[Influence of smoke tar on mRNA expression of aromatic hydrocarbon receptor and cytochrome P4501A1 gene of mice lungs].

Objective: To investigate the influence of the smoke tar on the expression of aromatic hydrocarbon receptor (AHR) and the cytochrome P4501Al (CYP1A1) gene of mice lungs.

Methods: The smoke tar of 5.29, 10.58 and 15.87 mg/kg was administered intraperitoneally in mice respectively. RNA of mice lungs was got with RNA kit. RT-PCR technique was used for determining AHR and CYP1A1 gene expression with beta-actin as control.

Results: The AHR gene expression level was (0.554 +/- 0.023) for the mice intraperitoneally administered with 5.29 mg/kg smoke tar for 72 hours with the significant difference in gene expression level compared with the Tween-80 group (0.484 +/- 0.045) (P < 0.05). The AHR gene expression levels were (0.555 +/- 0.014), (0.606 +/- 0.051), and (0.566 +/- 0.014), (0.684 +/- 0.069) for the mice intraperitoneally administered with 10.58 and 15.87 mg/kg smoke tar for 48 hours and 72 hours respectively with the significant difference in gene expression level compared with the Tween-80 group (0.486 +/- 0.060, 0.484 +/- 0.045) (P < 0.05, P < 0.01). The CYP1Al gene expression levels were (1.535 +/- 0.021), (1.643 +/- 0.046) and (1.624 +/- 0.056), (1.739 +/- 0.038) respectively with the significant difference compared with the Tween-80 group (l.436 +/- 0.016, 1.404 +/- 0.036) (P < 0.01).

Conclusion: The smoke tar can regulate up the expression of AHR and CYP1A1 gene at a certain dosage and time. The regulation of the smoke tar for the expression of AHR was earlier than for that of CYP1A1.