title: Chromium treatment decreases the sensitivity of 5-HT2A receptors.
abstract: BACKGROUND
  Recent case series suggest that chromium picolinate in doses of 400 microg daily may have antidepressant properties, perhaps through increasing the peripheral availability of tryptophan for brain serotonin (5-HT) synthesis.
  
  
  OBJECTIVE
  To determine the effects of chromium treatment on plasma tryptophan availability and on brain 5-HT function in human and animal models.
  
  
  METHODS
  We studied the effects of short-term chromium supplementation on plasma concentrations of tryptophan and other large neutral amino acids. Brain 5-HT function was assessed by measuring the corticosterone/cortisol response to the 5-HT precursor, 5-hydroxytryptophan (5-HTP), a response believed to be mediated via indirect activation of 5-HT(2A) receptors.
  
  
  RESULTS
  In rats, chromium increased peripheral and central tryptophan availability and elevated brain 5-HT content. Changes in peripheral tryptophan availability were not seen in humans but in both rats and humans, chromium lowered the cortisol response to challenge with 5-HTP.
  
  
  CONCLUSIONS
  Chromium can modify brain 5-HT function in humans and animals, perhaps by altering the sensitivity of central 5-HT(2A) receptors.
authors.affiliation: University Department of Psychiatry, Neurosciences Building, Warneford Hospital, Oxford OX3 7JX, UK.
authors.forename: M-J
authors.initials: MJ
authors.lastname: Attenburrow
authors.forename: J
authors.initials: J
authors.lastname: Odontiadis
authors.forename: B J
authors.initials: BJ
authors.lastname: Murray
authors.forename: P J
authors.initials: PJ
authors.lastname: Cowen
authors.forename: M
authors.initials: M
authors.lastname: Franklin
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002857:Chromium / Q000494:pharmacology*; D003345:Corticosterone / Q000097:blood; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051381:Rats; D017207:Rats, Sprague-Dawley; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism; D016037:Single-Blind Method; D014364:Tryptophan / Q000097:blood
chemical_list: D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin; D002857:Chromium; D012701:Serotonin; D014364:Tryptophan; D003345:Corticosterone