The cardiomyopathic hamster as model of early myocardial aging

Few experimental studies are available on aging, because of the lack of sui table experimental models to test specific pathophysiologic mechanisms. In the present study, the cardiomyopathic Syrian hamster is proposed as experi mental model of the aging myocardium. In fact, the hamster myocardium devel ops an early alpha to beta myosin isoform shifting in ventricles that is in dependent of hemodynamic overload and repeats the phenomenon physiologicall y occurring in healthy hamsters during the entire lifespan. At the same tim e, in atria there is a progressive decline of ANF production that is indepe ndent of intracavitary pressure. Conversely, ANF production in ventricles i s enhanced before the onset of hemodynamic overload, but parallel to the in crease in the fibrotic proportion of the ventricular wall. These characteri stics mimic the modifications occurring in otherwise healthy aged mammals a nd candidate the cardiomyopathic hamster as a model of early myocardial agi ng.