We investigated the accumulation and effects of cyanobacterial crude extract（CCE）containing microcystins（MCs） on the edible clam Corbicula leana P. Toxic effects were evaluated through the activity of antioxidant ...We investigated the accumulation and effects of cyanobacterial crude extract（CCE）containing microcystins（MCs） on the edible clam Corbicula leana P. Toxic effects were evaluated through the activity of antioxidant and detoxification enzymes： catalase（CAT）,superoxide dismutase（SOD）, and glutathione-S-transferases（GSTs） from gills, foot, mantle and remaining soft tissues. Clams were exposed to CCE containing 400 μg MC-LReq/L for10 days and were then kept in toxin-free water for 5 days. Clam accumulated MCs（up to 3.41 ± 0.63 μg/g dry weight（DW） of unbound MC and 0.31 ± 0.013 μg/g DW of covalently bound MC）. Detoxification and antioxidant enzymes in different organs responded differently to CCE during the experiment. The activity of SOD, CAT, and GST in the gills and mantle increased in MC-treated clams. In contrast, CAT and GST activity was significantly inhibited in the foot and mostly only slightly changed in the remaining tissues. The responses of biotransformation, antioxidant enzyme activity to CCE and the fast elimination of MCs during depuration help to explain how the clam can survive for long periods（over a week） during the decay of toxic cyanobacterial blooms in nature.展开更多
基金supported by the Ministry of Education, Culture, Sports, Science, and Technology of Japan (MEXT) under a Ph.D programsupported by Grants-in-Aid for Scientific Research (B) from the Japan Society for the Promotion of Science (JSPS) and MEXT
文摘We investigated the accumulation and effects of cyanobacterial crude extract（CCE）containing microcystins（MCs） on the edible clam Corbicula leana P. Toxic effects were evaluated through the activity of antioxidant and detoxification enzymes： catalase（CAT）,superoxide dismutase（SOD）, and glutathione-S-transferases（GSTs） from gills, foot, mantle and remaining soft tissues. Clams were exposed to CCE containing 400 μg MC-LReq/L for10 days and were then kept in toxin-free water for 5 days. Clam accumulated MCs（up to 3.41 ± 0.63 μg/g dry weight（DW） of unbound MC and 0.31 ± 0.013 μg/g DW of covalently bound MC）. Detoxification and antioxidant enzymes in different organs responded differently to CCE during the experiment. The activity of SOD, CAT, and GST in the gills and mantle increased in MC-treated clams. In contrast, CAT and GST activity was significantly inhibited in the foot and mostly only slightly changed in the remaining tissues. The responses of biotransformation, antioxidant enzyme activity to CCE and the fast elimination of MCs during depuration help to explain how the clam can survive for long periods（over a week） during the decay of toxic cyanobacterial blooms in nature.
