Abstract: To investigate the effects of chemerin on aerobic exercise-induced improvements of blood lipid and aortic sclerosis in atherosclerosis (AS) rats.Methods:Thirty male SD rats were randomly divided into AS model group (n=20) and control group (Con, n=10), the former rats were fed with 8-week high fat diet after an intra-peritoneal injection of vitamin D3 (600 thousand IU/kg body weight) to establish AS model rats while the latter fed with normal diet after an injection of the same amount of normal saline.The AS model rats were further randomly divided into 2 groups:AS group and exercise AS (EAS) group, 8 rats in each group.The EAS rats participated in moderate intensity aerobic exercise on a treadmill with an increasing load for 4 weeks, 6 days per week.The severity of AS were evaluated according to the plaques appeared in gross aortas stained with oil red O as well as the pathological changes of aortic paraffin section stained with HE.Blood lipid (serum levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), and high density lipoprotein (HDL)) were detected using full automatic biochemical analyzer.Fasting glucose were determined by Roche glucometer.Serum levels of chemerin were measured by ELISA.The mRNA and protein expression of chemerin in livers were detected by real time PCR and Western blot, respectively.Results:1) Successful establishment of AS model rats:compared with control, significant increases of serum levels of TC, TG and LDL as well as decrease of serum HDL were showed in the AS rats; and the atherosclerotic plaque appeared in the gross aortas and the proliferation and arrangement disorders of smooth muscle cells in aorta membrane were found in the AS rats.2) Compared with AS group, significant improvements of blood lipid (lower of TC, TG and LDL), as well as decreases of relative weight of perirenal adipose and AS severity (alleviations of gross and pathological disorders of aortas) were found in EAS rats.3) The serum chemerin as well as the mRNA and protein levels of chemerin in livers were significant higher in the AS rats than that of Con.4) The levels of chemerin in serum and livers were significant down-regulated in EAS rats compared with AS rats.Conclusions:1) The serum chemerin as well as the mRNA and protein levels of chemerin in livers were increased in AS rats.2) Aerobic exercise induced improvements of blood lipid and severity of AS in aortas, which may be associated with the decreases of chemerin in serum and livers.