Comparison of the effects of intramyocardial and intravenous injections of human mesenchymal stem cells on cardiac regeneration after heart failure.

Objective(s): Existing studies have demonstrated that intravenous and intramyocardial-administrated mesenchymal stem cells (MSCs) lead to tissue repair after cardiac disorders. We compared the efficiency of both administration methods. Materials and Methods: A rat model of isoproterenol-induced heart failure (ISO-HF) was established to compare the effects of intravenous and intramyocardial-administrated MSCs on cardiac fibrosis and function. The animals were randomly assigned into six groups: i) control or normal, ii) ISO-HF (HF) iii) ISO-HF rats treated with intramyocardial administration of culture medium (HF+IM/CM), iv) ISO-HF rats treated with intravenous administration of culture medium ( HF+IV/CM), v) ISO-HF rats treated with intravenous administration of MSCs (HF+IV/MSCs), vi) ISO-HF rats treated with intramyocardial administration of MSCs ( HF+IM/MSCs). Cultured MSCs and culture medium were administrated at 4 weeks after final injection of ISO. Heart function, identification of MSCs, osteogenic differentiation, adipogenic differentiation, cardiac fibrosis and tissue damage were evaluated by echocardiography, flow-cytometery, von Kossa, oil red O, Masson's trichrome and H & E staining, respectively. Results: Both intravenous and intramyocardial MSCs therapy significantly improved heart function and reduced cardiac fibrosis and tissue damage (P<0.05), whereas the cultured medium had no beneficial effects. Conclusion: In sum, our results confirm the validity of both administration methods in recovery of HF, but more future research is required. [ABSTRACT FROM AUTHOR]