温度胁迫对大鳞副泥鳅抗氧化与非特异性免疫指标的影响

为研究大鳞副泥鳅(Paramisgurnus dabryanus)对温度胁迫的适应能力,开展了温度胁迫与恢复实验。设置对照组(22℃)、高温组(29℃)、降温组(15℃)与低温组(8℃)4个处理,在胁迫期的第1、2、4、8、12h与恢复期第4、8、12、24h取肝脏,测定其超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、溶菌酶(LZM)、碱性磷酸酶(AKP)活力和丙二醛(MDA)、血清谷丙转氨酶(ALT)、谷草转氨酶(AST)含量。结果显示,胁迫期内肝脏SOD和CAT活力均在温度骤变的影响下受到抑制,显著低于对照组水平(P0.05),MDA含量则显著升高(P0.05);恢复期内各实验组SOD和CAT活力均逐渐升高,MDA含量逐渐降低,至恢复期结束时,对照组与各实验组间无显著差异(P0.05)。温度骤变条件下,各实验组肝脏LZM与AKP活力显著降低(P0.05),恢复期内高温组LZM与AKP活力无明显变化,降温组与低温组LZM与AKP活力则逐渐升高,至恢复期结束时与对照组无显著差异(P0.05)。温度胁迫显著升高血清中AST与ALT含量(P0.05),恢复期内各实验组AST与ALT含量均呈下降趋势,至恢复期结束时,除高温组ALT含量外均降至对照组水平。研究表明,温度胁迫显著降低大鳞副泥鳅SOD、CAT、LZM与AKP活力,MDA与血清转氨酶AST、ALT含量升高,其中,高温胁迫会对大鳞副泥鳅非特异性免疫机能造成不可逆破坏,其他抑制均为可恢复的。

Effects of Temperature Stress on the Partial Antioxidative and Non-Specific Immunity Indices of Paramisgurnus dabryanus

To investigate the effect of temperature stress on the antioxidative and nonspecific immune systems of Paramisgurnus dabryanus under transportation conditions, the liver activities of superoxide dismutase (SOD), catalase (CAT), lysozyme (LZM), and alkaline phosphatase (AKP) as well as the malondialdehyde (MDA) content, and the serum content of alanine aminotransferase (ALT) and aspartate transaminase (AST) were determined. The following results were obtained: The activities of SOD and CAT in the liver were significantly lower (P<0.05), and the MDA content was significantly higher (P<0.05), than the levels in the control group. During the recovery period, the activities of the two antioxidative enzymes in each experimental group increased gradually and the MDA content decreased gradually. There was no significant difference between the control group and each experimental group at the end of the recovery period (P>0.05). The liver activities of LZM and AKP in each experimental group were significantly lower than that of the control group (P<0.05) at the end of the stress period. During the recovery period, the LZM and AKP activities remained at the stress level at the end of the stress period, whereas their activities in the other experimental groups increased gradually and there was no significant difference (P>0.05) compared with the control group at the end of the recovery period. The changes in serum AST and ALT content during the stress period were significantly higher than those in the control group (P<0.05). During the recovery period, the AST and ALT content showed a downward trend until the end of the recovery period. In addition, the ALT content in the high-temperature group dropped to the control group level. The results showed that temperature stress significantly inhibited the antioxidative capacity and nonspecific immunity of P. dabryanus, where the high-temperature stress caused irreversible damage to the nonspecific immune function of the fish, whereas the other inhibition effects were recoverable.