{"id":"88f8806e-414e-5fe6-a04e-d64482e94f07","stable_key":"cb568d28-484a-5c2e-9fcc-2d780358e514:vc-transport-selenium-cytosolic-radical","predicate":"deficiency-reduces","statement":"Dialyzed liver cytosol from selenium-deficient rats lost NADPH-dependent ascorbyl-radical reducing activity attributed to thioredoxin reductase.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"138a7c49-a2d3-5e8b-b6fc-5c58d14e015d","mechanism_event_label":"Selenium deficiency impaired radical recycling in the rat liver’s soluble fraction.","subject":{"id":"dc89d7e2-8f89-577b-838f-42bf5d8ec7c8","slug":"selenium","display_name":"Selenium","entity_type_key":"nutrient_element"},"object":{"id":"70b75c79-ce3e-53f2-802c-ce402d06ef9a","slug":"ascorbyl-radical-reduction","display_name":"Ascorbyl radical reduction to ascorbate","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"138a7c49-a2d3-5e8b-b6fc-5c58d14e015d","stable_key":"cb568d28-484a-5c2e-9fcc-2d780358e514:vc-transport-selenium-cytosolic-radical-event","event_type":"biochemical_relationship","label":"Selenium deficiency impaired radical recycling in the rat liver’s soluble fraction.","description":"Dialyzed liver cytosol from selenium-deficient rats lost NADPH-dependent ascorbyl-radical reducing activity attributed to thioredoxin reductase.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"44c93642-76cb-5254-9edb-14a3020a5ae6","slug":"rat-txnrd1","display_name":"Rat thioredoxin reductase 1 / Txnrd1","entity_type_key":"protein"},"role":"enzyme","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"4aba2a5e-8d06-5304-bb01-c0402b225a94","slug":"nadph","display_name":"NADPH","entity_type_key":"small_molecule"},"role":"electron donor","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"17a4b1a5-451a-563f-8f20-2de8f4b0af8e","slug":"ascorbyl-radical","display_name":"Ascorbyl radical","entity_type_key":"chemical_species"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"dc89d7e2-8f89-577b-838f-42bf5d8ec7c8","slug":"selenium","display_name":"Selenium","entity_type_key":"nutrient_element"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"70b75c79-ce3e-53f2-802c-ce402d06ef9a","slug":"ascorbyl-radical-reduction","display_name":"Ascorbyl radical reduction to ascorbate","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"cross_nutrient","value_text":"true","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Purified rat liver enzyme, dialyzed cytosol and microsomes from control/selenium-deficient rats","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Dietary selenium depletion; isolated dialyzed cytosol","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Activity assignment also used inhibitor sensitivity; this is a fraction assay, not a direct human outcome.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin C research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-c","display_name":"Vitamin C","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Rattus norvegicus","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Selenium deficiency impaired radical recycling in the rat liver’s soluble fraction.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[may1998] Reduction of the ascorbyl free radical to ascorbate by thioredoxin reductase. (1998). https://pubmed.ncbi.nlm.nih.gov/9722529/ DOI: 10.1074/jbc.273.36.23039","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Liver cytosol","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"7b58bc33-02ce-512b-a325-1c6621cac809","evidence_kind":"source_excerpt","locator":"Lines 429-440","start_line":429,"end_line":440,"excerpt":"### vc-transport-selenium-cytosolic-radical\nDialyzed liver cytosol from selenium-deficient rats lost NADPH-dependent ascorbyl-radical reducing activity attributed to thioredoxin reductase.\nCondition category: nutrient_deficiency\nnutrient_topic: Vitamin C research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Selenium deficiency impaired radical recycling in the rat liver’s soluble fraction.\norganism: Rattus norvegicus\ntissue_or_cell_type: Liver cytosol\nexperimental_model: Purified rat liver enzyme, dialyzed cytosol and microsomes from control/selenium-deficient rats\nlimitations: Activity assignment also used inhibitor sensitivity; this is a fraction assay, not a direct human outcome.\nexposure: Dietary selenium depletion; isolated dialyzed cytosol\ncross_nutrient: true\n[may1998] Reduction of the ascorbyl free radical to ascorbate by thioredoxin reductase. (1998). https://pubmed.ncbi.nlm.nih.gov/9722529/ DOI: 10.1074/jbc.273.36.23039","model_system":"Purified rat liver enzyme, dialyzed cytosol and microsomes from control/selenium-deficient rats","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [may1998] Reduction of the ascorbyl free radical to ascorbate by thioredoxin reductase. (1998). https://pubmed.ncbi.nlm.nih.gov/9722529/ DOI: 10.1074/jbc.273.36.23039","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"fa811221-13bd-5c10-adc1-eaf097c7703c","stable_key":"import-cb568d28-484a-5c2e-9fcc-2d780358e514","title":"Vitamin C: mechanisms, deficiency and nutrient interactions (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"b7fd83f956abb81855f2ea23199ba14e465cd91f4a2ac560277ec21ddafd7bfc","revision_id":"6cde9bbb-d712-5746-82a6-85b144253efa","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}