Abstract: ObjectiveTo investigate the effects of 2,2',4,4'-tetrabrominated diphenyl ethers(BDE-47)on triiodothyronice(TT3),total thyroxine(TT4),thyroid-stimulating hormone(TSH),and mRNA levels of cyp2b10,cyp3a11, UOP-gluceronosyltranse-ferase 1 family(UGT1A1)and sulfotransferase(SULT1A1)in the liver of C57BL/6 mice.MethodsC57BL/6 mice were divided randomly into 6 groups and administrated with corn oil(negative control group),50 mg/kg/day pregnenolone(16α-carbonitrile)(positive control group),3 mg/kg/day 1,4 bis(23,5-dichloropyridyloxy)benzene(positive control group),0.5 mg/kg/day(low dose group),5 mg/kg/day(medium dose group),and 50 mg/kg/day(high dose group)BDE-47 for 4 days through intraperitoneal injection,respectively.The serum livels of T3,T4,and TSH were detected with electro-chemiluminescene(ECLI)and the mRNA levels of cyp2b10,cyp3a11,UGT1A1,and SULT1A1 in liver were detected with real-time PCR method.ResultsCompared with the control group,the levels of TT4 decreased significantly in all BDE-47 dose groups.TT3 in the medium and high dose BDF-47 groups decreased significantly(P<0.05).The mRNA levels of cyp3all were up-regulated in the three BDE-47 dose groups.Up-regulation expression of cyp2b10 was observed only in the high dose BDF-47 group.On the other hand,the mRNA levels of UGT1A1 and SULT1A1 were up-regulated in the medium and high BDE-47 dose groups.ConclusionBDE-47 could affect the homeostasis of thyroid hormone system and the molecular mechanisms might be involved in its activation to pregnane X-receptor and constitutive androstane receptor and regulations for the mRNA expression of UGT1A1 and SULT1A1.