摘要
为探讨金属硫蛋白(MT)对奶牛抗氧化应激机能的调控效果及其机理,选取24头中国荷斯坦奶牛经产泌乳母牛,随机均分为I、II、III、IV4组,分别按每头0(对照组),4.0,8.0和12.0mg静脉注射Zn-MT。每隔15d逐头采取血样,测定不同剂量的外源性MT和MT不同作用时间对奶牛抗氧化酶GSH-Px和CAT基因表达水平的影响。结果表明,补给外源性MT后,3个试验组GSH-Px和CAT基因表达水平都有不同幅度的提高,其中III组和IV组GSH-Px基因表达量分别较对照组有显著(P<0.05)提高。III组CAT基因表达水平显著(P<0.05)高于对照组;IV组CAT基因表达水平又比对照组、II组和III组分别提高了22.88%(P<0.01),17.71%(P<0.05)和7.10%(P>0.05)。而II组GSH-Px和CAT基因表达量与对照组差异均不显著(P>0.05)。从正试期间不同时间看,补给外源性MT后,各组GSH-Px和CAT基因表达水平逐步升高,至30d时达最高,45d时又有下降。尤其是30d时的GSH-Px基因表达水平及15和30d时的CAT基因表达水平均显著(P<0.05)高于第1天。说明外源性MT能有效调控奶牛GSH-Px和CAT基因表达水平,并表现出较为明显的剂量效应和时间效应。
The effect of exogenous metallothionein on gene expression of antioxidant enzymes in dairy cattle was conducted with 24 lactating Chinese Holstein cows,which were randomly divided into four groups （A,B,C,and D）,and supplemented with 0,4.0,8.0,and 12.0 mg Zn-MT respectively by intravenous injection.Blood samples were collected every 15 days and the levels of GSH-Px and CAT gene expression in the cows were determined.The levels of GSH-Px gene expression of the cows in groups C and D,and the level of CAT gene expression in group C were greater （P0.05） than those in group A.The level of CAT gene expression in group D was greater than those in groups A （P0.01）,B （P0.05）,and C （P0.05）,while there were no significant differences （P0.05） in either GSH-Px and CAT gene expression levels between groups A and B.The levels of GSH-Px and CAT gene expression peaked at the 30th day and descended at the 45th day after the supply of exogenous metallothionein.The levels of GSH-Px gene expression at the 30th day and CAT gene expression at the 15th day and the 30th day after the supply of exogenous metallothionein were greater （P0.05） than those before the supply.It is suggested that exogenous Zn-MT can promote the levels of GSH-Px and CAT gene expression of dairy cattle,showing a time-dependent and dose-dependent manner.
出处
《草业学报》
CSCD
北大核心
2010年第3期132-138,共7页
Acta Prataculturae Sinica
基金
国家自然科学基金项目(30671516
30170684)
湖南省自然科学基金重点项目(06JJ20091)资助
