title: Elevated plasma prolactin in abstinent methamphetamine-dependent subjects.
abstract: BACKGROUND
  Methamphetamine (MA) use disorders are pervasive global social problems that produce large medical and public health burdens. Abnormalities in pituitary hormonal regulation have been observed in preclinical models of substance abuse and in human substance abusers. They have, however, not been studied before in MA-dependent human subjects.
  
  
  OBJECTIVE
  To determine if MA-dependent research volunteers differ from healthy control subjects in plasma levels of adrenocorticotropic hormone (ACTH), cortisol, or prolactin, or in pituitary dopamine D(2) receptor availability during early abstinence from MA.
  
  
  METHODS
  MA-dependent subjects (N = 31), who were not seeking treatment, resided on an inpatient ward for up to 5 weeks. Abstinence was confirmed by daily urine drug screening. Venous blood was sampled for plasma hormone levels, and positron emission tomography with [(18)F]fallypride was performed to determine dopamine D(2) receptor availability during the first week of abstinence. Venous blood was sampled again for hormone levels during the fourth week of abstinence. Matched healthy volunteers (N = 23) participated as a comparison group.
  
  
  RESULTS
  MA-dependent and healthy comparison subjects did not differ in plasma ACTH or cortisol levels, but had an elevated plasma prolactin at both the first week and fourth week of abstinence. There was no group difference in pituitary dopamine D(2) receptor availability.
  
  
  CONCLUSIONS
  MA-dependent individuals have abnormalities in prolactin regulation, which is not likely due to alterations in pituitary dopamine D(2) receptor availability.
  
  
  CONCLUSIONS
  MA dependence is associated with elevated prolactin levels, which may contribute to medical comorbidity in afflicted individuals.
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, University of California Irvine, Irvine, CA, USA.
authors.forename: Todd
authors.initials: T
authors.lastname: Zorick
authors.forename: Mark A
authors.initials: MA
authors.lastname: Mandelkern
authors.forename: Buyean
authors.initials: B
authors.lastname: Lee
authors.forename: Ma-Li
authors.initials: ML
authors.lastname: Wong
authors.forename: Karen
authors.initials: K
authors.lastname: Miotto
authors.forename: Jon
authors.initials: J
authors.lastname: Shabazian
authors.forename: Edythe D
authors.initials: ED
authors.lastname: London
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D019969:Amphetamine-Related Disorders / Q000000981:diagnostic imaging / Q000378:metabolism*; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008694:Methamphetamine; D008875:Middle Aged; D010902:Pituitary Gland / Q000000981:diagnostic imaging / Q000378:metabolism; D011388:Prolactin / Q000097:blood*; D011877:Radionuclide Imaging; D017448:Receptors, Dopamine D2 / Q000378:metabolism
chemical_list: D017448:Receptors, Dopamine D2; D008694:Methamphetamine; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D006854:Hydrocortisone