We used in-tissue passive equilibrium sampling using the silicone polydimethylsiloxane (PDMS) to transfer chemical mixtures present in organs from marine mammals with lipid contents between 2.3 and 99 % into in vitro bioassays. Tissues from five harbor porpoises (Phocoena phocoena), one harbor seal (Phoca vitulina) and one orca (Orcinus orca) from the North and Baltic Seas were sampled until thermodynamic equilibrium was reached. Mixture effects were quantified with cellular reporter gene bioassays targeting the activation of the aryl hydrocarbon receptor (AhR-CALUX), the peroxisome proliferator-activated receptor gamma (PPARγ-bla) and the oxidative stress response (AREc32), with parallel cytotoxicity measurements in all assays. After removing co-extracted lipids and other matrix residues with a non-destructive cleanup method (freeze-out of acetonitrile extract followed by a primary secondary amine sorbent extraction), the activation of the PPARγ and AREc32 were reduced by factors of on average 4.3 ± 0.15 (n = 22) and 2.5 ± 0.23 (n = 18), respectively, whereas the activation of the AhR remained largely unaltered: 1.1 ± 0.075 (n = 6). The liver extracts showed the highest activation, followed by the corresponding kidney and brain extracts, and the blubber extracts of the animals were the least active ones. The activation of the PPARγ by the liver extracts was reduced after cleanup by a factor of 11 ± 0.26 (n = 7) and the AREc32 activity by a factor of 1.9 ± 0.32 (n = 4). The blubber extracts did not activate the AhR up to concentrations where cytotoxicity occurred or up to an acceptable lipid volume fraction of 0.27 % as derived from earlier work, whereas all liver extracts that had undergone cleanup activated the AhR. The developed in-tissue passive sampling approach allows a direct comparison of the bioassay responses between different tissues without further normalization and serves as a quantitative method suitable for biomonitoring of environmental biota samples.

我们使用有机硅聚二甲基硅氧烷 (PDMS) 进行组织内被动平衡采样，将海洋哺乳动物器官中脂质含量在 2.3% 到 99  %之间的化学混合物转移 到体外生物测定中。来自五只海豚 ( Phocoena phocoena )、一只海豹 ( Phoca vitulina ) 和一只逆戟鲸 ( Orcinus orca ) 的组织) 从北海和波罗的海取样，直到达到热力学平衡。使用针对芳烃受体 (AhR-CALUX)、过氧化物酶体增殖物激活受体 γ (PPARγ-bla) 和氧化应激反应 (AREc32) 激活的细胞报告基因生物测定对混合效应进行量化，同时对所有细胞进行平行细胞毒性测量化验。在使用非破坏性净化方法（乙腈提取物冷冻，然后进行初级仲胺吸附剂提取）去除共提取的脂质和其他基质残留物后，PPARγ 和 AREc32 的活化平均降低了 4.3 ± 0.15 ( n  = 22) 和 2.5 ± 0.23 ( n = 18)，而 AhR 的激活在很大程度上保持不变：1.1 ± 0.075 ( n  = 6)。肝脏提取物的活性最高，其次是相应的肾脏和脑提取物，动物的脂肪提取物活性最低。净化后，肝脏提取物对 PPARγ 的激活降低了 11 ± 0.26 ( n  = 7)，而 AREc32 活性降低了 1.9 ± 0.32 ( n  = 4)。直到发生细胞毒性的浓度或从早期工作中得出的可接受的 0.27% 的脂质体积分数，鲸脂提取物都没有激活 AhR  ，而所有经过净化的肝脏提取物都激活了 AhR。发达的组织内被动采样方法允许直接比较不同组织之间的生物测定响应而无需进一步标准化，并作为一种适用于环境生物群样本生物监测的定量方法。