American Journal of Clinical Nutrition, Vol 23, 691-695, Copyright © 1970 by The American Society for Clinical Nutrition, Inc.

Glucose and Insulin Response to Intravenous Glucagon during Starvation

¹ From the Thorndike Memorial Laboratory, Harvard Medical Services, Boston City Hospital, and the Department of Medicine, Harvard Medical School, Boston, Massachusetts

A group of obese, nondiabetic individuals fasted for prolonged periods were challenged periodically during starvation with 1.0 mg glucagon given intravenously. The overall rise in plasma glucose after glucagon was significantly dampened after 3 or 4 days of starvation but began to return toward the prefast level within 7 days in spite of continued starvation. A response similar to that noted in the prefast period persisted for as long as 30 days of fasting.

In spite of the multiple metabolic changes that ensue after the intravenous injection of glucagon, challenge with pharmacological amounts of this hormone may serve as an index of metabolic substrate being utilized in starvation. The present studies show that glucose response to glucagon fluctuates during prolonged starvation and that the overall insulin response to the hormone parallels the increments in plasma glucose.