Stimulatory effect of xenin-8 on insulin and glucagon secretion in the perfused rat pancreas.
Ramona A Silvestre, Jovita Rodríguez-Gallardo, Eva M Egido, Raquel Hernández, José Marco
Index: Regul. Pept. 115(1) , 25-9, (2003)
Full Text: HTML
Abstract
Xenin is a 25-amino acid peptide of the neurotensin/xenopsin family identified in gastric mucosa as well as in a number of tissues, including the pancreas of various mammals. In healthy subjects, plasma xenin immunoreactivity increases after meals. Infusion of the synthetic peptide in dogs evokes a rise in plasma insulin and glucagon levels and stimulates exocrine pancreatic secretion. The latter effect has also been demonstrated for xenin-8, the C-terminal octapeptide of xenin. We have investigated the effect of xenin-8 on insulin, glucagon and somatostatin secretion in the perfused rat pancreas. Xenin-8 stimulated basal insulin secretion and potentiated the insulin response to glucose in a dose-dependent manner (EC(50)=0.16 nM; R(2)=0.9955). Arginine-induced insulin release was also augmented by xenin-8 (by 40%; p<0.05). Xenin-8 potentiated the glucagon responses to both arginine (by 60%; p<0.05) and carbachol (by 50%; p<0.05) and counteracted the inhibition of glucagon release induced by increasing the glucose concentration. No effect of xenin-8 on somatostatin output was observed. Our observations indicate that the reported increases in plasma insulin and glucagon levels induced by xenin represent a direct influence of this peptide on the pancreatic B and A cells.
Related Compounds
Related Articles:
2012-12-15
[Am. J. Physiol. Gastrointest. Liver Physiol. 303(12) , G1347-55, (2012)]
2003-03-28
[Regul. Pept. 111(1-3) , 153-9, (2003)]
2010-10-01
[J. Endocrinol. 207(1) , 87-93, (2010)]
Metabolism and potency of xenin and of its reduced hexapseudopeptide psi fragment in the dog.
2003-12-26
[Life Sci. 74(6) , 697-707, (2003)]
Interaction of xenin with the neurotensin receptor of guinea pig enteral smooth muscles.
2002-03-01
[Peptides 23(3) , 523-9, (2002)]