Bouchard B, Gagné F, Fortier M, Fournier M
Environment Canada, Fluvial Ecosystem Research, 105 McGill, 7th Floor, Montréal, Quebec, Canada.
Comp Biochem Physiol C Toxicol Pharmacol. 2009 Aug;150(2):132-40. doi: 10.1016/j.cbpc.2009.04.002. Epub 2009 Apr 9.
The goal of this study was to examine the disruptive effects of municipal effluents on the immune and reproductive systems of freshwater mussels. For 30 days, caged mussels were immersed in the Rivière des Mille Iles (Quebec, Canada), 150 m both upstream and downstream from two urban wastewater treatment plants: station F (Fabreville) and station A (Auteuil), which serve the city of Laval. Station F is 12 km upstream from station A. The immune and reproductive statuses of the mussels were thereafter determined. Though the weight/shell length ratio was not affected, the effluent induced mortality up to 60% at downstream sites. Total hemocyte counts increased, and phagocytosis and lysozyme activities were induced at station F, whereas these responses were suppressed at station A. Heterotrophic bacteria levels in mussels were negatively correlated with phagocytosis, showing the importance of this process in defending against infection. Inflammation biomarkers such as nitric oxide and cyclooxygenase activity were the same for all sites but were positively correlated with phagocytosis activity. The production of vitellogenin (Vtg)-like proteins was significantly induced at the site downstream from station A and was strongly associated with phagocytosis. This was further supported through analysis of covariance, of Vtg responses against phagocytosis, revealing that Vtg was no longer induced at the sites upstream and downstream from station A. The data support the contention that Vtg was involved, in part at least, in the immune system in mussels. Both Vtg and immune status are impacted by urban effluents and should be considered when using the Vtg biomarker to search for the presence of (xeno)estrogens in contaminated environments.
本研究的目的是考察城市污水对淡水贻贝免疫和生殖系统的破坏作用。将置于笼中的贻贝在加拿大魁北克省的千岛河（Rivière des Mille Iles）中浸泡30天，该河位于两座城市污水处理厂（为拉瓦尔市服务）上游和下游150米处：F站（法布雷维尔站，Fabreville）和A站（奥蒂尤尔站，Auteuil）。F站在A站上游12公里处。之后测定贻贝的免疫和生殖状态。虽然体重/壳长比未受影响，但污水在下游位点导致高达60%的死亡率。F站的总血细胞计数增加，吞噬作用和溶菌酶活性被诱导，而在A站这些反应受到抑制。贻贝中的异养细菌水平与吞噬作用呈负相关，表明该过程在抵御感染中的重要性。炎症生物标志物如一氧化氮和环氧化酶活性在所有位点相同，但与吞噬作用活性呈正相关。在A站下游位点，类卵黄蛋白原（Vtg）样蛋白的产生显著诱导，且与吞噬作用密切相关。通过对Vtg反应与吞噬作用的协方差分析进一步证实，在A站上游和下游位点Vtg不再被诱导。数据支持这样的观点，即Vtg至少部分参与了贻贝的免疫系统。Vtg和免疫状态均受城市污水影响，在利用Vtg生物标志物在受污染环境中寻找（异种）雌激素时应予以考虑。
