Abstract
Studies on the absorption of glucagon preparation have until now been few, and so we studied the relationship between the absorption and the biological effects of glucagon preparation (NOVO) by determining IRG, BS, and IRI at appropriate intervals after.a subcutaneous injection of the agent of four different doses (O.5, 1.0, 5.0, and 10.0μg/kg) in normal fasting dogs.
Various pharmacokinetic parameters calculated according to Wagner-Nelson's one compartment model from plasma IRG concentration curves were as follows:
From the above data, it was clear that the absorption of glucagon preparation and its metabolic rate were very rapid. On the other hand, the hyperglycemic effect, one of the biological effects of glucagon, occurred promptly. It is within reason for a rapid absorption of glucagon to take place but the intensity of the hyperglycemic effect was not in proportion to the plasma IRG levels. Besides, it was demonstrated that the minimum dose of glucagon causing a hyperglycemic effect was 0.5 μg/kg.
The insulinogenic activity of glucagon was also observed promptly, and its peak time was at fifteen minutes after the injection. This effect depended on dosage but it was temporary, and disappeared at forty-five minutes after the injection with all the dosages employed in the present study.
Since plasma IRG levels were dose-dependent at this time, the results were inconsistent with the effect at peak time. It was assumed that some internal protection systems might act in accordance with first insulin secretion, causing a fall of blood glucose in pancreatic regions.
