Establishment Of A Rat Model Of The Post-dysenteric Bowel Dysfunction, Then The Change Of Gut Permeability And IL-1β In The Gut Mucosa

Backgrounds and Objective:Irritable bowel syndrome is a common functional gastrointestinal disorder.It's pathogenesis remains speculative and unclear.And an ideal animal model for the research of this disorder is still scarce.The aims of this study are:establishing a model of post-infectious bowel dysfunction in rat,measruing the gut permeability and investigating the expression of IL-1beta in ilem and colon mucosa in rat with post-infectious bowel dysfunction. Methods 40 male Wistar rats were randomly administered saline or Shigella flexmeri of 2ml in a concentration of 5*109cfu\ml by oral gavage. Stool form was observaed every day., and stool was collected for cultivation of shigella flexmeri on day1,3,14,21 , perceptual threshold was measured with rectal balloon distention on day 21,42,63 after infection for visceral sensitivity,on day 68 the gut permeability was measuered :after an overnight fast,rats were adminsterered a solution containing lactulose ,mannitol and sucralose,urine was collected for 0-5h and 6-24h separately,.urinary sugars were quantified by gas chromatography, 5-h excretion rate between lactoulose and mannitol and 6-24h excretion of sucralose were calculated.On day 69,histological change of distal ileum and proximal colon were observed for the inflammation,and expression of IL-1beta was determined by immunohistochemical staining (S-P method). Results 21 days after acute enteric infection , stool cultured negatively more than twice ,stool form altered and perceptual threshold decreased greatly in experiment group compared with control group(P<0.05),while no histological inflammation was found in distal ileum and proximal colon. 0-5h excretion rate between lactoulose and mannitol and 6-24h excretion of sucralose were increased significicalty in experiment group compared with control group(P<0.05), the positive rate of IL-1 beta in the distal ilem and proximal colon were higher than that in control groups. Conclusions It is successfully to establish a rat model of post-infectious bowel dysfunction with bacteria.Viscreal hypersensitivity exists in rats at day 21~63 after acute shigella flexmeri infection even enteral infection diminishes and histological normalizes. Gut permeability and the expression of IL-1beta in mucosa are increased in post-infection bowel dysfunction rat.