| Objective:To study the effect of a-tocopherol on the expression of Nogo-A and NgR proteins in rats following cerebral brain injury. And to explore its mechanism in nerve regeneration.Methods:One hundred and forty healthy SD rats, approximately 250-300 grams, were randomly divided into sham operation group, TBI group andα-tocopherol group. Each group was divided into 5 subgroups on average by observation time of 1 day,3 day,7 day,14 day and 21 day. Each subgroup contains 8 rats. TBI group andα-tocopherol group were set up by the improved device of Freeney weight dropping model with impact 600 grams.cm. The rats in sham operation group, were only opened the scalp and bone windows, not to be beated. The intraperitoneal injection ofα-tocopherol was performed in theα-tocopherol group with 200mg/kg.d 6 hours after the model was established. Then the same treatment continued from 1st day to the day when the rats were killed. Rats in sham operation group and TBI group received only equal amount of saline. The test of mNss was performed to value neurological function in according time after operation. The pathological changes were observed by HE drum dyeing,and Immunohistochemistry was used to detect the the expression of Nogo-A and NgR proteins.Results:1. Histopathological changes:HE staining showed that in the sham group, rat brain structure was clear, even and compact. The TBI group appeared flaky hemorrhage, edema, infiltration of flammatory cell, kyryolysis and necrosis. Gradually glial cells and fibrous tissues appeared proliferous. Theα-tocopherol group mitigated to some extent compared with the control group.2. Compared with the sham group, the expression of Nogo-A protein in TBI group was higher than sham operation group at all time points (P<0.01), reaching the peak value at 14 day. Compared with the TBI group, the expression of Nogo-A in a-tocopherol group was markedly lower at all time points (P<0.05). It was statistically significant.3. Compared with the sham group, the expression of NgR protein in TBI group declined significantly at 1 day after TBI, with the lowest level at 3d, and gradually recovered to the level of sham group in 7d. Then continued to increase until 21d. The expression at 14d and 21d was higher than that in the according time in the sham group (P<0.01). The trend of NgR protein in a-tocopherol group is same with TBI group. With the lowest level at 3d and gradually recovered to the level of sham group in 7d,the expression at 14d and 21d was lower than that in the according time in the TBI group (P<0.01).It was statistically significant.Conclusions:1.α-tocopherol can effectively reduce the expression of Nogo-A and NgR of rats following traumatic brain injury and then promote the nerve regeneration.2.α-tocopherol can obviously reduce the damaged degree of rats with traumatic brain injury and play a role of neuroprotection.
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