State Key Laboratory of Marine Environmental Science, Environmental Science Research Center, Xiamen University, Xiamen, 361005 Fujian, China.
Aquat Toxicol. 2010 Sep 1;99(3):413-22. doi: 10.1016/j.aquatox.2010.06.001. Epub 2010 Jun 9.
In this study, female and male Thais clavigera whelks were exposed to aqueous and dietary (using oysters as the prey) tributyltin (TBT) for up to 45 days, followed by a 30-day depuration, in order to examine the gender differences in TBT accumulation and transformation. The metabolites of TBT [dibutyltin (DBT) and monobutyltin (MBT)] were also measured in different tissues of the whelks (digestive, reproductive and remaining organs) during the exposure and depuration periods. By the end of the exposure period, all of the female whelks developed imposex after TBT exposure, and both the relative penis size index and the vas deferens sequence index were positively correlated with the tissue burden of TBT. However, biomagnification of TBT did not occur in the whelks. TBT was rapidly accumulated in their digestive and reproductive organs from both routes of exposure, and both elimination and biotransformation of TBT were also rapid. The redistribution of TBT among tissues was obvious during the exposure period but negligible during depuration. MBT was generally the major metabolite in each tissue, indicating a significant metabolism of TBT by the whelks. Accumulation, transformation, as well as elimination, were more significant following dietary exposure than following aqueous exposure. In particular, we observed gender-related differences in the biokinetics of TBT. Rapid biotransformation and elimination of TBT were detected in the male whelks, while the female whelks had higher bioaccumulation but lower elimination of TBT in their reproductive organs. Internal remobilization of TBT from digestive to reproductive organs was also more obvious in the females, indicating that the reproductive organs of females were the main targets of TBT accumulation.
在这项研究中，雌性和雄性泰国榧螺被暴露在水相和膳食相（以牡蛎作为食物）中的三丁基锡（TBT）中，为期长达 45 天，随后进行 30 天的净化，以研究 TBT 积累和转化过程中的性别差异。在暴露和净化期间，还测量了 TBT 的代谢物[二丁基锡（DBT）和单丁基锡（MBT）]在榧螺不同组织（消化、生殖和剩余器官）中的含量。暴露期结束时，所有雌性榧螺在 TBT 暴露后都出现了雄性先熟现象，并且相对阴茎大小指数和输精管序列指数都与 TBT 的组织负荷呈正相关。然而，TBT 在榧螺中没有发生生物放大。TBT 从两种暴露途径迅速积累在它们的消化和生殖器官中，并且 TBT 的消除和生物转化也非常迅速。暴露期间 TBT 在组织间的再分配非常明显，但在净化期间可忽略不计。MBT 通常是每个组织中的主要代谢物，表明 TBT 被榧螺显著代谢。膳食暴露后 TBT 的积累、转化和消除都比水相暴露后更为显著。特别是，我们观察到 TBT 的生物动力学存在与性别相关的差异。TBT 的快速生物转化和消除在雄性榧螺中被检测到，而雌性榧螺在生殖器官中具有更高的生物积累但较低的 TBT 消除。TBT 从消化道向生殖器官的内部再动员在雌性中也更为明显，表明雌性的生殖器官是 TBT 积累的主要靶标。
