title: Catechol-O-methyltransferase polymorphism alters hypothalamic-pituitary-adrenal axis responses to naloxone: a preliminary report.
abstract: BACKGROUND
  A common polymorphism in the catechol-O-methyltransferase gene involves a valine to methionine mutation that results in a threefold to fourfold decrease in enzyme activity. This polymorphism has been associated with altered mu-opioid receptor binding potential and prefrontal cognitive performance, as well as risk for several neuropsychiatric conditions. We hypothesized that subjects homozygous for the low-activity allele would have greater hypothalamic-pituitary-adrenal axis responses to opioid blockade than subjects with the high-activity allele.
  
  
  METHODS
  Forty-six healthy adults were genotyped and underwent a procedure in which adrenocorticotropin hormone and cortisol responses to the opioid antagonist naloxone were examined.
  
  
  RESULTS
  Findings showed that adrenocorticotropin hormone and cortisol responses were greater in subjects with the methionine/methionine genotype compared to subjects homozygous or heterozygous for the valine allele.
  
  
  CONCLUSIONS
  These findings suggest that individual differences in catecholamine metabolism may impact hypothalamic-pituitary-adrenal axis function and may play a pharmacogenetic role in responses to naloxone.
authors.affiliation: Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
authors.forename: Lynn M
authors.initials: LM
authors.lastname: Oswald
authors.forename: Mary
authors.initials: M
authors.lastname: McCaul
authors.forename: Leena
authors.initials: L
authors.lastname: Choi
authors.forename: Xioaju
authors.initials: X
authors.lastname: Yang
authors.forename: Gary S
authors.initials: GS
authors.lastname: Wand
mesh_terms: D000293:Adolescent; D000324:Adrenocorticotropic Hormone / Q000037:antagonists & inhibitors / Q000378:metabolism; D000328:Adult; D000483:Alleles; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D005260:Female; D015870:Gene Expression / Q000235:genetics; D005838:Genotype; D006801:Humans; D006854:Hydrocortisone / Q000037:antagonists & inhibitors* / Q000378:metabolism; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008715:Methionine / Q000235:genetics; D009270:Naloxone / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000494:pharmacology*; D010913:Pituitary-Adrenal System / Q000187:drug effects* / Q000378:metabolism; D011110:Polymorphism, Genetic / Q000235:genetics*
chemical_list: D009292:Narcotic Antagonists; D009270:Naloxone; D000324:Adrenocorticotropic Hormone; D008715:Methionine; D002394:Catechol O-Methyltransferase; D006854:Hydrocortisone