镧对条纹锯鮨组织抗氧化酶及Na^+/K^+-ATP酶活性的影响

Effect of Lanthanum on Activities of Antioxidases and Na^+/K^+-ATPase in Tissues of Centropristis striata

在水温17~26℃下,将平均体质量(68.19±4.00)g的条纹锯幼鱼饲养在体积200L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、20mg/L和30mg/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幼鱼的肝、肾、鳃组织超氧化物歧化酶、Na^+/K^+-ATP酶、过氧化氢酶活性和丙二醛含量的影响。90d的饲养结果表明,当镧质量浓度为5mg/L时,条纹锯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(0~2mg/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、30mg/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;镧对条纹锯肝、肾、鳃中Na^+/K^+-ATP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^+-ATP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 Lplastic 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 growth 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 La^3＋concentration of 5 mg/L,with the maximal weight gain rate of 74.29%and specific growth rate of 0.61%.La^3＋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 La^3＋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 La^3＋,the similar case in the activity of Na^＋/K^＋-ATPase in liver,kidney and gill,that is,Na^＋/K^＋-ATPase was activated at low-concentration of La^3＋exposure.Under the effect of high La^3＋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.