{"id":"5cdbd8a3-35dd-5bc2-bab6-ac57f5b2ef21","stable_key":"5102beb6-9f61-500e-af10-9ac63649e0b7:k-na-gradients-muscle-excitability","predicate":"modulates","statement":"The combined 85 mM Na/9 mM K bath reduced M-wave area and tetanic force versus 147 mM Na/4 mM K.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"6dfe9c4a-f458-51ba-be7f-416c3060632a","mechanism_event_label":"Both sodium and potassium gradients matter for muscle activation.","subject":{"id":"65e7fcad-670f-5dba-8488-896c86f2bbae","slug":"extracellular-potassium-concentration","display_name":"Extracellular potassium concentration","entity_type_key":"cellular_process"},"object":{"id":"6dc31e65-7861-50e5-8b55-5890f612ae28","slug":"skeletal-muscle-excitability","display_name":"Skeletal muscle excitability","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"6dfe9c4a-f458-51ba-be7f-416c3060632a","stable_key":"5102beb6-9f61-500e-af10-9ac63649e0b7:k-na-gradients-muscle-excitability-event","event_type":"biochemical_relationship","label":"Both sodium and potassium gradients matter for muscle activation.","description":"The combined 85 mM Na/9 mM K bath reduced M-wave area and tetanic force versus 147 mM Na/4 mM K.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"38de8704-84db-5770-ac1d-242cd787e798","slug":"sodium-ion","display_name":"Sodium ion","entity_type_key":"ion"},"role":"co-manipulated ion","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"78c07807-cf7b-5e9f-98bc-b005587b1bf2","slug":"skeletal-muscle-force","display_name":"Skeletal muscle force","entity_type_key":"cellular_process"},"role":"measured contraction","stoichiometry":null,"state_label":"","sequence_order":1,"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":2,"notes":""},{"entity":{"id":"6dc31e65-7861-50e5-8b55-5890f612ae28","slug":"skeletal-muscle-excitability","display_name":"Skeletal muscle excitability","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Reduced sodium and elevated potassium jointly impair excitability.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Isolated rat soleus, combined bath-ion perturbation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Combined perturbation cannot be attributed to potassium alone; not dietary excess.","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":"Both sodium and potassium gradients matter for muscle activation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[overgaard-1999-muscle] Relations between excitability and contractility in rat soleus muscle: role of the Na+-K+ pump and Na+/K+ gradients (1999). https://pubmed.ncbi.nlm.nih.gov/10373703/ DOI: 10.1111/j.1469-7793.1999.0215r.x","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Soleus muscle","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"8f1e1764-f039-5a61-bb12-6f3764224174","evidence_kind":"source_excerpt","locator":"Lines 715-725","start_line":715,"end_line":725,"excerpt":"### k-na-gradients-muscle-excitability\nThe combined 85 mM Na/9 mM K bath reduced M-wave area and tetanic force versus 147 mM Na/4 mM K.\nCondition category: normal\nnutrient_topic: Potassium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Both sodium and potassium gradients matter for muscle activation.\norganism: Rat\ntissue_or_cell_type: Soleus muscle\nexperimental_model: Isolated rat soleus, combined bath-ion perturbation.\nlimitations: Combined perturbation cannot be attributed to potassium alone; not dietary excess.\ncross_nutrient: Reduced sodium and elevated potassium jointly impair excitability.\n[overgaard-1999-muscle] Relations between excitability and contractility in rat soleus muscle: role of the Na+-K+ pump and Na+/K+ gradients (1999). https://pubmed.ncbi.nlm.nih.gov/10373703/ DOI: 10.1111/j.1469-7793.1999.0215r.x","model_system":"Isolated rat soleus, combined bath-ion perturbation.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [overgaard-1999-muscle] Relations between excitability and contractility in rat soleus muscle: role of the Na+-K+ pump and Na+/K+ gradients (1999). https://pubmed.ncbi.nlm.nih.gov/10373703/ DOI: 10.1111/j.1469-7793.1999.0215r.x","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}