The Establishment Of Rat Model With Intestinal Dysfunction Induced By Cold Restraint Stress And Study On Changes Of The Intestinal Barrier And Expressions Of IL-1β And IL-4 In The Gut Mucosa

Irritable bowel syndrome is the most common functional intestinal disorders,of which the pathogenesis is not yet clear.To establish rat model of intestinal dysfunction ,is benefit to study the its pathogenesis and guide the reasonable treatment .The further study for the patients with irritable bowel syndrome found that the existence of intestinal mucosal inflammatory response .The stress-induced animal experiments have shown that the damage of intestinal barrier and the increased mucosal permeability may be an important factor in inflammation.At present ,the study on intestinal barrier of the animal model of intestinal dysfunction has not reported and the experiment based on the model established conducted the related research,to explore the intestinal barrier changes possibly affected in the pathogenesis of the intestinal dysfunction and investigate the expression of IL- 1β,IL-4 in ilem and colon mucosa,so that provided a new direction to study the pathogenesis and treatment of IBS.Objective:To establish a rat model of intestinal dysfunction by cold-restraint stress and explore the effects of intestinal barrier changes and the expression of IL- 1β,IL-4 in gut mucosa on the pathogenesis of intestinal dysfunction.Methods:①Preparation for animal model :Forty Wistar rats of two month old were randomly divided into the model group,normal control group.The cold-restraint stress was performed to the model group.The methods as follows:the rat was placed into restraint device that partly limited its upper body and upper limb activity,than let it erect in the water of 8℃-10℃and the water surface was at the level of its xiphoid cartilage.Pay attention to the its response to the stress.When the rat breathed shallowly slow and two eyes closed tightly,the stress was stopped.The rat endured to the stress differently,and stress lasted from 0.5h to l.5h each time.The stress was performed one time one day,lasting for 5 days. In order to eliminate the biorhythm to the experiment,the stress was started to implement.The normal control group did not intervene.During the experiment,two groups,fences were scored according to the Bristol pattern,and colorectal distention was implemented to test the visceral sensitivity in 6th day,when intestinal permeability had been tested in 7th day,pathological changes of the colon and small intestine mucosa in two groups were measured . And the expression of IL-1β,IL-4 were determined by immunohistchemica1 staining﹙S-P method﹚.②Study on changes of intestinal barrier:Using gas chromatography,tested lactulose﹙L﹚and mannitol﹙M﹚excretion ration﹙L?M﹚in 5h urine and the sucralose excretion in 24h urine ,comparing the intestinal permeability of the model group and the normal group to reflect the changes of intestinal barrier.Result:①The fence of model group were mostly soft mass or muddy,Bristol score was 5.2±0.8;which of control group were delicately sausage or mass,Bristol score was 2.8±0.8,the difference was significant in the two groups﹙P<0.05﹚.The threshold of initial perception,pain and tolerance in the model group decreased more significantly than that in the normal control group﹙0.37±0.16 vs 0.58±0.05,0.89±0.30 vs 1.48±0.10,1.26±0.33 vs 2.00±0.08﹚,there was significant difference﹙P<0.05﹚.No significant structural damages and mucosa inflammation were obtained in model group.②The lactulose﹙L﹚ and mannitol﹙M﹚ excretion ration﹙L?M﹚in 5h urine and the sucralose excretion in 24h urine in the model group increased more significantly than that in the normal control group﹙0.74±0.06 vs 0.51±0.05,5.31±0.59 vs 3.81±0.58﹚,the difference was significant﹙P<0.05﹚.③The positive rate of IL-1βin the distal ilem and colon in model group were higher than that in control groups,the difference was significant﹙P<0.05﹚and the positive rate of IL-4 in the distal ilem and colon in model group comparing with that in control group,there was no significant difference﹙P>0.05﹚.Conclusions:①A rat model with intestinal dysfunction has been developed successfully by cold- restraint stress.②The intestinal permeability of the rat with intestinal dysfunction increases,and its may play a role in the pathogenesis of intestinal dysfunction.③The expression of higher IL-1βand normal IL-4 in the distal ilem and colon showing that existence the low grade mucosal inflammation in the intestinal mucosal with intestinal dysfunction.