RESUMO
The present study was undertaken to investigate the influence of vitexin on vascular smooth muscle contractility and to determine the mechanism involved. Intact or denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Vitexin more significantly relaxed phorbol ester-induced vascular contraction than thromboxane A2 or fluoride-induced contraction suggesting as a possible anti-hypertensive on the agonist-induced vascular contraction regardless of endothelial nitric oxide synthesis. Furthermore, vitexin significantly inhibited phorbol ester-induced increases in pERK1/2 levels. On the other hand, it did not significantly inhibit thromboxane A2-induced increases in pMYPT1 levels suggesting the mechanism involving the primarily inhibition of MEK activity and the subsequent phosphorylation of ERK1/2. This study provides evidence regarding the mechanism underlying the relaxation effect of vitexin on agonist-induced vascular contraction regardless of endothelial function.
Assuntos
Apigenina/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Animais , Aorta Torácica/efeitos dos fármacos , Western Blotting , Ativadores de Enzimas/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Contração Muscular/efeitos dos fármacos , Ésteres de Forbol/farmacologia , Proteína Fosfatase 1/metabolismo , Ratos , Ratos Sprague-Dawley , Fluoreto de Sódio/farmacologia , Tromboxano A2/farmacologia , Quinases Associadas a rho/metabolismoRESUMO
Double aortic arch is a rare anomaly of the aortic arch and this may cause tracheal damage by compressing the trachea during the first year of life. We report here on three fetal cases of double aortic arch and their outcomes. These malformations presented as an isolated right aortic arch or as a typical vascular ring form on the prenatal echocardiography that was obtained between 22 and 24 weeks gestation. In two of the three patients, the major intracardiac anomaly was a ventricular septal defect, and this was associated with the aortic malformation. A more detailed evaluation of the branching pattern of the aorta, and particularly whether the aorta gives off a left-sided limb of the double arch, could suggest the diagnosis of a double aortic arch in utero. Two patients underwent successful surgical correction and they showed good clinical outcomes. Fetal double aortic arch can be prenatally suspected after performing fetal echocardiography for those fetuses that show a right side aortic arch, and this can help to avoid delaying the postnatal management of this rare anomaly.
