Aerobic training induces differential expression of genes involved in lipid metabolism in skeletal muscle and white adipose tissues

Aerobic training induces adaptive responses in skeletal muscles and white adipose tissues, thus facilitating lipid utilization as energy substrates during a physical exercise session. However, the effects of training on cytokines levels and on transcription factors involved in lipid metabolism in muscle and different white adipose depots are still unclear; therefore, these were the aims of the present study. Nineteen adult male Wistar rats were randomly assigned to a trained group or a control, non-trained group. The 10-week training protocol consisted of running on a treadmill, during 1 hour per day, 5 days per week, at 75% of maximum aerobic speed. As expected, trained rats improved their aerobic performance and had augmented citrate synthase activity in the soleus, while the control rats did not. Although body weight was not different between groups, the adiposity index and white adipose depots (ie, epididymal and retroperitoneal) were reduced in trained rats. Training reduced serum concentration of insulin, but failed to change serum concentrations of glucose, triacylglycerol, total cholesterol, and nonesterified fatty acids. Training increased sterol regulatory element-binding protein-1c expression in the gastrocnemius and epididymal adipose tissue, and reduced peroxisome proliferator-activated receptor γ (PPARγ) expression in most of the tissues analyzed. The expression of PPARα and carnitine palmitoyltransferase 1 increased in the gastrocnemius and mesenteric adipose tissue but reduced in epididymal adipose tissue. Triacylglycerol content and tribbles 3 expression reduced in the gastrocnemius of trained rats. Tumor necrosis factor-α and interleukin-6 were increased in all adipose depots evaluated. Collectively, our data indicate that the 10-week aerobic training changed gene expression to improve muscle oxidative metabolism and facilitate lipid degradation in adipose tissues. Our data also highlight the existence of adaptive responses that are distinct between the skeletal muscle and white adipose tissue and between different adipose depots.

Differential modulation of cytosolic lipases activities in liver and adipose tissue by high-carbohydrate diets

Several studies have demonstrated that a high-fructose (FRUC) diet induces metabolic and haemodynamic abnormalities, known as the metabolic syndrome, which are characterised by obesity, glucose intolerance, insulin resistance, dyslipidaemia and hypertension. In this study, the effect of a FRUC diet (60 % fructose) for 8 weeks on the metabolism of lipids in liver and epididymal adipose tissue from Wistar rats was compared with the AIN-93M diet and the effects of the AIN-93M diet were compared with a chow diet. The FRUC diet induced marked increases in both hepatocyte lipid droplet volume and postprandial serum levels of triacylglycerol (TAG), but reduced the postprandial serum levels of insulin. The AIN-93M diet induced marked increases in the hepatocyte lipid droplet volume and the serum levels of insulin, without affecting the serum levels of TAG. We found that isocaloric substitution of cornstarch, dextrinised cornstarch and sucrose (AIN-93M diet) for fructose did not affect the hepatic VLDL-TAG secretion and adipose tissue glucose uptake, lipolysis and cytosolic lipases activities in rats. However, the high-fructose diet induced a severe steatosis in liver accompanied by a decrease in cytosolic lipases activities. In adipose tissue, the FRUC diet induced a decrease in the lipoprotein lipase activity, and an increase in lipogenesis. FRUC and AIN-93M diets induced changes in lipid homeostasis in liver and adipose tissue by distinct biochemical mechanisms.

Metal reinforcement for implant-supported mandibular overdentures

Complete and implant-supported mandibular overdenture bases can be a problem because they are especially prone to fracture. Metal reinforcement of the denture base can substantially reduce the incidence of fracture. This article describes 2 methods of reinforcing mandibular overdentures. The advantages of these methods and their indications are discussed.