急性温度胁迫对银鲳幼鱼抗氧化和免疫指标的影响

摘要

将银鲳（Pampus argenteus）幼鱼分别放置在22℃、27℃（对照组）和32℃的不同水温梯度下胁迫48 h，研究不同温度、不同时间（0、12、24、48 h）下银鲳幼鱼肝脏和血清中的抗氧化酶指标和免疫指标活力的变化。结果表明：肝脏中，超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活力22℃试验组变化基本一致，均呈现先升后降的趋势；谷胱甘肽过氧化物酶（GSH-PX）仅在22℃试验组出现显著波动（P＜0．05），其余组变化不显著（P＞0．05）；总抗氧化能力（T-AOC）22℃试验组在24 h和48 h差异显著（P＜0．05），32℃试验组0 h和48 h差异显著（P＜0．05）；丙二醛（MDA）22℃试验组随着时间的延长含量显著下降，24 h下降到最低值，随后维持最低值，32℃试验组MDA含量则随时间的延长呈现先下降后上升的趋势，对照组也出现了显著性变化（P＜0．05）。血清中，SOD 22℃试验组的活力呈现先升高后降低的趋势，32℃试验组则随着时间的延长含量直线上升，对照组也出现了波动；CAT和T-AOC 22℃试验组均变化不显著（P＞0．05），CAT 32℃试验组呈现先降低后升高的趋势，T-AOC 32℃试验组显著下降，对照组CAT和T－AOC都出现波动；GSH-PX和MDA 32℃试验组出现下降趋势，且差异显著（P＜0．05），GSH-PX 22℃试验组含量随时间延长呈现先降低后升高的趋势，MDA 22℃试验组和对照组都出现波动现象。免疫指标中，溶菌酶（LZM）活力的变化不显著（P＞0．05）；免疫球蛋白M（Ig M）各试验组活力均呈现显著性变化（P＜0．05）。不同温度组之间在同一时间也会出现显著性差异（P＜0．05）。在肝脏中，T-AOC 32℃试验组在48 h与其余两组差异显著（P＜0．05）；MDA除起始时间0 h外，其余时间段不同温度组间均出现显著性差异。而SOD、CAT、GSH-PX则不同温度组在同一时间内没有显著性差异（P＞0．05）；血清中，除了免疫指标中的LZM不同温度组在同一时间内没有显著性差异之外，其余各项指标均在同一时间段不同温度组之间出现显著性差异（P＜0．05）。实验结果表明，急性温度胁迫对银鲳幼鱼的肝脏造成了一定的损伤，并对其抗氧化能力和免疫应答反应产生了一定的影响，因此，在实际苗种生产和工厂化养殖过程中，应尽量避免急性温度变化对银鲳幼鱼产生的应激反应。%To understand the effect of temperature on antioxidant enzyme activities and immune indexes in the liver and serum of Pampus argenteus juveniles,we set three experimental temperature groups (22℃,the control group 27℃,32℃),and each with three replicates.P.argenteus juveniles were randomly divided into each replicate,and reared in corresponding temperature for 48h.The results of indexes in the liver suggested that the superoxide dismutase (SOD)and catalase (CAT)activities in 22℃ group changed similarly,both increased first and then decreased.No significant change was observed in glutathione peroxidase(GSH-PX) activity(P>0.05)except 22℃group,and the activity of GSH-PX in 22℃group decreased first and returned to the initial level,and then fell down.Total antioxidant capacity (T-AOC)in 22℃ group was significantly (P<0.05)different at 24h and 48h.In contrast,there were significant (P<0.05)differences between 0h and 48h in 32℃ group,then it decreased slightly at 12h and 24h.The content of Malondialdehyde (MDA) decreased significantly (P<0.05)in 22℃ group,the minimum occured at 24h and then remained a stable level.While in the 32℃ group it decreased first,then reached the minimum at 12h,and increased at last, but the content at 48h was lower than the initial level,and the control group also changed significantly (P<0.05 ).The results in serum showed that the activities of SOD in 22℃ group increased first,reached the maximum at 12h,then decreased and returned to the initial level at 24h,and finally remained stable.SOD in 32℃ group increased with the time,reached the maximum at 48h.The control group changed as well,it first increased to the maximum at 12h,and then decreased to the initial level at 24h,while reached the maximum at 48h.CAT as well as T-AOC in 22℃ group showed no significant change,both showed no significant difference(P>0.05).CAT in 32℃group first decreased and then increased,CAT reached the lower point at 12h,and the higher point at 48h.Both CAT and T-AOC in the control group changed(P<0.05)in different time,and both showed decreasing trend.Meanwhile,T-AOC,GSH-PX and MDA in 32℃ group showed decreasing trend,they all had significant differences (P <0.05 ).The level of GSH-PX in 22℃ group decreased slightly first and then increased,the GSH-PX activities peaked at 48h.The content of MDA in both 22℃ group and the control group changed with time,they both decreased first and increased at 24h,then decreased at 48h.However in immune indexes,the lysozyme (LZM) activity was unaffected,and no significant difference (P>0.05 )was observed.Ig M both in 22℃ group and 32℃ group had significant differences(P<0.05).At the same time,different experimental groups also had significant differences(P<0.05).In liver,T-AOC in 32℃group at 48h showed significant differences(P<0.05)when compared with the control group.The content of MDA had significant differences (P<0.05)both in experimental group and control group.While SOD,CAT and GSH-PX activity changed (P>0.05 ).In serum in the same period, LZM experimental group and the control group showed no significant change(P>0.05).For other antioxidant enzyme and immune indexes,all groups in the same time showed significant differences (P<0.05 ).The results indicate that acute temperature stress can injure the liver of P.argenteus juveniles,and have negative effect on their antioxidant activites and the immune indexes,thus in the process of practical production and industrial aquaculture,acute temperature stress should be avoided in P.argenteus juveniles.