Investigation of the effects of pentoxifylline and alpha tocopherol treatment on healing in rats with achilles tendon rupture

Objective : We aimed to investigate the effects of pentoxifylline and alpha-tocopherol treatments, when used separately and together, on rats with Achilles tendon injury. Materials and Methods: 48 Wistar female rats weighing 230±30 g were used in the study. Animals were housed in a cage in a room with controlled temperature (23-25°C), 60±5% humidity, and a 12:12 hour on/off cycle. Rats were randomly divided into 8 groups with 6 animals in each group. After one week acclimatization period, each rat was anesthetized by intraperitoneal injection of 10 mg/kg xylazine hydrochloride and 50 mg/kg ketamine HCl. After anesthesia, primary tendon repair was applied to all rats with end-to-end method after achilotomy. Postoperatively, pentoxifylline (PTX) was administered to groups 2a and 2b, alpha-tocopherol (aTP) to groups 3a and 3b, and both drugs to groups 4a and 4b were started to be administered intraperitoneally. Pentoxifylline was given at doses of 50 mg/kg/day and alpha-tocopherol at doses of 100 mg/kg/day. No drug was given to the control group throughout the experiment. At the end of the 14th day, the rats in groups 1a, 2a, 3a and 4a were sacrificed by applying cervical dislocation and their Achilles tendons were resected. These tendons were sent for histopathological examination. The rats in groups 2b, 3b, and 4b continued to be given the same doses of the drug. At the end of the 28th day, the remaining 4 groups were sacrificed in the same way, their tendons were collected and sent for histopathological examination. Results: As a result of the statistical analysis, the vascularity values of the 14th day PTX group were found to be statistically significantly higher than the control, aTP and PTX+aTP groups (p=0.018, p=0.027 , p=0.029). On the 14th day, the collagen arrangement of the PTX and aTP groups was found to be tighter and smoother than the control group (p=0.043, p=0.019). On the 28th day, the collagen sequence of the PTX group was found to be tighter and smoother than the aTP, PTX+aTP and control groups (p=0.003, p=0.016, p=0.03). Conclusion: Pentoxifylline contributed to tendon healing both by neovascularization in the early period and by correcting the collagen arrangement in the late period, while alpha tocopherol positively affected the collagen arrangement in the early period, but lost its effect in the late period. When pentoxifylline and alpha-tocopherol were used together, it did not provide a positive effect on tendon healing in the early and late periods. We think that further research is needed to understand the effects of this combination therapy on tendon healing. Keywords: Pentoxifylline, alpha tocopherol, vitamin E, achilles tendon, tendon healing