Veterinarski Glasnik 2020, 74 (1), 18-33

Introduction. Blood products, i.e. platelet rich plasma (PRP), leukocyte-poor plasma (PRP) and platelet poor plasma (PPP), have previously been used to improve muscle regeneration. In this study, six months’ frozen-stored PPP of individuals who practiced different types of physical exercise was analysed; it could steer mouse C2C12 myoblast cells towards proliferation, migration and myogenic differentiation, and it could affect the morphology/shape of myotubes. Materials and Methods. PPP of male Olympic weightlifters, football players and professional folk dancers, aged 15-19, was collected 12 h post-training and stored for 6 months at -20°C. C2C12 cell proliferation was assessed by MTT test, motility by scratch assay, myogenic differentiation by myotube formation and gelatinase activity by gel-zymography. Results and Conclusions. PPP induced proliferation and migration of C2C12 cells. Proliferative capacity was as follows: weightlifters > dancers > football players; mean migratory capacity was: weightlifters = dancers > football players. PPP induced formation of myotubes; significant inter-individual variations were detected: PPP from MASLOVARIĆ S. Irina et al.: Type of physical activity determine myotubes shape 19 weightlifters induced formation of round myotubes, and PPP from football players and dancers induced formation of elongated myotubes. The mean myotube area was as follows: football players > dancers > weightlifters. PPP gelatinolytic activity was observed; it was negatively correlated with C2C12 myoblast proliferation. These results provide general but distinct evidence that PPP of individuals practicing certain types of exercise can specifically modify myoblast morphology/function. This is significant for explaining physiological responses and adaptations to exercise. In conclusion, longterm, frozen-stored PPP preserves its potential to modify myoblast morphology and function.