壳聚糖对仔猪肠黏膜通透性及Occludin和ZO-1表达的影响

Effects of Chitosan on Intestine Permeability,Occludin and ZO-1 Expression in Piglets

旨在探讨日粮中添加壳聚糖对早期断奶仔猪肠道屏障功能的影响。将30头21d断奶仔猪((6.62±0.59)kg)随机分为3组,预试期采用大肠杆菌攻毒(109细胞.头-1),对照组饲喂基础日粮,试验组分别在基础日粮中添加50mg.kg-1金霉素和300mg.kg-1壳聚糖,饲养期21d。结果表明,与对照组相比,壳聚糖能降低血浆中D-乳酸(D-Lactate)含量(P<0.05)、二胺氧化酶(DAO)活性(P<0.05)和血清内皮素-1(ET-1)水平(P<0.05),但对血清一氧化氮(NO)含量无明显影响(P>0.05);免疫组化结果显示,壳聚糖组空肠黏膜Occludin(P<0.01)和ZO-1(P<0.05)蛋白表达提高;荧光定量PCR结果表明,壳聚糖组空肠黏膜Occludin(P<0.01)和ZO-1(P<0.05)mRNA表达丰度升高。结果说明,日粮中添加300mg.kg-1的壳聚糖能降低早期断奶仔猪小肠黏膜屏障功能的损伤作用。

In order to explore the effects of chitosan on intestinal barrier of weanling pigs, thirty piglets with an average body weight of （6.62±0.59） kg were challenged with enterotoxigenic Escherichia coli （10^9 cell per head） during preliminary trial period and randomly assigned to three treatment groups, a basal diet was added in control group, 50 mg·kg^-1 chlortetracycline, 300 mg·kg^-1 ehitosan were added in the experimental groups, respectively, for 21 d. The results showed that, compared with the control group, chitosan could decrease the level of D-Lactate（P〈0.05） and the activity of DAO（P〈0.05） in plasma and the level of ET-I（P〈0.05） in serum, but it had no significant effect on the contents of NO（P〉0.05） in serum. The result of immuno- histochemistry showed that the protein expression levels of Occludin （P〈0.01） and ZO-1 （P〈0.05） in piglets jejunum mucous added with chitosan were increased. The result of fluorescence quantitative PCR showed that the expression abundances of Occludin （P〈0. 01） and ZO-1 （P〈0.05） mRNA in piglets jejunum mucous added with ehitosan were improved. These result indi-cate that diet supplemented with 300 mg·kg^-1 chitosan can protect greatly the intestinal barrier of early weanling piglets from injuring.