Effect of indomethacin on responses of sheep isolated coronary artery to arachidonic acid.
Indomethacin (2.8 mumol/l) did not consistently affect basal tone of sheep coronary artery strips, while a ten-fold higher concentration increased tension in 50% of the preparations tested. When acetylcholine was used as a spasmogen, oscillations in induced tone and relaxations produced by arachidonic acid (6.6 mumol/l) were abolished by indomethacin, 2.8 mumol/l and 7 mumol/l, respectively. Prostacyclin (PGI2) and prostaglandin E1 decreased and PGE2 increased arterial tension while PGF2 alpha was inactive. Responses to PGI2 were reduced by indomethacin (28 mumol/l) but not by indomethacin (2.8 mumol/l). It is suggested that sheep isolated coronary arteries synthesize and release prostacyclin in the presence of acetylcholine and arachidonic acid and that such synthesis can be inhibited by indomethacin.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology*; D003331:Coronary Vessels / Q000187:drug effects*; D015237:Dinoprost; D015232:Dinoprostone; D004347:Drug Interactions; D011464:Epoprostenol / Q000494:pharmacology; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology*; D011453:Prostaglandins / Q000494:pharmacology; D011458:Prostaglandins E / Q000494:pharmacology; D011460:Prostaglandins F / Q000494:pharmacology; D012756:Sheep; D014664:Vasodilation / Q000187:drug effects
D001095:Arachidonic Acids; D011453:Prostaglandins; D011458:Prostaglandins E; D011460:Prostaglandins F; D016718:Arachidonic Acid; D015237:Dinoprost; D011464:Epoprostenol; D015232:Dinoprostone; D000109:Acetylcholine; D007213:Indomethacin