| Objective:To investigate the pathological mechanism of the changes in the permeability of blood brain barrier caused by diffuse axonal injury in the rat brain.Methods:In this experiment,70 male(SD)rats were randomly divided into normal control group(n=5),sham operation group(n=5),model group(n=30),PKC antagonist group(n=30).The model of diffuse axonal injury in rats was made by the method of optic nerve traction.All the rats were sacrificed before 1H from intravenous injection of Evans blue.Rats were killed at 1H,4h,8h,12h,24h after injury.A part of the brain tissue was taken out for the determination of OD620nm.HE staining was used to observe the morphological changes of diffuse axonal injury in the brain tissue.The protein expression level of beta-app and ZO-1 was detected by immunohistochemistry.The results were statistically analyzed,and the differences in the expression of beta-APP and ZO-1 in each group of brain tissues and the underlying mechanism were compared.Results:1.The amount of Evans blue extracted from brain tissue after Evans Blue(EB)injection was measured by a spectrophotometer.The index is expressed by OD620nm.The analysis results showed:(1)OD620nm comparison between normal control group and sham operation group,P>0.05;(2)OD620nm value and normality of lh group,4h group,8h group,12h group,and 24h group in DAI injury group The control group was compared with the sham group,P<0.05;(3)The OD620nm in the PKC antagonist group at 1h group,8h group,12h group,and 24h group was compared with the normal and sham groups,P>0.05;(4)DAI The OD620nm at the injury time was similar between the injury group and the PKC antagonist group,P<0.05 in the 8h group,the 12h group,and the 24h group.2.The analysis results of the target protein β-APP(the results of its analysis using the IOD measured by Image-pro Plus 6.0)show:(1)IOD comparison between normal control group and sham operation group,P>0.05;(2)DAI The IOD of the 1h,4h,8h,12h,and 24h groups in the injury group was compared with that of the normal control group and the sham operation group,P<0.05;(3)1h group,4h group,and 8h group in the PKC antagonist group The IOD of 12h group,24h group compared with normal control group and sham operation group,P<0.05;(4)The IOD of the same injury time between DAI injury group and PKC antagonist group was compared,1h group,4h group,8h group.The IOD values of the 12h group were P<0.05.3.The results of the analysis of the target protein ZO-1(the IOD measured by Image-pro Plus6.0)showed that:(1)IOD comparison between normal control group and sham operation group,P>0.05;(2)DAI The IOD of the 8h group,12h group,and 24h group of the injury group was compared with that of the normal control group and the sham operation group,P<0.05;(3)1h group,4h group,24h group and the normal control group and sham operation in the PKC antagonist group The IOD of the group was compared,P<0.05;and the IOD of the PKC antagonist group was greater in the 1h group and the 4h group than in the normal group and the sham group.The IOD of the ZO-1 protein in the 24h group of the PKC antagonist group was smaller than the normal group and false.Surgical group;(4)The DAI injury group and the PKC antagonist group had the same injury time,and the IOD values of ZO-1 in the 1h group,4h group,12h group,and 24h group were P<0.05.Conclusion:1.The expression of β-APP in brain tissue is correlated with the duration of DAI injury in rats,and there may be a peak between 8 hours and 12 hours,which provides a reference value for inferring the time of brain injury.2.Protein kinase C inhibitor H-7 can reduce the expression of β-APP caused by DAI in the first 12 hours of DAI injury,indicating that protein kinase C is involved in the expression of β-APP.3,protein kinase C inhibitor H-7 can significantly reduce the blood-brain barrier permeability,indicating that protein kinase C can improve blood-brain barrier permeability.4,protein kinase C inhibitor H-7 can increase the expression of ZO-1,so that the first 4 hours of DAI damage state,ZO-1 expression is higher than that of normal rats,indicating that in the diffuse axonal injury Initially,inhibition of PKC activity can increase ZO-1 expression.5.The expression of ZO-1 was negatively correlated with the duration of DAI injury state,indicating that diffuse axonal injury would reduce the expression of ZO-1 and increase the permeability of the blood-brain barrier. |
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