{"id":"526bc56f-a0d7-5c3e-a6ce-40a3a7f866a4","stable_key":"584c58f5-ab9f-53f3-97a9-55783db943b0:tryptophan-brain-competition","predicate":"competes_in_dietary_context","statement":"In rat meal experiments, brain tryptophan and 5-hydroxyindoles tracked the serum tryptophan-to-competing-neutral-amino-acid ratio better than serum tryptophan alone.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"84b86e33-e44d-5b63-9eff-dd97e8b5b219","mechanism_event_label":"A higher blood level need not mean more tryptophan reaches the brain.","subject":{"id":"f707c753-cc8c-5f06-90be-bb3d73c60a18","slug":"leucine","display_name":"L-Leucine","entity_type_key":"small_molecule"},"object":{"id":"339e0a83-8d3e-5544-a1c9-8d90528bb6b3","slug":"rat-brain-tryptophan-content","display_name":"Rat brain tryptophan content","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"84b86e33-e44d-5b63-9eff-dd97e8b5b219","stable_key":"584c58f5-ab9f-53f3-97a9-55783db943b0:tryptophan-brain-competition-event","event_type":"observed_relationship","label":"A higher blood level need not mean more tryptophan reaches the brain.","description":"In rat meal experiments, brain tryptophan and 5-hydroxyindoles tracked the serum tryptophan-to-competing-neutral-amino-acid ratio better than serum tryptophan alone.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"f707c753-cc8c-5f06-90be-bb3d73c60a18","slug":"leucine","display_name":"L-Leucine","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"339e0a83-8d3e-5544-a1c9-8d90528bb6b3","slug":"rat-brain-tryptophan-content","display_name":"Rat brain tryptophan content","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"769339cb-213b-559e-acc0-07ed00368b94","slug":"l-tryptophan","display_name":"L-Tryptophan","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"c85b327e-f132-5d9a-8e4b-c2976fcc0373","slug":"isoleucine","display_name":"L-Isoleucine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"190407ad-0219-54b5-b05f-7c75f3895ca6","slug":"l-phenylalanine","display_name":"L-Phenylalanine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""},{"entity":{"id":"bcfef85f-831d-5439-ba51-1aef4b090441","slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":5,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Overnight-fasted rats receiving defined meals with different amino-acid mixtures.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Not a validated universal human threshold or proof that protein-rich meals worsen mood.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Tryptophan collection; molecular form, preparation, species, exposure and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-tryptophan","display_name":"L-Tryptophan","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"A higher blood level need not mean more tryptophan reaches the brain.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Acute reduction of brain serotonin and 5-HIAA following food consumption: correlation with the ratio of serum tryptophan to the sum of competing amino acids. · 1975 · https://pubmed.ncbi.nlm.nih.gov/1080186/ · DOI 10.1007/BF01256759","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"5d20981f-4ad8-557a-9964-ec1cc1282820","evidence_kind":"source_excerpt","locator":"Lines 58-64","start_line":58,"end_line":64,"excerpt":"## tryptophan-brain-competition\nA higher blood level need not mean more tryptophan reaches the brain.\nIn rat meal experiments, brain tryptophan and 5-hydroxyindoles tracked the serum tryptophan-to-competing-neutral-amino-acid ratio better than serum tryptophan alone.\nModel: Overnight-fasted rats receiving defined meals with different amino-acid mixtures.\nLimitations: Not a validated universal human threshold or proof that protein-rich meals worsen mood.\nEvidence access: Primary abstract\nAcute reduction of brain serotonin and 5-HIAA following food consumption: correlation with the ratio of serum tryptophan to the sum of competing amino acids. · 1975 · https://pubmed.ncbi.nlm.nih.gov/1080186/ · DOI 10.1007/BF01256759","model_system":"Overnight-fasted rats receiving defined meals with different amino-acid mixtures.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; 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Not publisher full text.","file_path":"","sha256":"7dfd20063b91900cb5c6ad675e3e675b7e25ef0fb8304eabac6f263cc5518284","revision_id":"bfafd789-fdf5-521f-bd28-c662e01ec1ea","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}