早期断奶对仔猪肠通透性和肠上皮紧密连接蛋白Occludin mRNA表达的影响

Effects of Early Weaning on Intestinal Permeability and Tight Junction Protein Occludin mRNA Expression Levels of Piglets

本文旨在研究早期断奶仔猪的肠通透性变化并探讨其机制。试验采用32头21日龄断奶仔猪,并于仔猪21、28和35日龄取样测定血浆D-乳酸含量、二胺氧化酶(DAO)活性和尿中乳果糖/甘露醇比率观察肠通透性改变,同时检测肠上皮紧密连接蛋白Occludin mRNA表达水平。结果显示:与断奶前相比,28日龄时血浆D-乳酸含量、DAO活性和乳果糖/甘露醇比差异达到显著水平(P<0.05),且至35日龄时,肠道仍然维持这种较高的通透性;仔猪断奶后Occludin mRNA相对表达量下降明显,与断奶前相比差异显著(P<0.05),35日龄时,表达量有所恢复,但仍然低于断奶前表达水平。试验结果提示,早期断奶后仔猪肠道的通透性增加,肠屏障功能破坏,可能归因于肠上皮细胞紧密连接蛋白Occludin mRNA表达下降。

The aim of this paper is to study the changes of intestinal permeability and mechanisms in early weaning piglets. A total of 32 piglets weaned on the 21st day were sellected to measure plasma D-lactate level, DAO activity and urine lactulose mannitol ratio on the 21^st, 28^th and 35^th day to evaluate the intestinal permeability. Level of Occludin mRNA expression was researched at the same time. The results indicated that plasma D-lactate level, DAO activity and urine lactulose mannitol ratio increased significantly on the 28^th day and markedly maintained high level to on the 35^th day compared with the figures before weaning （P〈0.05） ; Occludin mRNA expression level decreased obviously after weaning （P〈0.05）, and recovered to some extent on the 35^th day. It is suggested that damage of intestinal barrier function and the increase of intestinal permeability may be due to the declined expression of tight junction protein Occludin mRNA.