急性温度胁迫对乌苏里拟鲿稚鱼抗氧化和非特异免疫功能的影响

Effects of Acute Temperature Stress on Antioxidant Enzyme Activities and Non-Specific Immune Function in Juvenile Bullhead Fish Pseudobagrus ussuriensis

为探究水温骤变对乌苏里拟鲿稚鱼抗氧化和非特异免疫指标的影响,在26℃的水体中挑选300尾体质量为(2.3±0.3)g的稚鱼快速置于18、26℃(对照组)和33℃水体中胁迫24 h,随后置于26℃水体中恢复48 h,分别于胁迫期(0、3、6、12、24 h)和恢复期(3、6、12、24、48 h)进行取样检测各项指标。试验结果显示:胁迫期内,各试验组超氧化物歧化酶和过氧化氢酶活性均呈不断上升趋势并显著高于对照组(P<0.05);丙二醛含量在6 h和24 h均显著高于对照组(P<0.05);谷胱甘肽含量则受到抑制并显著低于对照组(P<0.05)。至恢复期结束,各试验组超氧化物歧化酶活性和谷胱甘肽、丙二醛含量均与对照组无显著差异(P>0.05),其中33℃组过氧化氢酶活性显著高于对照组(P<0.05)。胁迫期内,各试验组谷丙转氨酶和谷草转氨酶活性均呈先升后降的趋势,18℃和33℃组谷丙转氨酶活性均显著高于对照组(P<0.05);温度骤变迫使18℃组溶菌酶活性显著下降(P<0.05),33℃组溶菌酶活性显著升高(P<0.05),至恢复期结束,各试验组谷草转氨酶和溶菌酶活性均恢复至对照组水平,仅33℃组谷丙转氨酶活性显著高于对照组(P<0.05)。试验结果表明,急性温度胁迫对乌苏里拟鲿稚鱼抗氧化和非特异性免疫功能产生了显著的影响,高温胁迫对乌苏里拟鲿幼鱼免疫机能造成了不可逆的损伤,建议日常养殖应密切关注水温变化,避免温度骤变对乌苏里拟鲿稚鱼造成损伤。

In order to explore the effects of sharp change in water temperature on antioxidant and non-specific immune functions of juvenile bullhead fish Pseudobagrus ussuriensis,bullhead juveniles with body weight of(2.3±0.3) g were rapidly exposed to 18 ℃,26 ℃(control group) and 33 ℃ water stress for 24 h from 26 ℃ water in a fibergrass breeding bucket with radius of 1 m and height of 1 m,and then subjected to recovery at 26 ℃ water for 48 h.The activities of superoxide dismutase(SOD),catalase(CAT),lysozyme(LZM),alanine aminotransferase(ATF),and aspartate aminotransferase(ASF),and contents of glutathione(GSH),malondialdehyde(MAD)and total protein were detected in the stress period of 0,3,6,12,and 24 h and recovery period of 3,6,12,and 24 h in the whole fish samples.The results showed that the activities of SOD and CAT were continuously increased during the stress period in the experimental groups,significantly higher than those in the control group(P<0.05).There was significantly higher content of malondialdehyde in the experimental groups than that in the control group at 6 and 24 h(P<0.05),while GSH content was inhibited,significantly lower than in the control group(P<0.05).At the end of the recovery period,SOD and GSH activities and MAD contents were not found to be significantly different in all experimental groups from those in control group(P>0.05),with significantly higher CAT activity in 33 ℃ group than those in control group(P<0.05).During the stress period,the activities of ATF and ASF were shown to be increased first and then decreased in all experimental groups,with significantly higher ATF activity in 18 ℃ and 33 ℃ groups than those in control group(P<0.05).The acute temperature change led to significantly decrease the LZM activity in the 18 ℃ group(P<0.05),and significantly increase the LZM activity in the 33 ℃ group(P<0.05).At the end of the recovery period,the ASF and LZM activities recovered to the control level in all experimental groups.There was significantly higher ASF activity in 33 ℃ group than that in control group(P<0.05).It was found that the acute temperature stress led to significant impact on the antioxidant enzymes and non-specific immune function of the juvenile Pseudobagrus ussuriensis,in which the high temperature stress caused irreversible damage to the immune function.It is recommended to pay more attention to changes in water temperature in daily aquaculture to avoid sharp temperature changes causing damage to the juvenile fish of P.ussuriensis.