Regulatory effect of CGRP on NOS in tibial fracture healing in the rat model of highly selective sensory and motor denervation / 医学研究生学报

ABSTRACT

Objective The aim of this study was to explore the regulatory effect of calcitonin gene-related peptide (CGRP) on nitric oxide synthase (NOS) and the nitric oxide (NO) pathway in tibial fracture (TF) healing in the rat model of highly selective denervation.Methods A total of 60 SD rats were randomly divided into three groups of equal number, TF control, TF + sensory denervation (SD), and TF + motor denervation (MD). At 1, 2, 3 and 4 weeks after modeling, osteotylus samples were obtained from the rats for observation of the bone morphology and determination of the expressions of CGRP and NOS by immunohistochemistry and HE staining.Results At 2 and 3 weeks after modeling, the rats of the TF+SD group, as compared with the TF controls, showed significantly decreased expression of CGRP (0.150±0.014 vs 0.210±0.013, P<0.05; 0.143±0.017 vs 0.203±0.013, P<0.05) and that of eNOS in the osteotylus (0.170±0.016 vs 0.219±0.026, P<0.05; 0.158±0.016 vs 0.201±0.013, P<0.05).Conclusion Selective denervation, especially sensory denervation, may change the expression of CGRP and thereby that of NOS in the osteotylus of the rat with tibial fracture, which consequently affects the growth of the osteotylus and fracture healing as well.