谷氨酸通过保护回肠结构完整性增强猪回肠屏障功能

Glutamate Enhances Porcine Ileal Barrier Function via Protecting Ileal Structural Integrality

本试验通过在断奶仔猪饲粮中添加谷氨酸,探究谷氨酸对断奶仔猪回肠结构及屏障功能的影响。选取14头28日龄健康、体重[(7.90±0.50)kg]相近的杂杜×长×大三元交断奶阉公猪,随机分为对照组和谷氨酸组,每组7个重复,每个重复1头猪。对照组饲粮是在玉米-豆粕型基础饲粮基础上添加1.0%的玉米淀粉,谷氨酸组饲粮是在玉米-豆粕型基础饲粮基础上添加1.0%的谷氨酸。试验期28 d,其中预试期7 d,正试期21 d。结果表明:与对照组相比,饲粮中添加1.0%的谷氨酸可显著增加断奶仔猪回肠单位长度重量及回肠单位长度黏膜重量(P<0.05);显著增加回肠绒毛高度及绒毛高度/隐窝深度(P<0.05),使回肠黏膜形态结构更完整;显著增加回肠上皮细胞紧密连接相关蛋白[闭合蛋白(occludin)、封闭蛋白-1(claudin 1)]及增殖标志蛋白(PCNA)的相对表达量(P<0.05);显著降低血清脂多糖(LPS)含量及二胺氧化酶(DAO)活性(P<0.05);显著上调回肠组织中酪氨酸激酶2(JAK2)/信号转导与转录激活子3(STAT3)信号通路相关蛋白的表达(P<0.05)。结果提示,饲粮中添加1.0%的谷氨酸可通过上调断奶仔猪回肠组织中JAK2/STAT3信号通路相关蛋白的表达,促进回肠上皮细胞增殖,进而保护其结构完整性,增强其屏障功能。

This study investigated the effects of glutamate on ileal structure and barrier function of weaned pig lets by adding glutamate into their diets.Fourteen Duroc×Landrace×Yorkshire crossbred piglets with the similar body weight[(7.90±0.50)kg]at the age of 28 days were selected and randomly divided into control group and glutamate group,with 7 replicates in each group and one pig in each replicate.The diet of control group was a corn soybean meal type based diet supplemented with 1.0%corn starch,while the diet of glutamate group was the corn soybean type basal diet supplemented with 1.0%glutamate.The experimental period was 28 days,including 7 days of pre feeding period and 21 days of trial period.The results showed as follows:com pared with the control group,dietary supplemented with 1.0%glutamate could significantly increase ileal weight per unit length and mucosal weight per unit length of weaned piglets(P<0.05);significantly increase the ileal villi height and villi height/crypt depth(P<0.05),and the ileal morphology was more complete;sig nificantly increase the relative expression levels of proteins related to tight junction(occludin and claudin 1)and proliferative marker protein[proliferating cell nuclear antigen(PCNA)]of ileal epithelial cells(P<0.05);significantly reduce the serum lipopolysaccharide content and diamine oxidase activity(P<0.05);sig nificantly up regulate the expression of proteins related to JAK2/STAT3 signaling pathway in ileum tissue(P<0.05).The results suggest that dietary supplementation with 1.0%glutamate can promote ileal epithelial cell proliferation by up regulating the expression of proteins related to JAK2/STAT3 signaling pathway in ileum tis sue,thus increasing barrier function and protecting the structural integrity of the ileum of weaned piglets.[Chi nese Journal of Animal Nutrition,2020,32(5):2101 2107]