The Tissue Concentration of UDP-N-acetylglucosamine Modulates the Stimulatory Effect of Insulin on Skeletal Muscle Glucose Uptake

To delineate the biochemical mechanism by which increased availability of GlcN impairs insulin action on skeletal muscle glucose uptake, we replenished the uridine pool during GlcN administration. Co-infusion of uridine with GlcN prevented the GlcN-induced fall in skeletal muscle UDP-glucose levels (24.9 ± 5.3 versus 10.1 ± 2.9 nmol/g; p < 0.01) and further increased the skeletal muscle UDP-GlcNAc levels (198.4 ± 26.3 versus 96.0 ± 8.4 nmol/g; p...