Early Stage Pathomechanism of Tendon Degeneration and Necrosis in Diabetic Foot

Objective: To investigate the mechanism of latent pathological changes in tendons in diabetic foot tendon gangrene (tendon degeneration and necrosis syndrome). Methods: Diabetic rat models were established by a one-off intraperitoneal injection of streptozotocin (STZ). We observed changes in body weight and fasting blood glucose levels of the rats over time. Rats were killed at specified intervals to detect pathological changes, ultrastructure and glucose, advanced glycation end product (AGE), hydroxyproline (Hyp) and myeloperoxidase (MPO) levels in tendon tissues in the model groups and the normal (control) group. Results: Changes in the ultrastructure, glucose, AGE, Hyp and MPO levels in the tendon tissues of all model groups were observed. However, the changes were to different degrees. The damage to tendon pathology and ultrastructure was directly proportional to the amount of time that had passed. The glucose, AGE and MPO levels were elevated, while the Hyp level was lower when compared with the normal group and the results were statistically significant (P <0.05 ~ P <0.001). Conclusion: The latent pathological changes observed in tendon tissues in the lower limbs of diabetic mellitus model rats occurred in the early stages of the disease. The mechanism might be associated with high glucose levels in tendon tissues, tendon tissue protein non-enzymic glycosylation, tendon matrix pathological changes and an inflammatory reaction.