The Effect Of IUGR On The Expression Of CLOCK And BMAL1 In CG-IUGR Rats

Objective: This experiment aims to confirm the relationship between glycolipid metabolism and expression of CLOCK and BMAL1 in hepar and skeletal muscles tissue,and analyze their roles played in the abnormal glycolipid metabolism of intrauterine growth retardation with catch-up(CG-IUGR)rats established by low caloric diet.Methods: Sprague-Dawley rats were divided into control and CG-IUGR groups.The model of CG-IUGR rat were replicated with low calorie diet.1.The body mass and body length of the rats in two groups were measured(from birth to 8 weeks of age)and their body mass index(BMI)were calculated.At 8 weeks of age,the perirenal fat of them were weighed.2.Glycolipid metabolism in two groups of8-week-old rats were detected: the levels of serum triglyceride(TG),total cholesterol(TC)and free fatty acid(FFA);the levels of fasting blood glucose(FBG)and serum insulin(FINS);glucose tolerance test(GTT)and insulin tolerance test(ITT);the level of serum insulin(INS)after glucose load 15 minutes.3.Glycogen synthase activity in both hepar and skeletal muscle were detected by biochemistry method.4.The mRNA and protein expression of CLOCK and BMAL1 in hepar and skeletal muscle tissue were detected by real-time fluorescence quantitative polymerase chain reaction(RTFQ-PCR)and Western Blot,respectively.5.The correlation between the mRNA expression of CLOCK and BMAL1 and the activity of GS were analysed by pearson,s correlation analysis.Results: 1.The body mass and BMI of CG-IUGR rats were markedly increased(P<0.05)in their growth and development period,and the weight of perirenal fat were also increased significantly at 8 weeks after birth(P<0.05).2.The levels of serum TG,TC and FFA in CG-IUGR rats were increased significantly(P<0.05);the levels of FINS were decreased slightly(P<0.05);the glucose levelsafter glucose and INS load in GTT and ITT tests were increased significantly(P<0.05);and the serum INS levels at the 15 minutes after glucose load were increased significantly(P<0.05).3.The activity of GS in hepar and skeletal muscle tissue of CG-IUGR rats were decreased(P<0.05).4.The mRNA and protein expression of CLOCK and BMAL1 in hepar and skeletal muscle tissue were decreased(P<0.05).5.The mRNA expression of CLOCK and BMAL1 in hepar and skeletal muscle tissue of CG-IUGR rats were positively correlation with the activity of GS(P<0.05).Conclusions:1.IUGR leads to a decreased glycolipid metabolism and glycogen synthase activity in both hepar and skeletal muscle tissue of the CG-IUGR rats.2.IUGR can down-regulate relative expression of CLOCK and BMAL1 in both hepar and skeletal muscle tissue of the CG-IUGR rats,which maybe involved in glycolipid metabolic disorder in male CG-IUGR rats.