In vivo, ex vivo, and in vitro studies on apelin's effect on myocardial glucose uptake

► Apelin enhances myocardial glucose uptake in vivo. ► Apelin triggers GLUT 4 translocation form cytosol to cell membrane. ► Apelin increases glucose uptake in cultured H9C2 cells. ► AMPK and IRS-1 participate in apelin's effect on glucose uptake in vivo and in vitro. ► Knockdown AMPK can inhibit apelin's effect on IRS-1 Ser-789 phosphorylation and glucose uptake.