Zhang Qian-Ru, Mu Wen-Yan, Zhang Jing-Yi, Liu Li, Wei Shu-He
Ying Yong Sheng Tai Xue Bao. 2014 Sep;25(9):2683-94.
Ragworm (Polychaeta) is an ecologically important species in intertidal mudflats and estuaries and is recognized as a sentinel species for environmental monitoring. In the intertidal belt of China, the ragworm Perinereis aibuhitensis is frequently exposed to various toxicants including cadmium (Cd) and petroleum hydrocarbons (PHCs). The present study investigated the influence of PHCs on accumulation of Cd and the induction of metallothionein (MT) in P. aibuhitensis by means of chronic microcosm experiment in which the ragworms were exposed to Cd or combinations of Cd and PHCs. The accumulation of Cd in P. aibuhitensis increased significantly with the Cd exposure concentration when exposed to Cd alone. Further, the bioconcentration factors (BCFs) for Cd in P. aibuhitensis increased with the duration of exposure. The addition of PHCs in Cd exposure solutions significantly increased the accumulation of Cd in P. aibuhitensis, compared with the control. Exposure to Cd induced the expression of MT, and the expression increased with the concen- tration up to 180 mg · kg(-1) DM Cd at which point the level of induction did not increase. PHCs without Cd did not significantly induce MT in P. aibuhitensis, but the addition of PHCs with Cd did influence the induction of MT compared to Cd without PHCs. Results indicated that PHCs could modulate the expression of MT during co-exposure with Cd. The potential substances other than metals influencing the interpretation of MT expression in wild P. aibuhitensis must be recognized when MT is used as a monitoring index.
沙蚕（多毛纲）是潮间带泥滩和河口生态系统中的重要物种，被视为环境监测的指示物种。在中国潮间带，双齿围沙蚕经常暴露于包括镉（Cd）和石油烃（PHCs）在内的各种有毒物质中。本研究通过慢性微观实验，研究了石油烃对双齿围沙蚕体内镉积累及金属硫蛋白（MT）诱导的影响，实验中沙蚕暴露于镉或镉与石油烃的混合物中。单独暴露于镉时，双齿围沙蚕体内的镉积累量随镉暴露浓度显著增加。此外，双齿围沙蚕体内镉的生物富集系数（BCFs）随暴露时间增加。与对照组相比，在镉暴露溶液中添加石油烃显著增加了双齿围沙蚕体内镉的积累。暴露于镉会诱导金属硫蛋白的表达，且表达量随浓度增加至180 mg·kg(-1) DM Cd时达到最高，此后诱导水平不再增加。不含镉的石油烃不会显著诱导双齿围沙蚕体内的金属硫蛋白，但与不含石油烃的镉相比，添加石油烃的镉会影响金属硫蛋白的诱导。结果表明，石油烃在与镉共同暴露时可调节金属硫蛋白的表达。当金属硫蛋白用作监测指标时，必须认识到除金属外其他可能影响野生双齿围沙蚕体内金属硫蛋白表达解读的潜在物质。
