TNNI3 and myocardial infarction: Thirty rats were experimentally induced to myocardial infarction by isoproterenol (ISO), which sharply increased the ST and deep Q wave, in addition to causing leakage of cardiac marker enzymes, such as cTnI (cardiac troponin I), CPK (creatine phosphokinase), CK-MB (creatine kinase MB isoenzyme), LDH (lactate dehydrogenase), ALT (alanine aminotransferase) and AST (aspartate aminotransferase), from cardiac tissue to circulation, cell membrane rupture, hypoxia, and cardiac hypertrophy.