{"id":"61deb23c-3359-5fe3-9dfc-ddbbde0f3b89","stable_key":"ae1ed35d-8ce7-5936-9067-a641374bbf79:carnosine-mouse-olfaction","predicate":"knockout_impairs","statement":"Aged Carns1-null mice showed reduced olfactory sensitivity and fewer olfactory receptor neurons; younger tested mice did not show this deficit.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"54ccd887-e942-53f1-879c-ebeb780c5fe6","mechanism_event_label":"The functional effect depended on age and tissue.","subject":{"id":"17665d7f-0637-5c4c-bb6d-611795507168","slug":"mouse-carns1","display_name":"Mouse carnosine synthase / Carns1","entity_type_key":"protein"},"object":{"id":"4e6916d4-0b83-5c9c-a4fb-caa08ad652f1","slug":"mouse-aging-olfactory-sensitivity","display_name":"Mouse olfactory sensitivity during aging","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"54ccd887-e942-53f1-879c-ebeb780c5fe6","stable_key":"ae1ed35d-8ce7-5936-9067-a641374bbf79:carnosine-mouse-olfaction-event","event_type":"observed_relationship","label":"The functional effect depended on age and tissue.","description":"Aged Carns1-null mice showed reduced olfactory sensitivity and fewer olfactory receptor neurons; younger tested mice did not show this deficit.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"17665d7f-0637-5c4c-bb6d-611795507168","slug":"mouse-carns1","display_name":"Mouse carnosine synthase / Carns1","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"4e6916d4-0b83-5c9c-a4fb-caa08ad652f1","slug":"mouse-aging-olfactory-sensitivity","display_name":"Mouse olfactory sensitivity during aging","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"9998eb9b-0d09-58c9-885b-a442477dec8d","slug":"carnosine","display_name":"L-Carnosine / beta-alanyl-L-histidine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Mouse aging study, 18–24 months versus eight months.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Cannot convert genetic aging effects into human intake thresholds.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Carnosine collection; isomer, preparation, species, exposure and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"carnosine","display_name":"L-Carnosine / beta-alanyl-L-histidine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"The functional effect depended on age and tissue.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Carnosine synthase deficiency is compatible with normal skeletal muscle and olfactory function but causes reduced olfactory sensitivity in aging mice. · 2020 · https://pubmed.ncbi.nlm.nih.gov/33040025/ · DOI 10.1074/jbc.RA120.014188","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"feda1049-cced-50bd-9dc1-91095ccdd611","evidence_kind":"source_excerpt","locator":"Lines 404-410","start_line":404,"end_line":410,"excerpt":"## carnosine-mouse-olfaction\nThe functional effect depended on age and tissue.\nAged Carns1-null mice showed reduced olfactory sensitivity and fewer olfactory receptor neurons; younger tested mice did not show this deficit.\nModel: Mouse aging study, 18–24 months versus eight months.\nLimitations: Cannot convert genetic aging effects into human intake thresholds.\nEvidence access: Primary abstract\nCarnosine synthase deficiency is compatible with normal skeletal muscle and olfactory function but causes reduced olfactory sensitivity in aging mice. · 2020 · https://pubmed.ncbi.nlm.nih.gov/33040025/ · DOI 10.1074/jbc.RA120.014188","model_system":"Mouse aging study, 18–24 months versus eight months.","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":"87dc5af2-4eb6-5980-b7e0-bf3697b1156e","stable_key":"import-ae1ed35d-8ce7-5936-9067-a641374bbf79","title":"Carnosine: synthesis, transport, carbonyl chemistry and nutrient interactions (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"469cbc38203db56bd031f9d8a2dd2bfa387713950ca30199511cd137e927aa7a","revision_id":"cc409a15-8b04-50ee-a7ff-d1bf32f686bb","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}