title: Acute tyrosine depletion and alcohol ingestion in healthy women.
abstract: BACKGROUND
  Recently we reported that, in vervet monkeys, ingestion of an amino acid mixture deficient in the catecholamine precursors, phenylalanine and tyrosine, produced a decrease in alcohol self-administration. We now report the results of a similar study in humans.
  
  
  METHODS
  Three groups of healthy female social drinkers were administered a nutritionally balanced amino acid mixture (B, n = 13), a mixture deficient in the serotonin precursor, tryptophan (Trp-free, n = 14), or a phenylalanine/tyrosine deficient mixture (Phe/Tyr-free, n = 12). Six hours after administration of the amino acid mixture, alcohol ingestion was measured during a free-choice "Taste Test."
  
  
  RESULTS
  Compared to the B mixture, Phe/Tyr-free, but not Trp-free, significantly decreased the ingestion of alcohol [p < 0.02]. Neither Phe/Tyr-free nor Trp-free significantly decreased orange juice ingestion or the self-reported "Liking" of either substance. Some subjects experienced transient nausea and/or regurgitated the amino acid mixtures, but excluding these subjects did not change the results.
  
  
  CONCLUSIONS
  The results suggest that (a) Phe/Tyr-free may be a suitable method for investigating the role of catecholamines in the self-administration and subjective effects of alcohol, (b) acutely decreased catecholamine neurotransmission might disrupt mechanisms mediating alcohol self-administration, and (c) acutely decreased serotonin neurotransmission seems not to alter alcohol self-administration.
authors.affiliation: Department of Psychiatry, McGill University, Montréal, Québec, Canada. cyje@musica.mcgill.ca
authors.forename: M
authors.initials: M
authors.lastname: Leyton
authors.forename: S N
authors.initials: SN
authors.lastname: Young
authors.forename: P
authors.initials: P
authors.lastname: Blier
authors.forename: G B
authors.initials: GB
authors.lastname: Baker
authors.forename: R O
authors.initials: RO
authors.lastname: Pihl
authors.forename: C
authors.initials: C
authors.lastname: Benkelfat
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000097:blood*; D000704:Analysis of Variance; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D010649:Phenylalanine / Q000008:administration & dosage / Q000097:blood* / Q000172:deficiency; D012646:Self Administration; D009435:Synaptic Transmission; D014364:Tryptophan / Q000008:administration & dosage / Q000097:blood* / Q000172:deficiency; D014443:Tyrosine / Q000008:administration & dosage / Q000097:blood* / Q000172:deficiency
chemical_list: D014443:Tyrosine; D010649:Phenylalanine; D014364:Tryptophan