氨氮胁迫对凡纳滨对虾肠道免疫相关指标的影响

为研究急性氨氮胁迫对凡纳滨对虾(Litopenaeus vannamei)肠道免疫功能的影响,将对虾暴露于氨氮浓度为20 mg·L^-1的海水中72 h,测定了不同时间点肠道中抗病原感染指标如酸性磷酸酶(ACP)、碱性磷酸酶(ALP)、溶菌酶(Lys)、酚氧化酶原(proPO)以及抗氧化功能指标如总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)、热休克蛋白70(HSP70)、热休克蛋白90(HSP90)等变化。结果显示,与对照组相比,氨氮胁迫后:1)ACP和ALP活性均于6 h显著升高(P<0.05),随后于48~72 h显著低于对照组(P<0.05);Lys活性于24 h显著升高至最大值(P<0.05),随后于72 h显著低于对照组(P<0.05)。2)T-AOC和SOD活性均于6 h和12 h显著高于对照组(P<0.05),随后于48 h和72 h显著降低(P<0.05)。3)HSP70基因表达水平于24 h显著升高至最大值,随后虽有降低,但仍显著高于对照组(P<0.05);HSP90和proPO基因表达水平均于12 h显著升高至最大值(P<0.05),随后于72 h降低至对照组水平(P>0.05)。研究表明,急性氨氮胁迫对凡纳滨对虾肠道免疫功能相关指标影响显著,对其肠道免疫防御系统有明显的损伤作用。

Response of non-specific immune related indexes in intestines of Litopenaeus vannamei under ammonia-N stress

This study evaluated the effects of acute ammonia-N stress on immune response in intestines of Pacific white shrimp Litopenaeus vannamei.Immune enzyme activities and gene expression level were detected in intestines after exposing to 20.0 mg·L^-1 ammonia-N stress for 72 h.Compared with the control group,acid phosphatase(ACP)and alkaline phosphatase(ALP)increased at 6 h(P<0.05),and then decreased to a lower level at 48 h and 72 h(P<0.05).Lysozyme(Lys)activity increased to the maximum at 24 h(P<0.05),and then reduced to be lower than the control at 72 h(P<0.05).Total antioxidant capacity(T-AOC)and superoxide dismutase(SOD)activity increased at 6 h and 12 h,and then decreased at 48 h and 72 h(P<0.05).The relative mRNA expression level of heat shock protein 70(HSP70)gene increased to the maximum at 24 h,and kept at a higher level during the whole experiment(P<0.05).The relative mRNA expression level of HSP90 and prophenoloxidase(proPO)gene increased and reached the maximum at 12 h(P<0.05),and then decreased to the control level at 72 h(P>0.05).These results revealed that acute ammonia-N stress could induce immune response in intestines of L.vannamei via confusion of immune enzyme activities and gene expression level.