肠道抗菌肽（AMPs）由肠粘膜上皮细胞合成或分泌的一类防御性肽类活性物质，在肠道的先天性免疫过程中具有重要的作用。猪肠粘膜上皮细胞可分泌β防御素2（BD2）、β防御素3（BD3）、RegIII γ、溶菌酶（LYS）和血管生成素4（ANG4）等多种抗菌肽。文章通过荧光定量PCR（realtime QPCR）分析新生仔猪RegIIIγ、ANG4、BD2、BD3和溶菌酶等抗菌蛋白在十二指肠、空肠、回肠内不同发育阶段的mRNA的表达变化。结果表明，所有抗菌肽的mRNA水平在出生后均逐渐升高，但在断奶后的表达水平降低，随后又显著升高。此外在肠道中最主要的抗菌肽是溶菌酶和RegIIIγ，意味着这两种抗菌肽在肠粘膜的先天免疫中具有十分重要的作用。

Antimicrobial peptides (AMPs) are a class of defensive peptides synthesized or secreted by intestinal cells. It plays an important role in intestinal innate immunity in piglets. There are a variety of AMPs secreted by intestinal epithelia, such as ANG4, BD2, BD3, lysozyme, and RegIIIγ. To characterize the expression pattern of these AMPs, the mRNA expression level of porcine RegIIIγ, ANG4, BD2, BD3, and lysozyme in the duodenum, jejunum, and ileum of piglets from 0 to 5 weeks was analyzed by realtime quantitative PCR (realtime PCR). The results showed that the mRNA levels of all antimicrobial peptides  gradually increased after birth, but the expression level after weaning decreased, and then increased significantly. In addition, the most important antimicrobial peptides in the intestine are lysozyme and RegIIIγ, which means that the two antimicrobial peptides play an important role in the innate immunity of the intestinal mucosa.