Gagné F, Blaise C, André C, Gagnon C, Salazar M
Aquatic Ecosystem protection research division, Water Science and Technology, Environment Canada, 105 McGill, Montreal, Que., Canada H2Y 2E7.
Chemosphere. 2007 Jun;68(4):731-43. doi: 10.1016/j.chemosphere.2006.12.101. Epub 2007 Feb 22.
The purpose of this study was to examine neuroendocrine-disrupting effects of two domestic wastewater aeration lagoons on freshwater mussels. Mussels were caged and placed in two final aeration lagoons for treating domestic wastewaters for 60 days, at a site 1km downstream of the dispersion plume on the eastern shores of the Richelieu River; the western shore served as the reference site. The mussels were analysed for gonad activity, oxidative metabolism of xenobiotics, stress biomarkers and neuroendocrine status (monoamine and arachidonic acid metabolism). The domestic wastewaters produced many different effects at all levels examined. The gonado-somatic index and vitellogenin-like proteins were significantly induced in both aeration lagoons and gonad pyrimidine synthesis (aspartate transcarbamylase activity) was significantly reduced, indicating that vitellogenin-like proteins were produced while DNA synthesis in gametes remained constant. Biomarkers of oxidative metabolism revealed that global heme oxidase (HO), glutathione S-transferase and xanthine (caffeine) oxydoreductase (XOR) activities were significantly induced in at least one of the aeration lagoons, but not downstream of the dispersion plume. The activities of 7-ethoxyresorufin (cytochrome P4501A1), dibenzoylfluorescein (cytochrome P450 3A4 and 3A5) and benzoyloxyresorurufin (cytochrome P450 3A4 and 2B6) dealkylases were readily induced by substances sharing structural similarities with coplanar polyaromatic hydrocarbons and hydroxylated or aminated aromatic or cyclic hydrocarbon compounds such as pharmaceuticals or steroids in the domestic wastewaters. Biomarkers of toxic stress revealed that exposure to aeration lagoons led to increased production of metallothioneins, lipid peroxidation and DNA strand breaks, with decreased heme oxygenase activity. LPO was significantly correlated with XOR, HO and cytochrome P4501A1 activities. Neuroendocrine effects included significant increases in dopamine and serotonin levels and in monoamine oxidase (MAO). Dopamine transport in synaptosome was significantly increased while serotonin transport activity was significantly decreased, suggesting the mussels were in a state of serotonergicity. Moreover, arachidonic acid cyclooxygenase (COX) activity was also readily increased in one aeration lagoon. Aeration lagoons for the treatment of domestic wastewaters are toxic, estrogenic and disrupt the metabolism of monoamines and COX in freshwater mussels.
本研究的目的是考察两个生活污水曝气塘对淡水贻贝的神经内分泌干扰效应。将贻贝装入笼中，放置在两个用于处理生活污水的最终曝气塘中60天，地点位于黎塞留河东岸扩散羽流下游1公里处；西岸作为参考地点。对贻贝的性腺活性、异生物质的氧化代谢、应激生物标志物和神经内分泌状态（单胺和花生四烯酸代谢）进行了分析。生活污水在所有检测水平上都产生了许多不同的影响。两个曝气塘中的性腺-体指数和类卵黄蛋白原均显著升高，性腺嘧啶合成（天冬氨酸转氨甲酰酶活性）显著降低，表明产生了类卵黄蛋白原，而配子中的DNA合成保持不变。氧化代谢生物标志物显示，至少在一个曝气塘中，总体血红素氧化酶（HO）、谷胱甘肽S-转移酶和黄嘌呤（咖啡因）氧化还原酶（XOR）活性显著升高，但在扩散羽流下游则不然。7-乙氧基异吩唑酮（细胞色素P4501A1）、二苯甲酰荧光素（细胞色素P450 3A4和3A5）和苯甲酰氧基异吩唑酮（细胞色素P450 3A4和2B6）脱烷基酶的活性很容易被生活污水中与共平面多环芳烃以及羟基化或胺化的芳香族或环状烃化合物（如药物或类固醇）结构相似的物质诱导。毒性应激生物标志物显示，暴露于曝气塘会导致金属硫蛋白产量增加、脂质过氧化和DNA链断裂，同时血红素加氧酶活性降低。脂质过氧化与XOR、HO和细胞色素P4501A1活性显著相关。神经内分泌效应包括多巴胺和血清素水平以及单胺氧化酶（MAO）显著增加。突触体中的多巴胺转运显著增加，而血清素转运活性显著降低，这表明贻贝处于血清素能状态。此外，在一个曝气塘中花生四烯酸环氧化酶（COX）活性也很容易升高。用于处理生活污水的曝气塘具有毒性、雌激素活性，并会干扰淡水贻贝中单胺和COX的代谢。
