Histological Study on the Possible Role of Platelet Rich Plasma in Repair of induced Acute Skeletal Muscle Injury in Adult Male Albino Rats.

Introduction: Musculoskeletal injuries are widespread causes of sport injuries. Ordinary therapy is inadequate for rapid healing. So, in this study, the therapeutic effects of platelet rich plasma (PRP) were investigated as it is simple, efficient, and minimally invasive, and lessen recovery time. Materials and Methods: Fifty-four adult male albino rats, were categorizes into four groups: Group I (control group). Group II had a crush injury to the right gastrocnemius muscle, then sacrificed after 2 hours. Group III received no treatment and were subdivided into subgroups III A and III B, each includes 6 rats sacrificed after 7 and 14 days, respectively. Group IV, were injected immediately after injury by 0.1 ml PRP in injury site, then were subdivided into subgroups IV A and IV B, each includes 6 rats sacrificed after 7 and 14 days, respectively. Blood samples were analyzed for serum creatine phosphokinase (CPK) level. Sections from the middle part of the right gastrocnemius muscle were processed for histological assessment using H. and E., Masson trichrome stain, immunohistochemical staining for myogenin immunoreactivity, in addition to semithin and ultra-thin sections for light and electron microscopic examination, followed by morphometric and statistical studies. Results: Sections of group II showed disorganized, fragmented, discontinued, and tapering muscle fibers, disrupted Z discs at focal areas and giant disfigured mitochondria. The CPK level and mean number of myogenin immunoreactive nuclei and mean area percent of fibrous tissue were elevated, while the mean diameter of muscle fibers was decreased versus the control. Group III showed partial improvement, significant decrease in CPK level and increase in mean area percent of fibrous tissue, mean number of myogenin immunoreactive nuclei and in fiber diameter. Group IV showed prominent improvement. Conclusion: Platelet rich plasma could enhance repair of acutely crushed skeletal muscle and accelerate the healing process with minimal fibrosis. [ABSTRACT FROM AUTHOR]