• Korean Journal of Veterinary Research
• /
• v.34 no.1
• /
• pp.69-75
• /
• 1994

Pregnant CD-1 mice were exposed to methylmercury in the drinking water at concentration of 20ppm with subcutaneous treatment of thiaminHCl(vitamin $B_1$) (100mg, 200mg or 300mg/ kg b.w.) or BAL(5.0 mg/kg b.w.) under the alone or combined base at the therapeutic agents from day 6 to 15 of gestation. Fetal growth parameters, including body weight and crown-rump length in the mice exposed to mercury, were reduced as placental weight compared to those in the control group(no treatment). The incidence of dead fetuses/resorption and malformed fetuses(especially cleft palate) was also increased even in the group treated with thrapeutic agents as well as in the mercury only treated group. However, all kinds of alteration indicated above, possibly induced by mercury, reduced/or decreased significantly compared to those of control. A subtle indication of maternal toxicity was noted in most experimental animals as evidenced by decreased water consumption and increased relative liver weight. The present study confirmed that methylmercuric chloride is embrytoxic and teratogenic in CD-1 mice when administered during organogenesis and that thiamin administration may have therapeutic application for the treatment or prevention against of deleterious effects induced by mercury during gestation period.

• Korean Journal of Environmental Biology
• /
• v.39 no.3
• /
• pp.311-318
• /
• 2021

In this experiment, we investigated the toxicity of tebuconazole (fungicide) using domestic frog embryos, along the FETAX (Frog Embryo Teratogenesis Assay-Xenopus) protocol. Bufo gargarizans, Hyla japonica, and Pelophylax nigromaculatus embryos were incubated, and investigation of the tebuconazole effect was performed by the probit analysis. As a result, depending on the concentrations of tebuconazole, the mortality and malformation rates were increased and larval body length was decreased. The teratogenic concentrations (EC₅₀) of tebuconazole were 34.4mg L^-1, 10.6mg L^-1, and 14.9mg L^-1, respectively, and the embryo lethal concentrations(LC₅₀) of tebuconazole were 74.7 mg L^-1, 38.5 mg L^-1, and 39.1 mg L^-1, respectively. The teratogenic index (TI) valuesof tebuconazole were 2.19, 3.58, and 2.65; thus, it showed teratogenicity in embryonic development of these three frogs. These results revealed that in this experiment, tebuconazole suppressed the development of embryos at a relatively low concentration. In addition, mortality, malformation ratios, malformation patterns, and growth rates were similar to the results from the other assay systems. Therefore, tebuconazole was thought to have an effect on the embryo development of domestic frogs. In future, it will be necessary to identify species specificity in order to the clarify the causes of differences in mortality, malformation rate, and malformation patterns depending on the species.

• Korean Journal of Veterinary Research
• /
• v.34 no.2
• /
• pp.361-368
• /
• 1994

Teratogenic and embryotoxic effects of mercury have been reported, however, there is little information about possible antidotes against mercury exposure during gestation. In order to evaluate therapeutic effects of selenium as an antidote against mercury poisoning, pregnant CD-1 mice were exposed to methylmercury chloride(20ppm) through the drinking water with treatment of sodium selenite (1.0mg, 2.0mg or 3.0mg/kg b.w., subcutaneously) or BAL(5.0mg/kg b.w., subcutaneously) under the single or combination base as the therapeutic agents from day 6 to 15 of gestation. Fetal growth parameters such as body weight and crown-rump length in the mice exposed to mercury, were reduced as was placental weight compared to those in the control. Treatment of selenium(alone, combination with BAL) reduced the harmful effects induced by mercury on the fetal growth parameters even though no specific relationship between dose and therapeutic effect. The incidence of dead fetuses/resorptions and malformed fetuses(especially cleft palate) was also increased in the mercury only treated group. Selenium treatment demonostrated reduced the incidence of abnormal fetuses under the exposure of mercury. Relative maternal organ weights(liver, kidney, spleen) were increased significantly but relative brain weight was decreased as evidenced by decreased in the mercury treated mice compared to that in the control. A subtle indication of maternal mercury toxicity evidenced by changes of relative maternal organ weights, decreased water and feed consumption were also prevented efficiently by selenium treatment. The present study suggests that methylmercuric chloride is embrytoxic and teratogenic in CD-1 mice when exposured during organogenesis and that selenium administration may have therapeutic application for the treatment of mercury poisoning although more applicable study in human should be performed with caution in the future.