Efeito do sildenafil na função endotelial de camundongos ateroscleróticos

• Ano de defesa: 2015
• Autor(a) principal: Leal, Marcos André Soares
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Ciências Fisiológicas; Centro de Ciências da Saúde; UFES; Programa de Pós-Graduação em Ciências Fisiológicas
• Palavras-chave em Português: Reatividade vascular; Anéis de aorta; Aterosclerose; Camundongos ApoE Knockout; Sildenafil; Óxido nítrico; Estresse oxidativo; Disfunção endotelial; GMP cíclico; Fosfodiesterase 5; Fisiologia; 612
• Link de acesso: http://repositorio.ufes.br/handle/10/8005

In previous studies we have shown that sildenafil ameliorates aortic relaxations in apolipoprotein E knockout (apoE) mice. Now, we tested the hypothesis that endothelial dysfunction (ED) in this model is characterized by contractile hyperresponsiveness to phenylephrine (PE) and that this abnormality could be repaired by the treatment with sildenafil. The aortic rings were evaluated in apoE mice treated with sildenafil (apoE-sil, 40 mg/kg/day) and compared with apoE and wild-type (WT) mice administered with vehicle (veh). The apoE-veh mice exhibited an imbalance of nitric oxide and reactive oxygen species (NO/ROS) levels and an increased maximum response (Rmax, 20%) and sensitivity (7%) to PE, which were not modified by endothelial removal. Under the prostanoids blockade, vasocontraction was decreased more in apoE-veh (-37%) than in WT (-27%) and apoE-sil (-30%) mice. NADPH-oxidase blockade abolished the enhanced contractile responsiveness in apoE-veh (-33%), without effects in WT and apoE-sil groups. The atherosclerotic lesions and the imbalance of NO/ROS were reduced (40%) in apoEsil mice. In conclusion, ED in apoE mice was characterized by decreased NObioavailability and contractile hyperresponsiveness, due to thromboxane and oxidative stress, and was normalized by sildenafil. The beneficial effects of this phosphodiesterase-5 inhibitor on ED and lipid deposition provide new insights for its use as adjuvant in the treatment of atherosclerosis.