[Model of diffuse axonal injury and focal brain injury in rats].

OBJECTIVE: To establish a rather ideal experimental brain injury model in rats, in which diffuse axonal injury(DAI) and focal brain contusion were made concurrently. METHODS: The pathophysiological changes were monitored, and the histological changes were observed under naked eye, microscope and electric microscope. RESULTS: 1. The mortality in the group suffering from DAI with focal contusion(Group A) was much higher than that in DAI(Group B) and sham group(Group C); 2. The time of post-injury primary coma in Group A [(5.19 +/- 0.49) h] was longer than that in Group B [(2.75 +/- 0.16) h] and Group C [(2.77 +/- 0.20) h] significantly(P < 0.01); 3. Immunohistological examination showed that the diffuse axonal injury could be seen in several parts of the brain(subcortical, corpus callosum and brainstem) in Group A; 4. We observed in Group A under electric microscope that the axons were swollen and degenerated fragmently, neurofilaments ranged disorderly and there was vacuolation. CONCLUSION: The model is cheap, simple and can be easily repeated. Furthermore it can be used to research the changes of pathophysiology, histology and moleculobiochemistry of head injury in human beings.