Cardiac, Metabolic and Molecular Profiles of Sedentary Rats in the Initial Moment of Obesity

Abstract

BackgroundDifferent types of high-fat and/or high-energy diets have been used to induce obesity in rodents. However, few studies have reported on the effects observed at the initial stage of obesity induced by high-fat feeding on cardiac functional and structural remodelling.ObjectiveTo characterize the initial moment of obesity and investigate both metabolic and cardiac parameters. In addition, the role of Ca2+ handling in short-term exposure to obesity was verified.MethodsThirty-day-old male Wistar rats were randomized into two groups (n = 19 each): control (C; standard diet) and high-fat diet (HF, unsaturated high-fat diet). The initial moment of obesity was defined by weekly measurement of body weight (BW) complemented by adiposity index (AI). Cardiac remodelling was assessed by morphological, histological, echocardiographic and papillary muscle analysis. Ca2+ handling proteins were determined by Western Blot.ResultsThe initial moment of obesity occurred at the 3rd week. Compared with C rats, the HF rats had higher final BW (4%), body fat (20%), AI (14.5%), insulin levels (39.7%), leptin (62.4%) and low-density lipoprotein cholesterol (15.5%) but did not exhibit alterations in systolic blood pressure. Echocardiographic evaluation did not show alterations in cardiac parameters. In the HF group, muscles were observed to increase their +dT/dt (C: 52.6 ± 9.0 g/mm2/s and HF: 68.0 ± 17.0 g/mm2/s; p < 0.05). In addition, there was no changes in the cardiac expression of Ca2+ handling proteins.ConclusionThe initial moment of obesity promotes alterations to hormonal and lipid profiles without cardiac damage or changes in Ca2+ handling.

Bloqueio de Receptores AT1 Melhora o Desempenho Funcional Miocárdico na Obesidade

“…7,[12][13][14] However, there are important divergences among studies regarding potential effects of high-fat diet induced obesity on myocardial performance. Jacobsen et al 15 found increased contractile phase during inotropic maneuver of papillary muscle in obese rats after three weeks of diet; other authors have found higher myocardial shortening velocity in experiments of 20, 8 30, 11 33, 13 and 35 weeks. 16 Other investigations have reported impaired cardiac contraction, showed by in vitro papillary muscles analysis of obese rats in experimental models with15 weeks of diet.…”

Avaliação da suplementação com caseína sobre o periodonto e osso mandibular de ratos alimentados com dieta padrão e dieta de cafeteria

“…O índice de adiposidade (IA) post-mortem foi calculado utilizando a fórmula: IA = [gordura corporal/peso corporal] x 100. A gordura corporal (g) foi calculada pela soma dos seguintes constituintes do tecido adiposo: gordura perigonadal + gordura retroperitoneal + gordura mesentérica (Jacobsen et al, 2017).…”

A Redução do Colágeno Tipo I está Associada ao Aumento da Atividade da Metaloproteinase-2 e da Expressão Proteica de Leptina no Miocárdio de Ratos Obesos

“…The sample size used in this study was based on the literature and on our previous studies. 13,[17][18][19] The control group was fed standard rat chow (RC Focus 1765, Agroceres ® , Rio Claro, SP, Brazil) containing 12.3% of kilocalories from fat, 57.9% from carbohydrates, and 29.8% from protein, whereas the obese group was fed one of four alternating high-fat diets (RC Focus 2413, 2414, 2415, and 2416, Agroceres ® , Rio Claro, SP, Brazil) containing 49.2% of kilocalories from fat, 28.9% from carbohydrates, and 21.9% from protein. The four high-fat diets had the same nutritional composition, except flavoring additives, namely, cheese, bacon, chocolate, or vanilla.…”