Fournier M, Pellerin J, Clermont Y, Morin Y, Brousseau P
INRS-Institut Armand-Frappier, 245 Boul. Hymus, Pointe-Claire, Quebec, Canada, H3G 1M8.
Toxicology. 2001 Mar 28;161(3):201-11. doi: 10.1016/s0300-483x(00)00387-5.
Marine bivalves are aquatic invertebrate organisms which can be used as bioindicators in environmental monitoring. In vivo effects of mercuric chloride (HgCl(2)) and methylmercury (CH(3)HgCl) on phagocytic function of Mya arenaria hemocytes were evaluated in this study. Clams were exposed to single metal in water for up to 28 days at concentrations ranging from 10(-9) to 10(-5) M. Phagocytic activity of hemocytes was determined by uptake of fluorescent microspheres and flow cytometry. All clams exposed to 10(-5) M HgCl(2) died by day 7 of exposure. The viability of hemocytes was decreased only in clams exposed to 10(-6) M HgCl(2) for 28 days. A significant decrease in phagocytic activity of hemocytes was observed in clams exposed to 10(-6) M of HgCl(2) for 28 days. A similar pattern was observed with CH(3)HgCl, but at an earlier time. Chemical analysis performed on the tissues of the animals clearly show a greater uptake of the organic form of mercury by clams. Furthermore, a clear correlation was established between body burden of mercury and effects on phagocytic activity of hemocytes. Overall, the results of this study show that both speciations of mercury inhibited phagocytic function of Mya arenaria hemocytes following in vivo exposures.
海洋双壳贝类是水生无脊椎动物，可作为环境监测中的生物指示物。本研究评估了氯化汞（HgCl₂）和甲基汞（CH₃HgCl）对砂海螂血细胞吞噬功能的体内影响。将蛤蜊置于含有单一金属的水中，浓度范围为10⁻⁹至10⁻⁵M，暴露长达28天。通过荧光微球摄取和流式细胞术测定血细胞的吞噬活性。所有暴露于10⁻⁵M HgCl₂的蛤蜊在暴露第7天时死亡。仅在暴露于10⁻⁶M HgCl₂ 28天的蛤蜊中，血细胞的活力有所下降。在暴露于10⁻⁶M HgCl₂ 28天的蛤蜊中，观察到血细胞吞噬活性显著降低。CH₃HgCl也观察到类似模式，但时间更早。对动物组织进行的化学分析清楚地表明，蛤蜊对有机汞形式的摄取量更大。此外，汞的体内负荷与对血细胞吞噬活性影响之间建立了明确的相关性。总体而言，本研究结果表明汞的两种形态在体内暴露后均抑制了砂海螂血细胞的吞噬功能。
