The role of thromboxane A2 in regulating porcine basilar arterial tone
The role of thromboxane A2 in regulating porcine basilar arterial tone
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DOI：
10.1046/j.1365-2885.1998.00135.x
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发表时间：
1998-06-01
影响因子：
1.3
通讯作者：
Nishio, A
中科院分区：
文献类型：
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作者：
Miyamoto, A;Nakamoto, T;Nishio, A
本研究的目的是阐明内源性花生四烯酸（AA）代谢产物参与调节猪离体基底动脉，冠状动脉，肺动脉和肠系膜动脉张力。环氧化酶抑制剂吲哚美辛可松弛基底动脉，但未检查其他动脉。奎纳克林（一种磷脂酶A2抑制剂）、OKY-046（一种血栓烷（TX）AZ合成酶抑制剂）和ONO-3708（一种TXA2/前列腺素H-2受体拮抗剂）可使内皮完整的基底动脉舒张。去甲二氢愈创木酸（一种脂氧合酶抑制剂）对音调没有影响。猪基底动脉自发释放TXB_2（TXA_2的稳定代谢产物）的量是其它动脉的6-10倍。吲哚美辛和OKY-046主要抑制TXB_2的产生。内皮剥脱减少吲哚美辛诱导的舒张和TXB2的量。这些结果表明，血管收缩物质（S）释放的内皮细胞和可能的平滑肌细胞在猪基底动脉在体外。主要的收缩物质是血栓素A（2）。另一方面，来自外周血管床的几条动脉不释放这种血管收缩物质。
The aim of the present study was to clarify the participation of endogenous arachidonic acid (AA) metabolites in regulating porcine basilar, coronary, pulmonary and mesenteric arterial tones in vitro. A cyclooxygenase inhibitor, indomethacin, relaxed basilar artery but not other arteries examined. Quinacrine (a phospholipase A(2) inhibitor), OKY-046 (a thromboxane (TX) AZ synthetase inhibitor) and ONO-3708 (a TXA(2)/prostaglandin H-2 receptor antagonist) produced relaxation in basilar arteries with intact endothelium. Nordihydroguaiaretic acid (a lipoxygenase inhibitor) had no effect on the tone. The amount of TXB2 (a stable metabolite of TXA(2)) spontaneously released from porcine basilar arteries was 6-10 fold more than those from other arteries. Indomethacin and OKY-046 mostly inhibited the production of TXB2. Endothelial denudation decreased indomethacin-induced relaxation and the amount of TXB2. These results suggest that a vasoconstricting substance(s) is released from endothelial cells and possibly smooth muscle cells in porcine basilar arteries in vitro. The main constricting substance is proposed to be TXA(2). On the other hand, several arteries from peripheral vascular beds did not release this vasoconstricting substance.