title: Decreased vascular contractility induced by hemin is associated with a reduced rho-kinase activity.
abstract: OBJECTIVE
  In this study, the role of rho-kinase activity in the modulation of vascular contractility induced by hemin, a heme oxygenase inducer, was investigated.
  
  
  METHODS
  Aortic rings from Wistar rats were incubated in physiological saline solution (PSS) containing hemin at 10-(4) M for six hours then contracted with phenylephrine, and a dose-response curve was established. The effect of Y-27632, a rho-kinase inhibitor, on the relaxation of the pre-contracted aortic rings was then studied.
  
  
  RESULTS
  Incubation of the aortic rings in hemin induced an increased expression of heme oxygenase 1 (HO-1). A reduction in the contractile force of aortic rings incubated in hemin was observed in response to phenylephrine. Y-27632 at a concentration of 10-(6) M induced a 36% relaxation of the control aortic rings but only a 20% relaxation in aortic rings treated with hemin.
  
  
  CONCLUSIONS
  These data suggest that the decreased vascular contractility induced by hemin could, in part, result from an inhibition of rho-kinase activity.
authors.affiliation: LAB.P.ART.-EA3852, Faculty of Medicine, University of Tours, 10 bis Boulevard Tonnellé, Tours, France.
authors.forename: Bonaventure
authors.initials: B
authors.lastname: Awede
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Lemaire
authors.forename: Pierre
authors.initials: P
authors.lastname: Bonnet
authors.forename: Veronique
authors.initials: V
authors.lastname: Eder
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects* / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D004790:Enzyme Induction; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D006427:Hemin / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D047428:Protein Kinase Inhibitors; D014662:Vasoconstrictor Agents; D006427:Hemin; D006419:Heme Oxygenase (Decyclizing); C491523:Hmox1 protein, rat; D054460:rho-Associated Kinases