豚鼠胆色素结石模型的肠道免疫屏障研究

Intestinal Mucosal Immune Barrier in Guinea Pig Model of Pigment Gallstone

目的探讨肠黏膜免疫屏障与胆色素结石形成间的相关性及其可能机制。方法豚鼠80只随机分为对照组(CON)、致石组(PS)、肠黏膜保护组(GLN),分别给予正常饲料、胆色素结石致石饮食、添加肠黏膜保护剂谷氨酰胺的致石饮食,饲养8周建立胆囊胆色素结石模型。检测并比较各组胆结石的成石率,绒毛形态,高倍镜下(×400)肠黏膜固有层和上皮内的、CD3+T细胞数、CD40+B细胞数和IgA阳性浆细胞数。结果致石组成石率为68.4%,明显高于对照组20.0%和保护组36.8%(P<0.05)。相比对照组,成石组肠壁各层变薄,炎性表现。阳性T淋巴细胞由每高倍视野(21.8±2.5)个降至(11.1±3.4)个,P<0.01;B淋巴细胞由每高倍视野(12.9±2.0)个降至(10.7±3.6)个,P<0.01;浆细胞数由每高倍视野(12.4±3.4)个降至(10.7±3.5)个,P<0.01。肠黏膜保护组肠壁炎性表现轻于致石组,各指标均较致石组高(P<0.01),有显著性差异。结论结石形成过程中,存在肠黏膜机械屏障和免疫屏障功能异常。谷氨酰胺可改善豚鼠的肠黏膜屏障功能,降低胆色素结石的形成率。

Objective To explore the correlation between intestinal mucosal immune barrier and pathogenesis of pigment gallstone and its possible mechanism. Methods Eighty guinea pigs were randomly divided into control group（group CON）,pigment gallstone group（group PS）,and intestinal mucosal protection group（group GLN）. The guinea pigs were fed with normal diet in group CON,pigment gallstonein ducing diet in group PS,and glutamine-supplemented diet in group GLN for 8 weeks. The guinea pig model of pigment gallstone was established. The incidence of pigment gallstone was detected. The morphology of intestinal mucosa was observed,and the numbers of CD3＋ T cell,CD40＋ B cell,and IgA＋ plasma cell were counted. Results The incidence of pigment gallstone was significantly higher in group PS than in groups GLN and CON （P 0.05）. Compared with group CON,the intestinal wall was significant thinner and represented obvious signs of inflammation in group PS,and the numbers of CD3＋T cell,CD40＋B cell,and IgA＋ plasma cell significantly decreased （CD3＋T cell, 21.8±2.5 vs 11.1±3.4,P 0.01;CD 40＋ B cell,12.9±2.0 vs 10.7±3.6,P 0.01;IgA＋ plasma cell,12.4±3.4 vs 10.7±3.5,P 0.01）. The signs of inflammation were less severe in group GLN than in group PS. There were significant differences in the numbers of CD3＋ T cell, CD40＋ B cell,and IgA＋ plasma cell between groups GLN and PS. Conclusion Intestinal barrier dysfunction,including mechanical barrier and immune barrier,is involved in the formation of pigment gallstone. Glutamine has proved to improve the function of intestinal mucosal barrier and decrease the incidence of pigment gallstone.