Interaction Between NO Donors and Iloprost in Human Vascular Smooth Muscle, Platelets, and Leukocytes

Endothelium-derived relaxing factor (EDRF) and donors of nitric oxide (NO) (glyceryl trinitrate, SIN-1--a metabolite of molsidomine--S-nitroso-N-acetyl-penicillamine, and sodium nitroprusside) but not prostacyclin and its analog, iloprost, relax strips of rabbit aorta. Strips of human coronary artery also relax when exposed to NO donors and prostacyclin; in this artery, SIN-1 and iloprost exert additive but not synergistic relaxant action. In mildly activated human platelets and leukocytes, SIN-1 and iloprost have a synergistic suppressive action. A similar synergistic thrombolytic effect between NO and prostacyclin was observed in whole rabbit blood in interactions with rabbit aortic endothelium. These findings suggest that because of this cell-selective synergism between NO donors and prostacyclin analogs, the concomitant use of molsidomine and iloprost for the treatment of ischemic heart and peripheral vascular disease should be attempted.