Effects of exercise intervention on serum-related factors and immunity in a rat model of insulin resistance / 中国组织工程研究

ABSTRACT

BACKGROUND:Type 2 diabetic patients suffered from different levels of insulin resistance and insulin secretion defects. Retinol binding protein 4 is a fat derived factor found in the blood and is considered tobe an important target for the treatment of visceral obesity and insulin resistance. OBJECTIVE:To observe the level of serum inflammatory cytokines and the changes of immune function in insulin resistance model rats after swimming. METHODS:A total of28 8-week-old Sprague-Dawleymale ratmodels were randomly divided into swimming group and rest group. Rat received intraperitoneal injection with 3 μg/g recombinant serum retinol binding protein 4, twice a day, with an interval of 12 hours, for 6 weeks. At 6 weeks after administration, rats in the swimming group were subjected to swimming without loading for 6 weeks, 60 minutes per day. Serum retinol binding protein 4 levels were measured with enzyme linked immunosorbent assay (ELISA) kit. Insulin sensitivity (insulin resistance index) was assessed with homeostasis model assessment. Terminal deoxynucleotidyl transferase dUTP nick end labeling method was used to mark the apoptotic cels in rat thymus. ELISA was used to detect serum interleukin-6 expression. ABC-ELISA was used to test Level of serum granulocyte macrophage colony stimulating factor. S-P One Step Method was used to test CD4 and CD8 activities in blood. RESULTS AND CONCLUSION:Interleukin-6 and granulocyte macrophage colony stimulating factor were significantly positively associated with insulin resistance index. The increase in insulin resistance index would induce the increase in the levels of serum inflammatory cytokine interleukin 6 and granulocyte macrophage colony stimulating factor, but exercises could decrease above levels. Thymus index, CD4, and CD4/CD8 were negatively associated with insulin resistance index. These results indicate that exercise intervention effectively improved immunity function of rats with insulin resistance and reduced insulin resistance index.