Leonards P E, Broekhuizen S, de Voogt P, Van Straalen N M, Brinkman U A, Cofino W P, van Hattum B
Institute for Environmental Studies, Vrije Universiteit, De Boelelaan 1115, 1081 HV Amsterdam, The Netherlands.
Arch Environ Contam Toxicol. 1998 Nov;35(4):654-65. doi: 10.1007/s002449900428.
Bioaccumulation of non-, mono-, and di-ortho-substituted chlorobiphenyls (CBs) was investigated in four species of mustelids (weasel, stoat, polecat, and otter) and their preys, from a restricted area in the northern part of The Netherlands. Diets of these mustelids ranged from terrestrial (weasel, stoat, and polecat) to aquatic (otter). Diet-specific biomagnification factors (BMFs), CB in diet relative to CB in mustelids, were calculated for the sum of 28 congeners (SigmaCB), for the sum of the toxic equivalent concentration (SigmaTEQ) and on an individual congener basis. Biotransformation was studied in relation to structural CB properties (vicinal H-atom substitution). In addition, the methylsulphonyl CB-metabolites were determined. The concentration of SigmaCB on lipid weight basis increased in the order weasel < stoat < polecat < otter. On the basis of SigmaTEQ, the order changed to weasel < polecat < stoat < otter. Most of the differences in BMFs between the CBs could be explained by the vicinal H-atom structure-activity rules. For all mustelids, the lowest BMFs were found for congeners with vicinal H-atoms in the meta, para position. Indications were found that all mustelid species can metabolize these congeners. For some of the CBs, their methylsulphonyl-CB metabolites were determined and found to be present in concentrations up to 350-fold higher than those of the parent compounds. In addition, the non-ortho CBs 126 and 169 are selectively retained in the liver of weasel, stoat, and otter. These CBs had the highest BMFs of all congeners. However, rather surprisingly, in polecat the highest BMFs were found for di-ortho-substituted CBs. This animal was able to metabolize all congeners with vicinal H-atoms in the ortho and meta position (non- and mono-ortho CBs). The information concerning the differences in bioaccumulation of CBs for closely related mustelid species increased the understanding of reported differences in PCB toxicity between mink and ferrets, and suggest that weasel, stoat, and otter are at least as sensitive to CBs as are mink, while polecats are less sensitive. As otter is exposed to much higher concentrations of CBs trough their diet than weasel and stoat, the toxic threat of CBs will be the greatest for this animal.
在荷兰北部的一个限定区域，对四种鼬科动物（黄鼬、白鼬、鸡貂和水獭）及其猎物体内非邻位、单邻位和双邻位取代的氯联苯（CBs）的生物累积情况进行了研究。这些鼬科动物的饮食范围从陆生（黄鼬、白鼬和鸡貂）到水生（水獭）。针对28种同系物的总和（ΣCB）、毒性当量浓度总和（ΣTEQ）以及单个同系物，计算了特定饮食的生物放大因子（BMFs，即饮食中的CB相对于鼬科动物体内的CB）。结合CB的结构特性（邻位氢原子取代情况）对生物转化进行了研究。此外，还测定了甲基磺酰基CB代谢物。以脂质重量为基础，ΣCB的浓度按黄鼬＜白鼬＜鸡貂＜水獭的顺序增加。基于ΣTEQ，顺序变为黄鼬＜鸡貂＜白鼬＜水獭。CBs之间BMFs的大多数差异可以通过邻位氢原子结构 - 活性规则来解释。对于所有鼬科动物，在间位、对位带有邻位氢原子的同系物的BMFs最低。有迹象表明所有鼬科动物物种都能代谢这些同系物。对于某些CBs，测定了它们的甲基磺酰基 - CB代谢物，发现其浓度比母体化合物高出350倍。此外，非邻位CBs 126和169选择性地保留在黄鼬、白鼬和水獭的肝脏中。这些CBs在所有同系物中具有最高的BMFs。然而，相当令人惊讶的是，在鸡貂中，双邻位取代的CBs具有最高的BMFs。这种动物能够代谢所有在邻位和间位带有邻位氢原子的同系物（非邻位和单邻位CBs）。关于亲缘关系密切的鼬科动物物种在CB生物累积方面差异的信息，加深了对已报道的水貂和雪貂之间PCB毒性差异的理解，并表明黄鼬、白鼬和水獭对CBs的敏感性至少与水貂一样，而鸡貂的敏感性较低。由于水獭通过饮食接触到的CBs浓度比黄鼬和白鼬高得多，CBs对这种动物的毒性威胁将最大。
