title: Decreased plasma tryptophan levels in major depression.
abstract: Total plasma tryptophan was significantly lower in 12 depressed patients than in 12 normal controls. The ratio of total tryptophan to neutral amino acids was also decreased in the depressed patients suggesting that tryptophan availability to the brain might be reduced. There was no correlation between basal tryptophan concentrations in the depressed subjects and the subsequent neuroendocrine response to intravenous tryptophan.
authors.affiliation: University Department of Psychiatry, Littlemore Hospital, Oxford, U.K.
authors.forename: P J
authors.initials: PJ
authors.lastname: Cowen
authors.forename: M
authors.initials: M
authors.lastname: Parry-Billings
authors.forename: E A
authors.initials: EA
authors.lastname: Newsholme
mesh_terms: D000328:Adult; D003866:Depressive Disorder / Q000097:blood*; D005260:Female; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007532:Isoleucine / Q000097:blood; D007930:Leucine / Q000097:blood; D008297:Male; D008875:Middle Aged; D011388:Prolactin / Q000097:blood; D014364:Tryptophan / Q000097:blood*; D014443:Tyrosine / Q000097:blood; D014633:Valine / Q000097:blood
chemical_list: D007532:Isoleucine; D014443:Tyrosine; D014364:Tryptophan; D011388:Prolactin; D013006:Growth Hormone; D007930:Leucine; D014633:Valine