Antidopaminergic effects of dietary tyrosine depletion in healthy subjects and patients with manic illness.
BACKGROUND: In rats, amino acid mixtures lacking tyrosine and its precursor phenylalanine decrease the release of dopamine produced by the psychostimulant drug amphetamine. Amphetamine has been proposed as a model for clinical mania. AIMS: To assess whether dietary tyrosine depletion attenuates the...
| Main Authors: | , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
2001
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| Summary: | BACKGROUND: In rats, amino acid mixtures lacking tyrosine and its precursor phenylalanine decrease the release of dopamine produced by the psychostimulant drug amphetamine. Amphetamine has been proposed as a model for clinical mania. AIMS: To assess whether dietary tyrosine depletion attenuates the psychostimulant effects of methamphetamine in healthy volunteers and diminishes the severity of mania in acutely ill patients. METHOD: Sixteen healthy volunteers received a tyrosine-free amino acid mixture and a control mixture in a double-blind crossover design 4 h before methamphetamine (0.15 mg/kg). Twenty in-patients meeting DSM-IV criteria for mania were allocated blindly and randomly to receive either the tyrosine-free mixture or the control mixture. RESULTS: The tyrosine-free mixture lowered both subjective and objective measures of the psychostimulant effects of methamphetamine. Ratings of mania were lower in the patients who received the tyrosine-free mixture. CONCLUSIONS; Decreased tyrosine availability to the brain attenuates pathological increases in dopamine neurotransmission following methamphetamine administration and putatively in mania. |
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