Résumé
Objective @#To ob serve the expression and trends of tight j unction proteins Occludin and zonula occluden-1 (ZO-1) in blood brain barrier (BBB) of rats with traumatic brain injury (TBI) , and to explore the intervention effect of cannabidiol (CBD) on the BBB . @*Methods @#The TBI model of rat was prepared by modified “Feeney free fall method ”and randomly divided into three groups : the sham operated group ( Sham group) , the model group (TBI + vehicle group) and the CBD intervention group ( TBI + CBD group) , with 24 rats in each group . Each group was subdivided into six time points : 8 h , 1 , 2 , 3 , 5 and 7 d after injury. The expression of Occludin and ZO-1 , which are closely related to the permeability of BBB , was detected by immunohistochemistry , immuno fluorescence staining and Western blot at different points . The permeability of BBB was detected by sodium fluores cein assay.@*Results @#The results of immunohistochemistry showed that compared with Sham group , the positive ex pression of Occludin and ZO-1 decreased with time after brain trauma ( P < 0.05) , and both reached the lowest level at 2 d . The expression levels of Occludin and ZO-1 were up regulated after 1 d of CBD intervention ( P < 0.05) . Immunofluorescence staining showed a similar trend to Western blot results , with Occludin and ZO-1 fluo rescence expression intensity and protein expression reduced after TBI compared with Sham group ( P < 0.05 ) . And the expression levels of Occludin and ZO-1 were up regulated after 2 d of CBD intervention (P < 0.05) . The results of fluorescein sodium experiment showed that the BBB integrity of brain tissue was destroyed after TBI , and the permeability increased after TBI (P < 0.01) . The permeability of BBB decreased after CBD intervention (P < 0.05) . @*Conclusion @#The expression of tight junction proteins O ccludin and ZO-1 decreases after TBI , and the permeability of BBB is disrupted , and CBD intervention reverses the disruption of the BBB by TBI .
Résumé
Objective @#To observe the expression of glial fibrillary acidic protein (GFAP) in the brain tissue of rats with traumatic brain injury (TBI) and the differential changes between brain regions.@*Methods @#The TBI model of rats was prepared by the modified Feeney free fall method , and it was randomly divided into the sham⁃operated qPCR were used to observe the morphological changes of activated astrocytes and the expression of GFAP in different brain regions after TBI.@*Results @#Immunohistochemical staining showed that astrocytes were activated in all brain regions on the right side of TBI , and the only brain regions that spilled over to the contralateral side ( left) were cortical region 1 and midbrain regions. RT⁃qPCR results showed that GFAP mRNA was highly expressed in all brain regions on the right side of TBI , affecting the contralateral cortex and midbrain regions. Western blot results showed that GFAP protein was highly expressed in all brain regions on the right side of TBI , and it spread to the contralateral midbrain regions. @*Conclusion @#TBI can cause the activation of astrocytes and increase GFAP expression in the right brain regions , while also affecting the contralateral (left) cortex 1 and midbrain regions.