Background and Objectives: β1 integrin acts as mechanical receptors and vinculin is major protein in the focal adhesion site that transfers mechanical signals. The purpose of this study was to investigate the effects of eccentric exercise on β1 integrin and vinculin proteins in fast and slow-twitch muscle of male Wistar rats. Materials and Methods: Eighteen Rats (286.44±29.7) following appropriate acclimatization with the environment and treadmill machine, were divided randomly in to three groups (Exp1, 2 and Controls).They ran 40 min downhill running on a 16 degree down sloped treadmill with the speed of 20m/min. After 48 h, animals were anesthetized and Soleus and EDL muscles were excised to measure β1integrin and Vinculin proteins using ELISA method. After 24 and 48 h, animal serum was also taken to measure Creatine Kinase activity. Data were analyzed using T-test and one way ANOVA. The level of significant was set at p<0.05. Results: Result showed that Creatin Kinase increased but not significantly. After 48 h following eccentric exercise, β1integrin and Vinculin significantly decreased (22 and 21% respectively) in the slow-twitch muscle.And also in the fast-twitch muscle β1 integrin was decreased (17%), but Vinculin was increased (7%) significantly. Conclusion: Because of increasing the Creatin kinase, about of eccentric exercise could cause injury, and protein degradation is continuing in the slow-twitch muscle even 48 h after the exercise. Hypertrophy and constriction induced injury will be continued in a longer period. However more researches are needed.
Keywords: Costameric, β1 integrin, Vinculin, Eccentric exercise, EDL and Soleus