title: Blockade of thromboxane and the prevention of eicosanoid-induced sudden death in mice.
abstract: We studied the effects of thromboxane-receptor antagonism and thromboxane synthetase inhibition in a thrombotic model of sudden death in mice. Intravenous injection of arachidonic acid (AA; 80 mg/kg) or the prostaglandin-endoperoxide analog U-46,619 (2.3 mg/kg) results in sudden death in approximately 90% of the animals. Pretreatment with the thromboxane receptor antagonist SQ-29,548 (0.3-10 mg/kg) protects dose-dependently against AA and U-46,619-induced sudden death. In contrast, CGS-13,080, a thromboxane synthetase inhibitor, shows a dose-dependent beneficial effect in AA-induced sudden death only. Although PTA2 has partial thromboxane agonistic properties in the rabbit, it protected the mice against AA-induced sudden death, thus demonstrating TxA2 antagonistic properties in this species. These data emphasize the importance of thromboxane A2 as a major mediator of arachidonic acid-induced sudden death and the effectiveness of thromboxane-receptor antagonists in endoperoxide-induced sudden death.
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000008:administration & dosage / Q000633:toxicity; D000081008:Bicyclic Monoterpenes; D019086:Bridged Bicyclo Compounds, Heterocyclic; D003645:Death, Sudden / Q000209:etiology / Q000517:prevention & control*; D005231:Fatty Acids, Unsaturated; D005343:Fibrinolytic Agents / Q000494:pharmacology*; D006834:Hydrazines / Q000494:pharmacology*; D007093:Imidazoles / Q000494:pharmacology*; D007275:Injections, Intravenous; D008297:Male; D051379:Mice; D010974:Platelet Aggregation / Q000187:drug effects; D011450:Prostaglandin Endoperoxides, Synthetic / Q000008:administration & dosage / Q000633:toxicity; D011725:Pyridines / Q000494:pharmacology*; D011956:Receptors, Cell Surface / Q000187:drug effects*; D011982:Receptors, Prostaglandin / Q000187:drug effects*; D017482:Receptors, Thromboxane; D013927:Thrombosis / Q000139:chemically induced / Q000150:complications / Q000517:prevention & control*; D013928:Thromboxane A2 / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000502:physiology*; D013930:Thromboxane-A Synthase / Q000037:antagonists & inhibitors
chemical_list: D001095:Arachidonic Acids; D000081008:Bicyclic Monoterpenes; D019086:Bridged Bicyclo Compounds, Heterocyclic; D005231:Fatty Acids, Unsaturated; D005343:Fibrinolytic Agents; D006834:Hydrazines; D007093:Imidazoles; D011450:Prostaglandin Endoperoxides, Synthetic; D011725:Pyridines; D011956:Receptors, Cell Surface; D011982:Receptors, Prostaglandin; D017482:Receptors, Thromboxane; D016718:Arachidonic Acid; D013928:Thromboxane A2; C020465:pinane-thromboxane A2; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; C045749:SQ 29548; C037787:pirmagrel; D013930:Thromboxane-A Synthase