【摘要】 在温度为（25±1）℃、p H为8. 0±0. 5条件下采用生物毒性实验方法研究了氨氮对罗氏沼虾（Macrobrachium rosenbergii）幼虾半致死浓度,并设置0、0. 43、0. 64、0. 85、1. 06 mg·L^-15个浓度研究氨氮胁迫48 h及恢复48 h对罗氏沼虾非特异性免疫的影响。结果显示:非离子氨对罗氏沼虾幼虾24、48、72、96 h半致死浓度分别为4. 25、2. 35、1. 86、1. 54 mg·L^-1,安全浓度为0. 154 mg·L^-1。氨氮胁迫48 h,罗氏沼虾SOD活性显著升高（P <0. 05）,而CAT和GSH-Px活性变化不显著（P> 0. 05）; 0. 43、0. 64、1. 06 mg·L^-1氨氮胁迫组罗氏沼虾MDA含量显著高于对照组（P <0. 05）。氨氮胁迫后恢复48 h,各组SOD活性均较胁迫时显著下降（P <0. 05）,但除0. 85 mg·L^-1组外的其它试验组仍显著高于对照组（P <0. 05）; 0. 85、1. 06 mg·L^-1组CAT活性较胁迫状态显著下降（P <0. 05）;试验组与对照组MDA含量无显著差异（P> 0. 05）。结果表明,低浓度氨氮短期胁迫对罗氏沼虾造成的氧化损伤在解除胁迫后可修复,但肌肉仍处于应激状态。更多还原

【Abstract】 Current study explored the influence of ammonia-N stress and post-exposure recovery on the nonspecific immunity of M. rosenbergii. The prawns were exposed to different concentrations of ammonia( 0,0. 43,0. 64,0. 85,1. 06 mg·L^-1) for 48 h,and then post-exposure recovery for 48 h was analyzed. The activities of superoxide dismutase（ SOD）, catalase（ CAT）, glutathione peroxidase（ GSH-Px） and malondialdehyde（ MDA） content were assessed in the muscle of M. rosenbergii under ammonia stress for 48 h and post-exposure recovery for 48 h. The results showed that the half lethal concentrations of non-ionic ammonia of 24 h,48 h,72 h and 96 h were 4. 25,2. 35,1. 86,1. 54 mg·L^-1,respectively. And the safe concentration was 0. 154 mg·L^-1 under the condition of（ 25 ± 1） ℃,pH 8. 0 ± 0. 5. The SOD activity in the muscle of M. rosenbergii was significantly raised by ammonia nitrogen at 48 h. However,compared to the control,the activities of CAT and GSH-Px in all ammonia treatments didn’t change significantly at 48 h（ P >0. 05）. The MDA content of 0. 43,0. 64,1. 06 mg·L^-1 ammonia treatments were significantly higher than that of the control at 48 h（ P < 0. 05）. After 48 h post-exposure recovery,compared to the ammonia exposure,SOD activity reduced significantly with the same ammonia treatment（ P < 0. 05）,but they were still significantly higher than that of the control group except for 0. 85 mg·L^-1（ P < 0. 05）. CAT activities in0. 85,1. 06 mg · L^-1 treatments reduced significantly at the same ammonia treatments after 48 h postexposure recovery（ P < 0. 05）,and MDA content of all treatments returned to the level of the control. The results indicate that oxidative damage of M. rosenbergii by ammonia-N recovers after 48 h post-exposure recovery,but oxidative stress still exists in the muscle.更多还原