Identification of epoxyeicosatrienoic acids as endothelium-derived hyperpolarizing factors
Identification of epoxyeicosatrienoic acids as endothelium-derived hyperpolarizing factors
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DOI：
10.1161/01.res.78.3.415
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发表时间：
1996-03-01
影响因子：
20.1
通讯作者：
Harder, DR
中科院分区：
文献类型：
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作者：
Campbell, WB;Gebremedhin, D;Harder, DR
内皮细胞释放几种化合物，包括前列环素、一氧化氮和内皮源性超极化因子（EDHF），介导血管活性激素的血管作用。EDHF的身份尚不清楚。由于花生四烯酸通过细胞色素P-450代谢成环氧二碳三烯酸（EETs）导致冠状动脉内皮依赖性松弛，我们想知道EETs是否代表edhf。预收缩的牛冠状动脉对甲胆碱以内皮依赖的方式松弛。细胞色素P-450抑制剂SKF 525A和咪康唑可显著减弱这些弛豫。四乙基铵（TEA）（一种Ca2+活化的K+通道抑制剂）和高[K+]（20 mmol/L）也能抑制它们。甲胆碱也引起冠状动脉平滑肌的超极化（-27 +/- 3.9 vs -40 +/- 5.1 mV）， SKF 525A和咪康唑完全阻断。在预先用[H-3]花生四烯酸标记的血管中，甲胆碱刺激6-酮前列腺素F1（α）、12-HETE和eet的释放。花生四烯酸可以放松预收缩的冠状动脉，而冠状动脉也被TEA、charybdotoxin（另一种Ca2+激活的K+通道抑制剂）和高[K+](o)阻断。14,15- eet, 11,12- eet, 8,9- eet和5,6- eet放松冠状动脉预收缩血管(EC（50), 1 × 10(-6) mol/L）。这四种区域异构体同样活跃。TEA、肉毒杆菌毒素和高[K+](o)能减弱EET的弛豫。11,12- eet超极化冠状平滑肌细胞，从-37 +/- 0.2 mV到-59 +/- 0.3 mV。在膜片钳的细胞附着模式下，14,15- eet和11,12- eet都增加了冠状动脉平滑肌细胞中Ca2+激活的K+通道的开放状态概率。这种作用被茶和肉毒杆菌毒素阻断。这些数据支持了eet是edhf的假设。
Endothelial cells release several compounds, including prostacyclin, NO, and endothelium-derived hyperpolarizing factor (EDHF), that mediate the vascular effects of vasoactive hormones. The identity of EDHF remains unknown. Since arachidonic acid causes endothelium-dependent relaxations of coronary arteries through its metabolism to epoxyeicosatrienoic acids (EETs) by cytochrome P-450 we wondered if the EETs represent EDHFs. Precontracted bovine coronary arteries relaxed in an endothelium-dependent manner to methacholine. The cytochrome P-450 inhibitors, SKF 525A and miconazole, significantly attenuated these relaxations. They were also inhibited by tetraethylammonium (TEA), an inhibitor of Ca2+-activated K+ channels, and by high [K+](o) (20 mmol/L). Methacholine also caused hyperpolarization of coronary smooth muscle (-27 +/- 3.9 versus -40 +/- 5.1 mV), which was completely blocked by SKF 525A and miconazole. In vessels prelabeled with [H-3]arachidonic acid: methacholine stimulated the release of 6-ketoprostaglandin F1(alpha), 12-HETE, and the EETs. Arachidonic acid relaxed precontracted coronary arteries, which were also blocked by TEA, charybdotoxin, another Ca2+-activated K+ channel inhibitor, and high [K+](o). 14,15-EET, 11,12-EET, 8,9-EET, and 5,6-EET relaxed precontracted coronary vessels (EC(50), 1x10(-6) mol/L). The four regioisomers were equally active. TEA, charybdotoxin, and high [K+](o) attenuated the EET relaxations. 11,12-EET hyperpolarized coronary smooth muscle cells from -37 +/- 0.2 to -59 +/- 0.3 mV. In the cell-attached mode of patch clamp, both 14,15-EET and 11,12-EET increased the open-state probability of a Ca2+-activated K+ channel in coronary smooth muscle cells. This effect was blocked by TEA and charybdotoxin. These data support the hypothesis that the EETs are EDHFs.