of heavy metals, on uranium-induced developmental toxicity was ev aluated in Swiss mice. A series of four Tiron injections was administe red intraperitoneally to pregnant mice immediately after a single subc utaneous injection of 4 mg/kg of uranyl acetate dihydrate given on day 10 of gestation and at 24, 48, and 72 h thereafter. Controls received 0.9% saline with or without uranyl acetate. Tiron effectiveness was a ssessed at 500, 1000 and 1500 mg/kg per day. Amelioration by Tiron of uranium-induced embryolethality was not noted at the two lower doses. The percentage of dead and resorbed fetuses in the Tiron-treated group s was not statistically different from that in the positive control gr oup. However, treatment at 1500 mg/kg per day showed isolated protecti ve effects against uranium fetotoxicity, such as that evidenced by the lack of differences in fetal body weight between this group and the u ranium-untreated group, as well as by a decrease in the number of skel etal defects. According to these results, the ability of Tiron to prot ect the developing mouse fetus against uranium-induced developmental t oxicity offers only modest encouragement with regard to its possible t herapeutic potential for pregnant women exposed to this metal.