Nebivolol alleviates aortic remodeling through eNOS upregulation and inhibition of oxidative stress in l-NAME-induced hypertensive rats

Abstract

ABSTRACTPurpose: To investigate the effect and mechanism of nebivolol on aortic remodeling in N-nitro-l-arginine methyl ester (l-NAME)-induced hypertension. Methods: Male Sprague–Dawley rats were treated with equal volumes of drinking water or l-NAME (60 mg/kg/day), alone or in combination with nebivolol (8 mg/kg/day) or atenolol (80 mg/kg/day) by gavage for 8 weeks. Systolic blood pressure (SBP), aortic morphometry, plasma nitric oxide (NO) levels, nitric oxide synthase (NOS) activity, and relaxation of aorta to acetylcholine were determined. Protein expression of endothelial NOS (eNOS), Akt, and NADPH oxidase (Nox) was evaluated. Results: l-NAME-treated rats showed an elevated SBP associated with aortic remodeling. l-NAME-treated rats showed reduced plasma NO levels and NOS activity and increased reactive oxygen species (ROS). Protein expression of eNOS, eNOS phosphorylated at Ser1177 (p-eNOS), Akt, and Akt phosphorylated at Ser473 (p-Akt) decreased, whereas that of Nox2, Nox4, and p22phox increased in the aortas from l-NAME-treated rats. Nebivolol treatment reduced SBP and ameliorated aortic remodeling. The effects of nebivolol were accompanied by increasing NO levels, NOS activity, and expression of eNOS, p-eNOS, Akt, and p-Akt, as well as reduction of ROS generation and Nox2, Nox4, and p22phox expression. These effects of nebivolol were not reproduced by atenolol. Conclusion: Our data indicate a protective role of nebivolol on the high blood pressure and vascular remodeling induced by l-NAME. The beneficial vascular effect of nebivolol is mediated by the upregulation of eNOS and inhibition of oxidative stress.