The Expression Of Occludin Protein And Its Influence In Blood-brain Barrier After Cardiopulmonary Resuscitation In Rats

Objective:To investigate The expression of Occludin protein and its influence in blood-brain barrier after cardiopulmonary resuscitation in ratsMethods:200 Sprague-Dawley male rats were randomly divided into two groups:group A(Sham group,n = 100) Only with the corresponding anesthesia and arteriovenous intubation and endotracheal intubation, without choking and CPR. And then divided it into two groups:group A1(50)and group A2(50). group B(CPR group,n=100) Production recovery model,when Spontaneous circulation recovery after cardiopulmonary resuscitation(CPR),divided it into two groups:group B1(50)and group B2(50). Change of MAP was measured within 60 minutes in group A after operation and group B after ROSC. Brains were decapitated at 2h、6h、12h、24h、and 48 h after operation and stabilize 10 minutes in A1 groups and after ROSC in B1. Western blot and immunohistochemical staining method was applied for brain tissue HIF-1a、VEGF and Occludin expression test, while water content of the brain was measured by wet and dry weight therapy. Evans blue had been injected by caudal vein tow hours ago when Brains were decapitated at2h、6h、12h、24h、and 48 h after operation and stabilize 10 minutes in A2 groups and after ROSC in B2.The permeability of BBB to Evans Blue was measured by fluorospectrophotometer.SPSS 14.0 software was used for Statistical analysis.The experimental results is compared between groups using one-way ANOVA,Statistical differences were considered significant when p < 0.05.Results:① The weight、respiration、heart rate in basic condition and the changes of MAP were no significant difference between groups(P> 0.05).②Brain HIF-1a protein expression in group B1 increased at 2h and reached its peak at 12 h after ROSC, then its expression decreased at 24 h and still above normal at 48 h,with asignificant difference compared with the group A1(P <0.05 or P <0.01);③Brain VEGF expression in group B1 increased at 2h and reached its peak at 12 h after ROSC, then its expression decreased at 24 h and still above normal at 48 h,with a significant difference compared with the group A1(P <0.05 or P <0.01);④Brain Occludin expression in group B1 drop at 2h and reached its lowest at 12 h after ROSC, then its expression increased at 24 h and still below normal at 48 h,with a significant difference compared with the group A1(P <0.05 or P <0.01);⑤ The water content of brain tissue in group B1 increased at 2h and reached its peak at 12 h after ROSC,then gradually decreased at 24 h,but maintain above normal at 48 h,with a significant difference compared with the group A1(P<0.01 or P <0.05);○6 The EB content of brain tissue in group B2 increased at 2h and reached its peak at 12 h after ROSC,then gradually decreased at 24 h,but maintain above normal at 48 h,with a significant difference compared with the group A2(P<0.01 or P <0.05);Conclusions1. Brain HIF-1a 、VEFG protein expression in every point of time after ROSC all exceeded the Sham group,While Brain Occludin expression all below the Sham group.The expression of Occludin decreased as the increasing of HIF-1a and VEFG. 2. The EB and water content of brain tissue in every point of time after ROSC all exceeded the Sham group. The BBB permeability increased as the decrease of Occludin. 3. The HIF-1a induce VEGF working at Occludin and reduce its expression, destroyed the TJ structure and increased the BBB permeability.