To explore the effect of digestive enzymes (protease, amylase and cellulase) activities in hepatopancreas of Cyclina sinensis exposed to heavy metal. The animals were exposed to the combined and isolated of Zn2 + , Cd2 + with dose of 0, 10, 20, 40, 80 mg/dm3 for 96 hours. The specific activities of protease, amylase and cellulase were analyzed by using enzyme analytical method. The results indicated that the activity of amylase in hepatopancreas of C. sinensis was the highest among all three digestive enzymes, and cellulase was the lowest. Different concentrations of Zn2+ on amylase showed a significant inhibition, so did it on the protease generally except 40 mg/dm3 of Zn2+ was activated, and cellulase generally reflected activation, only 10 mg/dm3 of Zn2+ was inhibited. 20 mg /dm of Zn2+ presented higher activated and activation on the enzyme decreased significantly with the increasing concentration. Different concentrations of Cd2+ on the three digestive enzymes had different levels of inhibition and the inhibition showed varied trends. Different concentrations of Zn2+ + Cd2+ on amylase and protease re-fleeted a significant inhibition, and inhibition strengthened when concentration increased. When 20 mg/dm3 and 40 mg/dm of Zn2+ + Cd2+ showed activation on cellulase, the other two concentrations( 10 mg/dm3 and 80 mg/dm3) showed inhibition. It was indicated that digestive enzyme activities in hepatopancreas of C. sinensis might be considered as the potential biomarkers of Zn2+ and Cd2+ contamination.%以酶学分析的方法研究了Zn2+、Cd2+单独及联合作用(Zn2++ Cd2+)对青蛤肝胰腺蛋白酶、淀粉酶和纤维素酶活性的影响,实验浓度分别设置为0、10、20、40、80 mg/dm3,染毒时间为4d.实验结果表明,3种消化酶活性大小为淀粉酶＞蛋白酶＞纤维素酶.不同浓度的Zn2+对淀粉酶表现为显著的抑制作用；除40 mg/dm3浓度组的Zn2+对蛋白酶有激活作用外,其余浓度组的Zn2+对蛋白酶均有抑制作用；除10 mg/dm3浓度组Zn2+对纤维素酶有抑制作用外,其余浓度组的Zn2+对纤维素酶均有激活作用.不同浓度的Cd2+对淀粉酶、蛋白酶和纤维素酶均有不同程度的抑制作用,且表现出不同的抑制趋势；不同浓度的Zn2++Cd2+对淀粉酶和蛋白酶均表现为显著的抑制作用,且随着实验设置浓度的升高抑制作用加强,而20 mg/dm3和40 mg/dm3浓度组对纤维素酶表现出激活作用,其他两个浓度(10、80 mg/dm3)则表现为抑制作用.青蛤肝胰腺消化酶活性可作为Zn2+和Cd2+污染监测的一种生物标记物.
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