OBJECTIVETo observe the effect of calorie restriction on the high fat diet rats mRNA expressions of liver forkhead box O1(FoxO1), phosphoenolpyruvate carboxykinase (PEPCK), glucose-6-phosphatase (G-6-P) and to explore the possible mechanisms.

METHODS24 normal 6-week-old male Wistar rats were randomly divided into three groups: normal chow group (NC, n = 7), high fat diet group (HF, n = 9) and calorie restriction group (CR, n = 8). They were fed for 12 weeks. At the end of the experiment, the rats were sacrificed and their fasting blood glucose (FBG), insulin (INS), triglycerides (TG), total cholesterol (TC) were measured. Their visceral fat (VF) and body weight (BW) were also measured and VF/BW was calculated. Gene expression was investigated by using semi-quantitative RT-PCR methods. Liver histology was studied with HE stained slides.

RESULTSCompared with the NC group, HF group rats developed visceral obesity which was accompanied by higher FBG, plasma INS, TG, and TC. The levels of FoxO1, PEPCK, and G-6-P increased by 18.9%, 33.8%, and 24.6%, respectively (P less than 0.01). Liver steatosis was observed with microscopy. The BW, VF FBG, INS, TG and TC of the CR group rats were lower in comparison to those of the HF group. The levels of FoxO1, PEPCK and G-6-P were lower by 26.6%, 35.0%, 34.3% (P less than 0.01). Meanwhile, liver steatosis was also milder.

CONCLUSIONCalorie restriction can inhibit the expressions of FoxO1, PEPCK and G-6-P, strengthen insulin signal conduction, suppress gluconeogenesis and thus regulate glycometabolism.