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
Summary
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 38.67±3.21 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
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