Università Cattolica del Sacro Cuore, Agricultural and Environmental Chemistry Institute, Piacenza, Italy.
Environ Toxicol Chem. 2011 Jan;30(1):132-41. doi: 10.1002/etc.359.
The aim of the current study was to investigate effects of temperature and a mixture of herbicides on the physiological status of the bivalve Mya arenaria. Bivalves acclimated to two temperatures (7 and 18°C) were exposed for 28 d to 0.01 mg/L of a pesticide formulation containing dichlorophenoxyacetic acid (2,4-D), 2-(2-methyl-4-chlorophenoxy) propionic acid (mecoprop), and 3,6-dichloro-2-methoxybenzoic acid (dicamba). At days 7, 14, and 28, mortality, immune parameters (hemocyte number, phagocytic activity, and efficiency), biomarkers of oxidative stress (catalase [CAT] and superoxide dismutase [SOD] activities and malondialdehyde [MDA] content), the metabolic enzyme cytochrome C oxidase (CCO), a biomarker of pesticide exposure (acetylcholinesterase [AChE]), and the activity of an enzyme related to gametogenesis (aspartate transcarbamylase [ATCase]) were monitored in clam tissues. Gonadosomatic index (GSI), condition factor (CF), and sex were also assessed. In clams acclimated to 7°C, exposure to pesticide enhanced CCO activity and CF and decreased MDA content, hemocyte number, CAT, and SOD activities. In clams kept at 18°C, pesticide effects appeared minor compared with samples kept at 7°C. In bivalves acclimated to 18°C, CCO, SOD, and ATCase activity and MDA content were enhanced, and hemocyte number, CAT, and AchE activities and phagocytosis were suppressed. In samples exposed to pesticides, increased temperature enhanced MDA content and CCO and SOD activity and suppressed hemocyte number and CAT and AchE activity. A gradual sexual maturation was observed in both sexes through experimental time, but females had a higher sensitivity to temperature and pesticides compared to males. Increased temperature altered the ability of the sentinel species Mya arenaria to respond to pesticide exposures. Further work is needed to understand the impacts of increasing temperature on the whole St. Lawrence estuary ecosystem.
本研究旨在探讨温度和除草剂混合物对双壳贝类贻贝（Mya arenaria）生理状况的影响。将适应两种温度（7°C 和 18°C）的双壳贝类暴露于含有 2,4-二氯苯氧乙酸（2,4-D）、2-（2-甲基-4-氯苯氧）丙酸（MCPA）和 3,6-二氯-2-甲氧基苯甲酸（麦草畏）的农药制剂中 0.01mg/L，持续 28 天。在第 7、14 和 28 天，监测死亡率、免疫参数（血细胞数量、吞噬活性和效率）、氧化应激生物标志物（过氧化氢酶 [CAT]和超氧化物歧化酶 [SOD]活性和丙二醛 [MDA]含量）、代谢酶细胞色素 C 氧化酶（CCO）、农药暴露生物标志物（乙酰胆碱酯酶 [AChE]）和与配子发生相关的酶（天冬氨酸转氨甲酰酶 [ATCase]）的活性。还评估了性腺指数（GSI）、条件因子（CF）和性别。在适应 7°C 的贻贝中，暴露于农药会增强 CCO 活性和 CF，并降低 MDA 含量、血细胞数量、CAT 和 SOD 活性。在保持在 18°C 的贻贝中，与保持在 7°C 的样本相比，农药的影响较小。在适应 18°C 的双壳贝类中，CCO、SOD 和 ATCase 活性和 MDA 含量增加，血细胞数量、CAT、AChE 活性和吞噬作用受到抑制。在暴露于农药的样本中，升高的温度会增加 MDA 含量以及 CCO 和 SOD 活性，并抑制血细胞数量、CAT 和 AChE 活性。在整个实验过程中，两性都观察到逐渐的性成熟，但与雄性相比，雌性对温度和农药更敏感。升高的温度改变了指示物种贻贝对农药暴露的反应能力。需要进一步的工作来了解温度升高对整个圣劳伦斯河口生态系统的影响。
