A pure enteroglucagon, oxyntomodulin (glucagon 37), stimulates insulin release in perfused rat pancreas

Oxyntomodulin, a gut peptide recently purified, has been tested in isolated perfused pancreases of normal rats. It was shown to stimulate insulin release monophasically in the presence of a low (6 mM) glucose concentration in the medium. Furthermore, oxyntomodulin potentiated glucose-induced insulin release (10 mM glucose) in a dose-dependent manner, although it was less powerful in this respect than equimolar concentrations of pancreatic glucagon. As oxyntomodulin belongs to the gut glucagon-like immunoreactants which are released during digestion, it is suggested that oxyntomodulin might be one of the factors that could functionally link the gut and the endocrine pancreas and contribute, at least in part, to the regulation of postprandial insulin release.