悬浮物对四角蛤蜊生存和抗氧化酶活性的影响

Effects of suspended solid on the survival,growth,and antioxidant enzyme activities of Mactra veneriformis

为了了解悬浮物对四角蛤蜊的生存、生长和生理状况的影响,在实验模拟条件下,设置100mg·L-1(B组)、1000mg·L-1(C组)和10000mg·L-1(D组)3个悬浮物梯度作为实验组,以不添加悬浮物的处理作为对照组(A组),采用酶试剂盒方法,研究了不同悬浮物浓度对四角蛤蜊鳃丝、内脏团超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活力的影响。结果表明:悬浮物胁迫条件下四角蛤蜊会出现慢性毒性效应,对其生存和生长产生一定影响;100和1000mg·L-1鳃丝SOD活力会产生适应性诱导反应,而10000mg·L-1鳃丝SOD活力先被显著抑制后又被显著诱导;内脏团SOD活力未随时间和悬浮物浓度发生明显变化(P>0.05),悬浮物胁迫没有对内脏团SOD活力产生显著影响;1000和10000mg·L-1鳃丝CAT活力呈现诱导-正常-诱导的变化趋势,100mg·L-1鳃丝CAT活力在实验后期才被显著诱导(P<0.05);内脏团CAT活力未随时间和悬浮物浓度发生明显的变化;悬浮物胁迫对内脏团抗氧化酶系统没有产生显著诱导和影响,鳃丝抗氧化酶活力会对悬浮物胁迫做出快速应激诱导反应,其对悬浮物胁迫反应更加灵敏。

A laboratory simulation experiment was conducted to investigate the effects of suspended solid on the survival, growth, and physiology of Mactra veneriformis. The M. veneriformis individuals were exposed to different concentrations of suspended solid （0 mg＆middot;L-1 group A）, 100 mg＆middot;L-1 （group B）, 1000 mg＆middot;L-1 （group C）, and 10000 mg＆middot;L-1 （group D）, and the changes of the superoxide dismutase （SOD） and catalase （CAT） activities in the visceral mass and gill filament of M. veneriformis were investigated. Under the stress of suspended solid, M. veneriformis appeared chronic toxic effect, with the survival and growth being inhibited to some extent. The gill SOD activity of the M. veneriformis exposed to 100 and 1000 mg＆middot;L-1 of suspended solid produced an adaptive induced response, but that of the M. veneriformis exposed to 10000 mg＆middot;L-1 of suspended solid was significantly inhibited first and induced then, as compared to the control group. The visceral SOD activity had less change with time and suspended solid concentration （P〉0.05）. The gill CAT activity of the M. veneriformis exposed to 1000 and 10000 mg＆middot;L-1 of suspended solid was up-regulated first, returned to normal then, and increased again, while that of the M. veneriformis exposed to 100 mg＆middot;L-1 of suspended solid was only upregulated significantly during the later period of the experiment. The visceral CAT activity had less change with time and suspended solid concentration. These findings showed that the visceral mass antioxidant system was not activated under suspended solid stress, but the gill filament antioxidant enzyme activity responded quickly to the stress, suggesting that the gill filament antioxidant system was more sensitive to suspended solid.