急性硫化物胁迫对日本沼虾免疫和抗氧化系统的影响

日本沼虾（Macrobrachium nipponense）在硫化物浓度为0.4、1.2和4.0mg/L的水体中暴露48h,研究硫化物胁迫对其血液免疫指标和机体抗氧化能力的影响。结果表明,硫化物对日本沼虾的24、48、72、96hLC50分别为22.5、15.2、12.5、11.35mg/L。血细胞密度（THC）和吞噬活力（吞噬百分比和吞噬指数）随硫化物质量浓度升高而降低,至48h,0.4、1.2和4.0mg/L组的THC显著降低,分别为对照组的85.71%、70.75%和57.48%。各试验组沼虾的凝血时间与对照组相比延长,1.2mg/L和4.0mg/L组分别从12h和6h开始显著长于对照组（P〈0.05）。沼虾肌肉中的总抗氧化能力（T-AOC）随硫化物浓度的升高而降低,至48h,1.2mg/L和4.0mg/L组显著低于对照组（P〈0.05）。超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活力随硫化物浓度的升高而增强,至48h,1.2mg/L和4.0mg/L组的SOD活力显著高于对照组（P〈0.05）,表明日本沼虾免疫系统对低浓度硫化物有一定的耐受力;当硫化物浓度过高时,沼虾的免疫能力降低,对机体抗氧化系统产生显著影响。

Effects of Acute Sulfide Stress on Immune Responses and Antioxidant System of Macrobrachium nipponense

Effects of acute sulfide stress on survival, immune responses and antioxidant system of Macrobrachium nipponense were studied with M. nipponense immersed in the sulfide solution with concentration of 0.4, 1.2 and 4.0 mg/L respectively. The results showed that LC50 of sulfide to M. nipponense was 22.5, 15.2, 12.5 and 11.35 mg/L respectively in 24h, 48 h, 72 h and 96 h. The total haemocyte count （THC） and phagocytic activity （including phagocytic percentage and phagocytic index） of the haemocyte decreased with sulfide concentrations increasing, and THC of 0.4, 1.2 and 4.0 mg/L groups decreased to 85.71%, 70.75% and 57.48% of the control group up to 48 h, respectively （P0.05）. Compared with the control group, coagulation time of the experimental groups was longer, with 1.2 mg/L and 4.0 mg/L groups significantly longer than the control group from 12 h and 6 h, respectively. The total antioxidant capability （T-AOC） of M. nipponense muscle decreased with the increase of sulfide concentrations, 1.2 mg/L and 4.0 mg/L groups, significantly lower than that of control group （P0.05） up to 48 h. Superoxide dismutase （SOD） and catalase （CAT） activities increased, with SOD activities of M. nipponense exposed to 1.2 mg/L and 4.0 mg/L sulfide up to 48 h significantly higher than that of the control. The result showed that M. nipponense had resistance to low concentration of sulfide to some degree. With concentration of sulfide excessively being higher, the immune system of M. nipponense was inhibited and its antioxidant system was significantly affected.