title: Naloxone-mediated activation of the hypothalamic-pituitary-adrenal axis in chronic fatigue syndrome.
abstract: BACKGROUND
  Opioidergic pathways have an inhibitory regulatory influence on the hypothalamic-pituitary-adrenal axis (HPA) in man. Previous studies have suggested impairment of pituitary-adrenal activation in chronic fatigue syndrome (CFS). We, therefore, decided to investigate the extent of opioid inhibition of HPA activity in CFS as a possible explanation for the reputed HPA hypofunctioning in patients with CFS.
  
  
  METHODS
  Thirteen patients with CFS, diagnosed according to CDC criteria, were compared with thirteen healthy subjects. Adrenocorticotropin (ACTH) and cortisol (CORT) responses were measured following the administration of the opiate antagonist naloxone.
  
  
  RESULTS
  Baseline ACTH and cortisol levels did not differ between the two groups. The release of ACTH (but not cortisol) was significantly blunted in the CFS subjects compared with controls.
  
  
  CONCLUSIONS
  Naloxone mediated activation of the HPA is attenuated in CFS. Excessive opioid inhibition of the HPA is thus an unlikely explanation for the HPA dysregulation in this disorder.
authors.affiliation: Department of Psychological Medicine, St Bartholomew's and the Royal London School of Medicine.
authors.forename: L V
authors.initials: LV
authors.lastname: Scott
authors.forename: F
authors.initials: F
authors.lastname: Burnett
authors.forename: S
authors.initials: S
authors.lastname: Medbak
authors.forename: T G
authors.initials: TG
authors.lastname: Dinan
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D019540:Area Under Curve; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D015673:Fatigue Syndrome, Chronic / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects*; D008297:Male; D008875:Middle Aged; D009270:Naloxone; D009292:Narcotic Antagonists; D009434:Neural Pathways / Q000503:physiopathology; D010913:Pituitary-Adrenal System / Q000187:drug effects*; D011957:Receptors, Opioid / Q000502:physiology
chemical_list: D009292:Narcotic Antagonists; D011957:Receptors, Opioid; D009270:Naloxone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone