早期断奶对仔猪小肠中谷氨酸/谷氨酰胺转运载体表达的影响

Effects of Early Weaning on Expression of Glutamate/Glutamine Transporters in Small Intestine of Piglets

本试验旨在研究早期断奶对仔猪小肠中谷氨酸/谷氨酰胺转运载体表达的影响。试验从40头母猪的仔猪中各选出体重相近、10日龄的杜长大三元杂交仔猪1头,共40头仔猪,随机不配对分为2组,每组20头仔猪,对照组为哺乳仔猪,随母猪喂养;试验组为断奶仔猪,隔离断奶饲养。试验期10 d。饲养结束,每组随机选取12头仔猪,屠宰后取空肠和回肠组织,测定谷氨酸/谷氨酰胺转运载体蛋白和mRNA表达情况,并检测小肠组织形态和小肠氧化应激水平。结果表明:与哺乳仔猪相比,早期断奶显著提高了仔猪空肠和回肠谷氨酸/胱氨酸交换载体(xCT)和中性氨基酸转运载体2(ASCT2)蛋白和mRNA表达量(P<0.05);皮尔森相关分析结果显示,断奶仔猪与哺乳仔猪的xCT和ASCT2蛋白表达量在空肠和回肠组织匀浆、细胞内质、细胞顶膜与空肠和回肠中对应mRNA表达量之间均呈正向线性关系,且差异显著(P<0.05)。与哺乳仔猪相比,断奶仔猪空肠和回肠绒毛高度降低,隐窝深度增加,差异均显著(P<0.05)。与哺乳仔猪相比,断奶仔猪空肠和回肠组织的总抗氧化能力均显著降低(P<0.05),且空肠氧化型谷胱甘肽(GSSG)含量显著提高(P<0.05),回肠谷胱甘肽(GSH)含量显著降低(P<0.05)。结果提示,早期断奶使仔猪小肠处于氧化应激状态,显著提高断奶仔猪小肠组织中xCT和ASCT2蛋白及mRNA表达量,以促进谷氨酸/谷氨酰胺的摄取,降低仔猪小肠的氧化应激水平。

The purpose of this study was to study the effects of early weaning on the expression of glutamate/glutamine transporters in small intestine of piglets.A total of 40 piglets with similar body weight and 10 days of age were selected from 40 piglets of different sows.They were randomly divided into 2 groups with 20 piglets in each group.Control group piglets were suckling piglets,feeding with sows.The experimental group piglets were weaning piglets,isolated and weaned.The trial lasted for 10 days.At the end of feeding,12 piglets were randomly selected from each group,jejunum and ileum were collected,and the gene and protein expression of glutamate/glutamine transporter were determined.The results showed as follows:compared with suckling piglets,early weaning significantly increased the expression of glutamate/cystine exchange transporter(xCT)and neutral amino acid transporter 2(ASCT2)proteins and mRNA in the jejunum and ileum of the piglets(P<0.05).Pearson correlation analysis results showed that the expression levels of xCT and ASCT2 proteins in issues homogenate,cell endoplasm,apical membrane of weaning piglets and suckling piglets showed a positive linear relationship with the expression levels of corresponding mRNA in jejunum and ileum(P<0.05).The height of villi in the jejunum and ileum of weaning piglets decreased,and the crypt depth increased,with significant differences(P<0.05).The total antioxidant capacity in jejunum and ileum of weaning piglets significantly reduced(P<0.05),and the content of oxidized glutathione(GSSG)in jejunum significantly increased(P<0.05),and the content of glutathione(GSH)significantly decreased in ileum(P<0.05).Early weaning places the small intestine of piglets in a state of oxidative stress,significantly increases the expression levels of xCT and ASCT2 proteins and their mRNA in the small intestinal tissues of weaning piglets,so as to promote the uptake of glutamate/glutamine and reduce the level of oxidative stress in the small intestine of piglets.