Changes of intestinal epithelial tight junction and the expression of occludin in non-alcoholic fatty liver disease rats

Objective To investigate the changes of intestinal epithelial tight junction and the expression and distribution of occludin in non-alcoholic fatty liver disease(NAFLD) rats.Methods Thirty male SD rats were divided into two groups.The rats in control group were fed with normal diets while the rats in model group were fed with high fat diets.All the rats were sacrificed after 12 weeks.HE staining of hepatic tissue in model group showed that the NAFLD was established.Small intestinal epithelial tight junctions were observed by electron microscope in all groups,and the distribution and expression of tight junction protein occludin were detected by immunohistochemistry.Results Electron microscope demonstrated tight junction in model group(0.50±0.21)μm was significantly shorter than that in control group(0.78±0.19)μm(P0.05).The immunohistochemistry revealed the occludin in control group was localized in the apical region of the lateral plasma membrane and linear distributed representing the region of tight junctions in surface and crypt epithelial cells,while the occludin distributed non-continuous in model group and expressing obviously attenuated.Conclusion The expression of occludin decreased in NAFLD rats and the intestinal epithelial tight junction was shortened.It suggests that intestinal barrier may play an important role in the pathophysiologic mechanism of NAFLD.