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Decreased vascular contractility induced by hemin is associated with a reduced rho-kinase activity.

Awede B, Lemaire MC, Bonnet P, Eder V - Cardiovasc J Afr (2013)

Bottom Line: The effect of Y-27632, a rho-kinase inhibitor, on the relaxation of the pre-contracted aortic rings was then studied.A reduction in the contractile force of aortic rings incubated in hemin was observed in response to phenylephrine.These data suggest that the decreased vascular contractility induced by hemin could, in part, result from an inhibition of rho-kinase activity.

View Article: PubMed Central - HTML - PubMed

Affiliation: LAB.P.ART.-EA3852, Faculty of Medicine, University of Tours, 10 bis Boulevard Tonnellé, Tours, France.

ABSTRACT

Objectives: 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.

Conclusion: These data suggest that the decreased vascular contractility induced by hemin could, in part, result from an inhibition of rho-kinase activity.

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Related in: MedlinePlus

Relaxation effect of Y-27632, a rhoA-kinase inhibitor, on aortic ring contraction induced by phenylephrine at 10-6 M. The clear column represents control aortic rings and shaded column aortic rings incubated in hemin. Values are expressed as percentage of the magnitude of contraction induced by 10-6 M of phenylephrine. ** Significantly different from control (p < 0.01.)
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Figure 2: Relaxation effect of Y-27632, a rhoA-kinase inhibitor, on aortic ring contraction induced by phenylephrine at 10-6 M. The clear column represents control aortic rings and shaded column aortic rings incubated in hemin. Values are expressed as percentage of the magnitude of contraction induced by 10-6 M of phenylephrine. ** Significantly different from control (p < 0.01.)

Mentions: The application of Y-27632, a specific and potent rho-kinase inhibitor, induced a relaxation in the isolated aortic rings. In the control aortic rings, the magnitude of the relaxation at 3 × 10-7 M of Y-27632 was 36% of the contraction induced by 10-6 M of phenylephrine. In aortic rings treated with hemin, the relaxation induced by Y-27632 was reduced to 20% of the contraction induced by phenylephrine (Fig. 2).


Decreased vascular contractility induced by hemin is associated with a reduced rho-kinase activity.

Awede B, Lemaire MC, Bonnet P, Eder V - Cardiovasc J Afr (2013)

Relaxation effect of Y-27632, a rhoA-kinase inhibitor, on aortic ring contraction induced by phenylephrine at 10-6 M. The clear column represents control aortic rings and shaded column aortic rings incubated in hemin. Values are expressed as percentage of the magnitude of contraction induced by 10-6 M of phenylephrine. ** Significantly different from control (p < 0.01.)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3721878&req=5

Figure 2: Relaxation effect of Y-27632, a rhoA-kinase inhibitor, on aortic ring contraction induced by phenylephrine at 10-6 M. The clear column represents control aortic rings and shaded column aortic rings incubated in hemin. Values are expressed as percentage of the magnitude of contraction induced by 10-6 M of phenylephrine. ** Significantly different from control (p < 0.01.)
Mentions: The application of Y-27632, a specific and potent rho-kinase inhibitor, induced a relaxation in the isolated aortic rings. In the control aortic rings, the magnitude of the relaxation at 3 × 10-7 M of Y-27632 was 36% of the contraction induced by 10-6 M of phenylephrine. In aortic rings treated with hemin, the relaxation induced by Y-27632 was reduced to 20% of the contraction induced by phenylephrine (Fig. 2).

Bottom Line: The effect of Y-27632, a rho-kinase inhibitor, on the relaxation of the pre-contracted aortic rings was then studied.A reduction in the contractile force of aortic rings incubated in hemin was observed in response to phenylephrine.These data suggest that the decreased vascular contractility induced by hemin could, in part, result from an inhibition of rho-kinase activity.

View Article: PubMed Central - HTML - PubMed

Affiliation: LAB.P.ART.-EA3852, Faculty of Medicine, University of Tours, 10 bis Boulevard Tonnellé, Tours, France.

ABSTRACT

Objectives: 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.

Conclusion: These data suggest that the decreased vascular contractility induced by hemin could, in part, result from an inhibition of rho-kinase activity.

Show MeSH
Related in: MedlinePlus