Identification of 15-hydroxy-11,12-epoxyeicosatrienoicacid as a vasoactive 15-lipoxygenase metabolite in rabbit aorta
Identification of 15-hydroxy-11,12-epoxyeicosatrienoicacid as a vasoactive 15-lipoxygenase metabolite in rabbit aorta
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DOI：
10.1152/ajpheart.01326.2007
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发表时间：
2008-03-01
影响因子：
4.8
通讯作者：
Campbell, William B.
中科院分区：
文献类型：
--
作者：
Chawengsub, Yuttana;Aggarwal, Nitin T.;Campbell, William B.
花生四烯酸（AA）引起内皮依赖性平滑肌超极化和舒张，其由15-脂氧合酶- I（15-LO-I）代谢物11，12，15-三羟基二十碳三烯酸（11，12，15-THETA）介导。我们认为AA依次被15-LO-I和氢过氧化物异构酶代谢为未鉴定的羟基环氧二十碳三烯酸（HEETA），其被可溶性环氧化物水解酶（sEH）水解为11，12，15-THETA。用14 C标记的AA孵育主动脉后，提取代谢物，并通过HPLC分离HEETA。质谱分析鉴定了15-羟基11，12-环氧二十碳三烯酸（15-H-11，12-EETA）。用甲醇和乙酸孵育主动脉孵育物，捕获酸敏感性15-H-11，12-EETA作为甲氧基二羟基二十碳三烯酸（MDHE）（367 m/z，M-H）。用sEH抑制剂12-（3-金刚烷-1-基-脲基）-十二烷酸（AUDA; 10（-6）M）预处理主动脉组织增加了15-H-11，12-EETA的形成，以MDHE测量。因此，15-H-11，12-EETA是11，12，15-THETA的酸敏感性和sEH敏感性前体。主动脉匀浆和内皮细胞含有对应于兔sEH的57-kDa蛋白。在预收缩的主动脉环中，AA（10（-7）-10（-4）M）和乙酰胆碱（10（-9）-10（-6）M）引起浓度相关的舒张作用，AUDA预处理增强了这种作用。通过将细胞外[K+]从4.8增加到20 mM，可抑制这些增强的舒张作用。在具有完整内皮的主动脉条中，AA（3 × 10（-6）M）诱导细胞膜超极化（从-31.0 +/- 1到-46.8 +/- 2 mV），AUDA可增强该超极化。这些结果表明，15-H-11，12-EETA由主动脉产生，由sEH水解为11，12，15-THETA，并通过膜超极化介导舒张。15-H-11，12-EETA代表内皮源性超极化因子。
Arachidonic acid ( AA) causes endothelium-dependent smooth muscle hyperpolarizations and relaxations that are mediated by a 15-lipoxygenase- I (15-LO-I) metabolite, 11,12,15-trihydroxyeicosatrienoic acid (11,12,15-THETA). We propose that AA is metabolized sequentially by 15-LO-I and hydroperoxide isomerase to an unidentified hydroxyepoxyeicosatrienoic acid ( HEETA), which is hydrolyzed by a soluble epoxide hydrolase (sEH) to 11,12,15-THETA. After incubation of aorta with 14C-labeled AA, metabolites were extracted and the HEETAs were resolved by performing HPLC. Mass spectrometric analyses identified 15-Hydroxy11,12-epoxyeicosatrienoic acid (15-H-11,12-EETA). Incubation of aortic incubates with methanol and acetic acid trapped the acidsensitive 15-H-11,12-EETA as methoxydihydroxyeicosatrienoic acids (MDHEs) (367m/z,M- H). Pretreatment of the aortic tissue with the sEH inhibitor 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA; 10(-6) M) increased the formation of 15-H-11,12-EETA, measured as MDHEs. Thus 15-H-11,12-EETA is an acid-and sEH-sensitive precursor of 11,12,15-THETA. Aortic homogenates and endothelial cells contain a 57-kDa protein corresponding to the rabbit sEH. In preconstricted aortic rings, AA (10(-7)-10(-4) M) and acetylcholine (10(-9) 10(-6) M) caused concentration-related relaxations that were enhanced by pretreatment with AUDA. These enhanced relaxations were inhibited by increasing extracellular [K+] from 4.8 to 20 mM. AA (3 x 10(-6) M) induced cell membrane hyperpolarization ( from -31.0 +/- 1 to - 46.8 +/- 2 mV) in aortic strips with an intact endothelium, which was enhanced by AUDA. These results indicate that 15-H-11,12-EETA is produced by the aorta, hydrolyzed by sEH to 11,12,15-THETA, and mediates relaxations by membrane hyperpolarization. 15-H-11,12-EETA represents an endothelium-derived hyperpolarizing factor.