Physiol. Res. 55: 365-372, 2006

A Study of Mechanisms Involved in Vasodilatation Induced by Resveratrol in Isolated Porcine Coronary Artery

H.-F. LI1,3, Z.-F. TIAN2, X.-Q. QIU2, J.-X. WU1, P. ZHANG1, Z.-J. JIA3

1Department of Physiology, College of Basic Medicine, Lanzhou University, 2Functional Laboratory of Medicine and 3College of Chemistry and Chemical Engineering, National Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, People's Republic of China

Received July 4, 2005
Accepted October 7, 2005
On-line available October 17, 2005

The present study was designed to investigate the acute relaxing effect of phytoestrogen resveratrol on isolated porcine coronary arteries and to determine the mechanisms underlying its vasodilatation. Rings of porcine coronary arteries were suspended in organ baths containing Krebs-Henseleit solution, and then isometric tension was measured. Resveratrol concentration-dependently relaxed arterial rings precontracted with 30 mM KCl. The IC50 value of resveratrol was 38.673.21 μM. Incubation with Nω-L-nitro-arginine (L-NNA), endothelium removal or the presence of a potent inhibitor of protein tyrosine phosphatase sodium orthovanadate partly decreased the relaxation induced by resveratrol. However, the relaxation induced by resveratrol was unaffected by the estrogen receptor antagonist tamoxifen, the inhibitor of prostanoid synthesis indomethacin, the antagonist of β-adrenoceptors propranolol or the protein synthesis inhibitor, cycloheximide. In addition, resveratrol significantly decreased the contractile responses of
5-HT, KCl and CaCl2, and shifted their cumulative concentration-response curves to the right. These results suggest that the mechanisms of vasorelaxation induced by resveratrol are heterogeneous, two mechanisms participating partially in the relaxation of porcine coronary artery were detected in the study, one being the nitric oxide released from the endothelium, the other causing inhibition of Ca2+ influx, but estrogen receptors were not involved in resveratrol-induced relaxation.

Key words
Resveratrol Coronary artery Calcium channel Vascular endothelium Nitric oxide

2006 by the Institute of Physiology, Czech Academy of Sciences