高铜日粮对肉鸡肝脏TrxR2基因mRNA表达和还原活性的影响

摘要

In order to examine the effect of high dietary copper on expression of TrxR2 mRNA in liver,and the reduction activity of TrxR2, the experiment was conducted with two hundred healthy 1 day-old Cobb broilers which were randomly divided into four groups based on diets as follows: control group (Cu 11 mg · kg-1 as the group Ⅰ ) and high copper groups (Cu content 110, 330, 550 mg · kg-1 , named group Ⅱ 、Ⅲ and Ⅳ ). The liver was taken from broiler in each group at the lOth , 30th and 50th days, respectively, reduction activity of the liver TrxR2 was detefmined by the method of DTNB, and the testing material was liver mitochondria which has been extraction from the liver, and the expression of the liver TrxR2 was determined by the method of semi-quantification and reverse transcription polymerase chain reaction (RT-PCR). The results showed that the reduction activity of liver TrxR2 decreased (P＜0. 05) and the expression of TrxR2 mRNA was reduced (P＜0. 05)at 50 d of Group Ⅳ , the reduction activity of liver TrxR2 was mcreased(P＜0. 05) at 30 d and reduced (P＞0. 05)at 50 d of Group Ⅲ , The experiental results indicated that fed high copper diets (330-550 mg · kg-1) could decrease TrxR2 mRNA expression in the liver and increase the reduction activity of TrxR2 first, and decrease it on 50 days.%本文旨在了解高铜日粮对肉鸡肝脏TrxR2基因mRNA表达和还原活性的影响.200羽1日龄Cobb商品代肉鸡随机分为4组,各组日粮中铜含量分别为:对照组(Ⅰ组)11 mg·kg-1、试验Ⅱ组110 mg·kg1、试验Ⅲ组330mg·kg-1和试验Ⅳ组550 mg·kg-1.饲养至10、30、50 d时每组各取5只鸡用于采集肝脏样品,提取肝脏线粒体用DTNB法测定肝脏TrxR2的还原活性,提取肝脏总RNA用RT-PCR法测定TrxR2 mRNA在肝脏中的表达量.结果显示,饲喂铜含量为550 mg·kg-1日粮50 d时还原活性降低(P＜0.05)、TrxR2基因mRNA的表达量降低(P＜0.05),饲喂铜含量为330 mg·kg-1日粮30 d时TrxR2的还原活性升高(P＜0.05)、50 d时降低(P＞0.05),表明饲喂高铜日粮(330～550 mg·kg-1)可导致TrxR2 mRNA在肝脏中的表达量降低,还原活性先升高后降低.