{"id":"13c2fb5e-7672-54ee-b738-6e4cb75b3d07","stable_key":"5102beb6-9f61-500e-af10-9ac63649e0b7:k-low-cardiac-hyperpolarization","predicate":"shifts","statement":"Acute low-K superfusion hyperpolarized rat ventricular resting voltage despite increasing calcium transients.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"3a82f69a-2f72-5dea-8772-68decd5dc3ca","mechanism_event_label":"A more negative resting voltage did not prevent calcium accumulation.","subject":{"id":"65e7fcad-670f-5dba-8488-896c86f2bbae","slug":"extracellular-potassium-concentration","display_name":"Extracellular potassium concentration","entity_type_key":"cellular_process"},"object":{"id":"96cda2ee-9d63-56c2-8e7f-0f5ddd408f44","slug":"resting-membrane-potential","display_name":"Resting plasma-membrane potential","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"3a82f69a-2f72-5dea-8772-68decd5dc3ca","stable_key":"5102beb6-9f61-500e-af10-9ac63649e0b7:k-low-cardiac-hyperpolarization-event","event_type":"biochemical_relationship","label":"A more negative resting voltage did not prevent calcium accumulation.","description":"Acute low-K superfusion hyperpolarized rat ventricular resting voltage despite increasing calcium transients.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"e359bc15-e675-5d83-b0fe-1d70814e130b","slug":"calcium-ion","display_name":"Calcium ion","entity_type_key":"ion"},"role":"calcium-transient readout","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"65e7fcad-670f-5dba-8488-896c86f2bbae","slug":"extracellular-potassium-concentration","display_name":"Extracellular potassium concentration","entity_type_key":"cellular_process"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"96cda2ee-9d63-56c2-8e7f-0f5ddd408f44","slug":"resting-membrane-potential","display_name":"Resting plasma-membrane potential","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"experimental_model","value_text":"Rat ventricular voltage and calcium recordings.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Do not equate hyperpolarization with protection from arrhythmia.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Potassium research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"potassium","display_name":"Potassium","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Rat","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"A more negative resting voltage did not prevent calcium accumulation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[aronsen-2015-cardiac] Hypokalaemia induces Ca2+ overload and Ca2+ waves in ventricular myocytes by reducing Na+,K+-ATPase alpha2 activity (2015). https://pmc.ncbi.nlm.nih.gov/articles/PMC4376427/ DOI: 10.1113/jphysiol.2014.279893","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Ventricle","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"cf7e1d3f-0d20-58d9-9d2d-f1ee892ec179","evidence_kind":"source_excerpt","locator":"Lines 634-643","start_line":634,"end_line":643,"excerpt":"### k-low-cardiac-hyperpolarization\nAcute low-K superfusion hyperpolarized rat ventricular resting voltage despite increasing calcium transients.\nCondition category: nutrient_deficiency\nnutrient_topic: Potassium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: A more negative resting voltage did not prevent calcium accumulation.\norganism: Rat\ntissue_or_cell_type: Ventricle\nexperimental_model: Rat ventricular voltage and calcium recordings.\nlimitations: Do not equate hyperpolarization with protection from arrhythmia.\n[aronsen-2015-cardiac] Hypokalaemia induces Ca2+ overload and Ca2+ waves in ventricular myocytes by reducing Na+,K+-ATPase alpha2 activity (2015). https://pmc.ncbi.nlm.nih.gov/articles/PMC4376427/ DOI: 10.1113/jphysiol.2014.279893","model_system":"Rat ventricular voltage and calcium recordings.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [aronsen-2015-cardiac] Hypokalaemia induces Ca2+ overload and Ca2+ waves in ventricular myocytes by reducing Na+,K+-ATPase alpha2 activity (2015). https://pmc.ncbi.nlm.nih.gov/articles/PMC4376427/ DOI: 10.1113/jphysiol.2014.279893","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"241226ee-6b7d-5cc7-9781-e6beb8ee1982","stable_key":"import-5102beb6-9f61-500e-af10-9ac63649e0b7","title":"Potassium: cross-nutrient mechanisms and deficiency (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":"a8f89f8d84b48c0f93048dfc45f7f57a67dd9a7249968a096a14aeb03d8b7a52","revision_id":"de4ec6f4-58a1-537b-8169-97b783898df1","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}