RESUMO
OBJECTIVE: To identify the effective injection route for adult human bone marrow stromal cells into traumatic brain injured rats. METHOD: The TBI rats were created by the lateral percussion model (HD1700, Dragonfly, Silver Spring, USA). Eight rats without stem cell transplantation were assigned to a control group. We performed adult human bone marrow stromal cell transplantation into the contralateral hemisphere (n=7), the ipsilateral brain lesion (n=8) and via a tail vein (n=11), respectively, at 24 hours after brain injury. For all of the groups, MRS (magnetic resonance spectroscopy) study, behavior tests, rotarod tests and Barnes maze tests were conducted on day 1, day 7, day 42 and day 84. Sixteen rats were randomly assigned and were sacrificed for immunohistochemical staining. RESULTS: At day 42 (p=0.048) and day 84 (p=0.031) after TBI, the ratio of N-acetylaspartate to creatine (NAA/Cr) of the ipsilateral hemisphere was decreased in the control group, as assessed by MRS, whereas the ratio was increased in the other groups. On the post hoc analysis, significant differences were obtained among the intravenous group and the control group for the NAA/Cr ratio of the ipsilateral hemisphere at day 84 after TBI (p=0.050). However, there was no significant improvement on the behavior test, the rotarod test and the Barnes maze test. The cells were positively stained with antibodies to MAB-1281 and to GFAP. CONCLUSION: We confirmed that adult human bone marrow stromal cell transplantation induced an increase of the NAA/Cr ratio of the ipsilateral hemisphere at day 84 in the intravenous group. Therefore, we suggest the intravenous route is more effective for mesenchymal stem cell transplantation.