Abstract 9347: Comparison of Cardiac Stem Cells and Mesenchymal Stem Cells Transplantation on the Cardiac Electrophysiology in Rat Model of Myocardial Infarction

Abstract

Introduction Whether transplanted cardiac stem cells (CSCs) and mesenchymal stem cells (MSCs) improved ventricular fibrillation threshold (VFT) similarly and whether severe malignant ventricular arrhythmia is induced in the myocardial infarction (MI) model are still unclear. We sought to compare the effects of the CSCs and MSCs transplantation on the electrophysiological characteristics and VFT. Hypothesis CSCs are superior to MSCs in modulating the electrophysiological abnormality and improving the VFT in rat model of MI. Methods MI was induced in 30 male Sprague-Dawley rats. Two weeks later, animals were randomized to receive 5×10 6 CSCs or 5×10 6 MSCs labeled with PKH26 in phosphate buffer solution (PBS) or PBS alone injection into the infarcted anterior ventricular free wall. Six weeks after the CSCs or MSCs or PBS injection, electrophysiological characteristics and VFT were measured. Labeled CSCs and MSCs were observed in 5 µm cryostat sections from each harvested heart. Results The VFTs were improved in the CSCs group compared with the MSCs group (table 1). Labeled CSCs and MSCs were identified in the infarct zone and infarct marginal zone. Labeled CSCs express Connexin-43 and α-sarcomeric actin, while Labeled MSCs express α-sarcomeric actin in vivo. Conclusions CSCs are superior to MSCs in improving the VFT in rats with MI. CSCs and MSCs express markers that suggest muscle phenotypes in vivo, but MSCs rarely express Connexin-43.