Therefore, the present study was designed to identify the following: (i) whether MICU1 expression is altered in Ang-II-induced cardiac hypertrophy, (ii) whether MICU1 deficiency aggravates cardiac hypertrophy, and if so, (iii) whether melatonin suppresses oxidative stress and attenuates mitochondrial abnormalities in cardiac hypertrophy by activating MICU1. Here, AGT is linked to cardiac hypertrophy.