Abstract: AIM: To observe the effect of pioglitazone on oxidative stress and insulin resistance in rats with high-fat diet.METHODS: Four-week male SD rats were chosen and divided into four groups: Control group, High-fat diet group, Pioglitazone group, Pioglitazon and high fat diet group. After 12 weeks feeding, the plasma glucose and insulin levels were detected, the insulin sensitivity index was counted. The liver intracellular glycogen content was measured using a glycogen assay kit. ROS generation in liver tissues was assessed by DHE fluorescence.RESULTS: The insulin sensitivity index of control group was -3.47±0.39 after feeding with high-fat diet for 12 weeks, the blood glucose content was increased,the insulin sensitivity index was decreased to -6.29±0.54, and pioglitazone increased the insulin sensitivity index to -4.54±0.33. The hepatic glycogen content in rats fed with high-fat diet was significantly decreased to (13.6±2.7) mg/g, confirming insulin resistance. But pioglitazone promoted hepatic glycogen content [(19.6±2.9) mg/g]. The DHE dyeing in hepatic tissue slices showed the ROS level was increased in rats with a high-fat diet. However, pioglitazone could decrease the ROS level of liver.CONCLUSION: Pioglitazone improves the hepatic insulin resistance condition by degrading oxidative stress level.

Key words: Insulin resistance, Insulin sensitivity index, Oxidative stress