Effects of DN-9693, a Selective Inhibitor of Cyclic AMP Phosphodiesterase, in Isolated and Perfused Canine Large Coronary Arteries

Abstract

In isolated canine epicardial coronary arteries perfused with Krebs-Henseleit solution at 37°C, DN-9693, a newly synthesized selective cyclic AMP phosphodiesterase inhibitor, induced vasodilation in a dose-related manner. The threshold dose for inducing vasodilation to DN-9693 was very small, but the maximum vasodilation was not great. The order of potency for ED₂₀ (20% dilatation) was DN-9693>IBMX>aminophylline, but that for ED₇₀ was IBMX>aminophylline >DN-9693, suggesting that these three PDE inhibitors have different properties.