Effects of FPL-55712 or indomethacin on leukotriene-induced coronary constriction in the intact pig heart.

Intracoronary leukotriene D4, 0.1-3.0 micrograms (0.2-6.0 nmol), produced dose-dependent decreases in coronary flow of anesthetized pigs. Pretreatment with intracoronary FPL-55712 (0.1, 0.3 and 1.0 mg) reduced coronary constriction due to 1.0 micrograms leukotriene D4 by up to 77%. FPL-55712 did not produce sustained alterations in coronary flow, left ventricular end-diastolic pressure, systemic arterial pressure, or heart rate. Indomethacin pretreatment (6 mg/kg i.v.) had no effect on leukotriene-induced coronary constriction. Inhibition produced by FPL-55712 may be useful in disease states involving leukotriene-mediated coronary constriction.