脂多糖应激对断奶仔猪肠黏膜免疫屏障的影响

选用12头(21±1)d断奶仔猪,随机分为2个处理,研究脂多糖(LPS)刺激对肠黏膜免疫屏障功能的影响。禁食12h后,LPS组仔猪腹膜注射100μg/kgBW LPS,对照组注射等量的生理盐水。48h后,屠宰仔猪,打开腹腔,取小肠组织样品,测定小肠上皮间淋巴细胞、杯状细胞、肥大细胞数、肠集合淋巴结增殖、凋亡细胞数。结果表明:LPS刺激显著降低十二指肠、回肠上皮间淋巴细胞数(P<0.01),极显著增加小肠各段肥大细胞数(P<0.01);LPS刺激显著增加回肠集合淋巴结凋亡细胞数(P<0.05),但对增殖细胞数没有影响(P>0.05);LPS刺激可增加仔猪小肠杯状细胞数,但两处理组间差异不显著(P>0.05)。这些结果显示,LPS应激可导致肠黏膜免疫屏障功能改变,进而加重机体出现急性感染症状。

Effect of Lipopolysaccharide Challenge on Intestinal Mucosal Immune Barrier in Weanling Pigs

Twelve Duroc × Large White × Landrace crossbred piglets weaned at (21±1) d were randomly allotted to one of two treatments to evaluate the effect of LPS challenged on intestinal mucosal immunity. After 12 h starving, pigs were injected intraperitoneally with 100 μg/kg BW of E. coli lipopolysaccharide (LPS) or equivalent amount of sterile saline. At 48 h after injection, pigs were euthanized for collection intestinal tissue for mucosal immune barrier measurements. The results indicated that the intraepithelial lymphocytes (IELs) number in duodenum and ileum decreased (P < 0.01) after LPS administration. An increase in mast cells number was observed after LPS treatment (P < 0.01);Pigs with LPS administration had higher (P < 0.05) lymphocyte apoptosis in the ileal peyer′ s patches than those with saline administration, there were no differences (P > 0.05) in the lymphocyte proliferation of ileal peyer′s patches between two treatments; LPS challenge increased intestinal goblet cells number,but no difference was observed(P > 0.05).These results show that LPS induces a number of physiological changes in intestinal mucosal immune barrier that may be responsible for the regulation of the acute phase response in piglets.