The Development Of An Experimental Brain Injury Model And The Expression Of BFGF And VEGF Following The Brain Injury

Objective: The present study describes the development of an experimental brain injury model, in which focal brain injury and diffuse axonal injury were induced at the same impact time. Study the expressions and interrelationship of bFGF and VEGF in different brain injuried areas and at different time with the model. Investigate the pathogenic mechanism of brain injury at molecular level and explore potential effective treatment for the dysfunction.Methods: We used the modified Marmarous rodent model of impact acceleration diffuse brain injury. 51 Spranue-Dawley(SD) rats were randomizly divided into sham, 1hr postinjury, 3hrs postinjury, 6hrs postinjury, 12hrs postinjury, 24hrs postinjury, 48hrs postinjury , 72hrs postinjury, altogether eight groups, every group n=6. The immunological positive of bFGF,> VEGF and neuropathological changes were observed on these rats using the method of immunohistochernical stain and histopathological HE staining. Three samples of S-D rats from 24hrs postinjury group were observed with electron microscope.Results: Massive and extensive SAH was observed in all injuried rats, intraventricular hemorrhage was also noted in some rats. Typical retraction bulls were observed in corpus callosum and brain stem at 24hrs postinjury. The expression of bFGF mRNA increased in cortices in 1hr postinjury and peaked in 12hrs postinjury in marginal areas of injured focus. It increased in cortices in 6hrs postinjury and peaked in 12hr postinjury in hippocampal CA1 sectors. The expression of VEGFmRNA increased following brain injury and peaked in 24hrs postinjury in marginal areas of focal brain injury, returned to normal in 72hrs. The expression of VEGFmRNA increased following brain injury in hippocampal CA1 sectors and peaked in 24hrs postinjury, reduced to normal in 72hrs.Conclusion: (1) It is the new model that the focal brain injury and diffuse axonal injury were established at the same impact time, that is useful, relatively simple, inexpensive, and the most important, is closer to actual status in human head injury.(2)There is a close relationship betweenbFGF, VEGF gene expression and the degree of brain injury. As a neurotrophic factor, bFGF may contribute to neuroprotective effects against injury and wound repairing following brain injury. The expression of bFGF and VEGF are positive correlation, bFGF might regulate the production of VEGF and effects with VEGF cooperatively.