Introduction: Skeletal muscle injuries comprise the greater part of sports-related injuries. Role of growth factors in healing of injured tissue encouraged the use of platelet-rich plasma (PRP).
Aim of the work: We aimed to study the effect of PRP on skeletal muscle injury.
Materials & Methods: Forty adult male rats were divided into four equal groups; control and 2, 7, 14 days after the injury. The injured muscles were either treated with PRP or left without treatment. The rats were sacrificed and the muscle specimens were processed for histological and immunohistochemical staining for detection of Anti-MyoD, anti-CD34 and anti TGFβ1 followed by morphometric study.
Results: PRP treatment induced initial intense inflammatory response with neutrophils and macrophages cell infiltrate subsided in the 7th day. When compared to untreated groups, PRP treated ones showed significant increases in the mean number of regenerating muscle fibers (22.03±4.08) and angiogenesis (10.83±2.46) on the 7th day. The median number of MyoD immunopositive stellate cells showed a significant increase on the 2nd day ,72 (62-78) and then decrease on the 7th day; 28(22-33) to be non significant after 14th days; 4(3-5) of injury. A significant decrease in the mean area % of collagen deposition (2.27±.0.59, 3.68±0.72 and 4.76±0.82) and TGF β1 immunoexpression, medians; 5 (4.20-5.70), 2.50 (2.10-3.50) and 2.30( 1.60-3.20) after 2, 7 and 14 days, respectively, were observed.
Conclusions: PRP could exert a promising effect on skeletal muscle injuries via enhancing myogenesis, neovascularization and reduction of fibrosis. Since autologous blood preparations are safe, PRP may serve as a valuable adjunct in management of such injuries.