黄连水煎液微粒体系对大鼠小肠上皮细胞紧密连接结构与紧密连接蛋白ZO-1表达的影响

目的 观察黄连水煎液微粒体系对大鼠小肠上皮细胞紧密连接结构与紧密连接蛋白-1（zonula occludens-1，ZO-1）表达的影响。方法 通过常规煎煮获得黄连水煎液，经高速离心得黄连水煎液微粒及去微粒水煎液。采用大鼠肠循环灌注模型，分别用空白Kreb-Ringers（K-R）液、黄连水煎液、微粒重悬液和去微粒水煎液对大鼠空肠段进行循环灌注。2 h后取下肠段，以透射电子显微镜观察细胞紧密连接结构的变化，采用免疫组织化学法检测空肠黏膜中ZO-1的表达水平。结果 空白K-R液组与去微粒水煎液组小肠上皮细胞间连接紧密无明显间隙，ZO-1蛋白呈蜂窝或点状聚集于上皮细胞周围；黄连水煎液组与微粒重悬液组小肠上皮细胞间隙增大，且ZO-1表达水平显著降低（P<0.05）。结论 黄连汤剂中活性成分肠吸收与黄连水煎液微粒体系调节小肠紧密连接结构和ZO-1表达水平有关。

Effect of Coptis chinensis Water Decoction Microparticle System on Tight Junction Structure and Expression of Tight Junction Protein ZO-1 in Intestinal Epithelial Cells of Rats

Objective To investigate the effect of Coptis chinensis water decoction microparticle system on tight junction structure and the expression of tight junction protein ZO-1 in the intestinal epithelial cells of rats. Methods Coptis chinensis water decoction was prepared by conventional decoction, and microparticles and microparticle-free water decoction were obtained by high-speed centrifugation. A rat model of intestinal perfusion was established, and Kreb-Ringers (K-R) buffer, Coptis chinensis water decoction, microparticle resuspension, or microparticle-free water decoction was used for perfusion of the jejunum. The jejunum was collected after 2 hours; a transmission electron microscope was used to observe the change in tight junction structure, and immunohistochemistry was used to measure the expression of ZO-1 in the jejunal mucosa. Results The K-R buffer group and the microparticle-free water decoction group showed tight junction of intestinal epithelial cells without marked intercellular space, and ZO-1 protein accumulated around the epithelial cells in a honeycomb or dotted shape; the Coptis chinensis water decoction group and the microparticle resuspension group had increased intercellular space between the intestinal epithelial cells and a significant reduction in the expression of ZO-1 (P<0.05). Conclusion The intestinal absorption of active components of Coptis chinensis decoction is associated with intestinal tight junction and the expression of ZO-1 regulated by the Coptis chinensis water decoction microparticle system.