{"id":"57579576-c425-58a2-9c38-0dbf90fc2ab1","stable_key":"b3c3f45a-50fb-5b79-98d7-5e5228df00db:cold-civd-ava-mechanism","predicate":"mediates","statement":"The initial cold-induced vasoconstriction involved constriction of the arteriovenous anastomoses and the two main finger arteries, and during cold-induced vasodilatation the large blood flow and high skin temperature were caused by relaxation of the smooth muscle cells of the arteriovenous anastomoses, with velocity fluctuations synchronous with the uncooled control finger.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"3165b3a6-027e-5936-98a6-7b4560eb63ab","mechanism_event_label":"Specific shunt vessels clamp shut and then open again, and both hands do it together.","subject":{"id":"d85b62ec-2a06-5909-b069-ad5973406790","slug":"arteriovenous-anastomoses","display_name":"Arteriovenous anastomoses of the finger","entity_type_key":"cellular_process"},"object":{"id":"3c70b9c2-914b-571a-9856-b8e19d51c054","slug":"cold-induced-vasodilatation","display_name":"Cold-induced vasodilatation in the extremities","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"3165b3a6-027e-5936-98a6-7b4560eb63ab","stable_key":"b3c3f45a-50fb-5b79-98d7-5e5228df00db:cold-civd-ava-mechanism-event","event_type":"biochemical_relationship","label":"Specific shunt vessels clamp shut and then open again, and both hands do it together.","description":"The initial cold-induced vasoconstriction involved constriction of the arteriovenous anastomoses and the two main finger arteries, and during cold-induced vasodilatation the large blood flow and high skin temperature were caused by relaxation of the smooth muscle cells of the arteriovenous anastomoses, with velocity fluctuations synchronous with the uncooled control finger.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"6bf71b35-989d-5a2e-a483-abbb15e979e4","slug":"skin-blood-flow","display_name":"Skin blood flow","entity_type_key":"cellular_process"},"role":"measured_property","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"d85b62ec-2a06-5909-b069-ad5973406790","slug":"arteriovenous-anastomoses","display_name":"Arteriovenous anastomoses of the finger","entity_type_key":"cellular_process"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"3c70b9c2-914b-571a-9856-b8e19d51c054","slug":"cold-induced-vasodilatation","display_name":"Cold-induced vasodilatation in the extremities","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/cold-research/10070133.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"645f4eccd5fc06bd968b4fddd514e55561f4403ec1c2e3437beae785c006e19f\", \"start_char\": 0, \"end_char\": 1121, \"text_sha256\": \"645f4eccd5fc06bd968b4fddd514e55561f4403ec1c2e3437beae785c006e19f\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Ultrasound Doppler of finger arteries during severe local cooling in 21 thermoneutral subjects","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Local cooling at 3 degrees C for 30 to 45 minutes","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Direct vessel-level measurement. It identifies which vessels open, and the synchrony with the control finger indicates central rather than purely local control.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake.","comparator":null,"unit":null,"notes":"","entity":{"slug":"cold-water-immersion","display_name":"Cold water immersion","entity_type_key":"drug"}},{"dimension":"organism","value_text":"Human","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Specific shunt vessels clamp shut and then open again, and both hands do it together.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[cold-p10070133] Perfusion of the human finger during cold-induced vasodilatation. (1999). https://pubmed.ncbi.nlm.nih.gov/10070133/ DOI: 10.1152/ajpregu.1999.276.3.r731","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Finger arteries and arteriovenous anastomoses","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"191dcf03-9682-58d9-893f-8b23618dd200","evidence_kind":"source_excerpt","locator":"Lines 234-245","start_line":234,"end_line":245,"excerpt":"### cold-civd-ava-mechanism\nThe initial cold-induced vasoconstriction involved constriction of the arteriovenous anastomoses and the two main finger arteries, and during cold-induced vasodilatation the large blood flow and high skin temperature were caused by relaxation of the smooth muscle cells of the arteriovenous anastomoses, with velocity fluctuations synchronous with the uncooled control finger.\nCondition category: normal\nnutrient_topic: Cold water immersion research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake.\nplain_language: Specific shunt vessels clamp shut and then open again, and both hands do it together.\norganism: Human\ntissue_or_cell_type: Finger arteries and arteriovenous anastomoses\nexperimental_model: Ultrasound Doppler of finger arteries during severe local cooling in 21 thermoneutral subjects\nlimitations: Direct vessel-level measurement. It identifies which vessels open, and the synchrony with the control finger indicates central rather than purely local control.\nexposure: Local cooling at 3 degrees C for 30 to 45 minutes\nevidence_span: {\"source_cache\": \"artifacts/cold-research/10070133.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"645f4eccd5fc06bd968b4fddd514e55561f4403ec1c2e3437beae785c006e19f\", \"start_char\": 0, \"end_char\": 1121, \"text_sha256\": \"645f4eccd5fc06bd968b4fddd514e55561f4403ec1c2e3437beae785c006e19f\"}\n[cold-p10070133] Perfusion of the human finger during cold-induced vasodilatation. (1999). https://pubmed.ncbi.nlm.nih.gov/10070133/ DOI: 10.1152/ajpregu.1999.276.3.r731","model_system":"Ultrasound Doppler of finger arteries during severe local cooling in 21 thermoneutral subjects","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [cold-p10070133] Perfusion of the human finger during cold-induced vasodilatation. (1999). https://pubmed.ncbi.nlm.nih.gov/10070133/ DOI: 10.1152/ajpregu.1999.276.3.r731","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"feeccadc-1392-573e-a0b5-0939ee5de6e2","stable_key":"import-b3c3f45a-50fb-5b79-98d7-5e5228df00db","title":"Cold water immersion: cold sensing, heat production, the catecholamine axis and what repeated exposure changes (2026-09-19)","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":"557f074d372c49c502c34e648651aff7ebf2c8816305d2d2f08e338a7e96a5f0","revision_id":"ecc19e8d-40db-5b5d-b98e-0507f645976c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}