Arachidonic acid metabolism in the marine fish Stenotomus chrysops (Scup) and the effects of cytochrome P450 1A inducers.
Arachidonic acid metabolism in the marine fish Stenotomus chrysops (Scup) and the effects of cytochrome P450 1A inducers.
复制标题
海鱼 Stenotomus chrysops (Scup) 中的花生四烯酸代谢和细胞色素 P450 1A 诱导剂的影响。
DOI：
10.1006/abbi.1998.0651
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发表时间：
1998
影响因子：
3.9
通讯作者：
Stegeman,JJ
中科院分区：
文献类型：
--
作者：
Schlezinger,JJ;Parker,C;Zeldin,DC;Stegeman,JJ
研究了海鱼、Stenotomus chrysops 中细胞色素 P450 介导的花生四烯酸 (AA) 代谢。与 AA 和 NADPH 一起孵育的肝微粒体产生环氧二十碳三烯酸 (EET) 及其水合产物（二羟基二十碳三烯酸，DHET），中链缀合 二烯醇（中链 HETE）和 AA 的 C16 至 C20 醇（ω 末端 HETE），均通过 HPLC 和 GC/MS 进行鉴定。怀孕女性的 AA 代谢率比男性低 4 倍，但代谢特征相同。 5,6-EET（从稳定代谢物推断）最丰富（占总 EET 的 47%），其次是 14,15-、11,12-和 8,9-EET（分别为 27%、13% 和 13%）。 12-HETE 占 HETE 总量的 25%，其次是 16-、15-、11-、19-、20-、8- 和 9-HETE。 scup CYP1A 和 scup CYP2B 样蛋白的抗体分别抑制肝微粒体 AA 代谢 30% 和 46%。 GC/MS 分析显示 EET 和 DHET 是攫取肝脏中的内源性成分；主要的EET是8,9-和14,15-EET，其次是少量的11,12-EET。手性分析显示优先选择内源 8,9-、11,12- 和 14,15-EET 的 S,R 对映体（光学纯度分别为 80%、64% 和 64%）。用 CYP1A 诱导剂苯并(a)芘 (BP) 处理 scup 可使肝微粒体 EET 和 HETE 的形成在春季增加 2.7 倍，在夏季增加 1.7 倍。 BP 处理不影响微粒体 EET 区域选择性，但使羟基化有利于 19-HETE 并诱导 17-HETE 形成。夏季 2,3,7,8-四氯二苯并-对二恶英 (TCDD) 治疗不会诱导肝微粒体 AA 代谢率，但 BP 和 TCDD 均增加肝脏内源性 EET 含量（分别为 5 倍和 3 倍），并转变为 14,15-EET。 BP 处理提高了内源 8,9-、11,12- 和 14,15-EET 的 S,R 对映体的选择性（光学纯度分别为 91%、84% 和 83%）。肾脏、鳃和心脏微粒体均代谢 AA，代谢率比肝微粒体低 10 至 30 倍。在心脏和肾脏中检测到的内源性 8,9- 和 14,15-EET 含量相似，而 11,12-EET 含量较少，并且心脏中 8(R),9(S)-EET 具有很强的对映选择性（光学纯度 78%），但在肾脏中则不然。 BP 治疗并没有改变这些器官中的总 EET 含量，但确实改变了心脏的区域化学分布，有利于 14,15-EET。因此，肝脏和肝外器官在体外和体内通过多种细胞色素 P450 (CYP) 形式将 AA 代谢为类二十烷酸。BP 或 TCDD 诱导肝脏内源性 AA 代谢，改变 EET 区域选择性，并与 BP 一起改变立体选择性。虽然 AhR 激动剂改变表达 CYP1A 和 AhR 的早期分化脊椎动物中 AA 的代谢，但影响的程度可能取决于诱导剂的类型。
Cytochrome P450-mediated arachidonic acid (AA) metabolism was investigated in the marine fish scup,Stenotomus chrysops.Liver microsomes incubated with AA and NADPH produced epoxyeicosatrienoic acids (EETs) and their hydration products (dihydroxyeicosatrienoic acids, DHETs), midchain conjugated dienols (midchain HETEs), and C16- through C20-alcohols of AA (ω-terminal HETEs), all identified by HPLC and GC/MS. Gravid females had 4-fold lower AA metabolism rates than males but identical metabolite profiles. The 5,6-EET (inferred from stable metabolites) was most abundant (47% of total EETs) followed by 14,15-, 11,12-, and 8,9-EET (27, 13, and 13%, respectively). The 12-HETE represented 25% of total HETEs followed in abundance by 16-, 15-, 11-, 19-, 20-, 8-, and 9-HETE. Antibodies against scup CYP1A and a scup CYP2B-like protein inhibited liver microsomal AA metabolism by 30 and 46%, respectively. GC/MS analysis revealed EETs and DHETs as endogenous constituents in scup liver; the predominant EETs were 8,9- and 14,15-EET, followed by a lesser amount of 11,12-EET. Chiral analysis showed a preference for the S,R-enantiomers of endogenous 8,9-, 11,12-, and 14,15-EET (optical purities 80, 64, and 64%, respectively). Treatment of scup with the CYP1A inducer benzo(a)pyrene (BP) increased liver microsomal formation of EETs and HETEs by 2.7-fold in spring and 1.7-fold in summer. BP treatment did not affect microsomal EET regioselectivity, but shifted hydroxylation in favor of 19-HETE and induced 17-HETE formation. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) treatment in summer did not induce liver microsomal AA metabolism rates, yet BP and TCDD both increased endogenous EET content of liver (5- and 3-fold, respectively), with a shift to 14,15-EET. BP treatment increased the selectivity for the S,R-enantiomers of endogenous 8,9-, 11,12-, and 14,15-EET (optical purities 91, 84, and 83%, respectively). Kidney, gill, and heart microsomes all metabolized AA, at rates 10- to 30-fold less than liver microsomes. Similar amounts of endogenous 8,9- and 14,15-EET and less 11,12-EET were detected in heart and kidney, and there was a strong enantioselectivity for 8(R),9(S)-EET in heart (optical purity 78%) but not in kidney. BP treatment did not alter the total EET content in these organs but did shift the regiochemical profile in heart to favor 14,15-EET. Thus, scup liver and extrahepatic organs metabolize AA via multiple cytochrome P450 (CYP) forms to eicosanoidsin vitroandin vivo.BP or TCDD induced endogenous AA metabolism in liver, altering EET regioselectivity and, with BP, stereoselectivity. While AhR agonists alter metabolism of AA in early diverging vertebrates expressing both CYP1A and AhR, the magnitude of effects may depend upon the type of inducer.