POTENT GLYCOGENIC EFFECT OF GLP-1(7-36)AMIDE IN RAT SKELETAL-MUSCLE

GLP-1(7-36)amide is an intestinal posttranslational proglucagon product released mainly after carbohydrate ingestion, the glucose dependent insulinotropic and antidiabetogenic actions of which have been documented. In this work, by exploring whether GLP-1(7-36)amide has any effect on the glucose metabolism of the muscle, we have observed that this peptide, at physiological concentrations, exerts in this tissue an increment of the D-[U-C-14]glucose incorporated into glycogen, which is accompanied by an increase in the glycogen synthase a activity; also, it stimulates both glucose oxidation and lactate formation. These data indicate that the skeletal muscle is one of the target tissues for GLP-1(7-36)amide, where its insulin-like effect explains, at least in part, its plasma glucose lowering action; thus, GLP-1(7-36)amide may well be implicated in the physiological control of glucose homeostasis after meals, not only by acting as an incretin, but also by directly promoting glucose disposal.