Functional outcome of bone marrow stem cells (CD45+/CD34-) after cell therapy in acute spinal cord injury:: In exercise training and in sedentary rats

Background. Cell therapy and exercise training may be options for spinal cord regeneration. Our objective was to evaluate the functional effects of autologous bone marrow stem cell (CD45(+)/CD34(-)) transplantation in acute spinal cord injury in exercise training and in sedentary rats. Materials and Methods. Fifty-five adult male Wistar rats underwent spinal cord contusion by Impactor (NYU). Locomotor rating scale was performed every 48 hours for 48 days. Animals with scores <= 12 were randomly divided into 4 groups: sedentary without parenchymal cell infusion; sedentary with parenchymal cell infusion; swimming training without parenchymal cell infusion; and swimming training with parenchymal cell infusion. Bone marrow stem cells were isolated by puncture-aspiration of the bone marrow and density gradient (d = 1.077). The animals underwent a 60-minute swimming session 6 times/week supporting an overload of 3% of body weight for 6 consecutive weeks. Comparisons between the groups in relation to differences between the beginning to the end of scores used the nonparametric Bonferroni test and post-hoc Mann-Whitney U test to identify significance. Results. Forty-two rats that obtained scores <= 12 underwent therapy with 9 animals in each of the 4 groups as completors (n = 36). There was significance (P <=.008) for sedentary without parenchymal cell infusion vs swimming training with parenchymal cell infusion. Conclusion. The combination of bone marrow stem cell therapy (CD45(+)/CD34(-)) and exercise training resulted in significant functional improvement in acute spinal cord injury.