微囊藻毒素在太湖白鲢体内的累积规律及其影响因素

太湖蓝藻水华及其次级代谢产物微囊藻毒素(MCs)的生物累积对生态系统和人体健康造成严重威胁,已成为最近环境科学研究的热点。本研究从太湖的不同区域(梅梁湖、西部沿岸区、南部沿岸区和湖心区)采集不同体重和体长的白鲢,利用固相萃取方法提取、高效液相色谱-质谱联用仪测定了白鲢不同器官中MCs的3种异构体MC-RR、MC-YR及MC-LR的含量,结合不同湖区的相关水质指标分析了MCs在白鲢体内的累积规律及其影响因素。研究结果表明:白鲢不同器官MCs的含量由高到低为:肠壁肾脏肝脏肌肉心脏,且肠壁累积的MCs显著高于肾脏、肝脏、肌肉和心脏。MC-RR含量是白鲢各器官累积MCs的异构体的主体,约占MCs的60%。梅梁湖鲢鱼的肌肉、肾脏和心脏中MCs均高于西部沿岸区、南部沿岸区和湖心区。生物指标(体重和体长)是影响白鲢肾脏内MCs和MC-RR含量以及肠壁内MCs含量重要因素。太湖水质指标总磷(TP)、藻细胞数量、湖泊营养指数及环节动物数量尤其是TP对白鲢肝脏累积MCs产生明显影响,TP、总氮(TN)、铵态氮(NH4-N)、内梅罗指数和环节动物数量尤其是NH4-N对肠壁累积MCs产生明显影响。

Accumulation of Microcystins in Silver Carp fromTaihu Lake and its InfluencingFactors

Cyanobacterial blooms took place in Taihu Lake every year and were widely concerned. Microcystins (MCs), the metabolites of cyanobacteria, could have potential adverse effects on ecosystems and human health. In order to examine accumulations of MCs in fish from different parts of Taihu Lake and its influencing factors, silver carp was sampled and MCs (MC-LR, MC-YR and MC-RR) were analyzed by high performance liquid chromatography tandem mass spectrometric. The results showed that MCs in different organs of silver carp was of such order: intestine wall > kidney > liver > muscle >heart, and MCs concentration in intestine wall was significantly higher than those in kidney, liver, muscle and heart. MC-RR was the main isomer of MCs which accounted for 60% of MCs. Concentrations of MCs in muscle, kidney and heart of silver carp from the Meiliang Bay were higher than those from West Coast, South Coast and Lake Center of Taihu Lake. Based onthe significant relationships between body length, weight and MCs concentrations in organs of silver carp, it wasindicated that body length and weight were important factors that influenced accumulation of MCs and MC-RR in kidney and that of MCs in intestine wall.The water quality index of Taihu Lake including TP, algae cell number, nutrition index and number of annelid, especially TP, played important roles in MCs accumulation in liver of silver carp whilethe water quality index including TP, TN, NH₄-N, Nemerow index and number of annelid, especially NH₄-N also played important roles in MCs accumulation in intestine wall of silver carp.