Effects Of Calorie Restriction And Exercise On The Expression Of ZAGmRNA In Adipose Tissue Of Mice

【Objective】The aim of this study is to assess the the effects of different levels of calorie restriction and aerobic exercise on the expression of ZAGmRNA in adipose tissue of mice, trying to explore the relationship between ZAG and lipid metabolism, finding a new target of treatment for obesity and related diseases, providing scientific and theoretical basis to guide weight loss and the public fitness.【Methods】Seventy-two KM male mice were randomly divided into 6 groups: control group(C, n=12), aerobic exercise group(Ex, n=12), 80%calorie restriction group(CR80%, n=12), 80%calorie restriction+aerobic exercise group(CR80%+Ex, n=12), 60%calorie restriction group(CR60%, n=12), 60%calorie restriction+aerobic exercise group(CR60%+Ex, n=12). Diet program: Ex group was paired-fed at the same amount as C group with basic diet and the other 4 groups(CR80%, CR80%+Ex,CR60%,CR60%+Ex group) with 82.5%, 82.5%, 65%, 65% amount of basic diet respectively for 8 weeks. Exercise program: Ex group, CR80%+Ex group and CR60%+Ex group were submitted to treadmill exercise at 10m/min for 60min/d,5d/wk for the first 4 weeks and 12m/min for 60min/d,5d/wk for the next 4 weeks. Body weight was recorded weekly. In the end of experiment, the weight gain, the relative weight of visceral fat and the serum levels of TG, TC, LDL-C, HDL-C were measured. The expression level of ZAGmRNA in adipose tissue of mice was detected by real time quantitative RT-PCR.【Results】1.Calorie restriction:1.1 There was no significant difference in the basic weight among 6 groups(P>0.05). After the experiment, the weight gain, the relative weight of visceral fat and the serum level of TG,TC,DL-C of CR80% group and CR60% group were significantly lower than those of C group, while the serum level of HDL-C and the expression level of ZAGmRNA in adipose tissue of mice in CR80% group were significantly higher than those of C group(P<0.05, P<0.01).1.2 After the experiment, the weight gain, the relative weight of visceral fat and the serum level of TG,TC,LDL-C of CR60% group were significantly lower than those of CR80% group(P<0.01). There was no significant difference in the serum level of HDL-C and the expression level of ZAGmRNA in adipose tissue between CR60% group and CR80% group(P>0.05).2.Aerobic exercise: The weight gain, the relative weight of visceral fat and the serum level of TG, TC, LDL-C of Ex group were significantly lower than those of C group(P<0.01); while the serum level of HDL-C and the expression level of ZAGmRNA in adipose tissue of Ex group were significantly higher than those of C group(P<0.05, P<0.01).3.Calorie restriction+Aerobic exercise:3.1 The weight gain, the relative weight of visceral fat and the serum level of TG of CR80%+Ex group was significantly lower than those of C group, Ex group and CR80% group(P<0.01).The serum level of TC, LDL-C of CR80%+Ex group was significantly lower than that of C group and CR80% group(P<0.05,P<0.01). The serum level of HDL-C was significantly higher than that of C group(P<0.01). The expression level of ZAGmRNA in adipose tissue of CR80%+Ex group were significantly higher than that of C group, Ex group and CR80% group( P<0.05, P<0.01).3.2 The weight gain of CR60%+Ex group was significantly lower than that of C group and Ex group(P<0.01). The relative weight of visceral fat and the serum level of TG, TC, LDL-C of CR60%+Ex group were significantly lower than those of C group, Ex group and CR60% group(P<0.01). The serum level of HDL-C and the expression level of ZAGmRNA in adipose tissue of CR60%+Ex group were significantly higher than those of C group and Ex group (P<0.05,P<0.01).3.3 The relative weight of visceral fat, the serum level of TG,LDL-C,HDL-C and the expression level of ZAGmRNA in adipose tissue of Ex group showed no significant difference with CR80% group(P>0.05); while the weight gain and the serum level of TC of Ex group were significantly higher than those of CR80% group(P<0.05,P<0.01). The weight gain, the relative weight of visceral fat and the serum level of TG, LDL-C of Ex group were significantly higher than those of CR60% group(P<0.01); while the expression level of ZAGmRNA in adipose tissue of Ex group was significantly lower than that of CR60%group(P<0.05).4.Correlation analysis: The expression level of ZAGmRNA in adipose tissue showed significant negative correlations with the weight gain, the relative weight of visceral fat, the serum levels of TG,TC,LDL-C and the calorie intake per day(P<0.01), but no correlation with the serum level of HDL-C(P>0.05).【Conclusion】1. Calorie restriction and aerobic exercise can both upregulate the expression of ZAGmRNA in adipose tissue of mice, reduce the amount of visceral fat, lower blood lipids and decrease the body weight. 80% calorie restriction was more reasonable than 60% calorie restriction.2. Compared with calorie restriction and aerobic exercise, calorie restriction combined with aerobic exercise can more effectively upregulate the expression of ZAGmRNA in adipose tissue of mice,reduce the amount of visceral fat, lower blood lipids and decrease the body weight.80% calorie restriction combined with aerobic exercise was more reasonable.3. 80% calorie restriction has the same effect as moderate-intensity aerobic exercise in upregulating the expression of ZAGmRNA in adipose tissue of mice, reducing the amount of visceral fat and lowering blood lipids. 4. The expression level of ZAGmRNA in adipose tissue showed significant negative correlations with the weight gain, the relative weight of visceral fat and the serum levels of TG,TC,LDL-C, suggesting that ZAG may play a vital role in promoting lipolysis and regulating lipid metabolism.