Effect of Naloxon on Counter Insulin Hormone Secretion in Insulin-Induced Hypoglycemia

To investigate the normal physiologic role of endogenous opiates in glucose homeostasis and as a preliminary study for clarifying the association of endogenous opites with pathophysilogy of NIDDM, we obseved the changes in the secretion of counter-insulin hormones in response to insulin-induced hypoglycemia with or without naloxone. 1. Blood glucose was decreased significantly more rapidly with naloxone infusion than after insulin alone, which seems to play a role in the early responses of ACTH and GH. 2. Not only was the more rapid response of ACTH and GH, but also the prolonged secretion of ACTH and Cortisol were observed after administration of insulin and naloxone. We concluded that endogenous opiates may be involved in the feedback regulation of secretion of ACTH and GH during hypoglycemia either at hypophysis or hypothalamus, and involved in glucose homeostasis via a certain direct mechanism other than regulation of counter hormone secretion.