5'adenosine monophosphate activated protein kinase (AMPK) bradycardia calciuneurin. CaMK (calmodulin-dependent kinase) IGF-1/Akt/mTOR signaling pathway NFKB (nuclear factor kappa B) overload PGC-1a (peroxisome proliferator-activated receptor gamma coactivator lo) p38 (mitogen activated kinase p38) reversibility specificity