Department of Nutrition, School of Public Health, University of Sao Paulo, Sao Paulo, Brazil.
Cell Biochem Funct. 2013 Apr;31(3):244-53. doi: 10.1002/cbf.2894. Epub 2012 Sep 24.
The aim of this study was to investigate the effect of isocaloric intake from a high-fat diet (HFD) on insulin resistance and inflammation in rats. Male Wistar rats were fed on an HFD (n = 12) or control diet (n = 12) for 12 weeks. Subsequently, all animals were euthanized, and blood glucose, insulin, free fatty acids, C-reactive protein, lipid profile, cytokines and hepatic-enzyme activity were determined. Carcass chemical composition was also analyzed. During the first and the twelfth weeks of the experimental protocol, the oral glucose tolerance test and insulin tolerance test were performed and demonstrated insulin resistance (P < 0.05) in the HFD group. Although food intake (g) was lower (P < 0.05) in the HFD group compared with the control group, the concentration of total cholesterol, low-density lipoprotein, C-reactive protein and liver weight were all significantly higher. The kinase inhibitor of κB, c-Jun N-terminal kinase and protein kinase B expressions were determined in the liver and skeletal muscle. After an insulin stimulus, the HFD group demonstrated decreased (P = 0.05) hepatic protein kinase B expression, whereas the kinase inhibitor of κB phospho/total ratio was elevated in the HFD muscle (P = 0.02). In conclusion, the isocaloric intake from the HFD induced insulin resistance, associated with impaired insulin signalling in the liver and an inflammatory response in the muscle.
本研究旨在探讨高热量饮食（HFD）对大鼠胰岛素抵抗和炎症的影响。雄性 Wistar 大鼠分别喂食 HFD（n = 12）或对照饮食（n = 12）12 周。随后，所有动物被安乐死，测定血糖、胰岛素、游离脂肪酸、C 反应蛋白、血脂谱、细胞因子和肝酶活性。还分析了胴体的化学成分。在实验方案的第一和第十二周，进行了口服葡萄糖耐量试验和胰岛素耐量试验，结果表明 HFD 组存在胰岛素抵抗（P < 0.05）。尽管 HFD 组的食物摄入量（g）较低（P < 0.05），但总胆固醇、低密度脂蛋白、C 反应蛋白和肝重的浓度均显著升高。还测定了肝脏和骨骼肌中的κB 激酶抑制剂、c-Jun N-末端激酶和蛋白激酶 B 的表达。在胰岛素刺激后，HFD 组肝蛋白激酶 B 的表达降低（P = 0.05），而 HFD 肌肉中的κB 激酶抑制剂磷酸化/总比值升高（P = 0.02）。总之，HFD 的等热量摄入可诱导胰岛素抵抗，与肝脏胰岛素信号转导受损和肌肉炎症反应有关。
