【摘要】 为探究不同剂量的有机磷农药辛硫磷在24、48、72和96 h染毒后对鲫(Carassius auratus gibebio)肝微粒体中CYP3A酶活性、mRNA及蛋白表达的影响,采用半静态染毒法,设置辛硫磷空白对照组低、中、高浓度组(0.082 5、0.165、0.330 mg/L),以红霉素-N-脱甲基酶(ERND)活性反映CYP3A酶活性,最后采用实时荧光定量PCR和Western blot法分别测定CYP3A-mRNA及蛋白的表达量。结果显示:辛硫磷能抑制CYP3A的酶活性并且下调CYP3A-mRNA的表达,72 h和96 h后,各浓度组中的mRNA的表达量相较对照组降低了50%以上。辛硫磷染毒后的CYP3A蛋白的表达量在各时间段中都呈现显著的剂量效应关系,在低、中浓度组间存在时间效应关系。结果表明,辛硫磷能作为一种抑制剂降低鲫肝脏中CYP3A酶活性、mRNA及蛋白表达量,其对蛋白表达抑制的剂量效应和时间效应影响更显著。更多还原

【Abstract】 Semi-static exposure experiment was carried out in this study to reveal the effects of phoxim on the activity,mRNA and protein expression of CYP3A in liver microsomes of Carassius auratus gibebio. The exposure experiment was designed in different concentrations of phoxim for 24,48,72 and 96 hours.Control groups with low,medium and high doses of phoxim(0.0825,0.165,and 0.330 mg/L)were set up.The activity of erythromycin N-demethylase(ERND)was used to reflect the activity of CYP3A.Quantitative real-time PCR and Western blot were used to reflect the mRNA and protein expression levels of CYP3A.The results showed that phoxim could inhibit the activity of CYP3A and down-regulate the mRNA expression of CYP3A.After 72 and 96 hours exposure,the expression of mRNA in each group was decreased by more than 50% compared with the control group(P<0.01).The protein expression of CYP3A after phoxim exposure showed a significant dose-dependent manner in all time groups,and there was a same trend between low and medium concentration groups.Consequently,this research suggested that phoxim could be a potent inhibitor to CYP3A to reduce the activity of CYP3A,the expression of CYP3A in the liver of Carassius auratus gibebio and the dose and time effects of phoxim on the inhibition of protein expression were more significant.更多还原