铅暴露对中华大蟾蜍耳后腺分泌蟾蜍甾烯的影响

The Effect of Lead on the Levels of Bufadienolides in Venom Secreted by Bufo bufo gargarizans Cantor

采用半静水式实验方法,研究Pb^(2+)暴露30 d对中华大蟾蜍(Bufo bufo gargarizans Cantor)生理状态和耳后腺分泌蟾蜍甾烯水平的影响。结果表明,随Pb^(2+)浓度(0.68~5.46 mg·L^(-1))升高,蜕皮和自发活动减少,存活率下降。进一步采用液相-质谱检测技术发现,0.68 mg·L^(-1)Pb^(2+)暴露下,10种蟾蜍甾烯水平出现1.5倍以上变化。5.46 mg·L^(-1)Pb^(2+)暴露下,17种蟾蜍甾烯水平发生下调(>1.5倍),其中bufarenogin水平显著下降(P<0.05),其他物质水平与对照组无显著性差异。这说明Pb^(2+)暴露对蟾蜍耳后腺中蟾蜍甾烯物质具有潜在影响。

The effect of Pb^2＋exposure for 30 days on the physiological status of Bufo bufo gargarizans Cantor and on the levels of bufadienolides in toad venom were studied, using the semi-static water design. With the increase of Pb^2＋concentration from 0.68 to 5.46 mg·L^-1, the toad＇s molting and spontaneous activity were remarkably inhibited, and the toad mortality increased. Furthermore, ultra performance liquid chromatography-mass spectrometry was used to monitor the relative levels of bufadienolides in toad venom. We found 10 kinds of bufadienolides with more than 1.5-fold change in 0.68 mg·L^-1Pb^2＋exposure group compared with control group. In Pb^2＋exposure group（5.46 mg·L^-1）, 17 kinds of bufadienolides were down-regulated with more than 1.5-fold change, in which the levels of bufarenogin was decreased significantly（P〈0.05）, while others had no significant change. These illustrated that Pb^2＋exposure could affect the levels of bufadienolides in toad venom.