Investigation of the Effect and Mechanism of Action of Different Vasodilator Substances on the Human Bypass Grafts

It is well known that the spasm of arterial and venous graft conduits is serious problem that can occur both during harvesting and after coronary artery bypass grafting. Today, in order to prevent and reverse bypass graft spasm using different vasodilator agents. Since that has not yet found the ideal vasodilator agent, we will examine the effect and mechanism of action of different vasodilator agents, potentially useful in the prevention and reversion of the bypass graft spasm. First, we will examine the effect and mechanism of action of nicorandil, potassium channel opener with NO realizing properties, on the isolated bypass grafts. Second, we will examine the antivasoconstrictor and vasorelaxant effect of the new calcium channel blockers, as well as the effects of combinations of the new calcium channel blockers and nitroglycerin on the human bypass grafts. Third, we will examine the antivasoconstrictor and vasorelaxant effect of the botulinum toxin type C on the bypass grafts. The second part of the research under this project will focus on examining the vasodilatory effect of polyphenolic flavonoids present in red wine (quercetin), green tea (epicatechin), and dark chocolate (epicatechin, procyanidin). Since there is no data on the effects of flavonoids on human blood vessels, we will be testing the effect on human grafts and define the contribution of different potassium and calcium channel subtypes in flavonoids action on this blood vessels is a very actual.