温度突变对凡纳滨对虾己糖激酶和丙酮酸激酶活力以及热休克蛋白表达的影响

Effects of acute temperature fluctuation on HK and PK activity,HSP70 relative content in Litopenaeus vannamei

研究了水温从17℃突变为27℃对凡纳滨对虾(Litopenaeus vannamei)稚虾己糖激酶(HK)和丙酮酸激酶(PK)活力及热休克蛋白(HSP70)表达的影响。主要结果如下:(1)温度突变后,凡纳滨对虾肝胰脏中己糖激酶活力逐渐增大,温度突变后3h达到最高,是温度突变前的2.54倍(P<0.05)。随后,对虾己糖激酶的活力逐渐下降,72h酶活力基本恢复到温度突变前的水平。(2)温度突变后1h,凡纳滨对虾丙酮酸激酶的活力降到最低,随后逐渐增大;6h达到最高,随后对虾丙酮酸激酶的活力逐渐下降并在72h恢复到温度突变前的水平。(3)温度突变0.5h后,凡纳滨对虾肌肉中HSP70的表达量迅速升高,1h达到最高,与温度突变前差异显著(P<0.05),随后下降到比温度突变前稍高的水平并趋于稳定。实验结果表明,温度突然升高后,己糖激酶活力升高,随后恢复到起始水平;糖酵解过程先受到抑制,之后得以恢复;温度突变可导致凡纳滨对虾对环境的抗逆性提高。

Effects of acute temperature fluctuation from 17 ℃ to 27℃ on the enzyme activities of hexokinase （HK）, pyruvate kinase （PK） and the relative content of HSP70 in juvenile Litopenaeus vannamei were investigated. The main results were as follows： （1） The HK activity increased gradually after acute temperature fluctuation, and reached the maximum level after 3 h, which was 2.54 folds higher than that before temperature fluctuation （P〈0.05）, then decreased to the level of the control group; （2） the PK activity decreased gradually after acute temperature fluctuation, and reached the minimum level after 1 h. After this, PK activity began to increase and reached the maximum level after 6 h. Then, the PK activity decreased to the value which was the same as the activity before ＂temperature fluctuation; （3） The HSP70 relative content elevated rapidly after temperature fluctuation, and reached the maximum level after 1 h （P〈0.05）, then decreased to a steady level. However, the value of the steady level was still significantly higher than the basic value of HSP70 relative content before temperature fluctuation （P〈0.05）. These results indicate that glucose metabolism is limited firstly, then recovered, and the ability to adapt to challenging environment is en- hanced in L. Vannamei after temperature fluctuation.