| Object Blood brain barrier(BBB) is a important structure base in maintaining inner circumstance stabilization of Central never system.The Aim of this experiment is study the character of BBB changes, the door of BBB and the expression of VEGF-A in rat brain trauma model. Method We make parital f-ocal contusion and laceration rat animal model .In the first part of experiment, Quantitative measurement of Evans blue (EB) extravasation in both cotex and hippocampus using fluorescence was employed at lh,6h,12h and 1d, 3d, 5d, 7d,10d after injury. We employed fluorescence microscope to observe if EB extravasation was existing in two sides cotex and hipocampus. We oberv-ed the function of blood vessel and endothelium in both sides hipp- ocampus at ultrastructure level at 3h, 12h, 3d after injury, employing transmission electronic microscope and lanthanum trance labelling. In the second part of this experiment,the rat brain coronal cryostatal section in different course after injury were incubation with VEGF -A, GFAP antibodies, employing im-munohistochemistry and immunofluorescence.The tissue adjective contusion contex and ipsilateral hippocampus was obtain in order to carry out Real-timeRT-PCR. Result â‘ The content of EB increased in 1-6h and 1-7d after injury.The extravasation peak course is 3h and 3d. The content descended in 12h after injury,but the quantity is above the level of control rats. The EB content of ipsilateral cortex in 10d and the ipsilateral hippocam- pus in 7d returned to control level. The The EB content of ipsilateral cortex in 3h was more than that in 3d. But The EB content of ipsilateral hippoc-a mpus in 3h had no differience with that in 3d.The EB content in contralateral cortex and contralateral hippocampus after had no differience with control group.We observed red fluorescence in ipsilateral hippocampus at 12h after injury, employing fluorescence microscope. â‘¡In ipsilateral hippocampus, lanth- anum nitrate diffused into brain tissue,and the vessel is intact at 3h and 3d after injury A lot of vesciles , vacuoles ,villus finger-like tuber was found in endothelium of capillary wall at the time.The lanthanum nitrate was also be found in brain tissue out of vessel in 12h. But the quantities of vacuoles, vil- lus is more less than opening time.â‘¢ The VEGF-A positive cells appeared in ipsilateral cortex ajective the contusion tissue and ipsilateral hippocampus from 1d to 7d after injury. The p-eak is 3d.This kind of cell disappeared at 10d after injury.Double immuno-fluorescent staining for VEGF-A and GFAP demonstrated that this kind of cells was astrocytes.The density of VEGF-A-positive astrocyte ajective contusion tissue was high ,and that remote from contusion tissue is low. The VEGF-AmRNA increased at 12h-7d after injury,the peak is 3d. Conclusion â‘ The BBB opening in ipsi- lateral cortext and ipsilateral hippocampus is biphasic. A little great molecular -weight protein leak in middle time between the two opening period. Zero-le- akage-rate is not e-xit in this time. â‘¡The BBB routeway in ipsilateral hi- ppocampus at opening time is opening of tight junction and enhanced transport ability of endothelium .Opening of tight junction exit in ipsilateral hippocampus at middle time. Transport ability of endo- thelium is much weaken than that in Opening time. â‘¢ VEGF-A-positive astrocyte appears after injury.VEGF-A is close relation with the second BBB opening,and has no relation with the first BBB opening.
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