Figure 4: Effects of hR on glucose uptake and expression of relevant genes in C2C12 myotubes. (a) The effects of hR on glucose uptake in C2C12 myotubes. (b) Expression of insulin receptor (IR). (c) Expression of glucose transporter 4 (GLUT4). The amount of each target mRNA was normalized by the amount of -actin mRNA and was expressed relative to the abundance of the target mRNA in cells transfected with Pc-3.1. **.