Absence of insulinotropic glucagon-like peptide-I(7-37) receptors on isolated rat liver hepatocytes.
The effects of glucagon and the glucagon-like peptide GLP-1(7-37) were compared in rat liver hepatocytes. Glucagon elevated cAMP, elevated intracellular free calcium ([Ca2+]i), activated phosphorylase and stimulated gluconeogenesis, whereas GLP-1(7-37) was without effect on any of these parameters. GLP-1(7-37) did not block any of the actions of glucagon. The glucagon analog, des His1[Glu9] glucagon amide, was a partial agonist in liver, but also was an effective antagonist of glucagon actions in liver but not those of GLP-1(7-37) in islet B cells. It was concluded that in the rat, GLP-1(7-37) is a potent insulin secretagogue [1] but is without effect on liver.
Blackmore
P F
PF
Department of Pharmacology, Eastern Virginia Medical School, Norfolk 23501.
Mojsov
S
S
Exton
J H
JH
Habener
J F
JF
D000818:Animals; D002118:Calcium / Q000032:analysis; D000242:Cyclic AMP / Q000032:analysis; D005934:Glucagon; D052216:Glucagon-Like Peptide 1; D004763:Glucagon-Like Peptides; D005943:Gluconeogenesis; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism*; D008297:Male; D010446:Peptide Fragments; D010455:Peptides / Q000378:metabolism*; D010762:Phosphorylase a / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D014407:Tumor Cells, Cultured
D010446:Peptide Fragments; D010455:Peptides; D004763:Glucagon-Like Peptides; D052216:Glucagon-Like Peptide 1; D005934:Glucagon; D000242:Cyclic AMP; D010762:Phosphorylase a; C051322:glucagon-like peptide 1 (7-37); D002118:Calcium