Integrin Signaling at 2hr and 48hr Post-Eccentric Exercise in Heat Treated Rat Skeletal Muscle

Abstract Introduction: Integrins (IN) are heterodimers made up of an alpha subunit and a beta subunit. They are transmembrane proteins that are capable of detecting and relaying signals from the extracellular matrix to the cytosol and vice versa. IN have been implicated in mechanotransduction and shear stress by becoming activated by these forces and starting intracellular cascades. Heat shock proteins are a highly conserved group of proteins that help protect cellular function by chaperoning and refolding proteins and by maintain actin structures of the cellular membrane. Methods: Heat shocked (HS+EE) and non-heat shocked (EE) male Wistar rats performed a two hour downhill treadmill exercise. The soleus (SOL), vastus lateralis white (VLW) and red (VLR) were harvested at 2hr and 48hr post exercise and tested for IN beta1 subunit, total and deactived c-Src527 and total and active ERK1/2 via SDS-PAGE and Westerm immunoblotting. Results: There were no significant differences between the treatment groups (EE and HS+EE) as well as the treatment groups versus controls in all muscles and at both time points. Conclusion: A two hour downhill treadmill protocol is not sufficient enough to activate IN and downstream proteins in healthy HS+EE and EE rat skeletal muscle at 2hr and 48hr post-exercise