Exercise training improves the adipocyte accumulation and muscle fibrosis of the muscle by TGF-β1 and α-SMA reduction after botulinum toxin type A administration in mice
Abstract Background: We aimed to investigate the effect of treadmill exercise on functional recovery of the mouse gastrocnemius muscle and nerve after botulinum toxin type A (BoNT-A) administration. Methods: After injecting 0.5 units of BoNT-A into the gastrocnemius muscle of ICR mice, treadmill exercise was carried out for a six-week period, after which the muscle volume, weight, and sciatic functional index (SFI) were obtained and nerve conduction study (NCS) and histological evaluation were performed. Results: There was no change in the gastrocnemius weight and volume, but NCS and SFI increased after exercise. Exercise prevented induced adipocyte accumulation and muscle fibrosis. Moreover, TGF-β1 and α-SMA expression decreased and CD34, BDNF, and SNAP-25 expression increased when treadmill exercise was performed after BoNT-A injection. Conclusions: The exercise was effective in the recovery of nerve function and would help in the recovery of muscle function by preventing accumulation of fat cells and muscle fibrosis after BoNT-A administration.