Exercício intervalado de alta intensidade causa remodelamento cardíaco benéfico através da modulação do SRA local em camundongos alimentados com dieta hiperlipídica ou rica em frutose

Abstract

HIIT (high-intensity interval training) has the potential to reduce cardiometabolic risk factors, but the effects on cardiac remodeling and local RAS in mice fed high-fat or high-fructose diets still need to be fully addressed. Sixty male C57BL/6 mice (12 weeks old) were randomly divided into three groups according to the diet offered (control, High-fat diet, or High-fructose diet) and were monitored for 8 weeks before the HIIT protocol. Then, mice were subdivided into six groups (n =10 each group), three groups started a 12-week HIIT protocol, whereas the other three remained sedentary. HIIT reduced body mass and systolic blood pressure while enhanced insulin sensitivity after high-fat or high-fructose intake. Moreover, HIIT reduced left ventricular hypertrophy and mass caused by both dietary schemes. Notably, HIIT modulated positively important keys factors in the local left ventricular renin-angiotensin-system (RAS): reduced protein expression of renin, ACE, and AT2 in both trained groups and reduced AT1R protein expression only in the high-fat trained group. HIIT elicited a beneficial role in the modulation of ACE2/Ang (1 7)/Mas receptor axis. ACE2 mRNA gene expression was enhanced in HIIT groups, complying with elevated Mas receptor mRNA gene expression after HIIT protocol and the beneficial effects observed. This study shows the effectiveness of HIIT sessions in producing significant improvements in insulin resistance and mitigating LV hypertrophy, though hypertension was controlled only in the high-fat-fed submitted to the HIIT protocol. Local RAS system in the heart mediates these findings and receptor MAS seems to play a pivotal role when it comes to the amelioration of cardiac structural and functional remodeling due to HIIT.