Effects Of Chronic Restraint Stress On The Intestinal Barrier Function Of Rat And The Mechanisms

Objective: To observe the the effect of chronic restraint stress on the intestinal barrier function of rats and the possible damaging or protective mechanisms in this process. To discuss the influences of glutamine (Gin) supplementation on the intestinal barrier function of rats under chronic restraint stress. Methods: Wistar rats were randomly divided into five groups: I control group, IJ one-week stress group,III two-week stress group. IV three-week stress group. V Gln+three-week stress group.The rats of II ,III,IV. V group were suffered through restraint stress.These rats were immobilized by restraint cages,6 hours per day.The growth,food intake and weight of rats were observed in this process.The treatment of five groups were ended up on the same day.The tissues of rats were collected to detect the indexes and make a pathological observation by using light microscope. Results: (1) When restraint stress began, all the treated groups had a trend to lose weight and decrease food intake compared with control,especially the three-week stress group (P<0.05); (2)The D-xylose level in plasma of II,III,IV group was higher than control significently (P<0.01); (3)The DNA content of small intestinal mucosa in II,III,IV group decreased significently in comparison with control (II and IV vs control P< 0.01, III vs control P<0.05).The protein content of small intestinal mucosa in three-week stress group reduced evidently compared with control and one-week stress group (P<0.05); (4)The level of acetylcholinesterase in plasma (/)<0.01) and the number of mast cells in small intestinal tissue (P<0.05) are lower than control significently.The CRH level of II and III group in plasma demonstrated a trend to increase compared with control.And the CRH level of three-week stress group was lower than II and III group evidently (P<0.05); (5)The NT content in plasma and intestinal mucosa demonstrated a change that increased in early stress phase and decreased in late stress phase in comparison with control; (6)The D-xylose level in plasma of Gln+three-week stress group increased significently compared with control (P<0.05) but was lower than other three treated groups evidently.The DNA content of small intestinal mucosa was elevated significently by glutamine supplementation (P<0.05) in comparison with three-week stress group and the protein content also had a trend to increase compared with three-week stress group.In brain,glutamine feeding made CRH content decrease and NT content increase significently compared with three-week stress group (P < 0.05).Themorphological observation showed that the structure of small intestinal villus was damaged by stress.After glutamine supplementing,the damage would reduce.The zone fasciculata of adrenal cortex had a failure characteristic.Conclusions:The intestinal barrier function of rats could be damaged by chronic restraint stress continuously.The mechanism might include the activation of mast cells and vagus.the action of CRH. NT maybe a protective factor in this process.Glutamine supplementation could ameliorate intestinal barrier function in stress rats through peripheral and central mechanisms.