title: Resveratrol activates membrane-bound guanylyl cyclase in coronary arterial smooth muscle: a novel signaling mechanism in support of coronary protection.
abstract: Resveratrol (RSVL), an edible polyphenolic stilbene, claims a myriad of cardiovascular benefits. However, the molecular underpinnings of such actions are poorly understood. Currently, in sheep coronary arteries (SCA), RSVL markedly (threefold) enhanced cGMP formation (t(1/2): 6.5 min; EC(50): 3 microM). This response was not abrogated by the phosphodiesterase inhibitor (IBMX, 0.5 mM), but was partly sensitive (20-30%) to either removal of the endothelium, treatment with the nitric oxide synthase-inhibitor (L-NMMA, 10 microM), or with the soluble GC (sGC)-inhibitor (ODQ, 10 microM). In membrane preparations from denuded SCA, either RSVL or the pGC agonist atrial natriuretic peptide (ANP, 0.1-1 microM) activated GC in the particulate, but not in the soluble, membrane fraction. By contrast, the nitric oxide donor, sodium nitroprusside (SNP, 1-10 microM), stimulated GC only in the soluble fraction. Further, pretreatment with RSVL partly desensitized the ANP response, but was additive to that of SNP. In arterial tension studies, RSVL relaxed PGF(2alpha)-precontracted denuded rings in a concentration-dependent manner, a response that was markedly enhanced (approximately 18 fold) in the presence of IBMX. Conversely, precontraction with phorbol ester, which also desensitizes pGC, blunted relaxations to RSVL but not to forskolin or SNP. These findings demonstrate that RSVL increases cGMP in coronary arteries, mostly by activation of pGC. This pathway triggers vasorelaxant responses that remain effective in endothelium-disrupted arteries.
authors.affiliation: Department of Applied Therapeutics, Faculty of Pharmacy, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait. aelmowafy@hsc.kuniv.edu.kw
authors.forename: Abdalla M
authors.initials: AM
authors.lastname: El-Mowafy
mesh_terms: D000818:Animals; D003331:Coronary Vessels / Q000166:cytology / Q000187:drug effects; D006152:Cyclic GMP / Q000378:metabolism*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000378:metabolism*; D066298:In Vitro Techniques; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D020011:Protective Agents / Q000494:pharmacology*; D000077185:Resveratrol; D012756:Sheep; D015398:Signal Transduction / Q000187:drug effects; D013267:Stilbenes / Q000494:pharmacology*; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D010975:Platelet Aggregation Inhibitors; D020011:Protective Agents; D013267:Stilbenes; D019323:omega-N-Methylarginine; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D000077185:Resveratrol