【摘要】 通过饲料暴露的方式研究了抗生素诺氟沙星(Norfloxacin,NFLX)对阿部鲻鰕鯱(Mugilogobius abei)Ⅰ相、Ⅱ相代谢酶活性以及CYP1A1和P-糖蛋白(P-gp)mRNA表达的影响.结果表明随着暴露时间的延长,NFLX对阿部鲻鰕鯱肝脏Ⅰ相代谢酶APND、ERND均表现出先诱导后抑制的作用.24h时NFLX的暴露浓度为20μg·g-1对Ⅰ代谢酶APND和ERND的诱导达到最大值.当暴露时间达到168h,APND和ERND均受到显著抑制.Ⅱ相代谢酶GST和MDA在72h受到最大诱导,经过168h暴露后,GST活性逐渐恢复到正常水平,而MDA含量在50μg·g-1浓度组仍然维持较高水平.CYP1A1和P-gpmRNA表达量随着暴露时间的延长而增加,168h达到最大.APND、ERND、GST、MDA、CYP1A1mRNA和P-gpmRNA响应敏感,适合作为NFLX暴露的生物标记物.更多还原

【Abstract】 The toxic effects of norfloxacin on the phaseⅠand phase Ⅱ enzyme activities,and mRNA expressions of CYP1A1 and P-gp in liver tissue of Mugilogobius abei were investigated by feeding the fish antibiotic-laced food.The enzymes APND and ERND were induced at the initial stages and gradually inhibited with the extension of exposure time.After 24 h exposure,the highest levels of APND and ERND were detected at a dose of 20μg·g-1.The induction of APND and ERND activity by norfloxacin decreased gradually until the activities were significantly inhibited after 168 h exposure.Induction GST and MDA by norfloxacin was observed in all treatment groups compared to the control group,and the highest value for GST and MDA occurred at 72 h.After 168 h exposure,GST returned to the normal level,but MDA still remained at a high level in the 50μg·g-1 treatment group.The mRNA expressions of CYP1A1 and P-gp were induced in all treatment groups.Furthermore,the induction increased with exposure time and reached the highest value at 168 h.APND,ERND,GST,MDA and CYP1A1 mRNA expression,as well as P-gp mRNA expression in Mugilogobius abei are sensitive parameters to use as biomarkers for evaluating the exposure to norfloxacin.更多还原