Wang GY, et al. - The effect and underlying signaling mechanisms of metformin on apoptosis and Connexin43 (Cx43) expression in H9c2 cells presenting with hyperglycemia conditions were examined in this study. The H9c2 cells could be protected by administrating metformin against hyperglycemia-induced apoptosis and Cx43 down-regulation, in part, mediated through the induction of autophagy pathway.