Intermittent fasting exerts beneficial metabolic effects on blood pressure and cardiac structure by modulating local renin-angiotensin system in the heart of mice fed high-fat or high-fructose diets.

Intermittent fasting (IF) sets the preference for fats as fuel and is linked to beneficial metabolic outcomes; however, the effects in the renin-angiotensin system (RAS) in the heart remains to be determined. We hypothesized that IF improves blood pressure and lipid profiles due to a less activated local RAS in the left ventricle of mice, irrespective of the dietary scheme. This study aimed to evaluate the effects of intermittent fasting on cardiovascular parameters and local RAS in the left ventricle (LV) of mice fed either a high-fat (HF) or high-fructose diet (HFru). Metabolic alterations were induced in C57BL/6 mice by providing them free access to a high-fat or a high-fructose (HFru) diet for 8 weeks. Following the 8-week metabolic alteration period, the mice were subjected to the IF protocol in which mice were deprived of food for 24 hours, every other day, for a period of 4 weeks. The IF protocol caused significant reduction in body weight, systolic blood pressure, blood glucose, total cholesterol, and triacylglycerol levels, in addition to augmenting the plasma and urinary uric acid levels, irrespective of the diet. Post IF protocol, beneficial LV remodeling was observed in animals fed either diet and included reduced LV mass, thickness, and cardiomyocyte cross-sectional area. These results comply with the improved RAS modulation, which favored ACE2/MAS receptor axis over the renin/ACE/AT1 axis. In conclusion, the significant decrease in weight brought about as a result of the IF protocol lead to modulation of the local RAS, with the consequential benefit of LV remodeling and reduction in blood pressure, irrespective of the diet.

Camelo L ，Marinho TS ，Águila MB ，Souza-Mello V ，Barbosa-da-Silva S ... -  《-》

High-intensity interval training has beneficial effects on cardiac remodeling through local renin-angiotensin system modulation in mice fed high-fat or high-fructose diets.

HIIT (high-intensity interval training) has the potential to reduce cardiometabolic risk factors, but the effects on cardiac remodeling and local RAS (renin-angiotensin system) in mice fed high-fat or high-fructose diets still need to be fully addressed. Sixty male C57BL/6 mice (12weeks old) were randomly divided into three groups, control (C), High-fat (HF), or High-fructose diet (HRU) and were monitored for eight weeks before being submitted to the HIIT. Each group was randomly assigned to 2 subgroups, one subgroup was started on a 12-week HIIT protocol (T=trained group), while the other subgroup remained non-exercised (NT=not-trained group). HIIT reduced BM and systolic blood pressure in high-fat groups, while enhanced insulin sensitivity after high-fat or high-fructose intake. Moreover, HIIT reduced left ventricular hypertrophy in HF-T and HFRU-T. Notably, HIIT modulated key factors in the local left ventricular renin-angiotensin-system (RAS): reduced protein expression of renin, ACE (Angiotensin-converting enzyme), and (Angiotensin type 2 receptor) AT2R in HF-T and HFRU-T groups but reduced (Angiotensin type 1 receptor) AT1R protein expression only in the high-fat trained group. HIIT modulated ACE2/Ang (1-7)/Mas receptor axis. ACE2 mRNA gene expression was enhanced in HF-T and HFRU-T groups, complying with elevated Mas (Mas proto-oncogene, G protein-coupled receptor) receptor mRNA gene expression after HIIT. This study shows the effectiveness of HIIT sessions in producing improvements in insulin sensitivity and mitigating LV hypertrophy, though hypertension was controlled only in the high-fat-fed submitted to 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.

de Oliveira Sá G ，Dos Santos Neves V ，de Oliveira Fraga SR ，Souza-Mello V ，Barbosa-da-Silva S ... -  《-》

Intermittent fasting, adipokines, insulin sensitivity, and hypothalamic neuropeptides in a dietary overload with high-fat or high-fructose diet in mice.

