COMPOSITION OF AMINO-ACID INFUSIONS AND EFFECT OF CHOLECYSTOKININ ON INSULIN RELEASE IN DOGS

In the present study we have examined if the different composition of intravenously administered amino acid solutions is of importance for the effect of cholecystokinin (CCK) on pancreatic insulin and glucagon release in dogs. In 6 conscious dogs CCK-9 was infused intravenously at stepwise increasing doses of 5, 10 and 20 pmol/kg.h during an intravenous background infusion of Aminosteril or Aminoplasmal. Aminosteril contains more insulinogenic amino acids while Aminoplasmal contains more glucagonogenic amino acids. CCK elicited a significant stimulation of insulin levels by 10-mu-U/ml (p < 0.01) in the presence of i.v. Aminosteril compared to that elicited by i.v. amino acids alone. Glucagon and glucose levels remained unchanged. During i.v. Aminoplasmal CCK-9 had no effect. Since in dogs the physiological plasma amino acid pattern following the ingestion of protein-rich meals is unknown the possibility cannot be excluded that in dogs CCK acts as a mediator of the intestinal signal which augments insulin release during ingestion of protein-rich meals.