{"id":"a74cc67e-2974-52f3-89a4-a95d8a520e65","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:ca-cardiac-sr-sparks","predicate":"produces","statement":"Localized sarcoplasmic-reticulum calcium release generates brief calcium sparks in rat cardiac myocytes.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"59af6b1d-54a3-5d18-b59d-9da7d5e45c30","mechanism_event_label":"Heart cells release small local bursts of stored calcium.","subject":{"id":"65c07c2e-dcd7-5d3b-9153-009ffa663e81","slug":"sarcoplasmic-reticulum-calcium-release","display_name":"Sarcoplasmic reticulum calcium release","entity_type_key":"cellular_process"},"object":{"id":"98a312e8-bf5a-549f-a4a6-bdb91b75cfc2","slug":"cardiac-calcium-sparks","display_name":"Cardiac calcium sparks","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"59af6b1d-54a3-5d18-b59d-9da7d5e45c30","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:ca-cardiac-sr-sparks-event","event_type":"mechanism","label":"Heart cells release small local bursts of stored calcium.","description":"Localized sarcoplasmic-reticulum calcium release generates brief calcium sparks in rat cardiac myocytes.","status":"provisional","compartment":{"slug":"sarcoplasmic-reticulum","display_name":"Sarcoplasmic reticulum"},"participants":[{"entity":{"id":"65c07c2e-dcd7-5d3b-9153-009ffa663e81","slug":"sarcoplasmic-reticulum-calcium-release","display_name":"Sarcoplasmic reticulum calcium release","entity_type_key":"cellular_process"},"role":"source_process","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"e359bc15-e675-5d83-b0fe-1d70814e130b","slug":"calcium-ion","display_name":"Calcium ion","entity_type_key":"ion"},"role":"released_ion","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"98a312e8-bf5a-549f-a4a6-bdb91b75cfc2","slug":"cardiac-calcium-sparks","display_name":"Cardiac calcium sparks","entity_type_key":"cellular_process"},"role":"local_signal","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"af4c313b-d451-559f-955b-9b761fe39da9","slug":"sarcoplasmic-reticulum","display_name":"Sarcoplasmic reticulum","entity_type_key":"organelle"},"role":"experimental_location","stoichiometry":null,"state_label":"","sequence_order":3,"notes":"Study location; presence here is not a separate transport or causal claim."},{"entity":{"id":"bc9ed3a1-38d5-5bc3-b2a5-9f9f7633660b","slug":"cytosol","display_name":"Cytosol","entity_type_key":"organelle"},"role":"experimental_location","stoichiometry":null,"state_label":"","sequence_order":4,"notes":"Study location; presence here is not a separate transport or causal claim."}]},"contexts":[{"dimension":"compartment_description","value_text":"SR to local cytosol","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Quiescent rat cardiac myocytes; confocal calcium imaging with ryanodine and SR-loading manipulations","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Imaging and ryanodine sensitivity establish localized release; the historical single-channel estimate is not encoded as settled channel stoichiometry.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Calcium research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"calcium","display_name":"Calcium","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Rattus norvegicus","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Heart cells release small local bursts of stored calcium.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[ca-cheng1993] Calcium sparks: elementary events underlying excitation-contraction coupling in heart muscle (1993). https://pubmed.ncbi.nlm.nih.gov/8235594/ DOI: 10.1126/science.8235594","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"research_relationship_category","value_text":"mechanism","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Cardiac myocytes","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"transport_or_reaction_direction","value_text":"SR lumen to cytosol","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"640b8859-516b-559d-b56d-d23debb80ebb","evidence_kind":"source_excerpt","locator":"Lines 809-821","start_line":809,"end_line":821,"excerpt":"### ca-cardiac-sr-sparks\nLocalized sarcoplasmic-reticulum calcium release generates brief calcium sparks in rat cardiac myocytes.\nCondition category: normal\nnutrient_topic: Calcium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Heart cells release small local bursts of stored calcium.\norganism: Rattus norvegicus\ntissue_or_cell_type: Cardiac myocytes\nexperimental_model: Quiescent rat cardiac myocytes; confocal calcium imaging with ryanodine and SR-loading manipulations\nlimitations: Imaging and ryanodine sensitivity establish localized release; the historical single-channel estimate is not encoded as settled channel stoichiometry.\nresearch_relationship_category: mechanism\ntransport_or_reaction_direction: SR lumen to cytosol\ncompartment_description: SR to local cytosol\n[ca-cheng1993] Calcium sparks: elementary events underlying excitation-contraction coupling in heart muscle (1993). https://pubmed.ncbi.nlm.nih.gov/8235594/ DOI: 10.1126/science.8235594","model_system":"Quiescent rat cardiac myocytes; confocal calcium imaging with ryanodine and SR-loading manipulations","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [ca-cheng1993] Calcium sparks: elementary events underlying excitation-contraction coupling in heart muscle (1993). https://pubmed.ncbi.nlm.nih.gov/8235594/ DOI: 10.1126/science.8235594","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"3c083fa0-59c6-50e9-af42-678d0e3c1006","stable_key":"import-434e1e27-eb90-583a-956b-62472726ffba","title":"Calcium: mechanism-first literature curation (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":"965c934d6b147f2b62f8d45ce6d7a87681a600bfe5c46a585b4704889afd3fc1","revision_id":"543ec48b-4f70-5197-9d76-f5a3c443664c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}