INS and Insulin resistance: To determine if the peripheral insulin resistance in the skmPAK1-iKO mice was underpinned by defects in GLUT4 vesicle translocation, mice were injected with insulin, the whole hindlimb muscle was rapidly excised for subcellular fractionation, and levels of GLUT4 that had translocated into the sarcolemmal/t-tubule membranes (P2 fraction) were quantified.