Lack of gastrointestinal glucagon response to hypoglycaemia in depancreatized dogs

Fasting (24 h) normal dogs and depancreatized dogs were injected intravenously with highly purified porcine insulin (Actrapid) in the doses of 0.2 U/kg and 0.5 U/kg, respectively. Blood glucose decreased from 152 +/- 41 (SEM) mg/100 ml to 39 +/- 7 mg/100 ml in the depancreatized dog and from 95 +/- 3 mg/100 ml to 42 +/- 4 mg/100 ml in the normal animal. Using a specific antiserum for "pancreatic" glucagon, the circulating level of glucagon immunoreactivity did not rise from the basal value of 247 +/- 31 pg/ml in the depancreatized group whereas it rose significantly from 223 +/- 24 pg/ml to 321 +/- 41 pg/ml in the normal group. In contrast intravenous infusion of 7 g of arginine increased "pancreatic" glucagon immunoreactivity in both groups. Thus, extrapancreatic glucagon of the pancreatic type does not respond to hypoglycaemia but to arginine infusion.