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(2007). https://pubmed.ncbi.nlm.nih.gov/17476361/ DOI: 10.1172/jci30558","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Hepatocytes and whole body","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":"3bf4bcdd-5740-526a-b3d1-1b1451763ace","evidence_kind":"source_excerpt","locator":"Lines 125-136","start_line":125,"end_line":136,"excerpt":"### metformin-oct1-variants-uptake\nSeven non-synonymous OCT1 polymorphisms showed reduced metformin uptake, including OCT1-420del, which has normal activity for model substrates.\nCondition category: machinery_impairment\nnutrient_topic: Metformin research collection; topical membership is not evidence of a direct clinical effect, and pharmacological exposure is not dietary intake.\nplain_language: A transporter can look normal on a test substrate and still handle this drug poorly.\norganism: Mouse and human, stated per record\ntissue_or_cell_type: Hepatocytes and whole body\nexperimental_model: Oct1-knockout mouse hepatocytes and mice, human variant uptake assays, and human glucose-tolerance studies\nlimitations: Pharmacogenetic association with drug response, not proof that OCT1 genotype should guide prescribing.\nexposure: Metformin in Oct1-deficient mice; seven non-synonymous human OCT1 variants; clinical glucose tolerance tests\nevidence_span: {\"source_cache\": \"artifacts/metformin-research/17476361.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"e8d05affc6b49c7273e21804d2ad9092ca826c8d81431ee093c6215f18f0bce1\", \"start_char\": 0, \"end_char\": 1361, \"text_sha256\": \"e8d05affc6b49c7273e21804d2ad9092ca826c8d81431ee093c6215f18f0bce1\"}\n[metformin-p17476361] Effect of genetic variation in the organic cation transporter 1 (OCT1) on metformin action. (2007). https://pubmed.ncbi.nlm.nih.gov/17476361/ DOI: 10.1172/jci30558","model_system":"Oct1-knockout mouse hepatocytes and mice, human variant uptake assays, and human glucose-tolerance studies","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [metformin-p17476361] Effect of genetic variation in the organic cation transporter 1 (OCT1) on metformin action. (2007). https://pubmed.ncbi.nlm.nih.gov/17476361/ DOI: 10.1172/jci30558","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"d0474bd9-7cfd-5695-a152-12f3633a6813","stable_key":"import-8b3cf083-ea9c-54f5-b42b-bf1fef5b2978","title":"Metformin: transport, molecular targets, gut mechanisms and nutrient interactions (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. 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