26RFa, a novel orexigenic neuropeptide, inhibits insulin secretion in the rat pancreas.
26RFa is a novel orexigenic neuropeptide identified as the endogenous ligand of the orphan G protein-coupled receptor GPR103. GPR103 shares sequence identity with the receptors for neuropeptide-Y and galanin, two peptides known to inhibit insulin secretion. We have investigated the effect of 26RFa on insulin and glucagon secretion in the perfused rat pancreas. 26RFa dose-dependently reduced glucose-induced insulin release, inhibited the insulin responses to both arginine and exendin-4 and did not affect glucagon output. The inhibitory effect of 26RFa on exendin-4-induced insulin secretion was not observed in pancreata from pertussis toxin-treated rats, thus suggesting that 26RFa may inhibit insulin secretion, at least in part, via a pertussis toxin-sensitive G(i) protein coupled to the adenylyl cyclase system.
Egido
Eva M
EM
Hospital Universitario Puerta de Hierro and Department of Physiology, Medical School, Universidad Autónoma de Madrid, San Martín de Porres 4, 28035 Madrid, Spain.
Hernández
Raquel
R
Leprince
Jérôme
J
Chartrel
Nicolas
N
Vaudry
Hubert
H
Marco
José
J
Silvestre
Ramona A
RA
D000595:Amino Acid Sequence; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005934:Glucagon / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D010179:Pancreas / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D007328:Insulin; D009479:Neuropeptides; D005934:Glucagon; D005947:Glucose