Induction of aryl hydrocarbon receptor and CYP1A1 mRNA by 2,3,7,8-tetrachlorodibenzo-p-dioxin in rat liver / 中华劳动卫生职业病杂志

ABSTRACT

<p><b>OBJECTIVE</b>To explore the toxic mechanism of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by studying the induction of cytochrome P4501A1 (CYP1A1) and aryl hydrocarbon receptor (AHR) mRNA in liver of TCDD-treated SD rats.</p><p><b>METHODS</b>Thirty female SD rats were randomly divided into control group and 5 exposure groups, every group had 5 rats. The animals were treated i.p. with 0.01, 0.1, 1, 10, 50 microg TCDD/kg BW. AHR and CYP1A1 mRNA expression were analyzed by RT-PCR after 24 h.</p><p><b>RESULTS</b>The contents of AHR and CYP1A1 mRNA were increased in all exposure groups except the 0.01 microg TCDD/kg BW group. AHR mRNA content was significantly increased in 50 microg TCDD/kg BW group (P<0.05); CYP1A1 mRNA contents were significantly increased in all exposure groups (P<0.05) but not 0.01 microg TCDD/kg BW group. There were dose-response relationship between TCDD doses and AHR, CYP1A1 gene expression.</p><p><b>CONCLUSION</b>Both AHR and CYP1A1 gene in liver of TCDD-treated SD rats can be induced 24 h after exposure and CYP1A1 gene is more inducible than AHR gene.</p>