{"id":"a8c3747a-a271-503e-a846-027d5f5af722","stable_key":"dff9f743-3766-5f20-a71e-d6d2bd5bfb6f:a-vision-light-calcium","predicate":"lowers","statement":"Rod calcium-flux recordings showed that illumination reduces outer-segment free calcium as entry falls while extrusion continues.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"c933348b-f72e-5ded-be05-8fe07ed6b8c3","mechanism_event_label":"The light response lowers intracellular calcium, providing a recovery signal.","subject":{"id":"4538a8ef-3b0a-5c56-91f7-58d4c97d7e2a","slug":"photoactivated-rhodopsin","display_name":"Photoactivated rhodopsin","entity_type_key":"protein_state"},"object":{"id":"a71fd204-5ccd-53be-8432-18bc3d2e7198","slug":"rod-outer-segment-calcium","display_name":"Rod outer-segment free calcium concentration","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"c933348b-f72e-5ded-be05-8fe07ed6b8c3","stable_key":"dff9f743-3766-5f20-a71e-d6d2bd5bfb6f:a-vision-light-calcium-event","event_type":"biochemical_relationship","label":"The light response lowers intracellular calcium, providing a recovery signal.","description":"Rod calcium-flux recordings showed that illumination reduces outer-segment free calcium as entry falls while extrusion continues.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"e359bc15-e675-5d83-b0fe-1d70814e130b","slug":"calcium-ion","display_name":"Calcium ion","entity_type_key":"ion"},"role":"regulated ion","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"1bb6df21-0a48-55d5-9fde-83fa2f9532bb","slug":"rod-cng-channel","display_name":"Rod cyclic nucleotide-gated channel","entity_type_key":"protein_complex"},"role":"entry pathway","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"4538a8ef-3b0a-5c56-91f7-58d4c97d7e2a","slug":"photoactivated-rhodopsin","display_name":"Photoactivated rhodopsin","entity_type_key":"protein_state"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"a71fd204-5ccd-53be-8432-18bc3d2e7198","slug":"rod-outer-segment-calcium","display_name":"Rod outer-segment free calcium concentration","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"The vitamin A chromophore-initiated electrical response changes calcium signaling inside the rod.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Calcium influx/efflux measurements during illumination","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Not a claim that dietary calcium intake determines rod calcium transients.","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":"Bufo marinus","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The light response lowers intracellular calcium, providing a recovery signal.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[yau-1985] Light-induced reduction of cytoplasmic free calcium in retinal rod outer segment (1985). https://pubmed.ncbi.nlm.nih.gov/2578628/ DOI: 10.1038/313579a0","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Rod outer segment","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"a8f5d8b6-b784-5e91-b959-a2815c94221e","evidence_kind":"source_excerpt","locator":"Lines 949-959","start_line":949,"end_line":959,"excerpt":"### a-vision-light-calcium\nRod calcium-flux recordings showed that illumination reduces outer-segment free calcium as entry falls while extrusion continues.\nCondition category: normal\nnutrient_topic: Vitamin A research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The light response lowers intracellular calcium, providing a recovery signal.\norganism: Bufo marinus\ntissue_or_cell_type: Rod outer segment\nexperimental_model: Calcium influx/efflux measurements during illumination\nlimitations: Not a claim that dietary calcium intake determines rod calcium transients.\ncross_nutrient: The vitamin A chromophore-initiated electrical response changes calcium signaling inside the rod.\n[yau-1985] Light-induced reduction of cytoplasmic free calcium in retinal rod outer segment (1985). https://pubmed.ncbi.nlm.nih.gov/2578628/ DOI: 10.1038/313579a0","model_system":"Calcium influx/efflux measurements during illumination","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [yau-1985] Light-induced reduction of cytoplasmic free calcium in retinal rod outer segment (1985). https://pubmed.ncbi.nlm.nih.gov/2578628/ DOI: 10.1038/313579a0","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}