The objective of this study was to test the hypothesis that vinculin and talin, two
cytoskeletal proteins of the myotendinous junction (MTJ), would be up-regulated following
damaging eccentric contractions. Mouse plantarflexor muscles were submitted in situ to three 5 min periods of eccentric contractions. Talin and vinculin content, in vitro contractile properties and MTJ histology were examined at 0, 3, 7, 14, and 28 days
post-exercise. The eccentric protocol led to significant decreases in maximum tetanic
tension at 0, 3, and 7 days post-protocol. Histological examination did confirm that
tissue damage was present at the MTJ where talin and vinculin are highly concentrated.
In the type I soleus muscle talin content increased slightly at 7 days post-eccentric
protocol compared to SHAM. In the type II plantaris muscle eccentric contraction led
to an increase for vinculin and talin contents that was 2 - 3 fold higher than in
the soleus; these significant changes were still present 28 days post-exercise. These
results show that eccentric contractions can trigger intense protein synthesis activity
at the MTJ most likely related to myofibrillogenesis associated with MTJ remodeling.
Skeletal muscle, talin, vinculin, mouse, mechanical stress
