Study On Correlation Of Cellular Immune And Intestinal Permeability After Severe Trauma-hemorrhagic Shock In Rats

Objective: Through the establishment of severe trauma-hemorrhagic shock animal model, we investigated the correlation of cellular immune and intestinal permeability after severe trauma-hemorrhagic shock in rats in order to further understand the mechanism of shock and its complications and provide a theoretical basis for clinical treatment in patients.Methods: Thirty healthy adult male SD rats were randomly divided into the experimental group with 24 rats and the control group with 6 rats. Carotid canuallation were applied and connected with baroreceptor to monitor blood pressure in all rats. The model of severe trauma-hemorrhagic shock was made in the experimental group, by which the femur bone was fractured and the femoral artery were canuallated with blood drowing out till the blood pressure dropped to 40mmHg. Then the blood samples were collected from the inferior vena venous at the onset of the shock, 1h, 2h and 3h after the set-up of the shock. The endotoxin, diamine oxidase and D-lactic acid in plasma were determined by ELISA method. The lymphocyte subsets CD3+CD4+ and CD3+CD8+ contents were determined by flow cytometry and CD4/CD8 were calculated. The pathological changs of the ileum mucosa were observed samultanueslly with HE staining.Results: The contents of endotoxin, diamine oxidase and D-lactic acid in blood were higher in experimental group than those in control group, accompanied with a gradually increasing trend to the maximum value with the increasing time after shock. There were the statistically significant differences in those indexes among the time points in experimental group (P<0.05). Helper T lymphocytes (CD3+CD4+) were decreased in experimental group compared with those in control group with a gradually decreased trend to the minimum value as shock prolonged. Suppressor T lymphocytes (CD3+CD8+) increased in experimental group compared with those in control group with a gradually increasing trend to the minimum value as shock prolonged. CD4/CD8 values were significantly lower in experimental group than those in control group with a gradually decreasing trend to the minimum value as shock prolonged (P<0.05). The pathological changs of distal ileum: The villi of distal ileum were normal and integrital in control group. In experimental group, there was basically integrital intestinal mucosa without pathological changs in villus epithelials at onset of the shock. There were partly shed and edema in intestinal mucosa with no significant infiltration of inflammatory cell at the 1st hour of shock. There were obviously shedding and edema with the infiltration of inflammatory cell such as lymphocytes infiltration in the intestinal villus epithelials at the 2nd hour of shock. There were remarkable shedding and edema as well as infiltration of inflammatory cell in intestinal villus epithelials at the 3rd hour of shock.Conclusion: This study demanstrates that the levels of serum endotoxin, D-lactate and diamine oxidase are positively correlated with the pathological changs of intestinal wall, while negatively correlated with CD4 and CD4/CD8 ratio after severe trauma-hemorrhagic shock. Those changes above happens almost synchronously. Therefore, the study inplies that the ischemia and hypoxia of intestinal epithelials during traumatic-hamorrhagic shock is correlated with the increase of intestinal permeability and decrease of cellular immune function.