title: Enhancement of tetrathiomolybdate-induced copper excretion in bile of sheep by the alpha 2-agonistic action of xylazine.
abstract: The effect of intravenous doses of cortisol and xylazine on the quantity of copper excreted in response to 100 and 200 mg doses of tetrathiomolybdate (TTM) was studied in seven sheep. Cortisol alone produced a non-significant 1.4-fold increase and had no enhancing action on the response to TTM. Xylazine produced a significant 2.25-fold increase, doubled the quantity of copper excreted in response to both doses of TTM and reduced bile flow by approximately 35 per cent. The alpha 2 antagonist, idazoxan, prevented both the latter effects showing that they were due to xylazine's alpha 2-agonistic action. It is suggested that the combination of an alpha 2-agonist with the intravenous injection of TTM in the treatment of acute copper toxicity in sheep could reduced by 50 per cent the amount of molybdenum needed.
authors.affiliation: Department of Animal Physiology and Nutrition, University of Leeds.
authors.forename: H W
authors.initials: HW
authors.lastname: Symonds
authors.forename: Y
authors.initials: Y
authors.lastname: Ke
mesh_terms: D000818:Animals; D001646:Bile / Q000032:analysis*; D003300:Copper / Q000032:analysis / Q000097:blood / Q000378:metabolism* / Q000652:urine; D004146:Dioxanes / Q000494:pharmacology; D005260:Female; D006854:Hydrocortisone / Q000494:pharmacology*; D019329:Idazoxan; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008982:Molybdenum / Q000494:pharmacology*; D012756:Sheep / Q000378:metabolism*; D013843:Thiazines / Q000494:pharmacology*; D014991:Xylazine / Q000494:pharmacology*
chemical_list: D004146:Dioxanes; D013843:Thiazines; D014991:Xylazine; D003300:Copper; D008982:Molybdenum; C020809:tetrathiomolybdate; D006854:Hydrocortisone; D019329:Idazoxan