盐度胁迫对近江牡蛎几种免疫因子的影响

试验分析了盐度从18骤变至3、25、40的第24 小时和第48 小时江牡蛎（Crassostrea hongkongensis）血淋巴超氧化物歧化酶（SOD）、碱性磷酸酶（AKP）、过氧化氢酶（CAT）和溶菌酶（LSZ）的活力变化，旨在研究盐度骤变对相关免疫因子的影响。结果显示，对照组（盐度18）4项免疫因子变化不显著（P＞0.05）。盐度25组AKP、LSZ活力在第24 小时极显著高于对照组（P〈0.01）。盐度3组SOD活力在第24 小时显著高于对照组（P〈0.01），其他酶活力与对照组相比差异不显著。盐度40组SOD活力在第24 小时显著低于对照组（P〈0.01），而LSZ活力在第48 小时急剧下降，极显著低于对照组（P〈0.01），其他酶活力与对照组相比差异不显著。由此可见，盐度骤变对近江牡蛎的免疫活力有明显的刺激作用，且可能在一定范围内能够增强机体免疫力。近江牡蛎对低盐有很强的适应能力，但在高盐胁迫下其免疫活力下降。

Effects of salinity stress on immune factors of Crassostrea hongkongensis

We examined the influence of abrupt changes of salinity from 18 to 3, 25, 40 at 24th hour and 48th hour on superoxide dismutase （SOD）, alkaline phosphatase （AKP）, catalase （CAT） and lysozyme （LSZ） of Crassostrea hongkongensis hemolymph, so as to investigate the effects of salinity stress on these immune factors. Results indicate that the changes of four immune factors are not significant （P〉0.05） in control group （salinity 18）. Changes of AKP and LSZ vitality of salinity 25 group are much higher than those in the control group （P〈0.01） at 24th hour. SOD activity of salinity 3 group is much higher than that of the control group （P〈0.01） at 24th hour, while the other factors show no significant difference compared with the control. In salinity 40 group, the SOD activity is significantly lower than that of the control group （P〈0.01） at 24th hour, and LSZ activity has no significant difference at 24th hour compared with the control, while sharply declines and becomes significantly lower than the control group （P〈0.01） at 48th hour; there are no significant difference of other factors compared with the control. The results suggest that salinity may stimulate the immune activity significantly and enhance the body＇s immune activity at a certain range. In addition, oyster has strong ability to adapt to low salinity, but in higher salinity stress, its immune activities become lower.