Intra-islet regulation of hormone secretion by glucagon-like peptide-1-(7--36) amide.
Glucagon-like peptide (GLP)-1-(7--36) amide, a peptide product of the posttranslational processing of pancreatic and intestinal proglucagon, has been shown to regulate insulin secretion. Monoclonal antibodies to glucagon and GLP-1-(7--36) amide were generated to localize GLP-1-(7--36) amide in the pancreatic islets by immunocytochemistry and radioimmunoassay. GLP-1-(7--36) amide immunoreactivity was found in some, but not all, glucagon-containing alpha-cells. Displaceable receptor binding for GLP-1-(7--36) amide and nonamidated GLP-1-(7--37) on hormone secretion were investigated using isolated pancreatic islet preparations. GLP-1-(7--37) and -(7--36) amide significantly increased insulin and somatostatin release in the concentration range of 0.01-100 nM in 11.0 mM glucose. GLP-1-(7--37) and -(7--36) amide had no effect on glucagon secretion in the presence of 11.0 mM glucose. GLP-1-(7--36) amide was released from isolated islets in response to 2.25, 5.5, and 11.0 mM glucose. These results suggest that pancreatic GLP-1 may be important in the regulation of intra-islet hormone secretion.
Heller
R S
RS
Department of Nutritional Sciences, University of California, Berkeley 94720-3104, USA.
Aponte
G W
GW
D000818:Animals; D005934:Glucagon / Q000378:metabolism; D052216:Glucagon-Like Peptide 1; D000067757:Glucagon-Like Peptide-1 Receptor; D004763:Glucagon-Like Peptides; D005947:Glucose / Q000494:pharmacology; D006728:Hormones / Q000378:metabolism*; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology / Q000502:physiology*; D008297:Male; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology*; D010455:Peptides / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018027:Receptors, Glucagon / Q000378:metabolism; D013004:Somatostatin / Q000378:metabolism
C000593835:Glp1r protein, rat; D000067757:Glucagon-Like Peptide-1 Receptor; D006728:Hormones; D007328:Insulin; D010446:Peptide Fragments; D010455:Peptides; D018027:Receptors, Glucagon; C055453:glucagon-like peptide 1 (7-36)amide; D013004:Somatostatin; D004763:Glucagon-Like Peptides; C055968:glucagon-like peptide 1 (1-37); D052216:Glucagon-Like Peptide 1; D005934:Glucagon; D005947:Glucose