{"id":"b73f6581-1ef6-59bd-858b-b62e776eab44","stable_key":"ae1ed35d-8ce7-5936-9067-a641374bbf79:carnosine-pept2-brain","predicate":"knockout_increases","statement":"After injected carnosine, Pept2-null mice had an approximately eightfold greater CSF-to-plasma concentration ratio.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"c44abf62-fe40-5b82-a8f8-8dac8d0a25fb","mechanism_event_label":"The transporter also changes distribution around the brain.","subject":{"id":"d36cda69-0855-55d3-be6a-d67c5bb1eb5b","slug":"mouse-slc15a2","display_name":"Mouse peptide transporter 2 / Slc15a2","entity_type_key":"protein"},"object":{"id":"69255e9c-f18a-55c9-bcbe-207113e214fe","slug":"mouse-carnosine-csf-plasma-ratio","display_name":"Mouse CSF-to-plasma ratio of exogenous carnosine","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"c44abf62-fe40-5b82-a8f8-8dac8d0a25fb","stable_key":"ae1ed35d-8ce7-5936-9067-a641374bbf79:carnosine-pept2-brain-event","event_type":"observed_relationship","label":"The transporter also changes distribution around the brain.","description":"After injected carnosine, Pept2-null mice had an approximately eightfold greater CSF-to-plasma concentration ratio.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"d36cda69-0855-55d3-be6a-d67c5bb1eb5b","slug":"mouse-slc15a2","display_name":"Mouse peptide transporter 2 / Slc15a2","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"69255e9c-f18a-55c9-bcbe-207113e214fe","slug":"mouse-carnosine-csf-plasma-ratio","display_name":"Mouse CSF-to-plasma ratio of exogenous carnosine","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 tracer disposition.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Endogenous plasma and CSF concentrations did not differ; tracer and steady-state results are distinct.","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 transporter also changes distribution around the brain.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Influence of genetic knockout of Pept2 on the in vivo disposition of endogenous and exogenous carnosine in wild-type and Pept2 null mice. · 2009 · https://pubmed.ncbi.nlm.nih.gov/19225147/ · DOI 10.1152/ajpregu.90744.2008","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":"af7f80c5-a3fa-5c9e-81d7-7e78b371fc6a","evidence_kind":"source_excerpt","locator":"Lines 100-106","start_line":100,"end_line":106,"excerpt":"## carnosine-pept2-brain\nThe transporter also changes distribution around the brain.\nAfter injected carnosine, Pept2-null mice had an approximately eightfold greater CSF-to-plasma concentration ratio.\nModel: Mouse tracer disposition.\nLimitations: Endogenous plasma and CSF concentrations did not differ; tracer and steady-state results are distinct.\nEvidence access: Primary abstract\nInfluence of genetic knockout of Pept2 on the in vivo disposition of endogenous and exogenous carnosine in wild-type and Pept2 null mice. · 2009 · https://pubmed.ncbi.nlm.nih.gov/19225147/ · DOI 10.1152/ajpregu.90744.2008","model_system":"Mouse tracer disposition.","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; 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