{"id":"fa590afd-9be4-5425-a69b-5cd0ad3af900","stable_key":"dff9f743-3766-5f20-a71e-d6d2bd5bfb6f:a-vision-excess-bisretinoids","predicate":"increases","statement":"Vitamin A-supplemented diets increased ocular A2E/bisretinoid accumulation in wild-type and Abca4-null mice relative to control diets.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"3e36cb92-9bf3-5a69-9d20-0e3c6b061052","mechanism_event_label":"Extra vitamin A increased visual-cycle by-products in these mice.","subject":{"id":"ce392c9e-6483-5914-b18b-d6a2520dbbf6","slug":"vitamin-a","display_name":"Vitamin A","entity_type_key":"chemical_species"},"object":{"id":"ca9091ab-d839-5ddc-a0ac-9868d957a742","slug":"a2e","display_name":"A2E bisretinoid","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"3e36cb92-9bf3-5a69-9d20-0e3c6b061052","stable_key":"dff9f743-3766-5f20-a71e-d6d2bd5bfb6f:a-vision-excess-bisretinoids-event","event_type":"biochemical_relationship","label":"Extra vitamin A increased visual-cycle by-products in these mice.","description":"Vitamin A-supplemented diets increased ocular A2E/bisretinoid accumulation in wild-type and Abca4-null mice relative to control diets.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"e45ac8b4-0e4b-560d-b34f-6358fbae4ee3","slug":"abca4","display_name":"ABCA4 retinoid transporter","entity_type_key":"protein"},"role":"genotype modifier","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"bbe7302a-1c34-5c2e-8811-6c6fdc255ab1","slug":"a2pe-h2","display_name":"A2PE-H2 bisretinoid precursor","entity_type_key":"lipid"},"role":"measured precursor","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"ce392c9e-6483-5914-b18b-d6a2520dbbf6","slug":"vitamin-a","display_name":"Vitamin A","entity_type_key":"chemical_species"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"ca9091ab-d839-5ddc-a0ac-9868d957a742","slug":"a2e","display_name":"A2E bisretinoid","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Dietary supplementation versus control; biochemical and morphologic endpoints","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"dietary vitamin A excess/supplementation","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"genotype","value_text":"wild type and Abca4-null","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Mouse exposure; no human dose or treatment recommendation follows. Degeneration depended on pigmentation and occurred on both diets.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin A research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-a","display_name":"Vitamin A","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Mus musculus","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Extra vitamin A increased visual-cycle by-products in these mice.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[radu-2008] Accelerated accumulation of lipofuscin pigments in the RPE of a mouse model for ABCA4-mediated retinal dystrophies following Vitamin A supplementation (2008). https://pubmed.ncbi.nlm.nih.gov/18515570/ DOI: 10.1167/iovs.07-1470","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Eye/RPE","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"1d7c4eb6-62db-59ba-8730-d7ed7623846d","evidence_kind":"source_excerpt","locator":"Lines 847-858","start_line":847,"end_line":858,"excerpt":"### a-vision-excess-bisretinoids\nVitamin A-supplemented diets increased ocular A2E/bisretinoid accumulation in wild-type and Abca4-null mice relative to control diets.\nCondition category: normal\nnutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Extra vitamin A increased visual-cycle by-products in these mice.\norganism: Mus musculus\ntissue_or_cell_type: Eye/RPE\nexperimental_model: Dietary supplementation versus control; biochemical and morphologic endpoints\nlimitations: Mouse exposure; no human dose or treatment recommendation follows. Degeneration depended on pigmentation and occurred on both diets.\nexposure: dietary vitamin A excess/supplementation\ngenotype: wild type and Abca4-null\n[radu-2008] Accelerated accumulation of lipofuscin pigments in the RPE of a mouse model for ABCA4-mediated retinal dystrophies following Vitamin A supplementation (2008). https://pubmed.ncbi.nlm.nih.gov/18515570/ DOI: 10.1167/iovs.07-1470","model_system":"Dietary supplementation versus control; biochemical and morphologic endpoints","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [radu-2008] Accelerated accumulation of lipofuscin pigments in the RPE of a mouse model for ABCA4-mediated retinal dystrophies following Vitamin A supplementation (2008). https://pubmed.ncbi.nlm.nih.gov/18515570/ DOI: 10.1167/iovs.07-1470","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"0c5474e2-be48-547b-b287-9c07a59c9ff1","stable_key":"import-dff9f743-3766-5f20-a71e-d6d2bd5bfb6f","title":"Vitamin A: forms, mechanisms, deficiency and excess (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":"b217224b262abbd77d6a0c8c9beefff9c022fae4d31e2a5273915d769b9a6546","revision_id":"61008909-871f-575c-b5e2-21542689ea3c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}