代谢
有机磷酸盐阻燃剂,三苯基磷酸盐(TPHP),在环境样品中的检测频率越来越高,其主要代谢物被认为是二苯基磷酸(DPHP)。关于这些化合物对鸟类物种的有害影响的信息有限。在这里,我们通过使用鸡胚胎肝细胞(CEH)筛选分析,研究了TPHP和DPHP对细胞毒性和mRNA表达的影响,以及TPHP的体外代谢。在暴露36小时后,观察到>10 uM TPHP暴露下的CEH细胞毒性(LC50 = 47 +/- 8 uM),而在DPHP浓度高达1000 uM时,没有观察到显著的细胞毒性效应。使用定制的鸡ToxChip聚合酶链反应(PCR)阵列,10 uM DPHP改变的基因数量(27个中的9个)大于10 uM TPHP改变的基因数量(27个中的4个)。重要的是,与脂质/胆固醇代谢相关的6个基因中有4个被DPHP显著地调节,这表明这是DPHP毒性的一个可能的重要途径。在暴露于10 uM的CEH中观察到TPHP的快速降解,但由此产生的DPHP浓度仅占初始TPHP剂量浓度的17%。在TPHP暴露的CEH中鉴定出了单羟基化-TPHP(OH-TPHP)和两个(OH)2-TPHP异构体,这些代谢物的浓度在0到36小时内增加。总的来说,这是首次报告表明,在27个与毒理学相关的基因中,DPHP比其前体改变了更多的转录物,并且TPHP在CEH中也通过羟基化途径被代谢。
The organophosphate flame retardant, triphenyl phosphate (TPHP), has been detected with increasing frequency in environmental samples and its primary metabolite is considered to be diphenyl phosphate (DPHP). Information on the adverse effects of these compounds in avian species is limited. Here, we investigate the effects of TPHP and DPHP on cytotoxicity and mRNA expression, as well as in vitro metabolism of TPHP, by use of a chicken embryonic hepatocyte (CEH) screening assay. After 36 hr of exposure, CEH cytotoxicity was observed following exposure to >10 uM TPHP (LC50 = 47 +/- 8 uM), whereas no significant cytotoxic effects were observed for DPHP concentrations up to 1000 uM. Using a custom chicken ToxChip polymerase chain reaction (PCR) array, the number of genes altered by 10 uM DPHP (9 out of 27) was greater than that by 10 uM TPHP (4 out of 27). Importantly, 4 of 6 genes associated with lipid/cholesterol metabolism were significantly dysregulated by DPHP, suggesting a potential pathway of importance for DPHP toxicity. Rapid degradation of TPHP was observed in CEH exposed to 10 uM, but the resulting concentration of DPHP accounted for only 17% of the initial TPHP dosing concentration. Monohydroxylated-TPHP (OH-TPHP) and two (OH)2-TPHP isomers were identified in TPHP-exposed CEH, and concentrations of these metabolites increased over 0 to 36 hr. Overall, this is the first reported evidence that across 27 toxicologically relevant genes, DPHP altered more transcripts than its precursor, and that TPHP is also metabolized via a hydroxylation pathway in CEH.
来源:Hazardous Substances Data Bank (HSDB)