镧对条纹锯(鮨)组织抗氧化酶及Na+/K+-ATP酶活性的影响

摘要

在水温17~26 ℃下,将平均体质量(68.19 ± 4.00)g的条纹锯(鮨)幼鱼饲养在体积200 L的塑料箱中,用氯化镧配制镧的质量浓度分别为0、0.1、2、5、10、20 mg/L和30 mg/L,每个质量浓度设3个平行,每个平行放入15尾鱼,每日更换50% 试验用水,以探究稀土元素镧对条纹锯(鮨)幼鱼的肝、肾、鳃组织超氧化物歧化酶、Na+/K+-A T P酶、过氧化氢酶活性和丙二醛含量的影响.90 d的饲养结果表明,当镧质量浓度为5 mg/L 时,条纹锯(鮨)生长的质量增加率和特定生长率最高,分别为74.29% 和0.61%;镧显著或极显著抑制肝、肾中超氧化物歧化酶和过氧化氢酶活性(P<0.05和 P<0.01);低质量浓度(0~2 mg/L)时,镧对鳃中的超氧化物歧化酶和过氧化氢酶活性无显著影响,高质量浓度时(20、30 mg/L)时,有抑制作用;镧极显著抑制肝中丙二醛含量(P<0.01),而在肾和鳃中丙二醛含量先升后降;镧对条纹锯(鮨)肝、肾、鳃中 Na+/K+-A T P 酶的活性影响大致相同,即在低质量浓度镧暴露时Na+/K+-ATP酶呈激活状态,在高质量浓度镧作用下,鳃中的 Na+/K+-ATP酶活性没有明显变化,肝、肾中的Na+/K+-A T P酶活性受到显著或极显著抑制(P<0.05和 P<0.01).%Juvenile Centropristis striata with body weight of(68.19 ± 4.00)g were reared in a 200 L plas-tic tank at a rate of 15 individuals per tank and exposed to lanthanum(La Ⅲ)prepared from lanthanum chloride at a dose of 0,0.1,2,5,10,20,and 30 mg/L at water temperature of 17—26 ℃ for 90 days in order to study the long-term effects of different concentrations of aqueous La on grow th and activities of superoxide dismutase(SOD),catalase(CAT)and Na+/K+-ATPase and malonaldehyde(MDA)content in liver,kidney and gill tissues of Centropristis striata.It was found that the juveniles had the best growth at the La3+concentration of 5 mg/L,with the maximal weight gain rate of 74.29% and specific growth rate of 0.61%.La3+led to significantly inhibit the activities of SOD and CAT(P<0.05 and P<0.01)in liver and kidney.Nevertheless,it has an insignificant influence on the activities of SOD and CAT in gill at low La3+concentration(0—2 mg/L),but inhibited their activities at high concentrations(20 mg/L and 30 mg/L).There was significantly lower MDA content in liver in the juveniles exposed to La 3+(P< 0.01), whereas there was increase in MDA content in kidney and gill first and then decline in the juveniles exposed to La3+,the similar case in the activity of Na+/K+-A T Pase in liver,kidney and gill,that is,Na+/K+-ATPase was activated at low-concentration of La3+exposure.Under the effect of high La3+concentration, however,there were no significant changes in the activity of Na +/K+-ATPase in gill,but the activity of such enzyme in liver and kidney(P<0.05 and P<0.01)was inhibited significantly.