Effects of chronic ammonia exposure on ammonia metabolism and excretion in marine medaka Oryzias melastigma
Effects of chronic ammonia exposure on ammonia metabolism and excretion in marine medaka Oryzias melastigma
复制标题
慢性氨暴露对海洋青鳉氨代谢和排泄的影响
DOI：
10.1016/j.fsi.2017.04.010
复制
发表时间：
2017-06-01
影响因子：
4.7
通讯作者：
Zhang, Li
中科院分区：
文献类型：
--
作者：
Gao, Na;Zhu, Limei;Zhang, Li
氨对水生生物有很高的毒性，但目前尚不清楚是排氨还是将氨代谢成毒性较低的化合物是海水鱼类对抗慢性氨暴露的主要解毒策略。在本研究中，我们研究了慢性氨暴露对海洋青海稻曲霉体内氨的代谢和排泄的影响。将这些鱼暴露在0、0.1、0.3、0.6和1.1mmolL(-1)NH4Cl添加的海水中8周。L(-1)NH4Cl0.3~1.1mmolNH4Cl0.3~1.1mmolNH4Cl0.3~1.1 mmolNH4Cl0.3~1.1 mmolNH4Cl0.3~1.1 mmolNH4Cl0.3~1.1mmol.然而，这种鱼可以采取解毒氨的策略。组织氨(T-AMM)在暴露2周后显著高于0和0.1 mmol L(-1)NH_4Cl处理组，但随着暴露时间的延长，T-AMM逐渐恢复，8周后达到对照水平。随着环境氨浓度的增加，氨基酸分解率降低，总氨产量降低。在0~0.6 mmoL L(-1)NH4Cl处理中，大部分代谢产物的浓度保持不变，而在1.1 mmolL(-1)NH4Cl处理中，5种氨基酸和3种与能量代谢相关的代谢物的浓度降低。在环境氨中，J(Amm)在0~0.6mmol.L(-1)范围内稳步增加，当环境氨浓度增加到1.1mmolL(-1)时，J(Amm)略有下降。总体而言，海洋青竹通过减少氨的产生和增加氨的排泄来调节组织中的T-AMM，从而应对亚致死性的氨环境。(C)2017爱思唯尔有限公司。保留所有权利。
Ammonia is highly toxic to aquatic organisms, but whether ammonia excretion or ammonia metabolism to less toxic compounds is the major strategy for detoxification in marine fish against chronic ammonia exposure is unclear to date. In this study, we investigated the metabolism and excretion of ammonia in marine medaka Oryzias melastigma during chronic ammonia exposure. The fish were exposed to 0, 0.1, 0.3, 0.6, and 1.1 mmol l(-1) NH4Cl spiked seawater for 8 weeks. Exposure of 0.3-1.1 mmol l(-1) NH4Cl had deleterious effects on the fish, including significant reductions in growth, feed intake, and total protein content. However, the fish could take strategies to detoxify ammonia. The tissue ammonia (T-Amm) in the 0.3-1.1 mmol l(-1) NH4Cl treatments was significantly higher than those in the 0 and 0.1 mmol l(-1) NH4Cl treatments after 2 weeks of exposure, but it recovered with prolonged exposure time, ultimately reaching the control level after 8 weeks. The amino acid catabolic rate decreased to reduce the gross ammonia production with the increasing ambient ammonia concentration. The concentrations of most metabolites remained constant in the 0-0.6 mmol l(-1) NH4Cl treatments, whereas 5 amino acids and 3 energy metabolism-related metabolites decreased in the 1.1 mmol l(-1) NH4Cl treatment. J(Amm) steadily increased in ambient ammonia from 0 to 0.6 mmol l(-1) and slightly decreased when the ambient ammonia concentration increased to 1.1 mmol l(-1). Overall, marine medaka cope with sublethal ammonia environment by regulating the tissue T-Amm via reducing the ammonia production and increasing ammonia excretion. (C) 2017 Elsevier Ltd. All rights reserved.