Experimental cardiac hypertrophy induced by isoproterenol in the rat

Isoproterenol (IPR) administered to rats in a dose of 5 mg/kg for seven days induces cardiomegaly. To determine the degree of myocardial enlargement, wet and dry heart weight, myocardial RNA, DNA, protein content and protein synthesis were measured. Wet and dry heart weight, and the level of cardiac RNA, DNA and protein were augmented by IPR treatment, with RNA increasing more than DNA and protein. Incorporation of 14C-leucine into the protein of the heart was enhanced by IPR. Thus the IPR-induced cardiomegaly may serve as a model for studying the development of cardiac hypertrophy under various conditions.