ArticleInternational journal of tryptophan research : IJTR2010
Specificity of the Acute Tryptophan and Tyrosine Plus Phenylalanine Depletion and Loading Tests Part II: Normalisation of the Tryptophan and the Tyrosine Plus Phenylalanine to Competing Amino Acid Ratios in a New Control Formulation.
Article in International journal of tryptophan research : IJTR, 2010. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers.
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Who cites it
10 citing papers in PubMed, 13 citations in OpenAlex.
- Tryptophan Metabolism: A Versatile Area Providing Multiple Targets for Pharmacological Intervention.Egyptian journal of basic and clinical pharmacology · 2019Article
- Dietary tryptophan depletion in humans using a simplified two amino acid formula - a pilot study.Food & nutrition research · 2016Article
- Assessment of the Human Kynurenine Pathway: Comparisons and Clinical Implications of Ethnic and Gender Differences in Plasma Tryptophan, Kynurenine Metabolites, and Enzyme Expressions at Baseline and After Acute Tryptophan Loading and Depletion.International journal of tryptophan research : IJTR · 2016Article
- Tryptophan metabolism, disposition and utilization in pregnancy.Bioscience reports · 2015Review
- Standardization of formulations for the acute amino acid depletion and loading tests.Journal of psychopharmacology (Oxford, England) · 2015Article
- Simplified dietary acute tryptophan depletion: effects of a novel amino acid mixture on the neurochemistry of C57BL/6J mice.Food & nutrition research · 2015Article
- Dietary manipulation of serotonergic and dopaminergic function in C57BL/6J mice with amino acid depletion mixtures.Journal of neural transmission (Vienna, Austria : 1996) · 2014Article
- Mechanisms of the pellagragenic effect of leucine: stimulation of hepatic tryptophan oxidation by administration of branched-chain amino acids to healthy human volunteers and the role of plasma free tryptophan and total kynurenines.International journal of tryptophan research : IJTR · 2014Article
- Appropriate amino acid mixtures for tryptophan depletion and tyrosine/phenylalanine depletion and the safety of long-term amino acid depletion in humans: reply.Psychopharmacology · 2013Article
- Novel nutritional treatment for manic and psychotic disorders: a review of tryptophan and tyrosine depletion studies and the potential of protein-based formulations using glycomacropeptide.Psychopharmacology · 2013Review
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Authors and funding
3 authors at 2 institutions in 2 countries.
Funding
Abstract
Current formulations for acute tryptophan (Trp) or tyrosine (Tyr) plus phenylalanine (Phe) depletion and loading cause undesirable decreases in ratios of Trp or Tyr + Phe to competing amino acids (CAA), thus undermining the specificities of these tests. Branched-chain amino acids (BCAA) cause these unintended decreases, and lowering their content in a new balanced control formulation in the present study led to normalization of all ratios. Four groups (n = 12 each) of adults each received one of four 50 g control formulations, with 0% (traditional), 20%, 30%, or 40% less of the BCAA. The free and total [Trp]/[CAA] and [Phe + Tyr]/[BCAA + Trp] ratios all decreased significantly during the first 5 h following the traditional formulation, but were fully normalized by the formulation containing 40% less of the BCAA. We recommend the latter as a balanced control formulation and propose adjustments in the depletion and loading formulations to enhance their specificities for 5-HT and the catecholamines.
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