Infarcted heart uptake and biodistribution of radiolabelled anti-myosin monoclonal antibody in rat and dog myocardial infarct models

Abstract A new mouse monoclonal antibody that recognizes α- and β-heavy chains of human atrial and ventricular myosin and β-heavy chain of human slow skeletal muscle myosin was obtained. The 125 I- and 111 In-labelled antibody, and its F(ab′) 2 and Fab fragments localize in isoproterenol induced infarcted rat heart, with the F(ab′) 2 fragment showing the highest uptake. Comparison with 99m Tc-pyrophosphate uptake in infarcted dog heart, induced by selective obstruction of a coronary artery, suggest that the 111 In-labelled F(ab′) 2 localizes specifically in infarcted myocardium only.