Aquatic Ecology and Toxicology Section, Department of Zoology, University of Heidelberg, Im Neuenheimer Feld 230, 69120, Heidelberg, Germany.
Environ Sci Pollut Res Int. 2011 Mar;18(3):446-60. doi: 10.1007/s11356-010-0390-3. Epub 2010 Sep 5.
The present study was part of a comprehensive weight-of-evidence approach with the goal of identifying potential causes for the declines in fish populations, which have been observed during the past decades in the Upper Danube River.
The specific goal was the investigation of the endocrine disrupting potential of sediment extracts from different sites along the Danube River. Parallel to the identification and quantification of target estrogens, two in vitro bioassays were employed to assess the estrogenic potential (yeast estrogen screen, YES) of the sediment samples and to evaluate their effects on the production of testosterone (T) and E2 (H295R Steroidogenesis Assay). Using a potency balance approach, the contribution of the measured compounds (Chem-EEQs) to the total endocrine activity measured by the YES (YES-EEQs) was calculated.
Of the nine sediment extracts tested five extracts exhibited significant estrogenic activities in the YES, which suggested the presence of ER agonists in these samples. The xenoestrogens nonylphenol (NP) and bisphenol A (BPA) and the natural estrogen estrone (E1) were detected while concentrations of 17β-estradiol (E2) and ethinylestradiol (EE2) were less than their respective limits of quantification in all sediment extracts. A comparison of the measured YES-EEQs and the calculated Chem-EEQs revealed that as much as 6% of estrogenic activity in extracts of most sediments could be explained by two xeno- and one natural estrogen. Exposure of H295R cells to sediment extracts from four different locations in the Danube River resulted in significantly increased concentrations of E2, but only slight inhibition of T synthesis. Furthermore, application of the H295R Steroidogenesis Assay provided evidence for endocrine disrupting potencies in sediment samples from the Upper Danube River, some of which were not detectable with the YES. In conclusion, differential endocrine activities were associated with several sediments from the Upper Danube River. Further investigations will have to show whether the observed activities are of biological relevance with regard to declines in fish populations in the Upper Danube River.
本研究是综合证据评估方法的一部分，旨在确定过去几十年来多瑙河上游鱼类数量下降的潜在原因。
具体目标是调查多瑙河不同地点的沉积物提取物的内分泌干扰潜力。在鉴定和量化目标雌激素的同时，还采用了两种体外生物测定法来评估沉积物样品的雌激素潜力（酵母雌激素筛选，YES），并评估它们对睾酮（T）和 E2（H295R 类固醇生成测定）产生的影响。使用效价平衡方法，计算出所测化合物（Chem-EEQs）对 YES 测量的总内分泌活性（YES-EEQs）的贡献。
在所测试的 9 种沉积物提取物中，有 5 种提取物在 YES 中表现出显著的雌激素活性，这表明这些样品中存在 ER 激动剂。检测到壬基酚（NP）和双酚 A（BPA）等外源性雌激素以及天然雌激素雌酮（E1），而所有沉积物提取物中 17β-雌二醇（E2）和乙炔雌二醇（EE2）的浓度均低于各自的定量限。对测量的 YES-EEQs 和计算的 Chem-EEQs 进行比较表明，在大多数沉积物提取物中，高达 6%的雌激素活性可以用两种外源性雌激素和一种天然雌激素来解释。将 H295R 细胞暴露于来自多瑙河四个不同地点的沉积物提取物中，导致 E2 的浓度显著增加，但 T 合成的抑制作用很小。此外，H295R 类固醇生成测定法的应用提供了多瑙河上游沉积物样本中存在内分泌干扰潜力的证据，其中一些用 YES 无法检测到。总之，多瑙河上游的几种沉积物与不同的内分泌活性有关。进一步的研究将不得不表明，观察到的活性与多瑙河上游鱼类数量下降是否具有生物学相关性。
