Original Articles Glucose Competence of the Hepatoportal Vein Sensor Requires the Presence of an Activated Glucagon-Like Peptide-1 Receptor

Activation of the hepatoportal glucose sensors by portal glucose infusion leads to increased glucose clearance and induction of hypoglycemia. Here, we investigated whether glucagon-like peptide-1 (GLP-1) could modu-late the activity of these sensors. Mice were therefore infused with saline (S-mice) or glucose (P-mice) through the portal vein at a rate of 25 mg/kg z min. In P-mice, glucose clearance increased to 67.5 6 3.7 mg/ kg z min as compared with 24.1 6 1.5 mg/kg z min in S-mice, and glycemia decreased from 5.0 6 0.1 to 3.3 6 0.1 mmol/l at the end of the 3-h infusion period. Co-infusion of GLP-1 with glucose into the portal vein at a rate of 5 pmol/kg z min (P–GLP-1 mice) did not increase the glucose clearance rate (57.4 6 5.0 ml/kg z min) and hypoglycemia (3.8 6 0.1 mmol/l) observed in P-mice. I