Characterization and distribution of myosin variants in normal and pathological human hearts.

Hybridomas were prepared from mice immunized with myosin from the enlarged left ventricle of a 53-year-old female bearing an obstructive cardiomyopathy. With several different experimental approaches using anti-myosin antibodies, at least two subpopulations of atrial and at least two subpopulations of ventricular myosin were detected, characterized and located in normal human hearts. The human atrium and human ventricle each contained small zones of myosin variation which were scattered, but probably not randomly distributed, within a large area of myocardium whose cellular distribution of myosin was constant. Recent applications of the same approach to the study of the regional variations of the different myosin forms within two pathological human hearts are discussed.