Combined transplantation of skeletal myoblasts and mesenchymal cells (cocultivation) in ventricular dysfunction after myocardial infarction.

OBJECTIVE Cell therapy in the myocardium has been mainly performed with satisfactory results using 2 cell types: skeletal myoblasts (myogenic) and mesenchymal cells (angiogenic). This study assessed the combined transplantation of those 2 cell types (SMM) into infarcted rats. METHODS Myocardial infarction was induced by ligature of the left coronary artery in 26 Wistar rats. After one week, the animals underwent echocardiography for assessing ejection fraction (EF%) and left ventricular end-diastolic and systolic volumes (EDV, ESV, mL). After 2 days, the animals were reoperated on and divided into 2 groups: 1) control (n = 10), which received 0.15 mL of culture medium; and 2) SMM (n = 16), which received 7.5x10(6) heterologous skeletal myoblasts and mesenchymal cells in the infarcted region. The cells were obtained from puncture of the iliac crest and biopsy of skeletal muscle, and were cultured in vitro. After one month, the animals underwent a new echocardiography. RESULTS No significant difference in EF, EDV, and ESV was observed between the 2 groups on baseline echocardiographic values. One month after transplantation, the following was observed: a reduction in EF in the control group (29.31 +/- 5.6% to 23.54 +/- 6.51%; P = 0.048); and an increase in EF in the SMM group (24.03 +/- 8.68% to 31.77 +/- 9.06%; P = 0.011). The presence of neovascularization and muscle fibers was identified in the regions of myocardial fibrosis in the SMM group. CONCLUSION Cocultivation of skeletal myoblasts and mesenchymal cells is functionally effective.