pH急性胁迫对刺参非特异性免疫酶活性的影响

Effects of acute pH stress on immunity enzyme of sea cucumber,Apostichopus japonicus

在对照组(pH 8.2)、低pH处理组(pH 7.3、7.5)和高pH处理组(pH 8.9、9.1)养殖水体条件下,对刺参进行急性胁迫处理,研究胁迫3、6、12、24、48、72和96 h对刺参体腔液中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、一氧化氮合成酶(NOS)和溶菌酶(LZM)活性的影响.结果表明:SOD活性在胁迫3~6 h后逐渐上升,在6 h时达到峰值,12~48 h逐渐下降,96 h时低pH处理组下降至对照组水平,而高pH处理组显著低于对照组(P<0.05);CAT活性在胁迫3~12 h后逐渐上升,在12 h时达到峰值,24~48 h逐渐下降,72~96 h时低pH处理组下降至对照组水平,而高pH处理组显著低于对照组(P<0.05);低pH处理组的NOS活性随着胁迫时间的增加变化不大,而高pH处理组在胁迫24 h后大幅下降,96 h时显著低于对照组(P<0.05);LZM活性随着胁迫时间的增加呈现逐渐下降的变化趋势,低pH处理组在胁迫72 h后显著低于对照组,而高pH处理组在胁迫12 h后显著低于对照组(P<0.05).刺参对pH胁迫有较强的适应性,pH胁迫在3~12 h能够诱导刺参体内的非特异性免疫系统发挥作用,非特异性免疫酶活性在12~24 h下降,免疫能力较低,病原敏感性增强.因此,在养殖过程中应注意pH变化的时序,避免因pH急性变化造成刺参的应激反应甚至病害的发生.

Superoxide dismutase(SOD),catalase(CAT),nitric oxide synthase(NOS)and lysozyme(LZM)activities of the cavity fluid of sea cucumber were monitored after undergoing different pH stress.The trial included 2 levels of low stress at pH 7.3 and 7.5,2 levels of high stress at pH 8.9 and 9.1,with pH 8.2 being the control.The immunity enzymes were measured at 3,6,12,24,48,72,96 h,respectively.The results showed that SOD activities increased gradually when the stress started.They peaked in 6 h and dropped afterwards.After 96 h,SOD activities under low pH stress were not significantly different from the control(P>0.05),while SOD activities from high pH groups were significantly lower than those of the control(P<0.05).CAT activities also enhanced within the first 12 hours and reached the peak then.Within 24-48 h,CAT activities declined rapidly.After 72 h those from low stress group dropped to the similar level of the control while those from high pH groups were significantly lower than those of the control(P<0.05).NOS activities did not change remarkably in low pH groups as the trial proceeded while those in high pH groups decreased sharply after 24 hours and were significantly lower than that of the control after 96 h(P<0.05).LZM activities went down along the experiment time.Those from low pH groups were below the level of the control after 72 h,while those from high pH groups were exceeded by the control after 12 h.Sea cucumber demonstrated favorable tolerance to pH stress.The nonspecific immunity system can be stimulated within 3-12 h while the system attenuated after 12 to 24 h,resulting in poor immunity and high susceptibility to pathogens.Therefore,sequential changes of pH should be paid serious attention in aquaculture,so that stress response and even diseases arisen from acute pH can be avoided.