Obesity reduces AT2 receptor participation in anti-contractile effect of mice aortic perivascular adipose tissue

Obesity reduces AT2 receptor participation in anti-contractile effect of mice aortic perivascular adipose tissue

• Autor
• Bruno Vinicius Duarte Marques
• Co-autores
• Nathalia Senger , Abiqueila Da Silva Alves , Maria Luiza Morais Barreto Chaves , Eliana Hiromi Akamine
• Resumo

• Obesity predisposes to numerous diseases that have been causing thousands of deaths per year. Adipose tissue dysfunction is associated with the development of these diseases. Perivascular adipose tissue dysfunction can lead to the development of vascular diseases. Several components of the renin angiotensin aldosterone system are expressed in PVAT, which may participate in the control of vascular tone. The aim of this study was to evaluate the role of the RAAS vasodilator axes (angiotensin II/ AT2R and angiotensin converting enzyme 2/ angiotensin 1-7/ Mas receptor) in the anti-contractile action of PVAT in the thoracic aorta of obese mice. CEUA: 53/2017; Four-week-old C57Bl/6 mice were submitted to a control (CTL) or high-fat (OB) diet for 16 weeks. The characterization of obesity and assessment of vascular reactivity of thoracic aorta rings without (PVAT-) and with (PVAT+) PVAT for norepinephrine were performed in the absence and presence of AT2 receptor antagonist, Mas receptor antagonist and nitric oxide synthase inhibitor. Anti-contractile effect of thoracic aortic PVAT is impaired in OB mice due to lower participation of the AT2 receptor, but this dysfunction is independent of changes in Mas receptor and nitric oxide. AT2 receptor protein expression was reduced in the aorta and increased in the PVAT of OB mice. To confirm the participation of the AT2 receptor in the anti-contractile effect of thoracic aortic PVAT, curves for norepinephrine were performed in PVAT- and PVAT+ rings from knockout mice for this receptor (KO), which were fed a control (CTL KO) and high-fat diet (OB KO). We show that the PVAT of CTL KO animals has no anti-contractile effect and that the presence of PVAT increases the norepinephrine contraction in OB KO mice. Therefore, our results show that the presence of the AT2 receptor is essential for the anti-contractile effect of aortic PVAT.

• Palavras-chave
• Perivascular adipose tissue, Renin-angiotensin system, Obesity
• Modalidade
• Pôster
• Área Temática
• Tecido adiposo perivascular