Exercise and the expression of TNF-α in the adipose tissue of rats with insulin resistance / 中华物理医学与康复杂志

ABSTRACT

Objective To observe the effect of exercise on the expression of TNF-α in the adipose tissue of insulin resistant rats fed a high fat diet. Methods Thirty healthy male rats were randomly divided into a high fat di- et group and a normal chow group. Eighteen weeks later, the high fat group was randomly divided into a resting group fed with the high fat diet only, and an exercise group fed the high fat diet, but receiving swimming training for 6 weeks. Changes in their metabolism of glucose and lipids were observed, and the insulin sensitivity index was calcu-lated. Meanwhile, the level of TNF-α mRNA in their adipose tissue was detected with a real-time fluorescence quan-titative polymerase chain reaction (PCR), and protein in the adipose tissue was measured using Western blotting. Results After 18 weeks of high fat diet feeding, the insulin sensitivity index of the high fat diet group decreased sig-nificantly as compared to the normal chow group, suggesting that insulin resistance had been acquired in the high fat diet group. 24 weeks later, the insulin sensitivity index of the resting group had decreased further, again significantly when compared to the normal chow group. Compared to the resting group, the insulin sensitivity index of exercise group was significantly higher, and the expression of TNF-α mRNA and protein in their adipose tissue was significant- ly increased. Conclusion Insulin resistance can be induced by high fat diet feeding. Exercise can improve insulin resistance by increasing the expression of TNF-α in adipose tissue.