Effect Of Acute Temperature Stress On Some Biochemical Markers Of Pampus Argenteus Juveniles

Water is the most important environment to fishes. As we all know,fishes are changes with water temperature, higher or lower water temperature will affect it’s health. Beside, if the abnormal temperature continue too long, it will also harm for the fish. So study the biochemical indicators reaction of the temperature stress have good to normal growth and fish migratory reproductive. Pampus argenteus have widely spread. It have reproductive characteristics of fish and fish bait, conduct P. argenteus against temperature stress response of the research will help to improve efficiency in aquaculture. At the same time, also can provide other fishes with theoretical reference.This paper used P. argenteus juveniles which had mean weight 18.8g and mean long 9.1cm. we set three experimental temperature groups, 22℃,27℃ and 32℃, the control group was 27℃, and each with three replicates.P. argenteus juveniles were randomly divided into each replicate, and reared in corresponding temperature for 48 h. We also set 4 time point（0h、12h、24h、32h） to get the experiment sample. 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 changes 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 between 24 h and 48 h. In contrast,there were significant（P<0.05） differences between 0h and 48 h in32℃ group, then it decreased slightly at 12 h and 24 h. The content of Malondialdehyde（MDA） decreased significantly（P<0.05） in 22℃ group,the minimum occured at 24 h and then maintened a stable level. While the32℃ group it decreased first, then reached the minimum at 12 h, and increased at last, but the content at 48 h 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 12 h, then decreased and returned to the initial level at 24 h,and finally keep stable. SOD in 32℃ group increased with the time,reached the maximum at 48 h. The control group changed as well, it first increased to the maximum level at 12 h, and then decreased to the initial level at 24 h, while at 48 h reached the maximum. CAT as well as T-AOC in22℃ group showed no significant changes, both showedno significant differences（P>0.05）. CAT in 32℃ group first decreased and then increased,in 12 h CAT the lower point, and in 48 h CAT the higher point.. Both CAT and T-AOC the control groupchanged（P<0.05） in different time, and both showed decreased trend. Meanwhil, T-AOC, GSH-PX and MDA in 32℃group showed decreasing trend, they all had significant differen（P<0.05）.The level of GSH-PX in 22℃ group decreased slightly first and then increased, the GSH-PX activities peaked at 48 h. The content of MDA in both 22℃ group and the control group changed with time, they both decreased first and increased at 24 h, then decreased at 48 h. However in immune indexes, the lysozyme（LZM） activity was unaffected, and no significant differences（P>0.05） was observed. Ig M both in 22℃ group and32℃ group had significant different（P<0.05）. Under the same time,different experimental groups also had significant differences（P<0.05）. In liver, T-AOC 32℃ group at 48 h had significant differences（P<0.05） when compared with control group. The content of MDA had significant different（P<0.05） both in experimental group and control group with time changed.While SOD, CAT and GSH-PX activity changed in the same time with all the experimental group and control group（P>0.05）. In serum, LZM experimental group and control group in the same period no significant changes were observed（P>0.05）. Other antioxidant enzyme and immune indexes, both experimental group and control group in the same time had significant differences（P<0.05）.In gut, the activities of pepsin and trypsin in 22℃ group had no significant changes observed（P >0.05）, amylase activitiy had decreased trend, in contrast, the activities of lipase had increased trend（P<0.05）.The lipase, pepsin as well as trypsin activities changed similarly in 32℃group, they all had significant increased（P<0.05）. While amylase had increased first and then decreased（P<0.05）. The changes of serum biochemical indexs as follows, the content of glucose（GLU）, lactic acid（LD）, cortisol（COR） in 22℃ group had significant changes observed（P<0.05）, they were significantly increased, triglyceride（TG） as well as creatinine（CREA） were decreased first and then increased, at last decreased（P<0.05）. At the same time, the content of total serum protein（TP）had decreased first and then increased（P<0.05）.In 32℃ group the content of TP and TG had decreased trend, GLU had no significant changes were observed（P >0.05）,LD and COR had opposite trend, the former had decreased first and then increased, while the later had increased first and then decreased（P<0.05）. The content of CREA had increased all the time.In the meantime, different experimental temperature groups in gut and serum had significantly changes. GPT in serum in two experimental groups changed in a opposite manner; GOT in liver in two experimental groups changed in a different way; in the two experimental groups, AKP varied in a opposite manner, but ACP changed in the same way; LDH in 22 ℃ groupchanged in a wave-like manner（P<0.05）; in 22 ℃ group, Na⁺, K⁺, Cl^- and Ca²⁺ concentrations in the three groups changed in different ways; the activity of Na⁺/K⁺-ATP in gill in 32 ℃ group decreased; Na⁺/K⁺-ATP activity in kidney in 22 ℃ group increased first and then decreased（P<0.05）; in two experimental groups, Ca²⁺/Mg²⁺-ATP activities in gill and kidney varied in a opposite manner（P<0.05）.The results indicate that acute temperature stress have injured the liver of P. argenteus juveniles, and have hegative effect on P. argenteus juveniles digestive system as well as the excretory system, and affected the normal metabolism of P.argenteus juveniles significantly, suggesting that the acute temperature stress should be avoid in the process of breeding in order to create a good growth environment for P.argenteus juveniles.