Heart cell transplantation improves heart function in dilated cardiomyopathic hamsters

Background-Little is known about the effect of heart cell transplantation i nto the dilated cardiomyopathic myocardium. This study was designed to eval uate the effect of heart cell transplantation into dilated cardiomyopathic hamsters, Methods and Results-Ventricular heart cells were isolated from l-week-old B IO 53.58 hamsters and cultured for 3 weeks before transplantation. The cell s were labeled with bromodeoxyuridine (BrdU) before transplantation for ide ntification. Adult hamsters (17 weeks old) were used as recipients. Heart c ells (4x10(6) cells) or culture medium was transplanted into the left ventr icular free wall (transplantation and control groups, respectively, n=12 ea ch). Sham-operated hamsters (n=12) underwent the surgery but not the transp lantation. Cyclosporine A was administered subcutaneously to all hamsters d aily after the operation. Four weeks after the transplantation, heart funct ion was evaluated with the use of a Langendorff preparation. Histology show ed severe focal myocardial necrosis in all groups. BrdU-stained tissue was found at the cell transplantation sites. The transplanted hearts had greate r (P<0.001) developed pressures at all balloon volumes and improved dP/dt ( transplantation 915+/-253 versus control 453+/-120 and sham 530+/-187 mm Hg /s, P<0.001, balloon volume of 15 muL). No differences in ventricular funct ion were found between control and sham-operated hamsters. Conclusions-The transplanted ventricular heart cells formed cardiac-like ti ssue in cardiomyopathic myocardium and improved its contractile function.