title: [Partial endothelium-dependent vasorelaxation of crocetin and its mechanism].
abstract: To investigate the vasorelaxation effect of crocetin (CCT) and its mechanism.
  
  
  
  Isolated aortic rings from Sprague-Dawley rats were mounted in the organ bath system. The tension of the aorta was recorded.
  
  
  
  CCT significantly provoked concentration-dependent relaxation in both endothelium-intact and-denuded aortic rings pre-constricted by phenylephrine (10⁻⁵ mol/L), and the vasorelaxation in endothelium-intact aortic rings was stronger than that in endothelium-denuded ones. CCT had no significant effects on aortic rings pre-constricted with KCl (6 × 10⁻² mol/L). Pretreatment with eith L-NAME (10⁻⁴ mol/L), an inhibitor of nitric oxide synthase (NOS), or indomethacin (10⁻⁵ mol/L), an inhibitor of cyclooxygenase, for 30 min significantly attenuated the relaxation of endothelium-intact aortic rings induced by CCT. Besides, both tetraethylammonium (a Ca²(+)-activated K(+) channel inhibitor, 5 × 10⁻³ mol/L) and 4-aminopyridine (a voltage-sensitive K(+) channel inhibitor, 10⁻³ mol/L), but not the ATP-sensitive K(+) channel inhibitor glibenclamide (3 × 10⁻⁶ mol/L), significantly attenuated CCT-induced relaxation in endothelium-denuded aortic rings.
  
  
  
  CCT had partial endothelium-dependent relaxation in rat aortas, which may be mediated by activating the endothelial NOS-NO and cyclooxygenase-prostacyclin pathways. The endothelium-independent relaxation in rat aortas induced by CCT may be mediated by Ca²(+)-activated K(+) channels and voltage-sensitive K(+) channels.
authors.affiliation: Department of Physiology, College of Medicine, Zhejiang University, Hangzhou 310058, China.
authors.forename: Jian-feng
authors.initials: JF
authors.lastname: Lu
authors.forename: Xu-yun
authors.initials: XY
authors.lastname: Li
authors.forename: Chun-hong
authors.initials: CH
authors.lastname: Shen
authors.forename: Yuan
authors.initials: Y
authors.lastname: Lu
authors.forename: Zhi
authors.initials: Z
authors.lastname: Li
authors.forename: Zhi-guo
authors.initials: ZG
authors.lastname: Ye
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xia
authors.forename: Hui-ping
authors.initials: HP
authors.lastname: Wang
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D002338:Carotenoids / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism; D010656:Phenylephrine / Q000494:pharmacology; D026902:Potassium Channel Blockers / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology; D014801:Vitamin A / Q000031:analogs & derivatives
chemical_list: D026902:Potassium Channel Blockers; D014665:Vasodilator Agents; C487773:trans-sodium crocetinate; D014801:Vitamin A; D010656:Phenylephrine; D009569:Nitric Oxide; D002338:Carotenoids; D019001:Nitric Oxide Synthase