Effect of resistance training on plasma FGF-2 and Myostatin level in male Wistar rats

The purpose of present study was to determine the effect of 8 weeks of  resistance training on serumic myostatin, and Fibroblast Growth Factor-2 (FGF-2) level in male Wistar rats. 20 adult male wistar rats(150-250gr) were randomly divided into 2 groups [control group; n=10 (C), resistance training; n=10 (R)]. Resistance training was conducted for 8 weeks (5 session/week) on a special 1 meter height ladder (divided by 26 stairs) with loading of 30٪ of body weight (suspended from the tail) in the first week and increased to 200٪ of body weight in the last week. Training includes 3 sets of 4 reps with 3 minutes rest between sets. At the end of last week blood samples were taken from the rats and myostatin, TGF-β1 and FGF-2 was measured in three groups with the ELISA kit. At the end of the study ،the plasma levels of the myostatin decreased [71/82±19/62 mg/dl (R) ver. 105/86±17/49 mg/dl(C). (p≤0/001)], but the level of FGF-2 increased significantly in resistance training group [102/462±11/135mg/dl (R) ver. 86/96±12/606 mg/dl (C) (p=0/048)]. In contrast, the serum level of TGF-β was not statistically different between the two groups [153/48±54/09 mg/dl (R).160/62±32/85 mg/dl (C). (p=0/725)]. This study shows that 8 weeks of resistance training reduces serum levels myostatin and increased serum levels of FGF-2. These two factors cause activation or non-activation of satellite cells (Muscle stem cells that control muscle hypertrophy). However the nerve - muscle agents in the first 8 weeks of resistance training have the maximum participation on strength increases, but in this research we see affect the signals of satellite cells in the first 8 weeks of resistance training can change significantly. Also, although serum levels of TGF-β1 in the exercise group was significantly different from the control group, but the overall value of the exercise group had slightly reduced.