Effects of glucagon-like peptide-1 (7-36)amide on insulin stimulated rat skeletal muscle glucose transport

Glucagon-like peptide-1 binding sites have been reported in peripheral tissues including muscle. However, the potential extra-pancreatic effects of glucagonlike peptide-1 (7-36)amide are controversial. To evaluate whether glucagon-like peptide-1 (7-36)amide has any effects on skeletal muscle glucose transport, isolated rat soleus muscles were incubated in increasing concentrations of insulin (0-150 nmol/l) in the presence or absence of 1 nmol/l glucagon-like peptide-1 (7-36)amide for 3 h. Subsequently glucose transport was measured as uptake of [H-3]-O-methylglucose. It was found that glucagon-like peptide-(7-36)amide has a small but significant stimulating effect on skeletal muscle glucose transport independent of the insulin concentration (P<0.01). However, because of the magnitude of the observed effect, the physiological importance of glucagon-like peptide-1 (7-36)amide on skeletal muscle glucose metabolism is questionable.