Influence of local administration of autologous platelet-rich plasma on the level of expression of matrix metalloproteinases in experimental tendinopathy

Abstract

Purpose: To evaluate the expression of matrix metalloproteinases in the calcaneal tendon tissue under conditions of experimental tendinopathy and under the influence of local administration of autologous platelet-rich plasma. Material and methods: The study was conducted on 20 mature Wistar rats divided into 5 groups. In all groups, experimental modeling of tendinopathy of the calcaneal tendon was performed by intra- and near-tendon injection of 0.5 ml of a 10 % suspension of sterile talc. Further, autologous platelet-rich plasma (PRP), hyaluronic acid preparation Rusvisk (Russia) or their sequential combination was injected into the area of tendinopathy. The results of the study were evaluated after 10 weeks; autopsy preparations prepared for immunohistochemical analysis were studied using light microscopy and morphometry. Results: Histological signs characteristic of tendinopathy were identified: disorganization of collagen structures, mucoid and lipoid degeneration, neovascularization, lymphoid-histiocytic infiltration. Injection of PRP into the area of simulated tendinopathy, hyaluronic acid, or their sequential combination led to changes in the immunohistochemical pattern of the tissue. As a result, there was a decrease in the expression of immunoreactive material in the cytoplasm of tenocytes and cells of the inflammatory infiltrate, compared with the picture observed in micropreparations in animals with tendinopathy, which were not subjected to any manipulations. Conclusion: The introduction of PRP into the area of the calcaneal tendon under conditions of experimental tendinopathy reduces the level of expression of matrix metalloproteinases and, thereby, preserves the structure of the tendon tissue, demonstrating tendoprotective properties.