盐度对青蛤抗氧化酶活性及生长的影响

Effects of water salinity on the antioxidant enzyme activities and growth of clam Cyclina sinensis

为了弄清盐度对青蛤(Cyclina sinensis)生长及免疫相关酶的影响,以期探讨其在不同盐度环境下养殖的可能性,本文研究了青蛤在盐度10、15、25(对照)和35下,0、3、6、12、24、48、96h内鳃、外套膜和肝胰腺中抗氧化酶(超氧化物歧化酶(SOD)和过氧化氢酶(CAT))的活性变化;同时研究了不同盐度下青蛤养殖2个月的月增长率和增重率变化。结果表明:青蛤不同组织中SOD和CAT活性以肝胰腺最高,外套膜次之,鳃最低。盐度10时,鳃中的SOD活性于3h显著高于对照盐度(P<0.05);外套膜中的SOD活性于3、6、12、24h,CAT活性于6、12h与对照有显著差异(P<0.05);肝胰腺中的SOD活性于3、6、12、24h,CAT活性于3、6h显著高于对照(P<0.05)。盐度15时,仅肝胰腺中的SOD和CAT活性于3h显著高于对照(P<0.05)。而盐度35时,鳃中的SOD活性于3、6h,CAT活性于3h显著高于对照(P<0.05);外套膜中的SOD和CAT活性于3、6、12、24h与对照有显著差异(P<0.05);肝胰腺中的SOD和CAT活性几乎整个时间段均与对照有显著差异(P<0.05)。此外,盐度35时的SOD和CAT活性波动幅度显著高于盐度10(P<0.05)。月增长率和增重率方面:盐度15较快,与对照无显著差异(P>0.05),各月间也无显著差异(P>0.05);盐度10则显著低于盐度15和对照,并且盐度10第2月份显著高于第1月份(P<0.05);而盐度35则极缓慢,各月间也无显著差异(P>0.05)。研究表明,青蛤受盐度胁迫时其抗氧化酶的波动基本于胁迫后的前24h内完成,青蛤对低盐的耐受性强于高盐,盐度高于35时青蛤抗氧化酶波动剧烈,且生长极慢。

In order to clarify the effects of water salinity on the growth and immune enzymes of clam Cyclina sinensis, and accordingly, to explore the possibility of breeding C. sinensis in different salinity environment, the individuals of the clam were undergone different salinity stress （10, 15, 25 （control）, and 35）, with the antioxidant enzymes superoxide dismutase （SOD） and catalase （CAT） in gill, mantle, and hepatopancreas at 0, 3, 6, 12, 24, 48, and 96 h of salinity stress measured respectively. The monthly length and weight gain rates were also measured after the individuals cultured under different salinity stress for two months. In different tissues of the clam, hepatopancreas had the highest antioxidant enzyme activities, followed by mantle, and gill. For the individuals under salinity 10, the SOD activity in gill at 3 h and in mantle and hepatopancreas at 3, 6, 12, and 24 h, as well as the CAT activity in mantle at 6 and 12 h and in hepatopancreas at 3 and 6 h, was significantly higher than that of the control （P 〈0.05）; for the individuals under salinity 15, only the SOD and CAT activities in hepatopancreas at 3 h were significantly higher than those of the control （P〈0.05）; whereas for the individuals under salinity 35, the SOD activity in gill at 3 and 6 h, in mantle at 3, 6, 12, and 24 h, and in hepatopancreas at 0, 3, 6, 12, 24, 48, and 96 h, as well as the CAT activity in gill at 3 h, in mantle at 3, 6, 12, and 24 h, and in hepatopancreas at 3, 6, 24, 48, and 96 h, was significantly higher than that of the control （P 〈0.05）. In addition, the variation extents of the SOD and CAT activities under salinity 35 were significantly higher than those under salinity 10 （P〈0.05）. The length and weight gain rates of the individuals under salinity 15 were greater, but had no significant differences with the control, and also, had no differences between the first month and the second month （P〉0.05）. Under salinity 10, the length and weight gain rates were significantly lower than those under salinity 15 and of the control, and had significant differences between the first and second months （P〈0.05）. Under salinity 35, both the length gain rate and the weight gain rate were the lowest, and had no significant differences between the first and second months. In conclusion, when stressed by salinity, the C. sinensis should take about 24 h for the restoration of its antioxidant enzyme activities. C. sinensis had a stronger tolerance against low salinity than against high salinity. When the salinity was at 35, the antioxidant enzyme activities of the clam varied greatly, and the growth was almost stopped.