三丁基锡对翡翠贻贝谷胱甘肽硫转移酶活性的影响

Effects of TBT on the Activity of Glutathione S-transferase in Green Mussel(Perna viridis)

在实验条件下,将翡翠贻贝分别暴露于1,10,100,1 000 ng/L的三丁基锡溶液中,1,4,7,14,21 d后取样,测定鳃和消化腺谷胱甘肽硫转移酶(Glutathione S-transferase,GST)同工酶的活性(GSTs,GST-μ,GST-π).结果表明:(1)生理条件下GST同工酶在鳃组织中分布高于消化腺,且活性大小为:GSTs>GST-π>GST-μ;(2)污染条件下,各GST同工酶活性随暴露时间的变化趋势各有不同.鳃和消化腺GSTs活性在暴露第1天被强烈诱导,而后逐步表现为抑制作用;鳃GST-π活性基本无显著变化,消化腺GST-π活性于第7天被诱导至高点,并逐渐恢复到对照水平或被抑制;消化腺GST-μ活性随着污染时间的延长整体受到抑制.

Green mussel Perna viridis were exposed to 1,10,100,1 000 ng/L tributyltin （TBT） for 1,4,7,14 and 21 days in experimental condition. Activities of glutathione S-transferases （GST） from Perna viridis were investigated as possible biomarkers of environmental contamination in the coastal zone. In the first phase of the study, the activity of enzymes was assayed in various tissues in order to select a more sensitive location. In the second phase, isoenzymes （GSTs, GST-π, GST-μ） were assayed to determine the most appropriate biomarker. The results of this study indicate that： （1） in control group, the activities of glutathione S-transferase isoenzymes in gill were higher than that of digestive gland,and the relative activities level of glutathione S-transferase isoenzymes was GSTs〉GST-π〉GST-μ; （2）during the pollution experiment, the activities of GST isoenzymes displayed a various trend ; the activity of GSTs in gill and digestive gland increased intensively in the first day, then decreased gradually with exposure time. As to gill GST- π,there were no significant differences among all groups ; digestive gland GST-π was induced to a summit at 7 d,and returned to control level or inhibited in the end. Digestive gland GST-μ was inhibited on the whole along the nollution veriod.