Bloqueio de Receptores AT1 Melhora o Desempenho Funcional Miocárdico na Obesidade

Abstract

Background: Obesity has been associated with chronic activation of the renin-angiotensin-aldosterone system and with significant changes in cardiac performance. Objective: To assess the impact of a blockade of angiotensin-II receptor type 1 (AT 1 receptor) on morphology and on myocardial functional performance in rats with high-fat diet-induced obesity. Methods: Wistar rats (n=48) were submitted to control (2.9 kcal/g) or high-fat (3.6 kcal/g) diet for 20 weeks. After the 16 th week they were divided into four groups: Control (CO), Obese (OB), Control Losartan (CL) and Obese Losartan (OL). CL and OL received losartan (30 mg/kg/day) in drinking water for four weeks. Subsequently, body composition, systolic blood pressure (SBP) and echocardiographic variables were analyzed. Papillary muscle function was assessed at baseline with 2.50 mM calcium concentration ([Ca 2+ ] o) and after inotropic maneuvers: post-pause potentiation (PPP), [Ca 2+ ] o elevation, and during beta-adrenergic stimulation with isoproterenol. Analysis of the results was performed by the Two-Way ANOVA and by the appropriate comparison test. The level of significance was set at 5%. Results: Although SBP change had been not maintained at the end of the experiment, obesity was associated with cardiac hypertrophy and with increased left ventricle posterior wall shortening velocity. In the study of papillary muscles in basal condition, CL showed lower developed tension maximum negative variation velocity (-dT/dt) than CO. The 60s PPP promoted lower-dT/dt and maximum developed tension (DT) in OB and CL compared with CO, and higher relative DT variation and maximum positive variation velocity (+dT/dt) in OL compared with CL and OB. Under 1.5, 2.0, and 2.5mM [Ca 2+ ] o , the OL group showed higher-dT/dt than CL. Conclusion: Losartan improves myocardial function in high-fat diet-induced obesity.

O Melhor do Ano 2020 nos Arquivos Brasileiros de Cardiologia e na Revista Portuguesa de Cardiologia

“…O aumento do índice de massa corporal (IMC), representando as alterações observadas na obesidade, é o terceiro fator de risco para as mulheres e o quarto para os homens, no ranking anteriormente mencionado. 9 Oliveira‐Júnior et al 11 levantaram a hipótese de que a obesidade se associaria com alterações no desempenho funcional miocárdico sustentadas em diferentes condições de estimulação e que seriam reduzidas com o antagonismo de receptores AT1. Estudaram ratos Wistar que receberam dieta controle ou hiperlipídica e foram divididos de acordo com a presença de obesidade.…”

Efeitos Anti-inflamatórios da Terapia com Atorvastatina na Síndrome Metabólica

“…8 Classically, ectopic fat deposition around visceral vessels and organs has contributed to low-grade chronic inflammatory conditions and insulin resistance onset, which is also common in obesity. 9,10 In this aspect, perivascular adipose tissue has an essential paracrine function sustained by substantial protein activation and vascular morphological changes; these mechanisms contribute to the endothelial dysfunction during MS. 8,11 Consequently, clarifying the potential efficiency of therapeutic interventions is essential to manage MS conditions. In this context, hydroxymethyl glutaryl coenzyme A reductase inhibitors (HMG-CoA), also called statins, are commonly used to treat atherosclerotic cardiovascular disease, and have proved efficacy in normalizing serum cholesterol levels.…”