Effects Of Exercise On Leptin And Downstream Factors In Hypothalamus Of Rats With High Fat Diet

Objective:By observing exercise effects on hypothalamus Leptin, neuorpeptideY (NPY), Agouti-related protein (AGRP), melanocortin-4receptor (MC4R) and thyrotropin-releasing hormone (TRH) mRNA expression, and melanin-concentrating hormone (MCH) secretion of high-fat diet rats, we want to explore the mechanism of appropriate exercise increase energy metabolism and prevent obesity.Method:Six-week-old male SD rats were randomly divided into:normal diet control group (C), normal diet control90-min exercise group (CE), high-fat diet control group (H), high-fat diet90-min exercise group (HE). Each group has eight. Exercise group undertake non-weight-bearing swimming exercise for8weeks. By the end of experiments, the triglyceride (TG), Cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterin (LDL-C) and free fatty acid (FFA) in serum were detected. The level of leptin in hypothalamus was detected by enzyme-linked immunosorbent assay (ELISA), and the mRNA expression of NPY, AGRP, MC4R and TRH were measured by real time polymerase chain reaction (RT-PCR). The expression of MCH was detected by ELISA.Result:1. The fat body weight retio, TG, TC, LDL-C and FFA were increased, and HDL-C was decreased significantly of high fat-diet group than those of control (P<0.01). Eight weeks of exercise (HE) could make these values decreased significantly compared with H group.2. The leptin secretion of hypothalamic MCH level, AGRP, and NPY mRNA expression of high fat-deit group were decreased significantly than those of control, while MC4R and TRH mRNA expression levels were lower than C group.3. Compared with H group, Leptin secretion increased significantly in HE group. The MCH level, AGRP, NPY mRNA expression of HE were remarkably lower than those of H group, while MC4R and TRH mRNA level were increased significantly compared with H group. The leptin secretion of hypothalamic was increased significantly by exercise, and the NPY mRNA expression of CE group was decreased significantly compared with control.Conclusions:1.High fat diet can significantly increase the fat body weight retio and the levels of TG、TC、LDL-C andFFA in blood serum of rats。2. High fat diet can reduce the level of leptin in hypothalamus of rats, elevate the content of expression of AGRP、NPY and the level of MCH, reduce the content expression of MC4R、TRH in rats.3. Exercise can elevate the level of leptin in hypothalamus of high-fat-diet rats, reduce the content of expression of AGRP、NPY and the level of MCH, elevate the content expression of MC4R、TRH in rats. And then educe the feeding and promote the energy consumption.4. Exercise can elevate the level of leptin in hypothalamus of Normal diet of rats, reduce the content of expression of NPY.