[The effect of calorie restriction on the expression of liver's gluconeogenesis genes of rats fed a high fat diet].
OBJECTIVE
To 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.


METHODS
24 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.


RESULTS
Compared 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.


CONCLUSIONS
Calorie restriction can inhibit the expressions of FoxO1, PEPCK and G-6-P, strengthen insulin signal conduction, suppress gluconeogenesis and thus regulate glycometabolism.
Luo
Ming-Juan
MJ
Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
Chen
Lu-Lu
LL
Zheng
Juan
J
Zeng
Tian-Shu
TS
Deng
Xiu-Ling
XL
D000818:Animals; D031204:Caloric Restriction; D004041:Dietary Fats; D051858:Forkhead Transcription Factors / Q000235:genetics; D005786:Gene Expression Regulation; D005943:Gluconeogenesis / Q000235:genetics*; D005952:Glucose-6-Phosphatase / Q000235:genetics; D008099:Liver / Q000378:metabolism*; D008297:Male; D009419:Nerve Tissue Proteins / Q000235:genetics; D019764:Phosphoenolpyruvate Carboxykinase (ATP) / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D000071161:Forkhead Box Protein O1
D004041:Dietary Fats; D051858:Forkhead Transcription Factors; D005952:Glucose-6-Phosphatase; D009419:Nerve Tissue Proteins; D019764:Phosphoenolpyruvate Carboxykinase (ATP); C074639:Foxo1 protein, rat; D000071161:Forkhead Box Protein O1