Abstract: To observe the influence of adiponectin with different doses on apolipoprotein A5 (apoA5)mRNA and protein expression levels and triglyceride(TG) content in HepG2 cells and to investigate the relationship between adiponectin  and TG and to establish  foundation for study on the mechanism of adiponectin in decreasing TG content.Methods HepG2 cells were divided into control group，low dose adiponectin group,middle dose adiponectin group and high dose adiponectin  group.The HepG2 cells in various groups were treated with  different doses of adiponectin （0,12.5,25.0 and 50.0 mg·L^-1）for  24 h,then the TG  contents in HepG2 cells in various groups were detected with   enzyme method.The  expression levels of apoA5 mRNA in  HepG2 cells were  detected with  real time  fluorescence quantitative PCR  method.The  expression levels of apoA5 protein in HeG2 cells were  detected with  Western blotting method. Results Compared with control group,the TG contents in HepG2 cells in different doses of adiponectin  groups were decreased obviously (P<0.05）.Compared with low dose group,the TG  contents in HepG2 cells in middle dose group and high dose group were decreased obviously (P<0.05）,but there was no significant difference between  high dose group and middle dose group(P>0.05).Compared with control group,the gene and 　protein expression levels of apoA5 in HepG2 cells in different doses of adiponectin  groups were increased obviously (P<0.05）.Compared with low dose group,the gene and protein expression levels of apoA5 in HepG2 cells in middle dose group and high dose group were increased obviously (P<0.05）,but there was no significant difference between  high dose group and middle dose group(P>0.05).  Conclusion Adiponectin may decrease the TG content in HepG2 cells in an dose-dependent manner.It indicats that the mechanism of adiponectin in decreasing TG content may be related to   increasing the  expression of apoA5 in HepG2 cells.

Key words: adiponectin, HepG2 cells, apolipoprotein A5, triglyceride