Acute Tyrosine Depletion and Alcohol Ingestion in Healthy Women

Authors

  • M. Leyton,

    Corresponding author
    1. Department of Psychiatry (M.L., S.N.Y., P.B., C.B.), the Department of Psychology (R.O.P.), the School of Dietetics and Human Nutrition (S.N.Y.), McGill University, Montréal, Québec; and Department of Psychiatry (G.B.B.), University of Alberta, Edmonton, Alberta, Canada.
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  • S. N. Young,

    1. Department of Psychiatry (M.L., S.N.Y., P.B., C.B.), the Department of Psychology (R.O.P.), the School of Dietetics and Human Nutrition (S.N.Y.), McGill University, Montréal, Québec; and Department of Psychiatry (G.B.B.), University of Alberta, Edmonton, Alberta, Canada.
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  • P. Blier,

    1. Department of Psychiatry (M.L., S.N.Y., P.B., C.B.), the Department of Psychology (R.O.P.), the School of Dietetics and Human Nutrition (S.N.Y.), McGill University, Montréal, Québec; and Department of Psychiatry (G.B.B.), University of Alberta, Edmonton, Alberta, Canada.
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  • G. B. Baker,

    1. Department of Psychiatry (M.L., S.N.Y., P.B., C.B.), the Department of Psychology (R.O.P.), the School of Dietetics and Human Nutrition (S.N.Y.), McGill University, Montréal, Québec; and Department of Psychiatry (G.B.B.), University of Alberta, Edmonton, Alberta, Canada.
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  • R. O. Pihl,

    1. Department of Psychiatry (M.L., S.N.Y., P.B., C.B.), the Department of Psychology (R.O.P.), the School of Dietetics and Human Nutrition (S.N.Y.), McGill University, Montréal, Québec; and Department of Psychiatry (G.B.B.), University of Alberta, Edmonton, Alberta, Canada.
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  • C. Benkelfat

    1. Department of Psychiatry (M.L., S.N.Y., P.B., C.B.), the Department of Psychology (R.O.P.), the School of Dietetics and Human Nutrition (S.N.Y.), McGill University, Montréal, Québec; and Department of Psychiatry (G.B.B.), University of Alberta, Edmonton, Alberta, Canada.
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  • Supported by grants from the Medical Research Council (MRC) of Canada, MT-7811 (S.N.Y.) and MT-12502. Recipients of a salary award from Fonds de la Recherche en Santé du Québec (FRSQ) (C.B.), a Scientist Award from MRC (C.B.), and a Young Investigators Award from the National Alliance for Research on Schizophrenia and Depression (NARSAD) (M.L.).

    A preliminary report based on this study was presented at the 1998 meeting of the American College for Neuropsychopharmacology, December 13–18, 1998, Puerto Rico.

Reprint requests: Marco Leyton, Ph.D., Department of Psychiatry, McGill University, 1033 Pine Avenue West, Montréal, Québec, CANADA H3A 1A1; Fax: 514-398-4866; E-mail: cyje@musica.mcgill.ca

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.

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