饲料铅对建鲤生产性能及组织酶活性的影响

探讨饲料中不同水平铅对建鲤(Cyprinus carpio var.Jian)生产性能、血清和肝胰脏酶活性的影响。试验选取483尾建鲤(初始平均体质量为22.95±0.15 g),随机分为7组,各组Pb2+理论添加量分别为0(对照组),2,5,10,20,50和100 mg.kg-1,每组3个重复,试验期60 d。试验结束后,测定建鲤生产性能、血清谷草转氨酶(AST)、谷丙转氨酶(ALT)和乳酸脱氢酶(LDH)的活性和肝胰脏中丙二醛(MDA)的含量,超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)的活性。结果表明,与对照组相比,铅暴露组建鲤的增重率和饵料系数无显著差异(P>0.05),但各铅暴露组的增重率呈下降趋势,饵料系数呈上升趋势;随着饲料中铅水平的增加,各铅暴露组血清AST,ALT和LDH的活性呈上升趋势;肝胰脏中MDA的含量呈上升趋势,SOD,GSH-PX的活性被铅诱导升高。结果表明,铅暴露会引起建鲤组织生化指标的改变,对鱼体有多种毒性效应,并且毒性效应指标的变化与铅污染水平有剂量—效应关系,使得鱼体受损,并且可以协同使用这些指标指示铅污染情况的发生。

Effects of dietary Pb on growth performance and enzyme activities of Jian carp

The effects of dietary lead levels on growth performance,metabolic enzyme activities in serum(ALT,AST and LDH),MDA content and antioxidant defense systems of hepatopancreas of Jian carp(Cyprinus carpio var.Jian) were investigated.Four hundred and eighty-three Jian carp(average initial weight,22.95±0.15 g) were randomly divided into seven treatments and exposed to 0,2,5,10,20,50 and 100 mg·kg-1 concentrations of Pb in diet for 60 days.The results showed that weight growth ratio and feed conversation ratio were not significantly affected by dietary Pb(P>0.05),but weight growth ratio presented a downward trend with the increasing Pb concentrations and feed conversation ratio presented an upward trend with the increasing Pb concentrations.After long term Pb exposure,AST activity presented an upward trend with the increasing Pb concentrations,significant increase of AST activity were only found in 100 mg·kg-1 Pb group(P<0.05),ALT and LDH activities presented an upward trend with the increasing Pb concentrations,significant increase of ALT and LDH activities were found in 20,50 and 100 mg·kg-1 Pb groups(P<0.05).The MDA content in hepatopancreas increased with the increasing Pb concentrations.SOD and GSH-PX activities were induced by dietary Pb.The dietary Pb could lead Pb concentration-dependent toxicity on Jian carp.The changes of the activities of metabolic enzyme activities in serum,MDA content and antioxidant defense systems of hepatopancreas could be used in indication of Pb contamination in diet.