Effects of inhibitions of thromboxane synthesis on reactions of the cat bronchus in situ to prostaglandins.
Cats were anesthetized by chloralose, relaxed by suxamethonium, and ventilated. The influence of 3 inhibitors of thromboxane synthesis, N.0096 (+-alpha -benzyl-alpha-p-chlorobenzyl-4-hydroxyacetophenon phenylhydrogen-phosphonate), imidazole and dipyridamole were studied on bronchial reaction to prostaglandins E2 and F2 alpha and arachidonic acid. During a bronchoconstriction maintained by infusion of 5-HT, N.0096 and imidazole dose-dependently potentiated the intensity and duration of the bronchodilator effect of PGE2. This effect was maximal at a total dose of 17 mg/kg N.0096 or 25-50 mg/kg imidazole, but decreased after higher doses which are supposed to inhibit cyclo-oxygenase also. Bronchoconstrictor reactions to single injections of arachidonic acid were inhibited by N.0096 in the same dose range. Reactions to PGF2 alpha were unaltered by both drugs. Dipyridamole was devoid of a comparable activity.
D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D001980:Bronchi / Q000187:drug effects*; D001993:Bronchodilator Agents; D002415:Cats; D004176:Dipyridamole / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D007093:Imidazoles / Q000494:pharmacology; D008297:Male; D011458:Prostaglandins E / Q000494:pharmacology*; D011460:Prostaglandins F / Q000494:pharmacology*; D012701:Serotonin / Q000494:pharmacology; D013928:Thromboxane A2 / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D013931:Thromboxanes / Q000037:antagonists & inhibitors*
D000098:Acetophenones; D001993:Bronchodilator Agents; D007093:Imidazoles; D011458:Prostaglandins E; D011460:Prostaglandins F; D013931:Thromboxanes; D012701:Serotonin; D013928:Thromboxane A2; D004176:Dipyridamole; C026526:N.0096