the fat increase in the diet promoted increase of the oxidative stress, evidenced by the decrease in the hepatic concentration of vitamin E, showing its antioxidant role against the probable generated free radicals, the ones which possibly exercised a role in the steatosis occurrence.

OBJECTIVE: The aim of the present study was to investigate the lipid profiles of the hepatic and adipose tissues of Wistar rats treated for 21 days with a diet high in saturated fat (high saturated fat, n=6) or high in hydrogenated fat, that is, having 50% partially hydrogenated vegetable oil in its composition (high hydrogenated fat, n=6), and compare them to those of a control group (control group, n=6). METHODS: Adipose tissue and total hepatic fat were higher in the saturated fat group than in the hydrogenated fat group. Hepatic lipid peroxidation was greatest in the saturated fat group, with consequent lower hepatic vitamin E and A levels. In contrast, serum vitamin A was highest in the saturated fat group. Analysis of hepatic lipid fractions found more cholesterol and less high density lipoprotein-cholesterol in the hydrogenated fat group. The hydrogenated fat group had the highest levels of triacylglycerols, followed by the saturated fat group. RESULTS: Significant amounts of trans fatty acids were detected in the hepatic and adipose tissues of the hydrogenated fat group. Among the identified fatty acids, 18:1n9 had a higher positive association with hepatic cholesterol and triacylglycerols, and a higher negative association with high density lipoprotein-cholesterol. Partially hydrogenated vegetable oil promotes greater accumulation of cholesterol and triacylglycerols in the liver than saturated fats. CONCLUSION: Trans fatty acids were incorporated into hepatocytes and adipocytes in a highly efficient manner.

AimMillions of people die each year due to cardiovascular disease (CVD). A Western lifestyle not only fuses a significant intake of fat with physical inactivity and obesity but also promotes CVD. Recent evidence suggests that dietary fat intake impairs the benefits of physical training. We investigated whether aerobic training could reverse the adverse effects of a high-fat diet (HFD) on the aorta. Then, we explored whether this type of exercise could reverse the damage to the heart that is imposed by fat-enriched diet (FED).MethodsRats were randomly assigned to two experiments, which lasted 8 weeks each. First, rats swam for 60 min and were fed either a regular diet [standard diet (STD)] or an HFD. After aortic samples had been collected, the rats underwent a histopathological analysis for different biomarkers. Another experiment subjected rats that were fed either an STD or an FED to swimming for 20 or 90 min.ResultsThe first experiment revealed that rats that were subjected to an HFD-endured increased oxidative damage in the aorta that exercises could not counteract. Together with increased cyclooxygenase 2 expression, an HFD in combination with physical training increased the number of macrophages. A reduction in collagen fibers with an increased number of positive α-actin cells and expression of matrix metalloproteinase-2 occurred concomitantly. Upon analyzing the second experiment, we found that physically training rats that were given an FED for 90 min/day decreased the cardiac adipose tissue density, although it did not protect the heart from fat-induced oxidative damage. Even though the physical training lowered cholesterol levels that were promoted by the FED, the levels were still higher than those in the animals that were given an STD. Feeding rats an FED impaired the swimming protocol’s effects on lowering triglyceride concentration. Additionally, exercise was unable to reverse the fat-induced deregulation in hepatic antioxidant and lipid peroxidation activities.ConclusionOur findings reveal that an increased intake of fat undermines the potential benefits of physical exercise on the heart and the aorta.

The purpose of this study was to evaluate the effects of different types of diets and the swimming exercise in tibias of rats. This study was approved by Ethical Committee in Animals Experiment. Sixty three‐month‐old male Wistar rats were randomly assigned to six groups (n=10): (G1) control AIN‐93 diet sedentary, (G2) control AIN‐93 diet aerobic training, (G3) high‐fat diet sedentary, (G4) high‐fat diet aerobic training, (G5) high‐fat‐protein diet sedentary, (G6) high‐fat‐protein diet aerobic training. Control diet is AIN‐93. The total caloric values of control, high‐fat and high‐fat‐protein diet is respectively 394.8 kcal, 609.8 Kcal, 609.8 Kcal for 100g of diet. Physical exercise consisted of swimming on a large aquarium. Rats swam 5 days a week, 60 minutes, during 8 weeks. Tibias were dissected and tested in a universal testing machine. Data were analyzed using specific tests; level of significance was set at 5%. Mean values of maximum load for groups: G1 (40.5±5.6)N, G2 (44.8±7.4)N, G3 (64.2±4.1)N, G4 (53.3±9.4)N, G5 (48.5±10.8)N and G6 (47.4±7.1)N. Data from our study suggest that a diet programs may influence bone resistance however changing its body weight.Grant Funding Source: FAPESP

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Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.