Novel metabolic pathways for linoleic and arachidonic acid metabolism
Novel metabolic pathways for linoleic and arachidonic acid metabolism
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DOI：
10.1016/0304-4165(96)00037-2
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发表时间：
1996-08-13
影响因子：
3
通讯作者：
Hammock, BD
中科院分区：
文献类型：
--
作者：
Moghaddam, MF;Motoba, K;Hammock, BD
小鼠肝微粒体氧化亚油酸形成9,10-或12,13-环氧十八烯酸酯。这些单环氧化物随后在没有微粒体环氧化物水解酶抑制剂1,2-环氧-3,3,3-三氯丙烷的情况下水解成相应的二醇。此外，9,10-和12,13-环氧十八烯酸酯均被小鼠肝微粒体P-450环氧化以明显相同的速率氧化为二环氧十八烯酸酯。环氧十八碳烯酸酯和二环氧十八碳酸酯均被微粒体转化为四氢呋喃二醇。亚油酸四氢氧化物作为次要代谢物产生。花生四烯酸被微粒体代谢为环氧二十碳三烯酸酯、二羟基二十碳三烯酸酯和单羟基二十碳四烯酸酯。从氯贝特（但不是苯巴比妥）处理的小鼠制备的微粒体表现出更高的环氧二十碳三烯酸酯和vic-二羟基二十碳三烯酸酯的生产率。这表明安妥明而非苯巴比妥可诱导小鼠体内的 P-450 环氧化酶和微粒体环氧化物水解酶。合成环氧二十碳三烯酸酯与微粒体的孵育导致二环氧二十碳二烯酸酯的产生。在化学生成的二环氧二十碳二烯酸酯异构体中，其中三种具有相邻双环氧化物的异构体被水解为其二醇环氧化物，后者通过微粒体以及可溶性环氧化物水解酶以更高的速率环化为相应的四氢呋喃二醇。没有观察到来自非相邻双环氧化合物的较大环状产物。我们的体外实验结果表明，亚油酸和花生四烯酸可以通过两个连续的微粒体细胞色素 P-450 环氧化，然后微粒体或可溶性环氧化物水解酶催化环氧化物的水解，代谢为其四氢呋喃二醇。 S-9 级分的孵育实验表明可溶性环氧化物水解酶在此转化中更为重要。本手稿是关于分离和鉴定一类有趣的氧脂质的区域异构体和几何异构体及其通过肝微粒体和 S-9 级分代谢为 THF-二醇的技术的第一份报告。
Mouse liver microsomes oxidized linoleic acid to form 9,10- or 12,13-epoxyoctadecenoate. These monoepoxides were subsequently hydrolyzed to their corresponding diols in the absence of the microsomal epoxide hydrolase inhibitor, 1,2-epoxy-3,3,3-trichloropropane. Furthermore, both 9,10- and 12,13-epoxyoctadecenoates were oxidized to diepoxyoctadecanoate at apparently identical rates by mouse liver microsomal P-450 epoxidation. Both epoxyoctadecenoates and diepoxyoctadecanoates were converted to tetrahydrofuran-diols by microsomes. Tetrahydroxides of linoleate were produced as minor metabolites. Arachidonic acid was metabolized to epoxyeicosatrienoates, dihydroxyeicosatrienoates, and monohydroxyeicosatetraenoates by the microsomes. Microsomes prepared from clofibrate (but not phenobarbital)-treated mice exhibited much higher production rates for epoxyeicosatrienoates and vic-dihydroxyeicosatrienoates. This indicated an induction of P-450 epoxygenase(s) and microsomal epoxide hydrolase in mice by clofibrate and not by phenobarbital. Incubation of synthetic epoxyeicosatrienoates with microsomes led to the production of diepoxyeicosadienoates. Among chemically generated diepoxyeicosadienoate isomers, three of them possessing adjacent diepoxides were hydrolyzed to their diol epoxides which cyclized to the corresponding tetrahydrofuran-diols by microsomes as well as soluble epoxide hydrolase at a much higher rate. Larger cyclic products from non-adjacent diepoxides were not observed. The results of our in vitro experiments suggest that linoleic and arachidonic acid can be metabolized to their tetrahydrofuran-diols by two consecutive microsomal cytochrome P-450 epoxidations followed by microsomal or soluble epoxide hydrolase catalyzed hydrolysis of the epoxides. Incubation experiments with the S-9 fractions indicate that the soluble epoxide hydrolase is more important in this conversion. This manuscript is the first report of techniques for the separation and identification of regio and geometrical isomers of an interesting class of oxylipins and their metabolism by liver microsomes and S-9 fractions to THF-diols.