Objective    To investigate the effect of the farnesoid X receptor (FXR) on fatty acid synthetase expression.       Methods    Human hepatoblastoma HepG2 cells were treated with a FXR’s agonist

chenodeoxycholic acid (CDCA) at 75 μmol/L for 6

12

24 and 48 h respectively

or at 25

50 and 75 μmol/L for 48 h. Expressions of FAS mRNA and protein were determined by RT-PCR and Western blot analysis respectively.     Results    RT-PCR and Western blot analysis indicated that the mRNA and protein were expressed in a time- and dose-dependent manner in the HepG2 cells treatmented by CDCA.       Conclusion    FXR agonist decreases the expression of fatty acid synthetase.