日粮补充L-亮氨酸对超早期断奶宫内发育迟缓仔猪肠道免疫功能的影响

Effect of Dietary L-Leucine Supplementation on Intestinal Immune Function in Ultra-Early Weaned Piglets with Intrauterine Growth Retardation

目的:研究L-亮氨酸对超早期断奶宫内发育迟缓(intrauterine growth retardation,IUGR)仔猪肠道免疫功能的调节作用。方法:选取14日龄断奶的正常初生体质量(normal birth weight,NBW)和IUGR新生仔猪各16头,分别饲喂基础日粮或添加0.35%L-亮氨酸实验日粮,即4个处理组,每组8头猪。结果:与NBW仔猪相比,IUGR仔猪血清溶菌酶活力和补体3(complement-3,C3)水平显著降低(P<0.05),空肠和回肠中杯状细胞(goblet cells,GC)和淋巴细胞(intraepithelial lymphocytes,IEL)数量显著减少(P<0.05),回肠中肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)含量显著升高(P<0.05),白细胞介素10(interleukin-10,IL-10)含量显著降低(P<0.05)。另外,IUGR仔猪回肠TNF-αm RNA表达量显著升高(P<0.05),IL-10 m RNA表达量显著降低(P<0.05)。日粮添加0.35%L-亮氨酸后,IUGR仔猪血清溶菌酶活力、C3和C4水平显著升高(P<0.05),回肠中GC数量及十二指肠和空肠中IEL数量显著增加(P<0.05),回肠中IL-10含量显著升高(P<0.05),并且IL-2和IL-10 m RNA表达量显著升高(P<0.05)。结论:IUGR会引起超早期断奶仔猪肠道黏膜发生炎症反应和肠道生长发育受限。L-亮氨酸可以有效缓解IUGR引起的肠道黏膜损伤,改善仔猪肠道的免疫功能。

Objective:To ascertain the effect of dietary leucine supplementation on intestinal immune function in ultra-early weaned piglets suffering from intrauterine growth retardation(IUGR).Methods:Sixteen normal birth weight(NBW)piglets weaned at14days of age and sixteen IUGR newborn piglets were selected according to their birth weight.All the piglets were randomly divided into four groups with8replicates in each group,and fed control diet alone or supplemented with0.35%L-leucine for21days,respectively.Results:Compared with NBW piglets,IUGR piglets showed significantly lower lysozyme activity and complement-3(C3)level in the serum(P<0.05),a significant reduction in the number of goblet cells(GC)and intraepithelial lymphocytes(IEL)in the jejunum and ileum(P<0.05)and interleukin-10(IL-10)content in the ileum,and a significant increase intumor necrosis factor-α(TNF-α)content in the ileum(P<0.05).In addition,IUGR piglets had significantly increased TNF-αmRNA expression but significantly decreased IL-10mRNA expression(P<0.05).Dietary supplementation with0.35%L-leucine significantly increased lysozyme activity and the levels of C3and C4in the serum,the numbers of GC in the ileum and IEL in the duodenum and jejunum,IL-10content in the ileum,and the mRNA expression of IL-2and IL-10in the ileum of IUGR piglets(P<0.05).Conclusion:IUGR could induce intestinal mucosal inflammatory response and hinder intestinal growth and development in early weaned piglets.L-Leucine could effectively alleviate intestinal mucosal injury caused by IUGR,and improve intestinal immune function in piglets.