Modelo de obesidade induzida por dieta hiperlipídica e associada à resistência à ação da insulina e intolerância à glicose / Model of high-fat diet-induced obesity associated to insulin resistance and glucose intolerance

OBJETIVO: Validar um modelo de obesidade induzida por dieta hiperlipídica, de baixo custo, fácil reprodutibilidade, que mimetizasse características observadas no humano e viabilizasse posteriores proposições terapêuticas. MATERIAIS E MÉTODOS: Dezesseis camundongos Swiss receberam dieta padrão (DP) ou dieta hiperlipídica (DH), durante 10 semanas. RESULTADOS: Embora o grupo DP tenha apresentado maior consumo de água (p < 0,01) e ração (p < 0,001), o grupo DH apresentou maior ganho de peso corpóreo (p < 0,5) e aumento de coxins adiposos (p < 0,001), favorecendo maior índice de adiposidade (p < 0,001), glicemia (p < 0,01) e área sob a curva nos testes de tolerância à insulina (p < 0,001) e à glicose (p < 0,01). CONCLUSÃO: Validou-se um modelo de obesidade induzida por dieta hiperlipídica associada à resistência à ação da insulina e à intolerância à glicose, em um período de 10 semanas.

OBJECTIVE: Validate a model of high-fat diet-induced obesity, of low cost, easy reproducibility, that could express characteristics observed in human, and would enable subsequent therapy proposals. MATERIALS AND METHODS: Sixteen Swiss mice received a standard diet (DP) or high-fat diet (DH) for 10 weeks. RESULTS: Although the DP group had greater water (p < 0.01) and feed (p < 0.001) consumption, the DH group had greater body weight (p < 0.5) and adipose tissue gain (p < 0.001), favoring higher adiposity index (p < 0.001), glucose (p < 0.01), and area under the curve in the insulin (p < 0.001) and glucose (p < 0.01) tolerance tests. CONCLUSION: A high-fat diet-induced obesity model has been validated, which was also associated with insulin resistance and glucose intolerance after a period of 10 weeks.

Aerobic exercise training induces metabolic benefits in rats with metabolic syndrome independent of dietary changes

OBJECTIVES: We evaluated the effects of aerobic exercise training without dietary changes on cardiovascular and metabolic variables and on the expression of glucose transporter Type 4 in rats with metabolic syndrome. METHODS: Twenty male spontaneously hypertensive rats received monosodium glutamate during the neonatal period. The animals were allocated to the following groups: MS (sedentary metabolic syndrome), MS-T (trained on a treadmill for 1 hour/day, 5 days/week for 10 weeks), H (sedentary spontaneously hypertensive rats) and H-T (trained spontaneously hypertensive rats). The Lee index, blood pressure (tail-cuff system), insulin sensitivity (insulin tolerance test) and functional capacity were evaluated before and after 10 weeks of training. Glucose transporter Type 4 expression was analyzed using Western blotting. The data were compared using analysis of variance (ANOVA) (p<0.05). RESULTS: At baseline, the MS rats exhibited lower insulin sensitivity and increased Lee index compared with the H rats. Training decreased the body weight and Lee index of the MS rats (MS-T vs. MS), but not of the H rats (H-T vs. H). There were no differences in food intake between the groups. At the end of the experiments, the systolic blood pressure was lower in the two trained groups than in their sedentary controls. Whole-body insulin sensitivity increased in the trained groups. Glucose transporter Type 4 content increased in the heart, white adipose tissue and gastrocnemius muscle of the trained groups relative to their respective untrained groups. CONCLUSION: In conclusion, the present study shows that an isolated aerobic exercise training intervention is an efficient means of improving several components of metabolic syndrome, that is, training reduces obesity and hypertension and increases insulin sensitivity. .