| 摘要: |
| 以鲻鱼(Mugil cephalus)幼鱼为研究对象, 研究低浓度氨氮长时间胁迫对组织细胞免疫指标和遗传物质代谢的影响。实验分0.35、0.7、1.5 和3 mg/L 氨氮处理组, 分别于0、5、10、15、20d取样并进行相关指标测定。结果显示: 肝脏和鳃丝的丙二醛(MDA)含量表现出先上升后下降的趋势,MDA 活性与氨氮浓度呈一定的正相关。氨氮对MDA 的影响具有不同组织和不同时序的选择性。不同浓度氨氮胁迫下, 鳃丝和肝脏Na+-K+-ATP 活性均呈现先升高后降低, 并随着时间的增加逐渐趋于稳定。Na+-K+-ATP 活性与氨氮浓度呈一定的负相关性, 尤其是3 mg/L 处理组与对照组差异性显著(P < 0.05)。在氨氮浓度0.7 mg/L 和1.5 mg/L 时, 肌肉中RNA/DNA 均表现出不同程度的增加, 各浓度组与对照组差异不显著; 而高浓度(3 mg/L)比值基本无变化。肝脏和鳃丝的Na+-K+-ATP 酶的mRNA表达量, 在氨氮胁迫第5d 时检测到达最高, 随后表达量缓慢回落, 实验20d 除3 mg/L 处理组表达量仍高于对照组水平外, 其他处理组均降至对照组水平。Na+-K+-ATP 酶的表达水平变化趋势与Na+-K+-ATP 活性基本一致。结果表明, 在一定浓度的氨氮长时间胁迫作用下, 抗氧化免疫系统和肌肉中的核酸代谢受到了一定的影响。 |
| 关键词: 氨氮 鲻鱼幼鱼 丙二醛(MDA) Na+-K+-ATP RNA/DNA 比值 mRNA 表达量 |
| DOI：10.11693/hyhz20130300010 |
| 分类号: |
| 基金项目:国家重点基础研究发展计划(973 项目), G2010CB429005 号 |
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| EFFECT OF AMMONIA STRESS ON IMMUNITY INDICATORS OF JUVENILE MUGIL CEPHALUS |
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East China Sea Fisheries Research Institute Chinese Academy of Fishery Sciences,East China Sea Fisheries Research Institute Chinese Academy of Fishery Sciences,East China Sea Fisheries Research Institute Chinese Academy of Fishery Sciences,ＳＨＡＮＧＨＡＩ ＯＣＥＡＮＯＬＩＧＹ ＵＮＩＶＥＲＣＩＴＹ,ＳＨＡＮＧＨＡＩ ＯＣＥＡＮＯＬＩＧＹ ＵＮＩＶＥＲＳＣＩＴＹ
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| Abstract: |
| To evaluate the effects of ammonia on immunity and metabolism of juvenile Mugil cephalus, their tissues were exposed to different ammonia levels: 0.35 (natural seawater or control), 0.7, 1.5, and 3.0 mg/L for 20days and sampled randomly on Days 0, 5, 10, 15, and 20. The results indicate that as the exposure time lasted, malondialdehyde (MDA) content in liver and gill decreased after an initial increase. Ammonia concentration was positively correlated to the MDA content significantly. The relationship of ammonia stress and MDA content in liver and gill is somewhat tissue and
sequence specific. The activity of Na+-K+-ATP in liver and gill decreased after an initial increase with exposure time lasted; and ammonia concentration showed significant negative correlation to Na+-K+-ATP activity. The ratio of RNA/DNA in muscle slightly increased but lower than the control except at 3.0 mg/L (P > 0.05) treatment group. The mRNA expression of Na+-K+-ATPase increased till Day 5, then resumed to the level same as control after Day 20 except for 3.0 mg/L group staying at higher level than the control’s. The variation trends of mRNA expression of Na+-K+-ATPase were largely the same to the activity of Na+-K+-ATP. The results indicate that ammonia-nitrogen stress in a certain concentration for a long time could disturb the antioxidant immune system and nucleic acid metabolism in muscle of juvenile Mugil cephalus. |
| Key words: sammonia exposure juvenile Mugil cephalus malondialdehyde(MDA) Na+-K+-ATP ratio of RNA/DNA mRNA expression |
