Bladder Function Recovery in Rats With Traumatic Spinal Cord Injury After Transplantation of Neuronal-Glial Restricted Precursors or Bone Marrow Stromal Cells

Purpose: We investigated functional recovery of the lower urinary system in rats with spinal cord injury after transplanting neuronal restricted precursors/glial restricted precursors or neural cells derived from bone marrow stromal cells into the injured area of the spinal cord. Materials and Methods: A total of 30 rats underwent experimentation in 4 groups, including group 1-sham operation, group 2-spinal cord injury plus neuronal restricted precursor/glial restricted precursor transplantation, group 3-spinal cord injury plus bone marrow stromal cell transplantation and group 4-spinal cord injury control. All rats in the 4 groups were investigated urodynamically and sacrificed on day 28 after transplantation. The cells transplanted into the injured spinal cord underwent histological investigation. Results: Transplanted cells (neuronal and glial restricted precursors, and bone marrow stromal cells) were found to maintain a presence in the injured spinal cord area. Baseline pressure, maximum capacity, mean uninhibited contraction amplitude, mean voiding pressure, voided volume and post-void residual volume were significantly better in groups 2 and 3 than in group 4, while baseline pressure in group 2 was better than that in group 3. We found no significant difference among the groups according to mean uninhibited contraction frequency. Conclusions: Although neuronal/glial restricted precursor transplanted rats seemed to have more improvement, all rats in groups 2 and 3 showed some significant improvement in lower urinary system function. On the other hand, the level of this improvement was far from complete functional recovery.