title: Endothelium-dependent and independent vasorelaxant effects of aqueous extract of Tridax procumbens Lin. leaf in rat aortic rings.
abstract: Tridax procumbens leaf extract induced aortic relaxation in a concentration-dependent manner, for both phenylephrine (PE) and KCl- induced contractions in isolated rat aortic rings. The relaxation effect of the extract on PE-induced contraction was 57% greater than that on KCl- induced contraction. The extract caused dose-dependent relaxations in precontracted isolated rat aorta with phenylephrine; the relaxation was attenuated by the removal of endothelium. However, the relaxation responses to sodium nitroprusside were not significantly abolished by the removal of endothelium. The vasorelaxatory effect of the extract was completely abolished in presence of L-NAME. The results indicate that the vasorelaxant effect of T. procumbens extract is probably mediated by both endothelium-dependent and-independent mechanisms.
authors.affiliation: Department of Physiology, College of Medicine, Lagos State University, Ikeja, Lagos, Nigeria. hmsalahdeen@yahoo.ca
authors.forename: Hussein M
authors.initials: HM
authors.lastname: Salahdeen
authors.forename: Gbolahan O
authors.initials: GO
authors.lastname: Idowu
authors.forename: Babatunde A
authors.initials: BA
authors.lastname: Murtala
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects*; D019659:Asteraceae / Q000737:chemistry*; D020013:Calcium Signaling / Q000187:drug effects; D006152:Cyclic GMP / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects*; D005260:Female; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology; D009599:Nitroprusside / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D015290:Second Messenger Systems / Q000187:drug effects; D012997:Solvents; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000302:isolation & purification / Q000494:pharmacology*; D014867:Water
chemical_list: D010936:Plant Extracts; D012997:Solvents; D014665:Vasodilator Agents; D014867:Water; D009599:Nitroprusside; D010656:Phenylephrine; D009569:Nitric Oxide; D006152:Cyclic GMP; D000109:Acetylcholine; D011188:Potassium; D019331:NG-Nitroarginine Methyl Ester