Accordingly, the goal of the present study was to test whether intracellular Zn2+ release besides Ca2+ release due to an increased oxidative stress/defective antioxidant defence system in cardiomyocytes under hyperglycemia mediates in part RyR2 leak and consequently diastolic dysfunction in heart from streptozotocin (STZ)-diabetic rats by using N-acetyl cysteine (NAC), under in vivo and in vitro approaches. This evidence concerns the gene RYR2 and Hyperglycemia.