{"id":"a1e39098-a5d9-57bc-b53e-59118517378f","stable_key":"8c946991-97f0-55ee-8df0-00e67621962f:nad-plus-liver-nam-export","predicate":"supplies","statement":"Mouse tracer experiments identified liver conversion of tryptophan to NAD followed by nicotinamide release to support other tissues.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"fbb62438-f647-500a-9db2-b961e26564e3","mechanism_event_label":"One organ can help supply another with recycled vitamin material.","subject":{"id":"1558bafc-a4a2-55a2-89e4-e09d62d51f69","slug":"mouse-liver-tryptophan-nad-flux","display_name":"Mouse liver tryptophan-to-NAD flux","entity_type_key":"cellular_process"},"object":{"id":"08c27a3f-552e-5c92-8688-321a9b64a0d6","slug":"nicotinamide","display_name":"Nicotinamide","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"fbb62438-f647-500a-9db2-b961e26564e3","stable_key":"8c946991-97f0-55ee-8df0-00e67621962f:nad-plus-liver-nam-export-event","event_type":"observed_relationship","label":"One organ can help supply another with recycled vitamin material.","description":"Mouse tracer experiments identified liver conversion of tryptophan to NAD followed by nicotinamide release to support other tissues.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"1558bafc-a4a2-55a2-89e4-e09d62d51f69","slug":"mouse-liver-tryptophan-nad-flux","display_name":"Mouse liver tryptophan-to-NAD flux","entity_type_key":"cellular_process"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"08c27a3f-552e-5c92-8688-321a9b64a0d6","slug":"nicotinamide","display_name":"Nicotinamide","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"283ed24b-06a1-50aa-9281-df3bac6ce37e","slug":"nad-plus","display_name":"NAD+","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"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":3,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary full text","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Mouse circulating/tissue stable-isotope flux measurements.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Does not imply that all tissues lack de novo synthesis or that liver is the only contributor under every condition.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"NAD+ collection; molecular form, preparation, species, exposure and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"nad-plus","display_name":"NAD+","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"One organ can help supply another with recycled vitamin material.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Quantitative Analysis of NAD Synthesis-Breakdown Fluxes. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29685734/ · DOI 10.1016/j.cmet.2018.03.018","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"322d702b-870b-574f-b076-15ea08ac7674","evidence_kind":"source_excerpt","locator":"Lines 188-194","start_line":188,"end_line":194,"excerpt":"## nad-plus-liver-nam-export\nOne organ can help supply another with recycled vitamin material.\nMouse tracer experiments identified liver conversion of tryptophan to NAD followed by nicotinamide release to support other tissues.\nModel: Mouse circulating/tissue stable-isotope flux measurements.\nLimitations: Does not imply that all tissues lack de novo synthesis or that liver is the only contributor under every condition.\nEvidence access: Primary full text\nQuantitative Analysis of NAD Synthesis-Breakdown Fluxes. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29685734/ · DOI 10.1016/j.cmet.2018.03.018","model_system":"Mouse circulating/tissue stable-isotope flux measurements.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; evidence access and experimental limitations specified.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"f59aa302-d463-5462-876f-e21e64861eac","stable_key":"import-8c946991-97f0-55ee-8df0-00e67621962f","title":"NAD+: compartmental supply, consumption and cross-nutrient mechanisms (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"9f5324d0d652c80ad630b3100e28ce34cd2ce260ea2e1324332a4262ce72ae09","revision_id":"0e07909c-e8bc-5950-bafc-61371d9d6412","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}