Content changes in TGF-β and IGF-1 and their significance in the discs of diabetic rats

Abstract

Objective: To measure the content changes in transforming growth factor-β (TGF-β) and insulin-like growth factor-1 (IGF-1) in discs in diabetic rats and normal rats in three different periods after treatment with streptozocin (STZ) and to discuss the significance of the content changes.

Methods: Thirty Sprague-Dawley (SD) rats were divided into the treated group and the control group, with 15 rats in each group. In the treated group, the STZ solution was injected into the peritoneal of SD rats to establish the diabetic model. In the control group, no special treatment was performed on the SD rats. Complete lumbar discs in the two groups were obtained in the second, fourth, and sixth week, respectively. After paraffin-embedded sections and hematoxylin and eosin (HE) staining, the morphology changes in the disc were observed, and the TGF-β and IGF-1 contents were measured by the immunohistochemical method.

Results: HE staining showed degenerative changes in the disc in the treated group in the three different periods, but no changes were observed in the disc in the control group. The immunohistochemical method showed that the TGF-β and IGF-1 contents in the treated group were significantly lower than those in the control group in the three different periods (p < 0.05). No significant differences were found between TGF-β and IGF-1 in the two groups in the three different periods (p > 0.05).

Conclusion: Compared with those in the control group, the disc of STZ-induced diabetic rats in the treated group exhibited degenerative changes, and the TGF-β and IGF-1 contents significantly decreased. Thus, the decrease in the TGF-β and IGF-1 contents caused by diabetes could be one of the factors causing disc degeneration.