Ichihara Kazuo PhD; Morimoto, Toshihiro; Tsujitani, Michihiko PhD; Abiko, Yasushi MD, PhDCoronary Artery Disease: April 1992 Article: PDF Only Buy Abstract Background The effect of LP-805, a newly developed vasodilator, on coronary vasoconstriction induced by ergonovine was studied. Methods Mongrel dogs of either sex were anesthetized with pentobarbital and ventilated with room air. Coronary angiography was performed before and after intracoronary administration of 1.6 mg of ergonovine. LP-805 (30 or 100 ng/kg) was injected intravenously 2 minutes before ergonovine injection. Results Intravenous injection of LP-805 increased the diameter of the normal coronary arteries by about 15% to 38%. Intracoronary injection of ergonovine decreased the coronary artery diameter by 20% to 25%. The ergonovine-induced vasoconstriction of the coronary arteries was inhibited by LP-805 in a dose-dependent manner. Conclusions: Ergonovine does not provoke vasoconstriction in the presence of LP-805, as it does in the absence of LP-805. © Lippincott-Raven Publishers.