Abstract: Objective To observe the expression of carnitine palmitoyltransferase Ⅰ (CPTⅠ) and peroxisome proliferators activated receptorγ(PPARγ) in high-fat-fed aged rats and rosiglitazone intervention. Methods Wistar rats were divided into control group, high-fat diet (HF) group and high-fat diet plus rosiglitazone maleate tablets (RSG) group, (n=20 in each group). Insulin sensitivity was evaluated by conscious hyperinsulinemic-euglycemic clamp techniques, the expression of CPTⅠmRNA and PPARγmRNA and protein were analyzed by RT-PCR and Western-blot. Results Skeletal muscle triglyceride was significantly higher and glucose infusion rate was significantly lower in the control group than those in the high-fat diets group. The expression of CPTⅠ and PPARγ decreased in HF group, RSG group reserves above of all the changes. Conclusion It is suggested that a increased expression of CPTⅠand PPARγ play a pivotal role in insulin-sensitizing effect of rosiglitazone treatment, maybe the one of the mechanism of improving insulin resistance.

Key words: Aging, Insulin resistance, Carnitine palmitoyltransferase（CPTⅠ）, PPAR gamma, Rosiglitazone