重金属离子对凡纳滨对虾的致病机理研究

Pathogenetic Mechanism of Heavy Metal Ions on Litopenaeus vannamei

研究了重金属离子Cd2+、Pb2+、Cr3+对凡纳滨对虾血清SOD、CAT活性的影响。结果表明,低、中等浓度的Cd2+、Pb2+、Cr3+均对凡纳滨对虾血清SOD活性表现为较强的诱导作用。在一定的时间和较高浓度下,Cd2+、Pb2+、Cr3+均对凡纳滨对虾血清SOD、CAT活性表现出显著抑制作用,具有一定的时间、剂量效应关系。在较低的Cd2+、Pb2+、Cr3+浓度下,SOD、CAT活性明显高于对照,且随着各处理浓度的增加和时间的延长(72h),Cd2+、Pb2+、Cr3+对血清SOD、CAT活性表现出更加明显的抑制作用,即在低剂量、短时间内会导致酶活性提高;而在高剂量或长时间作用下,对虾SOD、CAT活性表现为抑制作用,且表现出2种金属离子对血清SOD、CAT活性的抑制作用比单一的金属离子抑制作用更加显著,显示出Cd2+、Pb2+、Cr3+复合污染具有明显协同作用。金属离子的胁迫下使SOD、CAT的活性比例失调,使对虾的生理代谢紊乱,加速对虾的衰老和死亡。

This paper studied the effects of Cd^2 ＋ , Pb^2 ＋ and Cr^3 ＋ on the superoxidc dismutase （SOD） , catalase （CAT） activity of Litopenaeus vannamei in serum. The results showed that the SOD and CAT activity were induced significantly under low - lying - moderate concentration of Cd^2 ＋ , Pb^2 ＋ and Cr^3 ＋ ions. The SOD and CAT activity was inhibited significantly under difinite time and upper concentration of Cd^2 ＋ , Pb^2 ＋ and Cr^3 ＋ ions, while there was an obvious dose - time response relationship. Low Cd^2 ＋ , Pb^2 ＋ and Cr^3 ＋ ion concentrations increased the activities of SOD and CAT activity significantly （P 〈 0.05） in postlarvae, the SOD and CAT activity was significantly inhibited with increased concentration and prolonged exposure of Cd^2 ＋ ,Pb^2 ＋ and Cr^3 ＋ ions, and that the effects of combined pollutant was heavier than those of single pollutant. The syn ergystic function of Cd^2 ＋ ,Pb^2 ＋ and Cr^3 ＋ ions was obvious, thus, the active proportion of SOD and CAT was maladjusted under intimidated metal ions, which braught physiological decompensation, conescenee and death.