Abstract
In the previous study, we found that a dose response relationship after intravenous injection of 1.0, 0.1 and 0.01 mg of glucagon existed concerning insulin secretion, but not concerning hyperglycemic response. In the present investigation, the effect of intramuscular injection of 3 different doses of glucagon on hyperglycemic response and insulin secretion was studied in 20 normal subjects to compare with the previous results. For this purpose, 1.0, 0.1 and 0.01 mg of glucagon (Novo) or 2 of these 3 doses were administered to each subject within a week after overnight fasting and serum glucose and insulin concentrations were estimated during a period 2 hours.
1. A dose response relationship was observed concerning hyperglycemic action. The maximum increment of serum glucose was 48.7 ± 3.3 mg/dl with 1.0 mg, 22.5 ± 3.9 mg/dl with 0.1 mg (p< 0.005 vs 1.0 mg), and 4.7 1.2 mg/dl with 0.01 mg (p<0.005 vs 0.1 mg), respectively. When we injected 1 mg, the peak value was obtained after 30 min., and the hyperglycemic response lasted for 2 hours. The peak value and glucose area during the 2 hour period were found to be higher than those in intravenous injection of 1 mg glucagon. The peak time occurred earlier and the duration of hyperglycemia became shorter as the doses decreased. 2. Insulin secretion after glucagon injection, like the hyperglycemic response, decreased as the doses decreased. The Maximum serum insulin (IRI) increment was 44.9±6.9μu/ml with 1.0 mg, 15.7±2.2μu/ml with 0.1 mg (p <0.005 vs 1.0 mg), and 2.5±0.8μu/ml with 0.01 mg (p <0.005 vs 0.1 mg), respectively. When 1 mg of glucagon was administered, the peak value was obtained at 30 min. after injection and the secretion lasted for 2 hours. Although the duration of insulin secretion is found to be longer than that of intravenous injection, the peak value is higher in intravenous injection. The peak time became earlier and the duration of insulin secretion became shorter as the doses decreased.
These and the previous data indicate that intramuscular injection of 1 mg glucagon is best for recovery from the hypoglycemic state. Intravenous administration of 1 mg glucagon is recommended to obtain maximum release of insulin releases.
