Effect Of Acute Psychological Stress On Gastrointestinal Barrier Function And Colonic Dynamics

Objective:To observe gastrointestinal membrane barrier function and colonic dynamics in wistar rats under acute psychological stress.Methods:Fifty-five male wistar rats under3hours of restraint stress were randomly divided into4groups, respectively having0hours (14),3hours (14),9hours (14),21hours (13) of recovery. Additional13rats which subjected to3hours of fasting to food and water were treated as control. Feces output were collected and counted after the3hours of stress or fasting. Rats were anesthetized using pentobarbital at respective time point. Blood plasma was collected and stored at-80℃until serving for detection of diamine oxidase(DAO) and D-lactic acid (d-lact). Stomach, ileum and colon were assessed in naked eyes and samples of each were collected for mucosa membrane damage assessments after HE staining. One of the tight junction proteins, occludin, was detected using immunohistochemistry staining in ileum and colon membrane. Apoptosis in ileac membrane were elevated using TUNEL technology.Results:After3hours of restraint stress, gastric membrane showed extensive erosion, which recovered during time. Gastric membrane in HE showed congestion, hemorrhage, epithelial cell necrosis after3hours of restraint stress and recovered during time. Ileac and colonic membrane showed similar reaction but much more moderate. Apoptosis increased after the stress significantly. Anti-occludin staining showed decreased optical density in stress rats, but without statistical significance. There was no significant difference between restraint animals and the control in plasma DAO and d-lact. Feacal output significantly increased in the stressed animals. Conclusions:(1) The restraint method used in the study successfully induced acute psychological stress of wistar rat.(2) Acute psychological stress resulted in damage of the gastrointestinal membrane from morphology to barrier function.(3) Barrier dysfunction of this model might mainly due to epithelial cell apoptosis increase, accompanying with tight junction damage to some extent.(4) Psychological stress promoted colonic dynamics.