Insulin‐like growth factor II stimulates glucose transport in human skeletal muscle

Abstract

We investigated the effect of insulin‐like growth factor II (IGF‐II) and insulin‐like growth factor binding protein‐1 (IGFBP‐1) on 3‐O‐methylglucose transport in incubated human skeletal muscle strips. Increasing physiological concentrations of IGF‐II stimulated glucose transport in a dose‐dependent manner. Glucose transport was maximally stimulated in the presence of 100 ng/ml (13.4 nM) of IGF‐II, which corresponded to the effect obtained by 100μU/ml (0.6 nM) of insulin. Exposure of muscle strips to IGFBP‐1 (500 ng/ml) inhibited the maximal effect of IGF‐II on glucose transport by 40%. Thus, it is conceivable that IGF‐II and IGFBP‐I are physiological regulators of the glucose transport process in human skeletal muscle.