title: Growth hormone, prolactin and cortisol nyctohemeral variations during naloxone-induced opiate receptor blockade in man.
abstract: To evaluate the role of endogenous opioid peptides in prolactin (Prl), growth hormone (GH) and cortisol neuroregulation, 50 mg of the opiate antagonist naloxone was infused over 24 h to 6 normal male volunteers. An additional naloxone dose (5 mg) was given iv as a bolus injection at 20.00 h. blood specimens were collected hourly by means of a portable constant withdrawal pump. Naloxone failed to alter 24 h secretion of GH and Prl. The sleep-related GH and Prl rise was also unaffected by the opiate blocker. Moreover, naloxone failed to alter the circadian rhythm of cortisol and its 24 h concentration. The results do not suggest, a major role of opiate receptors in spontaneous GH, Prl and cortisol secretion in man.
mesh_terms: D000328:Adult; D002940:Circadian Rhythm / Q000187:drug effects; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects; D008297:Male; D009270:Naloxone / Q000494:pharmacology*; D011388:Prolactin / Q000097:blood*; D011957:Receptors, Opioid / Q000187:drug effects*; D012890:Sleep / Q000187:drug effects
chemical_list: D011957:Receptors, Opioid; D009270:Naloxone; D011388:Prolactin; D013006:Growth Hormone; D006854:Hydrocortisone