{"id":"ca5b5c59-48b7-5ab5-8586-1e6d3b448a60","stable_key":"fcc4fa9c-4dc8-5566-b780-1a486c4d3e72:alcohol-acetaldehyde-not-ethanol","predicate":"reduces","statement":"Acetaldehyde, but not ethanol, impaired net formation of PLP from pyridoxal, pyridoxine and pyridoxine phosphate by erythrocytes, and the effect was abolished when the B6-phosphate phosphatase was inhibited by 80 mM phosphate, while pyridoxal kinase and pyridoxine phosphate oxidase activities were not decreased.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"cc92f825-93e5-55d0-9949-50edd08954ce","mechanism_event_label":"It is the breakdown product that destroys the vitamin, and it works by exposing it to a phosphatase rather than by blocking its synthesis.","subject":{"id":"5fa32382-7b38-5a03-aa8a-168d01358750","slug":"acetaldehyde","display_name":"Acetaldehyde","entity_type_key":"small_molecule"},"object":{"id":"76d223d9-8bf7-542c-8280-10795c1bd46f","slug":"erythrocyte-plp-synthesis","display_name":"Erythrocyte pyridoxal 5′-phosphate synthesis","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"cc92f825-93e5-55d0-9949-50edd08954ce","stable_key":"fcc4fa9c-4dc8-5566-b780-1a486c4d3e72:alcohol-acetaldehyde-not-ethanol-event","event_type":"biochemical_relationship","label":"It is the breakdown product that destroys the vitamin, and it works by exposing it to a phosphatase rather than by blocking its synthesis.","description":"Acetaldehyde, but not ethanol, impaired net formation of PLP from pyridoxal, pyridoxine and pyridoxine phosphate by erythrocytes, and the effect was abolished when the B6-phosphate phosphatase was inhibited by 80 mM phosphate, while pyridoxal kinase and pyridoxine phosphate oxidase activities were not decreased.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"5f8b9315-9005-5777-ac74-f210045e18b4","slug":"plp-phosphatase","display_name":"Membrane-associated neutral phosphatase hydrolysing B6 phosphate esters","entity_type_key":"protein"},"role":"acting_enzyme","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"e653a47d-0723-5479-9572-6ed51aa8d5b0","slug":"ethanol","display_name":"Ethanol","entity_type_key":"drug"},"role":"inactive_comparator","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"5fa32382-7b38-5a03-aa8a-168d01358750","slug":"acetaldehyde","display_name":"Acetaldehyde","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"76d223d9-8bf7-542c-8280-10795c1bd46f","slug":"erythrocyte-plp-synthesis","display_name":"Erythrocyte pyridoxal 5′-phosphate synthesis","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/alcohol-research/4359937.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"1df4485150b1be55f3e5214c424f960ff627cfc317e643c86a0f6747efed8b08\", \"start_char\": 0, \"end_char\": 1650, \"text_sha256\": \"1df4485150b1be55f3e5214c424f960ff627cfc317e643c86a0f6747efed8b08\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Plasma PLP in 66 alcoholic subjects without liver abnormality, plus erythrocyte enzyme assays","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Chronic alcohol abuse; acetaldehyde and ethanol applied to erythrocytes","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Selecting subjects without abnormal liver function isolates the vitamin effect from liver disease. The phosphatase mechanism is shown in erythrocytes, not liver.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Alcohol research collection; topical membership is not evidence of a direct clinical effect, and ethanol is recorded separately from the acetaldehyde it becomes.","comparator":null,"unit":null,"notes":"","entity":{"slug":"ethanol","display_name":"Ethanol","entity_type_key":"drug"}},{"dimension":"organism","value_text":"Human","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"It is the breakdown product that destroys the vitamin, and it works by exposing it to a phosphatase rather than by blocking its synthesis.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[alcohol-p4359937] Vitamin B6 metabolism in chronic alcohol abuse. Pyridoxal phosphate levels in plasma and the effects of acetaldehyde on pyridoxal phosphate synthesis and degradation in human erythrocytes. (1974). https://pubmed.ncbi.nlm.nih.gov/4359937/ DOI: 10.1172/jci107607","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Plasma and erythrocytes","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":"96715e05-9820-5911-ba15-8204c7799a1c","evidence_kind":"source_excerpt","locator":"Lines 644-655","start_line":644,"end_line":655,"excerpt":"### alcohol-acetaldehyde-not-ethanol\nAcetaldehyde, but not ethanol, impaired net formation of PLP from pyridoxal, pyridoxine and pyridoxine phosphate by erythrocytes, and the effect was abolished when the B6-phosphate phosphatase was inhibited by 80 mM phosphate, while pyridoxal kinase and pyridoxine phosphate oxidase activities were not decreased.\nCondition category: nutrient_deficiency\nnutrient_topic: Alcohol research collection; topical membership is not evidence of a direct clinical effect, and ethanol is recorded separately from the acetaldehyde it becomes.\nplain_language: It is the breakdown product that destroys the vitamin, and it works by exposing it to a phosphatase rather than by blocking its synthesis.\norganism: Human\ntissue_or_cell_type: Plasma and erythrocytes\nexperimental_model: Plasma PLP in 66 alcoholic subjects without liver abnormality, plus erythrocyte enzyme assays\nlimitations: Selecting subjects without abnormal liver function isolates the vitamin effect from liver disease. The phosphatase mechanism is shown in erythrocytes, not liver.\nexposure: Chronic alcohol abuse; acetaldehyde and ethanol applied to erythrocytes\nevidence_span: {\"source_cache\": \"artifacts/alcohol-research/4359937.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"1df4485150b1be55f3e5214c424f960ff627cfc317e643c86a0f6747efed8b08\", \"start_char\": 0, \"end_char\": 1650, \"text_sha256\": \"1df4485150b1be55f3e5214c424f960ff627cfc317e643c86a0f6747efed8b08\"}\n[alcohol-p4359937] Vitamin B6 metabolism in chronic alcohol abuse. Pyridoxal phosphate levels in plasma and the effects of acetaldehyde on pyridoxal phosphate synthesis and degradation in human erythrocytes. (1974). https://pubmed.ncbi.nlm.nih.gov/4359937/ DOI: 10.1172/jci107607","model_system":"Plasma PLP in 66 alcoholic subjects without liver abnormality, plus erythrocyte enzyme assays","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [alcohol-p4359937] Vitamin B6 metabolism in chronic alcohol abuse. Pyridoxal phosphate levels in plasma and the effects of acetaldehyde on pyridoxal phosphate synthesis and degradation in human erythrocytes. 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