Sildenafil preserves diastolic relaxation after reduction by L-NAME and increases phosphodiesterase-5 in the intercalated discs of cardiac myocytes and arterioles
Clinics
; 66(7): 1253-1258, 2011. ilus, tab
Article
de En
| LILACS
| ID: lil-596917
Bibliothèque responsable:
BR1.1
ABSTRACT
OBJECTIVES:
We investigated the influence of sildenafil on cardiac contractility and diastolic relaxation and examined the distribution of phosphodiesterase-5 in the hearts of hypertensive rats that were treated with by NG-nitro-L-arginine methyl ester (L-NAME).METHODS:
Male Wistar rats were treated with L-NAME and/or sildenafil for eight weeks. The Langendorff method was used to examine the effects of sildenafil on cardiac contractility and diastolic relaxation. The presence and location of phosphodiesterase-5 and phosphodiesterase-3 were assessed by immunohistochemistry, and cGMP plasma levels were measured by ELISA.RESULTS:
In isolated hearts, sildenafil prevented the reduction of diastolic relaxation (dP/dt) that was induced by L-NAME. In addition, phosphodiesterase-5 immunoreactivity was localized in the intercalated discs between the myocardial cells. The staining intensity was reduced by L-NAME, and sildenafil treatment abolished this reduction. Consistent with these results, the plasma levels of cGMP were decreased in the L-NAME-treated rats but not in rats that were treated with L-NAME + sildenafil.CONCLUSION:
The sildenafil-induced attenuation of the deleterious hemodynamic and cardiac morphological effects of L-NAME in cardiac myocytes is mediated (at least in part) by the inhibition of phosphodiesterase-5.Mots clés
Texte intégral:
1
Collection:
01-internacional
Base de données:
LILACS
Sujet principal:
Pipérazines
/
Sulfones
/
L-NAME
/
Antienzymes
/
Coeur
/
Hypertension artérielle
Limites:
Animals
Langue:
En
Journal:
Clinics
Sujet du journal:
MEDICINA
Année:
2011
Type de document:
Article
Pays d'affiliation:
Brésil
Pays de publication:
Brésil