Glucagon-like peptide-1 binding to rat skeletal muscle.
We have found [125I]glucagon-like peptide-1(7-36)-amide-specific binding activity in rat skeletal muscle plasma membranes, with an estimated M(r) of 63,000 by cross-linking and SDS-PAGE. The specific binding was time and membrane protein concentration dependent, and displaceable by unlabeled GLP-1(7-36)-amide with an ID50 of 3 x 10(-9) M of the peptide; GLP-1(1-36)-amide also competed, whereas glucagon and insulin did not. GLP-1(7-36)-amide did not modify the basal adenylate cyclase activity in skeletal muscle plasma membranes. These data, together with our previous finding of a potent glycogenic effect of GLP-1(7-36)-amide in rat soleus muscle, and also in isolated hepatocytes, which was not accompanied by a rise in the cell cyclic AMP content, lead use to believe that the insulin-like effects of this peptide on glucose metabolism in the muscle could be mediated by a type of receptor somehow different to that described for GLP-1 in pancreatic B cells, where GLP-1 action is mediated by the cyclic AMP-adenylate cyclase system.
Delgado
E
E
Fundación Jiménez Díaz, Departamento de Metabolismo, Nutricón y Hormonas, Madrid, Spain.
Luque
M A
MA
Alcántara
A
A
Trapote
M A
MA
Clemente
F
F
Galera
C
C
Valverde
I
I
Villanueva-Peñacarrillo
M L
ML
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001667:Binding, Competitive; D002462:Cell Membrane; D005934:Glucagon / Q000378:metabolism*; D052216:Glucagon-Like Peptide 1; D000067757:Glucagon-Like Peptide-1 Receptor; D004763:Glucagon-Like Peptides; D007328:Insulin / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D011972:Receptor, Insulin / Q000187:drug effects / Q000378:metabolism; D018027:Receptors, Glucagon / Q000302:isolation & purification / Q000378:metabolism*
C000593835:Glp1r protein, rat; D000067757:Glucagon-Like Peptide-1 Receptor; D007328:Insulin; D010446:Peptide Fragments; D011498:Protein Precursors; D018027:Receptors, Glucagon; C055453:glucagon-like peptide 1 (7-36)amide; D004763:Glucagon-Like Peptides; D052216:Glucagon-Like Peptide 1; D005934:Glucagon; D011972:Receptor, Insulin; D000262:Adenylyl Cyclases