黑斑蛙与非洲爪蟾蝌蚪急性毒性试验方法敏感性的比较

两栖动物蝌蚪急性毒性试验是评价化学品急性毒性的一种方法。以毒死蜱、乙草胺、重铬酸钾和全氟辛烷磺酸盐(PFOS)为测试物,比较了我国本土黑斑蛙(Rana nigromaculata)与国际通用种非洲爪蟾(Xenopus laevis)在蝌蚪急性毒性试验中的敏感性。结果发现：2类蝌蚪分别进行的11次试验中,空白对照组黑斑蛙蝌蚪死亡率(0.9%)远低于非洲爪蟾蝌蚪的死亡率(5.8%);重铬酸钾和PFOS对黑斑蛙蝌蚪的96 h-LC₅₀分别为34.0 mg·L^-1和81.0 mg·L^-1,而对非洲爪蟾蝌蚪的96 h-LC₅₀分别为51.6 mg·L^-1和92.1 mg·L^-1,显示黑斑蛙蝌蚪对这2种化学品的敏感性略高于非洲爪蟾蝌蚪;毒死蜱和乙草胺对黑斑蛙蝌蚪的96 h-LC₅₀分别为0.41 mg·L^-1和4.1 mg·L^-1,而对非洲爪蟾蝌蚪的96 h-LC₅₀分别为0.12 mg·L^-1和3.1 mg·L^-1,显示黑斑蛙蝌蚪对这2种化学品的敏感性略低于非洲爪蟾。鉴于2类蝌蚪对化学品的敏感性存在差异,且黑斑蛙蝌蚪的自然死亡率低,材料更易获得,笔者认为黑斑蛙蝌蚪比非洲爪蟾更适合作为蝌蚪急性毒性试验的材料,用于我国化学品环境管理中的毒性评价。

Comparison of the Sensitivity of Rana nigromaculata with Xenopus laevis in Tadpole Acute Toxicity Test

Amphibian tadpole acute toxicity test is a method for evaluating acute toxicity of chemicals. Using dursban, acetochlor, potassium dichromate and perfluorooctane sulfonate (PFOS) as test chemicals, we compared the sensitivity of native species Rana nigromaculata with general species Xenopus laevis in tadpole acute toxicity test. In control groups, we found that the mortality of R. nigromaculata tadpoles (0.9%) was obviously lower than that of X. laevis tadpoles (5.8%). 96 h-LC₅₀ of potassium dichromate and PFOS for R. nigromaculata tadpoles were 34.0 mg·L^-1 and 81.0 mg·L^-1, while 96 h-LC₅₀ of potassium dichromate and PFOS for X. laevis tadpoles were 51.6 mg·L^-1 and 91.2 mg·L^-1, respectively. The data showed that R. nigromaculata was more sensitive than X. laevis to potassium dichromate and PFOS. 96 h-LC₅₀ of dursban and acetochlor for R. nigromaculata tadpoles were 0.41 mg·L^-1and 4.1 mg·L^-1, while the 96 h-LC₅₀ for X. laevis tadpoles were 0.12 mg·L^-1 and 3.1 mg·L^-1, respectively. The data showed that R. nigromaculata was slightly less sensitive than X. laevis to dursban and acetochlor. Considering the difference in the sensitivity between R. nigromaculata and X. laevis tadpoles as well as the low mortality and higher availability of R. nigromaculata, it is concluded that R. nigromaculata is more suitable than X. laevis as test species in tadpole acute toxicity test for Chinese environmental management of chemicals.