Glucose-dependent stimulatory effect of glucagon-like peptide 1(7-36) amide on the electrical activity of pancreatic beta-cells recorded in vivo.
The stimulatory effect of the glucagon-like peptide (GLP)-1(7-36) amide on electrical activity in pancreatic b-cells recorded in vivo was studied. The injection of GLP-1 produces a lengthening of the active phase with respect to the silent phase, leading to a stimulation of insulin release, which produces a secondary decrease in blood glucose concentration and eventually, to the hyperpolarization of the membrane at a blood glucose level of approximately 5 mmol/l. The injection of GLP-1 at a glycemic level <5 mmol/l does not stimulate electrical activity. This is in contrast to the effect of tolbutamide, which stimulates electrical activity at low glucose concentrations. These results demonstrate that in vivo, the stimulatory effect of GLP-1 on insulin secretion is at least partially mediated by its effect on beta-cell electrical activity. Furthermore, the glucose dependence of the effect confers to GLP-1, a security factor that supports its potential use in the treatment of type 2 diabetes.
Fernandez
J
J
Instituto de Neurociencias, Campus de San Juan, Universidad Miguel Hernandez, San Juan de Alicante, Spain.
Valdeolmillos
M
M
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D004594:Electrophysiology; D005934:Glucagon; D052216:Glucagon-Like Peptide 1; D004763:Glucagon-Like Peptides; D005947:Glucose / Q000494:pharmacology*; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D009994:Osmolar Concentration; D010446:Peptide Fragments / Q000494:pharmacology*; D014044:Tolbutamide / Q000494:pharmacology
D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D010446:Peptide Fragments; C055453:glucagon-like peptide 1 (7-36)amide; D004763:Glucagon-Like Peptides; D052216:Glucagon-Like Peptide 1; D005934:Glucagon; D014044:Tolbutamide; D005947:Glucose