Response of extrapancreatic glucagon to gastrointestinal hormones in pancreatectomized dogs.

Abstract

In order to investigate the effect of gastrointestinal hormones upon the secretion of extrapancreatic glucagon, tetragastrin, secretin, caerulein and cholecytokinin-pancreozymin octapeptide (CCK-octa) were administered during saline or arginine infusion in pancreatectomized dogs. Intravenous administration of tetragastrin (7 p g/kg) did not elicit any changes in plasma glucagon during saline infusion, while the plasma glucagon increased significantly following tetragastrin infusion during arginine infusion. The administration of secretin (3 U/kg) did not affect the plasma level of glucagon during saline or arginine infusion at all. Plasma glucagon did not change after the administration of caerulein (0.5pg/kg) during saline infusion, whereas it increased significantly following caerulein administration during arginine infusion. Intravenous administration of CCK-octa in a dose of 20 U/kg did not affect the plasma level of glucagon during saline infusion but exerted a significant rise of extrapancreatic glucagon during arginine infusion. It is concluded from the present experiment that the administration of tetragastrin, caerulein or CCK-octa enhances the release of extrapancreatic glucagon stimulated by arginine infusion while secretin infusion does not affect the secretion of extrapancreatic glucagon.tetragastrin ; secretin ; caerulein ; CCK-octapeptide ; arginine Since the establishment of the presence of extrapancreatic glucagon (Matsuyama and Foa 1974;Vranic et al. 1974), the regulation of extrapancreatic glucagon has been reported by many authors (Lefebvre and Luyckx 1981;Ohneda 1981). Among various factors, gastrointestinal factors have been considered to play an important role in the secretion of extrapancreatic glucagon. In a previous study from our laboratory it was demonstrated that extrapancreatic glucagon responds to intraluminal administration of glucose and arginine (Ohneda et al. 1984). Therefore, a participation of gastrointestinal hormones can be presumed in the regulation of extrapancreatic glucagon during nutrient ingestion. In this study, the effect of gastrointestinal hormones upon the secretion of extrapancreatic glucagon was investigated using pancreatectomized dogs.