Effect of rosiglitazone on insulin sensitivity and uncoupling protein gene mRNA expression in high fat rat model of insulin resistance

Aim:To explore the effect of rosiglitazone, a ligand of peroxisome proliferator activated receptors γ (PPARγ) , on improving insulin sensitivity and uncoupling proteins (UCPs) gene mRNA expression in high fat rat model of insulin resistance.Methods:The rats were allocated into three groups,eight rats in each group. One group was given standard food and the other 2 groups were given high fat diet for making insulin resistance model. One of the groups given high fat diet were treated once by gavage with rosiglitazone(8 mg·kg -1 ·d -1 ) for 14 days after four week high fat diet. The change of insulin sensitivity was valued by hyperinsulinemic euglycemic clamp. The change of UCPs mRNA in liver and muscle was measured using RT PCR. Results:Compared with high fat group, the level of FFA in rosiglitazone group was lower( P 0.05), and the glucose infusion rate was higher ( P 0.01).UCP 3 mRNA in rosiglitazone group increased by 46.2 % in muscle and UCP 2 mRNA increased by 34.9% in liver and body weight for rats in rosiglitazone group was increased. Conclusion:Rosiglitazone can reduce the level of serum FFA, improve insulin sensitivity,but increase the body weight. The effect of the improved sensitivity may involve in the overexpression of UCPs gene.