Study Of Phase Expression Of Neuritin In Rats After Traumatic Brain Injury

Traumatic brain injury (TBI) is that the head was hit suddenly by external force, that causedstructural change and damage of skull, meninges, cerebrovasculars, brain tissue and crania nerve,eventually leading to brain damage.TBI caused the highest mortality, morbidity and poorprognosis in all types of trauma. Various neurotrophic factors play a vital role in prognosis of TBI,prevention of nerve cell degeneration and apoptosis after TBI. Neuritin is a new factor thatassociated with neurotrophic factor, the expression of post-traumatic brain injury is unclear.Objective: Neuritin protein was detected at different time in brain tissues of SD rats TBImodel, and discussed the significance of neuritin protein on the repair process of post-TBI. Tofurther research the neurotrophic effect of neuritin protein after TBI lays a certain foundation.Methods: Tally42rats were randomly divided into two groups: normal group (n=6) andoperation group (n=36).Control groups was left cerebral hemisphere and operation group wasright cerebral hemisphere. Operation group was divided into6subgroups, namely,6h、12h、24h、3d、7d and14d(n=6).Rats brain injury model was established by improved Feeney method.Neurobehavioral scores were recorded by the eight arm maze. The changes of morphology of thebrain tissue were observed by HE staining. neuritin protein in rats’ brain tissues was detected byimmunohistochemical and western-blot at different time.Results: Neurobehavioral scores: The number of errors of working memory and referencememory and the test time increased in post-operation rats compared with pre-operation. There wasstatistically significant (p <0.05).The HE staining showed that post-operation6hours, never cellsbegan to edema, reached the peak after24hours. On the third day, a large number of never cellswere necrosis, a lot of Glial cells proliferated on the seventh day and recovered normally on thefourteenth day. There was no change in control group. The immunohistochemical analysis showedthat the positive expression of neuritin was strong in cytomembrane and cytoplasms of neuronsafter6hours in operation group. Neuritin protein was strongest positive expression from12hoursto7days, expression of neuritin decreased on the14days. Neuritin protein in control group andnormal group was weakly positive. Neuritin protein expression: expression of neuritin proteinbegan to increase at6hours in operation group, reached the peak at24hours and decreased fromthe3days to the7thday. It was statistically significant (p <0.01) compared with control group andnormal group, significant decrease on the14day (p <0.05).Conclusion：Neuritin protein in brain tissue significantly increased after TBI and there wasa certain phase, up-regulation of neuritin protein may play an important role in repair process ofpost-TBI.