Effects of resveratrol on vascular tone of isolated pulmonary arteries and veins

The first aim of this study was to investigate the effect of resveratrol on and the role of NOS and cyclooxgenase inhibition on resveratrol-induced vasodilatation in sheep isolated pulmonary arteries and veins. The second aim is to determine the role of resveratrol on hypoxia induced vasoconstriction. Isolated pulmonary vessels were suspended in an organ bath filled with Krebs-Henseleit solution. Isometric contractions were recorded continuously via an isometric transducer connected to a computerized polygraph system. L-NAME (10-4M) and indomethacin (10-5M) were used to investigate the role of NO and cyclooxygenase product. Resveratrol induced concentrationdependently vasodilatation was unaffected by L-NAME or indomethacin in precontracted isolated pulmonary vessels. In our experiments we observed that resveratrol (20.M) significantly decreased the contractile responses of U46619 (10-6M) in pulmonary veins. But 5-HT- induced contraction was not changed in the presence of resveratrol in pulmonary arteries. These results suggest that vasodilatation induced by resveratrol is not NO or COX mediated mechanisms. In addition to these data, in the presence of resveratrol, hypoxia induced pulmonary vasoconstriction was decreased in pulmonary veins precontracted with U46619 but not in pulmonary arteries precontracted with 5-HT. Our study showed that: (a) resveratrol induced vasodilatation in sheep isolated pulmonary arteries and veins are not mediated via NO or prostanoids, (b) resveratrol reduced HPV in precontracted veins. Keywords : Resveratrol, Pulmonary arteries, Pulmonary veins