Vitamin D improves the content of TGF-β and IGF-1 in intervertebral disc of diabetic rats

Objective: The contents of transforming growth factor-beta and insulin-like growth factor-1 in disc of diabetic rats were measured at three different periods after injected with 1,25-Dihydroxyvitamin D3, and compared with that in normal rats. The significance of content changes was also discussed. Methods: Fourty-five Sprague-Dawley (SD) rats were divided into three groups, namely the experimental group (STZ+calcitriol), control group (STZ+citrate buffer), and normal group (citrate buffer). Complete lumbar discs in these groups were obtained at the second, fourth, sixth week, respectively. After paraffin-embedded sections and HE staining, the structure and morphology changes of disc were observed. The content of transforming growth factor-beta and insulin-like growth factor-1 was measured by immunohistochemical method, and the expression of transforming growth factor-beta and insulin-like growth factor-1 was detected by Western Blot. Results: In hematoxylin-eosin staining, degenerative changes were observed in disc of experimental and control group at three different periods, and there were no changes in disc in normal group. Immunohistochemical method indicated the content of transforming growth factor-beta and insulin-like growth factor-1 in experimental and control group was significantly lower than normal group at three different periods (P< 0.05). And there were significant differences between experimental and control group at three different periods (P< 0.05). Conclusion: Vitamin D can protect the degeneration of intervertebral disc and improve the content of transforming growth factorb and insulin-like growth factor-1 in the intervertebral disc, which provides a new idea for the prevention and treatment of degenerative changes of the intervertebral disc in diabetic patients.