Role of NOD receptor in insulin resistance of rat skeletal muscle

Objective To investigate the role of nucleotide binding oligomerization domain(NOD)receptor in insulin resistance of skeletal muscle in different obesity susceptible rats induced by high fat diet.Methods Male Sprague-Dawley(SD)rats were randomly divided into control group and high fat group fed with normal and high-fat diet,respectively.The rats in high fat group were subdivided into obesity-prone(OP)group and obesity-resistant(OR)group at 8th week.Oral glucose tolerance test(OGTT)was performed at 19th week and all the rats were sacrificed at 20th week.Lee's index,fat content and homeostasis model assessment of insulin resistance(HOMA-IR)were measured.Glucose transporter 4(GLUT4),NOD1 and NOD2 mRNA expression were determined with real-time PCR.Results Body weight,fat content,fasting insulin level and HOMA-IR in rats of OP group were higher than control and OR group(P<0.01).Though there was no difference in body weight between rats in OR and control group,OR group showed higher Lee's index,fat content and HOMA-IR compared with those of the control group(P<0.01 or P<0.05).Expression of GLUT4 mRNA in rat skeletal muscle of OP group was down-regulated and NOD2 mRNA was significantly up-regulated than those of the control and OR group(P<0.01 or P<0.05).Conclusion High fat diet might be a NOD2 activator in rat skeletal muscle and play an important role in skeletal muscle insulin resistance.