Several groups have demonstrated that induction of heme-oxygenase-1 (HO-1) could protect the myocardium against ischemic events; however, heme accumulation could lead to toxicity. The aim of the present study was to investigate the role of autophagy in heme toxicity. H9c2 cardiomyoblast cells were treated with different dose of hemin or cobalt-protoporphyrin IX (CoPP