Activation peptide of coagulation factor IX improves the prognosis after traumatic brain injury

Recently, coagulation factor IX and its activation peptide have been reported to suppress the permeability of vascular endothelial cells. In this study, the therapeutic effects of a synthesized activation peptide is investigated in traumatic brain injury model rats. In cerebral contusion, dysfunction of the blood brain barrier with increasing vascular permeability promotes the progression of neuropathy after injury. The model rats were generated by controlled cortical impact. Then, rats were intravenously injected with 350 μg/kg of the synthesized activation peptide or PBS as a control, every day for a month. Behavioral studies were conducted during a month of observation. For morphological analysis, macro- and microscopic observation were performed. Water content of brain tissue was used to assess edema. To assess the function of blood brain barrier, Evans Blue method was employed. In the neurological examinations and beam-walking, the treated rats performed significantly better than control rats. Measurements of cerebral defect volume showed that the treatment significantly reduced it by 82%. Nissl stain showed that neural cells adjacent to impacts were lost in control rats, but saved in treated rats. The treatment significantly reduced brain edema and extravascular leakage of Evans blue. Intravenous injection with a synthesized activation peptide significantly reduced damage to neural tissue and improved neural functioning in the model rats.