The intermittent fasting (IF) might have benefits on metabolism and food intake. Twelve-week old C57BL/6 J mice were fed a control diet (C, 10% kcal fat), a high-fat diet (HF, 50% kcal fat) or a high-fructose diet (HFru, 50% kcal fructose) for 8 weeks, then half of the animals in each group underwent IF (24 h fed, 24 h fasting) for an additional 4 weeks. Although food intake on the fed day remained the same for all groups, all fasting groups showed a reduction in body mass compared to their counterparts. IF reduced total cholesterol, triacylglycerol, fasting glucose, fasting insulin resistance index, and plasma leptin, but increased plasma adiponectin. IF reduced Leptin gene expression in the HF-IF group, but increased proinflammatory markers in the hypothalamus, also in the C-IF group. Both groups HFru-IF and C-IF, showed alterations in the leptin signaling pathway (Leptin, OBRb, and SOCS3), mainly in the HFru-IF group, suggesting leptin resistance. NPY and POMC neuropeptides labeled the neurons of the hypothalamus by immunofluorescence, corroborating qualitatively other quantitative findings of the study. In conclusion, current results are convincing in demonstrating the IF effect on central regulation of food intake control, as shown by NPY and POMC neuropeptide expressions, resulting in a lower weight gain. Besides, IF improves glycemia, lipid metabolism, and consequently insulin and leptin resistance. However, there is increased expression of inflammatory markers in mouse hypothalamus challenged by the HF and HFru diets, which in the long term may induce adverse effects.

Spezani R ，da Silva RR ，Martins FF ，de Souza Marinho T ，Aguila MB ，Mandarim-de-Lacerda CA ... -  《-》

A study of the interactive effects of oral contraceptive use and dietary fat intake on blood pressure, cardiovascular reactivity and glucose tolerance in normotensive women.

Straznicky NE ，Barrington VE ，Branley P ，Louis WJ ... -  《JOURNAL OF HYPERTENSION》

Açaí seed extract prevents the renin-angiotensin system activation, oxidative stress and inflammation in white adipose tissue of high-fat diet-fed mice.

The role of the renin-angiotensin system (RAS), oxidative stress, and inflammation on the development of obesity and its comorbidities has been extensively addressed. Euterpe oleracea Mart. (açaí) seed extract (ASE), with antioxidant and anti-inflammatory properties and capable to modulate plasma renin levels, has been evidenced as a potential regulator of body mass. We hypothesized that the supplementation with ASE might exert beneficial effects on obesity-related white adipose tissue changes and metabolic disorders by interfering with the local adipose tissue overexpression of RAS, inflammation, and oxidative stress in C57BL/6 mice fed a high-fat (HF) diet. The animals were fed a standard diet (10% fat, control), 60% fat (HF), HF + ASE (300 mg/kg per day) and HF + ENA (enalapril, 30 mg/kg per day) for 12 weeks. ASE and ENA prevented weight gain and adiposity, adipocyte hypertrophy, dyslipidemia, and insulin resistance. In adipose tissue, ASE increased the insulin receptor expression and reduced renin and AT1 receptor expression, which was associated with decreased plasma levels of renin and angiotensin II. Differently, ENA increased the expression of angiotensin-conversing enzyme 2, AT2, B2, and Mas receptors in adipose tissue. Also, ASE but not ENA decreased malondialdehyde and 8-isoprostane levels in adipose tissue. Finally, ASE and ENA reduced the adipose tissue inflammatory markers tumor necrosis factor alpha and interleukin 6. These results demonstrate that ASE prevented the adipocyte hypertrophy, obesity, hyperlipidemia, hyperglycemia, and insulin resistance in HF diet-fed mice. The downregulation of RAS in adipose tissue, reducing oxidative stress and inflammation, may contribute to the prevention of obesity-related disorders.

Santos IB ，de Bem GF ，da Costa CA ，de Carvalho LCRM ，de Medeiros AF ，Silva DLB ，Romão MH ，de Andrade Soares R ，Ognibene DT ，de Moura RS ，Resende AC ... -  《-》