{"id":"1003a851-75b9-5b65-b6f3-951f4f8e9097","stable_key":"488ea171-36b8-5ef6-b5d3-98563980fdbf:hbot-no-inactivation","predicate":"inactivates","statement":"Brain nitric oxide metabolite levels fell by 31% and correlated with the fall in blood flow, while estimated hydroxyl radical production rose by 56%, and the blood-flow decrease was completely abolished by intravascular superoxide dismutase.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"1621225d-6420-5eb7-9fcb-e2558a6c7f6e","mechanism_event_label":"Superoxide destroys the molecule that keeps vessels relaxed, and removing superoxide removes the effect.","subject":{"id":"011511ed-2be5-566d-bd1b-9d580dab1e9c","slug":"superoxide-anion","display_name":"Superoxide radical anion","entity_type_key":"ion"},"object":{"id":"f2a6b7ab-ad41-5ada-8895-41d6ce42f4e4","slug":"nitric-oxide","display_name":"NO","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"1621225d-6420-5eb7-9fcb-e2558a6c7f6e","stable_key":"488ea171-36b8-5ef6-b5d3-98563980fdbf:hbot-no-inactivation-event","event_type":"biochemical_relationship","label":"Superoxide destroys the molecule that keeps vessels relaxed, and removing superoxide removes the effect.","description":"Brain nitric oxide metabolite levels fell by 31% and correlated with the fall in blood flow, while estimated hydroxyl radical production rose by 56%, and the blood-flow decrease was completely abolished by intravascular superoxide dismutase.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"b1260ac2-0427-5a4e-b08f-e8ad5d278574","slug":"hydroxyl-radical","display_name":"Hydroxyl radical","entity_type_key":"chemical_species"},"role":"co_product","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"19f2bdc0-4888-57d5-860f-119d5d478eb4","slug":"sod1","display_name":"Human copper-zinc superoxide dismutase / SOD1","entity_type_key":"protein"},"role":"rescuing_enzyme","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"011511ed-2be5-566d-bd1b-9d580dab1e9c","slug":"superoxide-anion","display_name":"Superoxide radical anion","entity_type_key":"ion"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"f2a6b7ab-ad41-5ada-8895-41d6ce42f4e4","slug":"nitric-oxide","display_name":"NO","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/hbot-research/11139368.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"9823a7f177483257b812d7c8c8e8052c3f04d6a7aa052876369c7c64b55668f3\", \"start_char\": 0, \"end_char\": 1672, \"text_sha256\": \"9823a7f177483257b812d7c8c8e8052c3f04d6a7aa052876369c7c64b55668f3\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Regional cerebral blood flow measurement in rats with nitric oxide metabolite and hydroxyl radical assays","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Oxygen at 5 atmospheres absolute for 30 minutes, with L-NAME, a nitric oxide donor, or intravascular superoxide dismutase","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Five atmospheres is well above therapeutic pressure and was chosen to study oxygen toxicity. The superoxide dismutase rescue is the key mechanistic step.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Hyperbaric oxygen 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":"hyperbaric-oxygen","display_name":"Hyperbaric oxygen therapy","entity_type_key":"drug"}},{"dimension":"organism","value_text":"Rat","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Superoxide destroys the molecule that keeps vessels relaxed, and removing superoxide removes the effect.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[hbot-p11139368] Hyperbaric oxygen reduces cerebral blood flow by inactivating nitric oxide. (2000). https://pubmed.ncbi.nlm.nih.gov/11139368/ DOI: 10.1006/niox.2000.0313","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Brain","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"9b8749b4-1e29-5cac-bb52-63f84c498147","evidence_kind":"source_excerpt","locator":"Lines 166-177","start_line":166,"end_line":177,"excerpt":"### hbot-no-inactivation\nBrain nitric oxide metabolite levels fell by 31% and correlated with the fall in blood flow, while estimated hydroxyl radical production rose by 56%, and the blood-flow decrease was completely abolished by intravascular superoxide dismutase.\nCondition category: normal\nnutrient_topic: Hyperbaric oxygen research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake.\nplain_language: Superoxide destroys the molecule that keeps vessels relaxed, and removing superoxide removes the effect.\norganism: Rat\ntissue_or_cell_type: Brain\nexperimental_model: Regional cerebral blood flow measurement in rats with nitric oxide metabolite and hydroxyl radical assays\nlimitations: Five atmospheres is well above therapeutic pressure and was chosen to study oxygen toxicity. The superoxide dismutase rescue is the key mechanistic step.\nexposure: Oxygen at 5 atmospheres absolute for 30 minutes, with L-NAME, a nitric oxide donor, or intravascular superoxide dismutase\nevidence_span: {\"source_cache\": \"artifacts/hbot-research/11139368.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"9823a7f177483257b812d7c8c8e8052c3f04d6a7aa052876369c7c64b55668f3\", \"start_char\": 0, \"end_char\": 1672, \"text_sha256\": \"9823a7f177483257b812d7c8c8e8052c3f04d6a7aa052876369c7c64b55668f3\"}\n[hbot-p11139368] Hyperbaric oxygen reduces cerebral blood flow by inactivating nitric oxide. (2000). https://pubmed.ncbi.nlm.nih.gov/11139368/ DOI: 10.1006/niox.2000.0313","model_system":"Regional cerebral blood flow measurement in rats with nitric oxide metabolite and hydroxyl radical assays","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [hbot-p11139368] Hyperbaric oxygen reduces cerebral blood flow by inactivating nitric oxide. (2000). https://pubmed.ncbi.nlm.nih.gov/11139368/ DOI: 10.1006/niox.2000.0313","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"dbf39b48-c95e-5291-b404-349ffbc4488f","stable_key":"import-488ea171-36b8-5ef6-b5d3-98563980fdbf","title":"Hyperbaric oxygen: the exposure, its reactive species, the signals they carry, and the nutrient-dependent enzymes that handle them (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":"fb2443321804010d82c6b96ab61cc51b4b6628ddbb15751cb0e90b491606e79c","revision_id":"bb699ea5-b492-5728-b22c-48f0842a8ac9","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}