Influence of hemorrhagic shock on tight junction protein Occludin in intestinal mucosa of rats / 中华创伤杂志

ABSTRACT

Objective To investigate the effect of hemorrhagic shock on intestinal epithelial tight junction and expression of protein Occludin.Methods Twenty-four SD rats were allocated to sham operation group,hemorrhagic shock 0.5-hour,2-hour,and 4-hour groups according to random number table,with 6 rats per group.A model of hemorrhagic shock in the rat was induced by the improved Wiggers method.Blood samples were drawn from abdominal aorta.Activity of plasma diamine oxidase (DAO) was determined by active colonmetric method; content of plasma D-lactic acid (D-LA) by spectrophotometer method; plasma endotoxin levels by turbidimetry; bacterial translocation by bacterial culture of mesenteric lymph nodes and liver tissues; pathological changes of intestinal mucosa by light microscope; ultrastructure of intestinal epithelial cells by electron microscopy; Occludin mRNA expression in small intestinal mucosa by RT-PCR; Occludin expression by Western blot and imnmnohistochemical method.Results Levels of DAO [(72.68-± 10.24) mg/ml],D-LA [(9.28 ± 0.53) μg/ml] and endotoxin [(41.25 ±3.68) pg/L] in hemorrhagic shock 0.5-hour group increased markedly as compared with those in sham operation group (P ＜0.05).Bacteria were cultivated from the liver tissues and mesenteric lymph nodes in hemorrhagic shock 2-hour group and much more colonies of bacteria were observed in hemorrhagic shock 4-hour group (P ＜ 0.01).Morphology and ultrastructure of the small intestinal epithelium manifested immediate damage in hemorrhagic shock 0.5-hour group and much worse detriment was obsevved with a prolonged bleeding time.Occludin mRNA expression in small intestinal mucosa decreased in hemorrhagic shock 0.5-hour group,followed by a further reduction in hemorrhagic shock 2-hour group (P ＜0.05).Localized expression of Occludin in hemorrhagic shock O.5-hour group was weakly positive.Occludin content in hemorrhagic shock 2-hour group showed significant reduction when compared with that in hemorrhagic shock O.5-hour group (P ＜ 0.01) and its localized express was negative as well.Conclusion Occludin expression in intestinal epithelial cells decreases obviously with a prolonged bleeding time,which is presumed to be an important basis for disruption of cellular tight junction.