盐度变化对虹鳟和硬头鳟抗氧化酶活性的影响

本文研究了不同盐度驯化方式下虹鳟(Oncorhynchus mykiss,(99.44±0.26)g(简写为99 g))和两种规格硬头鳟(Oncorhynchus mykiss,(99.01±0.61)g(简写为99 g)和(394.50±1.16)g(简写为395 g))的血清抗氧化酶活性变化。实验设置4种盐度驯化方式:淡水对照组(T0组);从淡水直接过渡到盐度30(T30组);从淡水直接过渡至盐度14,然后以升盐速度2/d(T2组)和6/d(T6组)至盐度30。盐度驯化结果显示:99 g硬头鳟和虹鳟血清中超氧化物歧化酶(SOD)、丙二醛(MDA)和谷胱甘肽过氧化物酶(GSH-Px)活性均受盐度驯化方式、时间及其交互作用影响显著。T30组99 g虹鳟和99 g硬头鳟的SOD、GSH-Px和MDA活性在0.5、1、4、8、15和40 d这6个取样点均显著高于对照组(P<0.05)。盐度驯化40 d后,T2组99 g虹鳟SOD活性、GSH-Px活性和MDA含量与对照组无显著差异,99 g硬头鳟GSH-Px活性与对照组无显著差异,T6组99 g虹鳟和99 g硬头鳟的SOD和GSH-Px活性显著高于对照组。T2组395 g硬头鳟SOD活性、过氧化氢酶(CAT)活性和MDA含量与对照组相比无显著差异(P>0.05),而T6和T30组395 g硬头鳟血清中SOD活性、CAT活性、GSH-Px活性和MDA含量显著高于对照组(P<0.05)。研究结果表明,T2组渐变盐度方式更适合虹鳟和硬头鳟盐度驯化,395 g硬头鳟对盐度驯化的适应能力优于99 g硬头鳟。

Effects of Salinity Change on Antioxidant Enzyme Activities of Rainbow and Steelhead Trout(Oncorhynchus mykiss)

The aims of the study were to compare different salinity acclimation methods in rainbow trout(Oncorhynchus mykiss,(99.44±0.26)g(abbreviated as 99 g in the following text))and steelhead trout in two sizes(O.mykiss,(99.01±0.61)g(abbreviated as 99 g in the following text)and(394.50±1.16)g)(abbreviated as 395 g in the following text)by referring to the serum antioxidant enzyme activities.Fish were distributed to four groups and treated with different salinity acclimation methods,freshwater(T0),from freshwater to seawater(T30),from freshwater to salinity of 14,after 24 hours,increase salinity at a rate 2 d-1(T2)and 6 d-1(T6)to salinity of 30,respectively.(1)Two-way ANOVAs indicated that the acclimation methods and time have a significant effect on serum SOD,MDA,GSH-Px in 99 g rainbow trout and steelhead.(2)In T30 group,the activities of superoxide dismutase(SOD),glutathio-ne peroxidase(GSH-Px)and malondialdehyde(MDA)of 99 g rainbow trout and 99 g steelhead were significantly higher than those of control groups,in 0.5,1,4,8,15 and 40 d.At the end of experiment,the activities of SOD,GSH-Px and MDA in rainbow trout of T2 group have no significant difference from those of control,the activities of GSH-Px in steelhead of T2 group have no significant difference from that of control as well,but the activities of SOD,GSH-Px in 99 g rainbow trout and steelhead trout of T6 group were significantly higher than those of control.In the group of T2,the SOD,CAT and MDA activities of 395 g steelhead have no significant difference from that of control(P>0.05).However,in the groups of T6 and T30,the SOD,CAT and MDA activities of 395 g steelhead were significantly higher than those of control(P<0.05).The results indicated that the rainbow trout and steelhead trout have the better adaptability for acclimation method in T2 group.The adaptability of 395 g steelhead trout to salinity acclimation is better than 99 g steelhead trout.