title: Effects of aspirin on xylazine-induced hypoxaemia in sheep.
abstract: Aspirin (10 mg kg-1) administered intravenously to conscious sheep four hours before intravenous xylazine injection (50 micrograms kg-1), failed to abolish or attenuate the hypoxaemic effect of xylazine in this species. Serum thromboxane levels measured in one animal revealed that aspirin administered in this way reduced serum thromboxane levels by 95 per cent. Xylazine (3 x 10(-5) M--4 x 10(-3) M) failed to induce platelet aggregation in vitro. It appears that the mechanism whereby xylazine causes arterial hypoxaemia in sheep does not involve a cyclo-oxygenase-dependent aggregation of platelets.
authors.affiliation: Department of Pharmacology, Cambridge.
authors.forename: A M
authors.initials: AM
authors.lastname: Nolan
authors.forename: B A
authors.initials: BA
authors.lastname: Callingham
authors.forename: R J
authors.initials: RJ
authors.lastname: Evans
mesh_terms: D000818:Animals; D001241:Aspirin / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D000860:Hypoxia / Q000139:chemically induced / Q000517:prevention & control / Q000662:veterinary*; D007275:Injections, Intravenous / Q000662:veterinary; D008297:Male; D010100:Oxygen / Q000097:blood; D010974:Platelet Aggregation; D010976:Platelet Count / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000139:chemically induced*; D013843:Thiazines / Q000009:adverse effects*; D013931:Thromboxanes / Q000097:blood; D014991:Xylazine / Q000009:adverse effects*
chemical_list: D013843:Thiazines; D013931:Thromboxanes; D014991:Xylazine; D001241:Aspirin; D010100:Oxygen