Pb2+胁迫对草鱼过氧化氢酶和髓过氧化物酶的影响

摘要:铅及其化合物是水体中常见的重金属污染源,会对鱼类产生巨大的危害.为了研究铅及其化合物对草鱼血清的抗氧化能力的影响,本文分别用不同浓度的Pb2+溶液处理草鱼,探究草鱼血清中过氧化氢(H2O2)含量的变化以及与草鱼血清中过氧化氢酶(CAT)和髓过氧化物酶(MPO)活性的关系.结果表明,低浓度的Pb2+对草鱼血清中H2O2具有刺激作用,其含量随着Pb2+浓度的增加而升高,当Pb2浓度为0.25 mmol·L-1时达到最高值.与H2O2含量变化相反,草鱼血清中CAT和MPO的活性随Pb2+浓度的增高而降低.在0.01mmol·L-1Pb2+作用时,CAT在48h时活力最强,以后逐渐衰减；而MPO的活力普遍增强,在72h最强,并在96h后维持较强的活力.在高浓度(0.25 mmol· L-1)Pb2+作用时,CAT和MPO活性是受抑制的,其中CAT在48 h最低,然后酶活逐渐恢复,96h时达到正常水平；MPO活力一直没有恢复,在72 h时活力最低.

Effects of Pb2+ on catalase and mMyeloperoxidase in serum of cenopharyngodon idellus (grass carp)

Lead and its compounds are common heavy metal pollutions in water,which are harmful to fish.To study the influence of lead and its compounds on the resistance ability of blood serums oxidation of grass carp,we used Pb2+ solution with different concentrations to treat grass carp.The changes of hydrogen peroxide(H2O2) content,the activities of catalase(CAT) and myeloperoxidase(MPO) in the grass carp blood serum had been investigated.The results indicated that Pb2+ in the lower concentration range would induce the rise of H2O2 in grass carp serum and the H2O2 content was at higher levels with the increasing of the concentration of Pb2+.Particularly,H2O2 content reached the maximum when the concentration of Pb2+ was in 0.25mmol·L-1,The activities of CAT and MPO increased weakly induced by Pb2+ in 0.01mmol·L-1 concentration,and they both reduced gradually with the increase of concentration of Pb2+.Thereinto,in the 0.01 mmol·L-1group,the activity of CAT reached the peak at 48h,then reduced gradually.The activity of MPO was enhanced generally and reached the peak at 72 h and maintained at a high level after 96 h.The activities of CAT and MPO were inhibited by high concentration of 0.25 mmol·L-1 Pb2+ treated.The inhibition of CAT was the highest at 48h then it recovered to normal level at 96 h.The activity of MPO had not recovered.The lowest activity presented at 72 h.