Expression of Occludin Protein in Intestinal Epithelial Cells in Mice Model of Severe Acute Pancreatitis

Objective To observe the expression of occludin protein in intestinal epithelial cells in mice model of severe acute pancreatitis(SAP) and investigate the relationship between occludin protein expression and intestinal mucosal barrier injury.Methods The mice model of SAP was established.The ultrastructural changes in intestinal epithelial cells were observed under electron microscope,and the expression of occluding protein in intestinal epithelial cells was determined.Results The ultrastructure of intestinal epithelial cells was normal in control group.In experimental group,there was no ultrastructural change in intestinal epithelial cells at 3 hours,but the ultrastructural changes were found at 6,12,and 24 hours and were most prominent at 24 hours.We found that the microvilli were rare,disrupted,and even absent;the organelles were damaged;the heterochromatin was condensed along the nuclear membrane;and the cell junctions became widen.Occludin protein was uniformly distributed at the top of the junctions of intestinal epithelial cells in control group,but uneven distributed in experimental group.In experimental group,the expression of occludin decreased gradually and reached the minimum level at 24 hours.The average optical densities of occludin protein were 0.344 8±0.002 8 in control group and 0.343 1±0.002 0,0.342 3±0.001 9,0.339 4±0.001 5,and 0.309 5±0.002 7 in experimental group at 3,6,12,and 24 hours,respectively.There was no significant between-group difference in the average optical density at 3 hours,but the differences were significant at 6,12,and 24 hours(P 0.05).Conclusion Intestinal mucosal barrier injury and widening of the junctions of intestinal epithelial cells occur in early stage of SAP in mice,and the decreased expression level of occludin may be involved in the possible mechanism.