Hepatic biotransformation and metabolite profile during a 2-week depuration period in Atlantic salmon fed graded levels of the synthetic antioxidant, ethoxyquin.
Hepatic biotransformation and metabolite profile during a 2-week depuration period in Atlantic salmon fed graded levels of the synthetic antioxidant, ethoxyquin.
复制标题
喂食分级水平的合成抗氧化剂乙氧基喹啉的大西洋鲑鱼在为期两周的净化期内的肝脏生物转化和代谢物谱。
作者：
Victoria J Berdikova Bohne;K. Hamre;A. Arukwe
合成抗氧化剂乙氧喹（EQ）越来越多地用于动物饲料，并已成为致癌性测试的候选者。EQ通过“残留”过程对鱼类和鱼类消费者都有潜在的毒理学和不良健康影响。尚未对EQ的毒理学方面进行系统研究。本研究旨在研究鲑鱼在18 mg（低）、107 mg（中）和1800 mg/kg饲料（高）喂养12周后，在2周净化期间的肝脏代谢、代谢物表征和EQ毒理学方面。采用实时聚合酶链反应与特异性引物对和动力学的两个确定的肝脏代谢产物的肝生物转化酶的基因表达和催化活性的变化进行了研究。使用高效液相色谱（HPLC）方法进行EQ代谢分析，并显示检测到四种化合物，其中两种化合物被定量，即母体EQ和EQ二聚体（EQDM）。两种代谢物被鉴定为脱乙基EQ（DEQ）和醌亚胺，但未进行定量。第0天肝脏中定量EQ相关化合物的浓度与测量的膳食EQ呈线性正相关（母体EQ和EQDM的R2分别为0.86和0.92）。而低情商喂养组显示出时间特异性增加的芳烃受体（AhR）mRNA的表达，中剂量组显示出减少AhR mRNA在净化第7天。细胞色素P450 1A 1的表达在净化期下降。在净化期间，饮食EQ的消耗产生CYP 3A、谷胱甘肽S-转移酶（GST）和尿苷二磷酸葡萄糖醛酸转移酶（UDPGT）mRNA的表达。在CYP 3A和II相基因中观察到类似的效应模式，并支持我们先前的假设，即这些酶受相同诱导剂（即EQ代谢物）的共同调节。CYP 3A、UDPGT和GST基因表达在第7天的增加与低浓度DEQ一致。低浓度的DEQ可能诱导CYP 3A，随后增加EQ向DEQ的生物转化。UDPGT的增加似乎是DEQ排泄所需的同步机制。饲料EQ的生物转化被证明是通过在大西洋鲑鱼肝脏中同时诱导I期和II期解毒系统来实现的。因此，明显的低浓度的推定DEQ可能占诱导阶段I和II解毒酶至少在净化。这个推测的假说是目前在我们的实验室使用体外和基因组方法进行系统研究的主题。
The synthetic antioxidant ethoxyquin (EQ) is increasingly used in animal feeds and has been candidate for carcinogenicity testing. EQ has the potential for toxicological and adverse health effects for both fish and fish consumers through "carryover" processes. The toxicological aspects of EQ have not been systematically investigated. The present study was performed to investigate the hepatic metabolism, metabolite characterization, and toxicological aspects of EQ in salmon during a 2-week depuration after a 12-week feeding period with 18 mg (low), 107 mg (medium), and 1800 mg/kg feed (high). The alteration in gene expressions and catalytic activities of hepatic biotransformation enzymes were studied using real-time polymerase chain reaction with specific primer pairs and by kinetics of two identified hepatic metabolites. Analysis of EQ metabolism was performed using high performance liquid chromatography (HPLC) method and showed the detection of four compounds of which two were quantified, parent EQ and EQ dimer (EQDM). Two metabolites were identified as de-ethylated EQ (DEQ) and quinone imine, but these were not quantified. The concentration of the quantified EQ-related compounds in the liver at day 0 showed a positive linear relationship with measured dietary EQ (R2= 0.86 and 0.92 for parent EQ and EQDM, respectively). While the low-EQ-feeding group showed a time-specific increase of aryl hydrocarbon receptor (AhR) mRNA expression, the medium-dose group showed decreased AhR mRNA at depuration day 7. Expression of CYP1A1 was decreased during the depuration period. Consumption of dietary EQ produced the expression of CYP3A, glutathione S-transferase (GST), and uridine diphosphate glucuronosyl-transferase (UDPGT) mRNA during the depuration period. A similar pattern of effect was observed for both CYP3A and phase II genes and supports our previous postulation of common regulation of these enzymes by the same inducer, namely EQ metabolites. The increase of CYP3A, UDPGT, and GST gene expressions at day 7 was in accordance with the low concentration of DEQ. The low concentration of putative DEQ may induce the CYP3A with subsequent increase in the biotransformation of EQ into DEQ. The increase in UDPGT may seem to be a synchronizing mechanism required for the excretion of DEQ. The biotransformation of dietary EQ is proven by simultaneous induction of both phase I and II detoxification system in the liver of Atlantic salmon. Therefore, the apparent low concentration of putative DEQ may account for the induced phase I and II detoxifying enzymes at least during depuration. This speculated hypothesis is currently a subject for systematic investigation in our laboratory using in vitro and genomic approaches.
DOI：
10.1073/pnas.85.21.8261
发表时间：
1988-11-01
影响因子：
11.1
作者：
TALALAY, P;DELONG, MJ;PROCHASKA, HJ
通讯作者：
PROCHASKA, HJ
影响因子：
3.8
作者：
BUETLER, TM;GALLAGHER, EP;EATON, DL
通讯作者：
EATON, DL