Induction of hyperinsulinemia and hyperglycemia in dogs by administration of diabetogenic bovine pituitary peptide

Abstract

A peptide exhibiting diabetogenic and anti-insulin properties isolated from bovine adenohypophysis was administered subcutaneously in single doses to four dogs for 2 to 3 consecutive days. Ten hours after each injection, the animals were given an oral glucose load and a series of blood samples were obtained for glucose and insulin determinations. In one dog, the procedure was repeated 13 days after the first one. In another animal, the same procedure was carried out three times. Glucose tolerance was clearly impaired and serum insulin rose excessively in three of the four animals. In the fourth animal the response was observed but only after the third injection. Thus, insulin resistance appears to be a major mechanism by which this peptide induces loss of carbohydrate tolerance.