Thirty days of combined consumption of a high-fat diet and fructose-rich beverages promotes insulin resistance and modulates inflammatory response and histomorphometry parameters of liver, pancreas, and adipose tissue in Wistar rats.

OBJECTIVE: The aim of this study was to verify the effects of consumption of a high-fat diet (HFD) combined with fructose-rich beverages (FRT) in promoting metabolic and physiologic changes associated with insulin resistance. METHODS: Thirty-two male Wistar rats (250 ± 10 g) were randomly allocated into four groups (n = 8) that received either a standard diet (CON), HFD, FRT, or HFD + FRT for 30 d. Insulin sensitivity and glucose tolerance were evaluated using the insulin tolerance test (ITT) and oral glucose tolerance test (OGTT). Serum samples were used to analyze the metabolic parameters and hormone levels. Interleukin (IL)-6, IL-10, IL-1ß, and tumor necrosis factor-α assays were performed in the liver, pancreas, gastrocnemius muscle, and epididymal adipose tissue by enzyme-linked immunosorbent assay. Histologic and morphometric analyses were performed on the liver, pancreas, and adipose tissues. RESULTS: Consumption of HFD + FRT promoted a significant increase (P < 0.05) in body weight, index adiposity, and in the area under the curve of ITT (P < 0.001) and OGTT (P < 0.001) when compared with the CON group. Consumption of FRT alone increased fasting glucose (P = 0.015), insulin (P = 0.035), and homeostasis model assessment index (P = 0.018), and these changes were of greater magnitude when FRT was combined with HFD. Moreover, the rats fed an HFD + FRT demonstrated a significant increase in lipid droplets in the liver (P < 0.001), an increase in adipocyte area, and an increase in inflammatory cytokines in the liver, pancreas, skeletal muscle, and adipose tissue. CONCLUSION: Consumption of an HFD + FRT promotes insulin resistance, increases inflammatory cytokines, and modulates histomorphometric parameters of the liver, pancreas, and adipose tissue, typical of insulin resistance in humans.

Physical training improves exercise tolerance, cardiac function and promotes changes in neurotrophins levels in chagasic mice.

AIMS: To investigate the effects of moderate aerobic physical training on cardiac function and morphology as well as on the levels of glial cell-derived neurotrophic factor (GDNF), nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) of animals infected with the Y strain of Trypanosoma cruzi. MAIN METHODS: Twenty-eight male C57BL/6 mice were distributed into 4 groups: sedentary control (SC), trained control (TC), sedentary infected (CHC) and trained infected (CHT). The infection was performed by intraperitoneal injection of trypomastigote forms and the animals were adapted to treadmill in the week before the beginning of the training protocol, initiated 45 days post infection. Maximal exercise test (TEM) was performed at the baseline as well as at the end of the 4th, 8th and 12th weeks of training. At the end of the 12th week, all animals were evaluated for cardiac morphology and function by echocardiography. KEY FINDINGS: CHC group showed a larger area of right ventricle (RVA), increased end-systolic volume and reduction in ejection fraction (EF), stroke volume (SV), cardiac output (CO) and fractional area change (FAC). The training reduced the RVA and improved the FAC of chagasic animals. GDNF level was higher in TC and CHC groups compared to SC in heart and BDNF levels were higher in CHC compared to SC in heart and serum. SIGNIFICANCE: Physical training ameliorated the cardiac function of infected animals and promoted adjusts in BDNF and GDNF levels. These findings evidenced these neurotrophins as possible biomarkers of cardiac function responsive to exercise stimulus.