A, western blot corresponding to neonatal rat cardiomyocytes lysates immunostained with pAMPK, AMPK, pmTOR and mTOR (n = 5). B, representative western blot of HL‐1 lysates immunostained with pAMPK, AMPK, mTOR and pmTOR (n = 5). C, western blot corresponding to neonatal rat cardiomyocytes lysates immunostained with LC3 and p62. D, western blot corresponding to HL‐1 lysates immunostained with LC3 and p62 (n = 5). Bar graphs show the mean ± SEM. Statistical significance (Mann–Whitney U test): *P ≤ 0.05; **P ≤ 0.01.