应用黑斑蛙胚胎测试化学品发育毒性的方法

Developmental Toxicity Assay for Chemicals Using Pelophylaxnigromaculatus Embryos

选择合适的尤其是本土生物种进行化学品生态毒性评估,对于各国化学品的环境管理十分重要。本文选择我国本土两栖种黑斑蛙的胚胎为试验生物,以半数致死浓度LC50、半数致畸浓度TC50、致畸指数TI及最小抑制生长浓度MCIG为终点指标,建立了黑斑蛙胚胎发育毒性试验方法。以五氯酚、视磺酸、氯化镉、重铬酸钾为测试物研究了方法的敏感性,并以五氯酚为测试物研究了方法的可重复性。结果显示:五氯酚、视磺酸、氯化镉和重铬酸钾对黑斑蛙胚胎的LC50分别为572.3μg·L-1、54.8μg·L-1、6.8 mg·L-1和97.5 mg·L-1。五氯酚、视磺酸和氯化镉对黑斑蛙胚胎的TC50分别为246.5μg·L-1、18.7μg·L-1和3.4 mg·L-1,TI分别为2.3、2.9和2.0,MCIG分别为160.0μg·L-1、10.1μg·L-1和2.4 mg·L-1。重复性试验发现,五氯酚的LC50、TC50、TI及MCIG的变异系数分别为12.6%、18.0%、23.0%和18.6%。与文献中非洲爪蟾胚胎试验的数据比较,这些数据显示黑斑蛙胚胎与非洲爪蟾胚胎对测试物的敏感性存在一定的差异,各个终点指标的变异系数相当。因此,本文建立的黑斑蛙胚胎发育毒性试验可以用于化学品的发育毒性评价,为我国化学品环境管理提供技术支持。

It is important for chemical environmental management in each country to assess chemical ecotoxicity using an appropriate test organism, in particular, native species. Based on several endpoints including median lethal concentration（LC50）, median teratogenic concentration（TC50）, teratogenic index（TI） and minimum concentration to inhibit growth（MCIG）, an embryo developmental toxicity assay was established using the embryos of the native amphibian Pelophylax nigromaculatus. Choosing pentachlorophenol（PCP）, retinoic acid（RA）, cadmium chloride（CdCl2）and potassium dichromate（K2Cr2O7） as test chemicals, we evaluated the sensitivity of the assay. Also, we tested the assay repeatability using PCP as a test chemical. The LC50 values of PCP, RA, CdCl2 and K2Cr2O7for P. nigromaculatus embryos were 572.3 μg·L-1, 54.8 μg·L-1, 6.8 mg·L-1and 97.5 mg·L-1, respectively. The TC50 values ofPCP, RA, and CdCl2 were 246.5 μg·L-1, 18.7 μg·L-1and 3.4 mg·L-1, respectively. The TI values of PCP, RA, and CdCl2 were 2.3, 2.9 and 2.0, respectively. The MCIG values of PCP, RA, and CdCl2 were 160.0 μg·L-1, 10.1 μg·L-1and 2.4 mg·L-1, respectively. In repeated trials, the coefficients of variationfor LC50, TC50, TI and MCIG of PCP for the assay were 12.6%, 18.0%, 23.0% and 18.6%, respectively. In comparison with the data concerning Frog Embryo Teratogenesis Assay-Xenopus given in the literature, P. nigromaculatus embryos to certain chemicals exhibited different sensitivity from X. laevis embryos, with comparable coefficients of variation for these endpoints among two species.Therefore, the P. nigromaculatus embryo developmental toxicity assay established in this study can be used to assay developmental toxicity of chemicals, which could provide a technical support for China＇s environmental management.