Agricultural University Wageningen, Division Toxicology, Tuinlaan 5, 6703 HE Wageningen, The Netherlands.
Environ Toxicol Pharmacol. 1998 Oct;6(2):91-102. doi: 10.1016/s1382-6689(98)00026-x.
In the serious decline of European otters (Lutra lutra) over the last decades, polychlorinated biphenyls (PCBs) are considered to be one of the major factors. As no experiments can be conducted with otters, an eco-epidemiological study was performed to derive no observed effect concentrations (NOECs) for PCBs in the otter. A strong negative correlation was found between hepatic vitamin A and polychlorinated biphenyl (PCB) concentrations expressed as TCDD-equivalents (TEQs), coinciding with a higher incidence of infectious diseases. The no-effect concentration for vitamin A reduction was 2 ng TEQ/g lipid, 10-fold reduction was already found in animals with 5 ng TEQ/g lipid. The TEQ-levels measured with a reporter gene assay based on chemical-activated luciferase expression (the CALUX assay) correlated well with the TEQ levels calculated based on non- and mono-ortho PCB concentrations. The TEQ levels in blood and liver correlated well when expressed on a lipid basis. In living captive otters blood plasma TEQ levels (either measured based on gas chromatography (GC) or CALUX measurement) were lower than in the feral otters, and positively correlated with plasma total and free thyroid hormone but not with plasma retinol levels. Hepatic vitamin A concentration was found to be a physiologically relevant effect parameter. The NOEC for hepatic vitamin A reduction was translated into TEQ levels in fish and sediment. The CALUX response in 50-500 μl blood plasma proved to be a sensitive non-destructive biomarker for quantification of internal TEQ levels.
在过去几十年中，欧洲水獭（Lutra lutra）的数量严重下降，多氯联苯（PCBs）被认为是主要因素之一。由于不能对水獭进行实验，因此进行了生态流行病学研究，以确定水獭体内 PCBs 的无观察效应浓度（NOEC）。研究发现，肝脏维生素 A 与多氯联苯（PCB）浓度呈强烈负相关，其表达形式为 TCDD 等效物（TEQs），这与传染病发病率较高有关。维生素 A 减少的无效应浓度为 2ng TEQ/g 脂质，在 5ng TEQ/g 脂质的动物中已经发现了 10 倍的减少。基于化学激活荧光素酶表达的报告基因检测（CALUX 检测）测量的 TEQ 水平与基于非和单-邻位 PCB 浓度计算的 TEQ 水平相关性良好。以脂质为基础表示时，血液和肝脏中的 TEQ 水平相关性良好。在圈养的水獭中，无论是基于气相色谱（GC）还是 CALUX 测量，血浆 TEQ 水平（测量值）都低于野生水獭，并且与血浆总甲状腺素和游离甲状腺素呈正相关，但与血浆视黄醇水平无关。肝脏维生素 A 浓度被认为是一个生理相关的效应参数。肝维生素 A 减少的 NOEC 被转化为鱼类和沉积物中的 TEQ 水平。50-500μl 血浆中的 CALUX 反应被证明是一种敏感的非破坏性生物标志物，可用于定量测定内部 TEQ 水平。
