Gagné F, Blaise C
St. Lawrence Centre, Environment Canada, 105 McGill Street, Montréal, Québec, Canada H2Y 2E7.
Comp Biochem Physiol C Toxicol Pharmacol. 2003 Oct;136(2):117-25. doi: 10.1016/s1532-0456(03)00171-6.
Sex differentiation and gametogenesis represent critical steps in the reproductive process and are subject to hormonal control by serotonin, dopamine and steroids such as estradiol-17beta and testosterone. The purpose of this study sought to examine the endocrine-disrupting activity that a primary-treated municipal effluent might have on the metabolism of biogenic amine levels. First, serotonin receptors transfected in Chinese hamster ovary (CHO) cells were used to screen for the presence of serotonin receptor agonist or antagonist. Second, one group of Elliptio complanata mussels were exposed to single compounds likely to be found in municipal wastewaters and another group was exposed in situ to the municipal effluent plume for 90 days in experimental cages. Results showed that solid phase C-8 extracts of surface water downstream a municipal effluent could activate the transport of serotonin by receptors at a distance of at least 5 km from its outfall thereby indicating the presence of serotonin mimics in the effluent dispersion plume. Levels of serotonin and monoamine oxidase (MAO) activity in nerve ganglia of mussels exposed for 90 days to the municipal effluent were, respectively, reduced and increased at a distance 10-km downstream. Injections of estradiol-17beta and nonylphenol in mussels decreased the levels of serotonin and dopamine, but increased MAO activity in the gonad and nerve ganglia. Exposure to estrogenic chemicals present in municipal effluents may therefore alter the normal metabolism of serotonin and dopamine, both of which are involved in sexual differentiation in bivalves and fish. Chemicals acting through E2 receptor-mediated pathways and serotonin receptors are likely to cause the observed effects.
性别分化和配子发生是生殖过程中的关键步骤，受血清素、多巴胺以及雌二醇 - 17β和睾酮等类固醇激素的控制。本研究旨在探讨初级处理后的城市污水可能对生物胺水平代谢产生的内分泌干扰活性。首先，利用转染了血清素受体的中国仓鼠卵巢（CHO）细胞来筛选血清素受体激动剂或拮抗剂的存在。其次，将一组椭圆蚌暴露于城市污水中可能存在的单一化合物，另一组在实验笼中于原位暴露于城市污水羽流中90天。结果表明，城市污水下游地表水的固相C - 8提取物能够在距离排放口至少5公里处激活受体介导的血清素转运，从而表明污水扩散羽流中存在血清素模拟物。在下游10公里处，暴露于城市污水90天的蚌神经节中的血清素水平和单胺氧化酶（MAO）活性分别降低和升高。向蚌体内注射雌二醇 - 17β和壬基酚会降低血清素和多巴胺水平，但会增加性腺和神经节中的MAO活性。因此，暴露于城市污水中存在的雌激素化学物质可能会改变血清素和多巴胺的正常代谢，而这两种物质都参与双壳贝类和鱼类的性别分化。通过E2受体介导途径和血清素受体起作用的化学物质可能会导致观察到的效应。
