Liraglutide enhances myotube differentiation and muscle contractile activity upon electric pulse stimulation in mouse skeletal muscle cells

Glucagon-like peptide-1 (GLP-1) is a potent incretin hormone produced by L-cells in the ileum and colon. Skeletal muscle, the most important organ for glucose metabolism, is also affected by GLP-1. Short-term administration of liraglutide, a GLP-1 analog, ameliorated glucose uptake in palmitate-treated type II diabetes models; however, the influence of long-term liraglutide administration on normal muscle cells has not been evaluated. We analyzed the effects of chronic (3 consecutive days) administration of liraglutide at various concentrations on healthy C2C12 skeletal muscle cells by investigating morphological changes, muscle contractile properties, and glucose uptake. Liraglutide administration at an appropriate dose (0.5 μm) had positive effects, including the promotion of muscle hypertrophy, in C2C12 cells; however, excessive administration (10 μm) had atrophic effects. Therefore, proper liraglutide dosing is very important.