1. Academic Validation
  2. Stimulatory effect of xenin-8 on insulin and glucagon secretion in the perfused rat pancreas

Stimulatory effect of xenin-8 on insulin and glucagon secretion in the perfused rat pancreas

  • Regul Pept. 2003 Aug 15;115(1):25-9. doi: 10.1016/s0167-0115(03)00147-2.
Ramona A Silvestre 1 Jovita Rodríguez-Gallardo Eva M Egido Raquel Hernández José Marco
Affiliations

Affiliation

  • 1 Department of Physiology, Medical School, Hospital Universitario Puerta de Hierro, Universidad Autónoma de Madrid, Madrid, Spain. rsilvestre.hpth@salud.madrid.org
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.

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