Intracoronary genistein acutely increases coronary blood flow in anesthetized pigs through beta-adrenergic mediated nitric oxide release and estrogenic receptors.
Various studies have suggested that the phytoestrogen genistein has beneficial cardioprotective and vascular effects. However, there has been scarce information regarding the primary effect of genistein on coronary blood flow and its mechanisms including estrogen receptors, autonomic nervous system, and nitric oxide (NO). The present study was planned to determine the primary effect of genistein on coronary blood flow and the mechanisms involved. In anesthetized pigs, changes in left anterior descending coronary artery caused by intracoronary infusion of genistein at constant heart rate and arterial pressure were assessed using ultrasound flowmeters. In 25 pigs, genistein infused at 0.075 mg/min increased coronary blood flow by about 16.3%. This response was graded in a further five pigs by increasing the infused dose of the genistein between 0.007 and 0.147 mg/min. In the 25 pigs, blockade of cholinergic receptors (iv atropine; five pigs) and alpha-adrenergic receptors (iv phentolamine; five pigs) did not abolish the coronary response to genistein, whose effects were prevented by blockade of beta(2)-adrenergic receptors (iv butoxamine; five pigs), nitric oxide synthase (intracoronary N(omega)-nitro-L-arginine methyl ester; five pigs) and estrogenic receptors (ERs; ERalpha/ERbeta; intracoronary fulvestrant; five pigs). In porcine aortic endothelial cells, genistein induced the phosphorylation of endothelial nitric oxide synthase and NO production through ERK 1/2, Akt, and p38 MAPK pathways, which was prevented by the concomitant treatment by butoxamine and fulvestrant. In conclusion, genistein primarily caused coronary vasodilation the mechanism of which involved ERalpha/ERbeta and the release of NO through vasodilatory beta(2)-adrenoreceptor effects.
Grossini
Elena
E
Laboratorio di Fisiologia, Dipartimento di Medicina Clinica e Sperimentale, Facoltà di Medicina e Chirurgia, Università del Piemonte Orientale A. Avogadro, I-28100 Novara, Italy. grossini@med.unipmn.it
Molinari
Claudio
C
Mary
David A S G
DA
Uberti
Francesca
F
Caimmi
Philippe Primo
PP
Surico
Nicola
N
Vacca
Giovanni
G
D000758:Anesthesia; D000818:Animals; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000187:drug effects*; D000242:Cyclic AMP / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005260:Female; D019833:Genistein / Q000008:administration & dosage / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects; D007275:Injections, Intravenous; D009569:Nitric Oxide / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000378:metabolism / Q000502:physiology*; D011960:Receptors, Estrogen / Q000378:metabolism / Q000502:physiology*; D012039:Regional Blood Flow / Q000187:drug effects*; D015398:Signal Transduction / Q000187:drug effects; D013552:Swine; D014664:Vasodilation / Q000187:drug effects
D011943:Receptors, Adrenergic, beta; D011960:Receptors, Estrogen; D009569:Nitric Oxide; D019833:Genistein; D000242:Cyclic AMP; D019869:Phosphatidylinositol 3-Kinases; D048049:Extracellular Signal-Regulated MAP Kinases