Effects of Naloxone on Insulin-Induced Release of Pituitary Hormones

Abstract
To evaluate the role of endogenous opiates on the regulation of the pituitary hormonal stress response, in 6 normal subjects the insulin-induced secretion of PRL [prolactin], GH [growth hormone] and ACTH with and without naloxone, a specific opiate antagonist, was studied. During hypoglycemia, naloxone infusion reduced plasma PRL levels at 90 min, lowered the overall GH response and enhanced that of ACTH. Endogenous opiates apparently have a modulatory role in the stress-induced secretion of pituitary hormones.