{"id":"e616f5dd-d742-5fc7-80fa-1e10e1c078b9","stable_key":"6d38d43e-01e4-5641-93be-65654271e242:zn-sig-copper-zinc-absorption","predicate":"reduced","statement":"Raising rat dietary copper from 3 to 24 mg/kg reduced 65Zn absorption by about 20%; further increases to 300 mg/kg did not add inhibition or change zinc association with intestinal metallothionein.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"0def4fb7-b95c-5d4d-9ddd-91b3e5960811","mechanism_event_label":"Copper also affected zinc absorption, with a different response pattern.","subject":{"id":"9f0afdde-1ec1-5c8a-bb5e-f3b2b75f67f6","slug":"copper","display_name":"Copper","entity_type_key":"nutrient_element"},"object":{"id":"957321e4-a5db-5a5d-851b-72069bab3efd","slug":"intestinal-zinc-absorption","display_name":"Intestinal zinc absorption","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"0def4fb7-b95c-5d4d-9ddd-91b3e5960811","stable_key":"6d38d43e-01e4-5641-93be-65654271e242:zn-sig-copper-zinc-absorption-event","event_type":"biochemical_relationship","label":"Copper also affected zinc absorption, with a different response pattern.","description":"Raising rat dietary copper from 3 to 24 mg/kg reduced 65Zn absorption by about 20%; further increases to 300 mg/kg did not add inhibition or change zinc association with intestinal metallothionein.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"0429f0ff-c033-514b-9a4f-6f0f83268095","slug":"zinc","display_name":"Zinc","entity_type_key":"nutrient_element"},"role":"affected_nutrient","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"a6a5a097-aa7f-5655-972f-93891c8e7d54","slug":"rat-intestinal-metallothioneins","display_name":"Rat intestinal metallothioneins measured without isoform resolution","entity_type_key":"protein_set"},"role":"unchanged_association","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"9f0afdde-1ec1-5c8a-bb5e-f3b2b75f67f6","slug":"copper","display_name":"Copper","entity_type_key":"nutrient_element"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"957321e4-a5db-5a5d-851b-72069bab3efd","slug":"intestinal-zinc-absorption","display_name":"Intestinal zinc absorption","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Zinc (affected_nutrient); Rat intestinal metallothioneins measured without isoform resolution (unchanged_association)","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/zinc-signaling-sources/479878-abstract.txt\", \"locator\": \"Primary indexed abstract\", \"file_sha256\": \"643b0358984f3caac8a20e3202c14a073d11ff88758c7a9637b6f8523195658b\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Dietary radiotracer experiments in rats","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"High dietary zinc or copper and reciprocal 64Cu/65Zn absorption measurements.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"High animal dietary concentrations are not human intake thresholds. Copper displacement from metallothionein was the authors’ mechanistic interpretation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Zinc research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"zinc","display_name":"Zinc","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Rattus norvegicus","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Copper also affected zinc absorption, with a different response pattern.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[zn-sig-479878] Intestinal metallothionein and the mutual antagonism between copper and zinc in the rat. (1979). https://pubmed.ncbi.nlm.nih.gov/479878/ DOI: 10.1016/s0162-0134(00)80054-9","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Small intestine","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"f92730fc-1c87-53d3-ac19-251e2b964c61","evidence_kind":"source_excerpt","locator":"Lines 929-941","start_line":929,"end_line":941,"excerpt":"### zn-sig-copper-zinc-absorption\nRaising rat dietary copper from 3 to 24 mg/kg reduced 65Zn absorption by about 20%; further increases to 300 mg/kg did not add inhibition or change zinc association with intestinal metallothionein.\nCondition category: normal\nnutrient_topic: Zinc research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Copper also affected zinc absorption, with a different response pattern.\norganism: Rattus norvegicus\ntissue_or_cell_type: Small intestine\nexperimental_model: Dietary radiotracer experiments in rats\nlimitations: High animal dietary concentrations are not human intake thresholds. Copper displacement from metallothionein was the authors’ mechanistic interpretation.\nexposure: High dietary zinc or copper and reciprocal 64Cu/65Zn absorption measurements.\ncross_nutrient: Zinc (affected_nutrient); Rat intestinal metallothioneins measured without isoform resolution (unchanged_association)\nevidence_span: {\"source_cache\": \"artifacts/zinc-signaling-sources/479878-abstract.txt\", \"locator\": \"Primary indexed abstract\", \"file_sha256\": \"643b0358984f3caac8a20e3202c14a073d11ff88758c7a9637b6f8523195658b\"}\n[zn-sig-479878] Intestinal metallothionein and the mutual antagonism between copper and zinc in the rat. (1979). https://pubmed.ncbi.nlm.nih.gov/479878/ DOI: 10.1016/s0162-0134(00)80054-9","model_system":"Dietary radiotracer experiments in rats","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [zn-sig-479878] Intestinal metallothionein and the mutual antagonism between copper and zinc in the rat. (1979). https://pubmed.ncbi.nlm.nih.gov/479878/ DOI: 10.1016/s0162-0134(00)80054-9","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"c5ee0fee-ce5c-58de-905a-10fb0ea0723c","stable_key":"import-6d38d43e-01e4-5641-93be-65654271e242","title":"Zinc: transport, enzyme loading, deficiency and nutrient interactions (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":"2e731dd54477ec1254e97df3323e1208d38f1375effed19252e71ab4f600d13a","revision_id":"c72258b9-ac09-5408-9d44-a921ad1f96a3","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}