抄録
The innervation of skeletal tissues may be actively involved in bone repair and in remodeling of callus tissue during fracture healing. Neuropeptides which have been localized in nerves in bone and periosteum have especially been implicated as mediators of bone formation and bone resorption. The aim of this study was to assess the effect of capsaicin induced sensory denervation on bone healing subsequent to experimental fracture of rat tibiae. X-ray findings, histologic findings, and osteocalcin-immunohistochemistry were used in the assessments. The appearance of callus formation in X-ray findings was slightly delayed in the capsaicin treatment group. However, remodeling was completed in the treatment and control groups at 35 days. Histologic findings showed a slight delay of membranous and enchondral ossification in the treatment group with significantly decreased histologic score at 7 and 11 days. Osteocalcin immunoreactivity was found in cells surrounding newly formed bone and in some periosteal cells, but there were few immunoreactive cells in the cartilage layers. Immunoreactive cells were significantly decreased in the treatment group at 4 and 7 days. The results of this study suggest that neuropeptides may regulate osteogenic activity of bone cells and be involved in differentiation of mesenchymal cells into osteoblastic subsets in the early stage during fracture healing.
