The triterpenoid alpha, beta-amyrin prevents the impaired aortic vascular reactivity in high-fat diet-induced obese mice

• Autor(a) principal: Santos, Flávia Almeida
• Data de Publicação: 2017
• Outros Autores: Batista-Lima, Francisco José, Nunes, Paulo Iury Gomes, Viana, Ana Flávia Seraine Custódio, Silva, Armenio André de Carvalho Almeida da, Fonseca, Said Gonçalves da Cruz, Chaves, Mariana Helena, Rao, Vietla Satyanarayana, Magalhães, Pedro Jorge Caldas, Brito, Teresinha Silva de, Carvalho, Karine Maria Martins Bezerra
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/26578
• topic: Obesidade; Dieta; Aorta Torácica; Aorta, Thoracic

To characterize the pro tective effects of the triterpenoid mixture alpha, beta-amyrin (AMY, 20 mg/kg, during 15 days) on the reactivity of isolated aorta of high- fat diet (HFD)-induced obese mice. Male Swiss mice were fed with HFD or normal diet (ND) for 15 weeks. Contractions of thoracic aorta in response to KCl or phen- ylephrine (PHE) and relaxation by acetylcholine (ACh) or sodium nitroprusside (SNP) were analyzed. HFD-fed mice developed hyperglycemia, hyperlipidemia, and significant body weight gain, parameters prevented by AMY treat- ment. Whereas aortic contractility did not differ in re- sponse to KCl, contractions induced by PHE (1 μ M) as well as relaxation induced by ACh (1 – 30 μ M) or SNP (1 nM – 0.1 mM) on PHE-contracted aorta were decreased ( p < 0.05) in tissues of HFD compared to ND mice, phenomenon significantly ( p < 0.05) diminished in HFD mice treated with AMY. The relaxant actions of ACh and SNP were inhibited ( p < 0.05) by tetraethylammonium (TEA, 5 mM), apamin (0.1 μ M), and 4-aminopyridine (4-AP; 3 mM) in aortae from ND group, but not from HFD. Treatment of HFD mice with AMY rescued the inhibitory effect of TEA ( p < 0.05) on vasorelaxant actions of ACh and SNP. 1H-[1,2,4]oxadiazolo[4,3- a]quinoxalin-1-one (ODQ) inhibited similarly the relaxant effects of SNP in all groups. 8-Br-cGMP relaxed with similar profile aortae of all groups. By preventing HFD- induced obesity in mice, AMY rescued the blunted con- tractile response to PHE, and the attenuated vasorelaxation and K + channel activation (opening) induced by ACh and SNP in isolated aorta.