低温应激对拟穴青蟹不同形态群体抗氧化酶活性的影响

The Effect of Low Temperature Shock on Antioxidant Enzyme Activity of Different Morphological Populations of Scylla Paramamosain

通过低温应激比较拟穴青蟹螯足腕节外缘只有1根刺(Sp)和螯足腕节外缘有2根刺(Sr)的群体其鳃超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性的变化,获得的主要结果有:温度从25℃骤降至15℃,应激第3 h Sp群体鳃的SOD和CAT活性显著上升,应激第12和24 h两种酶活性都恢复至起始水平;在24 h的应激过程中,Sr群体鳃的SOD活性表现为先下降,后恢复至起始水平,CAT活性在整个应激过程中保持较高水平。温度从25℃骤降至11℃,应激第1 h Sp群体鳃的SOD和CAT活性显著上升,之后CAT活性始终高于第0 h,SOD活性在第12 h低于第0 h,第24 h又上升至第0 h的水平;Sr群体鳃的SOD活性在第1 h下降,第6 h快速上升,第12和24 h又下降至第1 h的水平,CAT活性在整个应激过程中变化较小。温度骤降18℃,在整个应激过程中,Sp群体鳃SOD和CAT活性的变化较小,Sr群体鳃的SOD和CAT活性受到显著抑制,在第24 h两种酶的活性降至最低。实验结果表明,在一定范围的低温应激下Sp群体鳃的抗氧化酶活性有所提高,剧烈的低温应激则导致Sr群体鳃的抗氧化酶活性受到抑制,由此可看出拟穴青蟹Sp群体比Sr群体更能耐受环境温度的急剧降低。

Through low temperature shock, this study compared superoxide dismutase （SOD） and catalase （CAT） activities in gill between the population of scylla paramamosain with one spine on the outer margin of the carpus in both chelipeds （Sp） and the other population with no spine on the outer margin of the carpus in either chelipeds （Sr）. From 25℃ rapidly reduced to 15℃, SOD and CAT activities of Sp significantly increased at the 3th hour of shock, and the two kinds of enzyme activities were restored to the initial level at the 12th and 24th hours of shock. During the twenty-four hours of shock, SOD activity in the gill of Sr initially decreased and then returned to the starting level, and CAT activity maintained a high level during the shock process. From 25℃rapidly reduced to 11℃, SOD and CAT activities in the gill of Sp both significantly increased at the lth hour of shock, then CAT activity maintained a high level at the other time points, but SOD activity at the 12,h hour was lower than that at the zero hour, and SOD activity at the 24th hour rose to the level at the zero hour. SOD activity in the gill of Sr significantly decreased at the lth hour of shock, and quickly increased at the 6th hour of shock, then returned to starting level at the 24th hour of shock. For CAT activity in the gill of Sr, the enzyme activity varied little during the shock process. From 25℃ rapidly reduced to 7℃, SOD and CAT activities in the gill of Sp varied little during the shock process, but SOD and CAT activities in the gill of Sr were obviously inhibited, especially at the 24th hour of shock. Overall, antioxidant enzyme activity in the gill of Sp was improved under a certain range of low temperature shock, but antioxidant enzyme activity in the gill of Sp was depressed after dramatical temperature decrease, which illustrated that Sp adapted better to rapid environmental temperature decrease than Sr.