Abstract：
Dynamic impacts of short-term enrofloxacin (ENR) exposure on juvenile marine fish are not well understood, and the underlying mechanisms remain unclear. We therefore investigated the accumulation and elimination of ENR in the liver of juvenile black seabream Acanthopagrus schlegelii. Meanwhile, the dynamic alterations of biochemical parameters and liver transcriptomes after short-term bath immersion and withdrawal treatment were explored. The results indicated that the contents of ENR in the liver were significantly increased after bath administration for 24 h, and then quickly declined to very low concentrations along with the decontamination time increasing. Judging from the changes in biochemical indicators and liver transcriptomic alterations, 0.5 and 1 mg/L ENR exposure for 24 h triggered oxidative stress, impairment of immune system, as well as aberrant lipid metabolism via differential molecular pathways. Interestingly, biochemical and transcriptome analysis as well as integrated biomarker response (IBR) values showed that more significant changes appeared in 1 mg/L ENR group at decontamination periods, which indicated that the impact of high dose ENR on juvenile A. schlegelii may persist even after depuration for 7 days. These results revealed that the risk of short-term bath of 1 mg/L ENR should not be overlooked even after depuration period. Therefore, attention should be paid to the dosage control when administering the drug to juvenile A. schlegelii, and the restoration of physiological disturbance may be an important factor in formulating a reasonable treatment plan.
摘要：
短期恩诺沙星（ENR）暴露对幼年海鱼的动态影响尚不清楚。和潜在的机制仍然不清楚。因此，我们研究了幼年黑草刺五加鱼肝脏中ENR的积累和消除。同时,研究了短期浸泡和停药治疗后生化指标和肝转录组的动态变化。结果表明，浸浴24h后，肝脏中ENR的含量显着增加，然后随着去污时间的增加迅速下降到非常低的浓度。从生化指标的变化和肝脏转录组的改变来看,0.5和1毫克/升ENR暴露24小时引发的氧化应激，免疫系统受损，以及通过差异分子途径的异常脂质代谢。有趣的是,生化和转录组分析以及综合生物标志物反应（IBR）值显示，在净化期，1mg/LENR组出现更显著的变化，这表明高剂量ENR对幼年A.schlegelii的影响即使在净化7天后仍可能持续。这些结果表明，即使在净化期后，短期使用1mg/LENR的风险也不容忽视。因此,在给青少年A.schlegelii服用药物时应注意剂量控制，生理障碍的恢复可能是制定合理治疗方案的重要因素。
