title: Endothelium-dependent vascular relaxation induced by Globularia alypum extract is mediated by EDHF in perfused rat mesenteric arterial bed.
abstract: The vasodilatory effect of Globularia alypum L. (GA) extract was evaluated in rat mesenteric arterial bed pre-contracted by continuous infusion of phenylephrine (2-4 ng/mL). Bolus injections of GA elicited dose-response vasodilation, which was abolished after endothelium removal. Addition of a nitric oxide synthase inhibitor, N(G)-nitro-l-arginine methyl ester (100 µmol/L), alone or in the presence of a cyclooxygenase inhibitor, indomethacin (10 µmol/L), did not significantly affect the vasodilation of the mesenteric arterial bed in response to GA extract. These results suggest that GA-induced vasodilation is endothelium dependent but nitric oxide and prostacyclin independent. In the presence of high K(+) (60 mmol/L), the GA vasodilatory effect was completely abolished, suggesting that the vasodilation effect is mediated by hyperpolarization of the vascular cells. Also, pre-treatment with atropine (a muscarinic receptors antagonist) antagonized the GA-induced vasodilation, suggesting that the vasodilatory effect is mainly mediated by the endothelium-derived hyperpolarizing factor through activation of endothelial muscarinic receptors.
authors.affiliation: Laboratoire des molécules bioactives, Faculté des sciences et techniques, Université Sidi Mohamed Ben Abdellah, Fès, Morocco.
authors.forename: Aziz
authors.initials: A
authors.lastname: Chokri
authors.forename: Kaouakib
authors.initials: K
authors.lastname: El Abida
authors.forename: Younes Filali
authors.initials: YF
authors.lastname: Zegzouti
authors.forename: Rachid
authors.initials: R
authors.lastname: Ben Cheikh
mesh_terms: D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001685:Biological Factors / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D011464:Epoprostenol / Q000494:pharmacology; D005260:Female; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects* / Q000378:metabolism; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D010656:Phenylephrine / Q000494:pharmacology; D010936:Plant Extracts / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D051381:Rats; D011976:Receptors, Muscarinic / Q000378:metabolism; D028083:Scrophulariaceae / Q000737:chemistry*; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D001685:Biological Factors; D004791:Enzyme Inhibitors; D010936:Plant Extracts; D011976:Receptors, Muscarinic; D014665:Vasodilator Agents; C067410:endothelium-dependent hyperpolarization factor; D010656:Phenylephrine; D009569:Nitric Oxide; D001285:Atropine; D011464:Epoprostenol; D019001:Nitric Oxide Synthase; D011451:Prostaglandin-Endoperoxide Synthases; D011188:Potassium; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin