Role of prostaglandins in urotensin II-induced vasodilatation in the coronary arteries of aged rats
Role of prostaglandins in urotensin II-induced vasodilatation in the coronary arteries of aged rats
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DOI：
10.1016/j.ejphar.2005.09.018
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发表时间：
2005-10-31
影响因子：
5
通讯作者：
Katano, Y
中科院分区：
文献类型：
--
作者：
Ishihata, A;Ogaki, T;Katano, Y
内皮功能受衰老调节。本研究的目的是阐明年龄是否影响尾加压素II诱导的冠状动脉血管舒张，以及年龄是否影响响应尾加压素II的内皮因子的产生。我们研究了尾加压素II对Langendorff灌注大鼠心脏冠状动脉血流的影响。测定了青年和老年大鼠冠脉流出液中一氧化氮（NO）、前列环素和前列腺素（PG）E-2的含量。尾加压素11增加冠状动脉血流在Langendorff灌注心脏在年轻和老年大鼠和血管舒张之间没有显着差异。用NO合成酶抑制剂NG-硝基-L-精氨酸（L-NNA）预处理可显著抑制尾加压素II诱导的年轻大鼠血管舒张，但对老年大鼠无明显影响。此外，尾加压素11只在年轻大鼠中增加NO的产生。另一方面，环氧合酶抑制剂双氯芬酸显着衰减尾加压素II诱导的冠状动脉血管舒张在年轻和老年大鼠。尾加压素11显著增加血管舒张性前列环素和PGE（2）释放到冠状动脉流出液中。即使在老年冠状动脉中，这些前列腺素类的产生也得以维持。提示老年大鼠冠状动脉内皮细胞NO的产生受到抑制，前列环素和前列腺素E_2可能在尾加压素Ⅱ引起的冠状动脉舒张中起重要调节作用。(c)2005 Elsevier B. V.保留所有权利。
Endothelial function is modulated by aging. The objective of this study was to elucidate whether aging influences urotensin II-induced coronary vasodilatation, and whether aging influences the production of endothelial factors in response to urotensin II. We examined the effects of urotensin II on coronary flow in Langendorff-perfused rat hearts. The production of nitric oxide (NO), prostacyclin and prostaglandin (PG)E-2 were determined in the coronary effluent of both young and aged rats. Urotensin 11 increased coronary flow in Langendorff-perfused hearts in both young and aged rats and vasodilation did not differ between young and aged rats. Pretreatment with a NO synthase inhibitor, NG-nitro-L-arginine (L-NNA), significantly inhibited urotensin II-induced vasodilatation in young rats, but not in aged rats. In addition, urotensin 11 increased the production of NO only in young rats. On the other hand, the cyclooxygenase inhibitor diclofenac significantly attenuated the urotensin II-induced coronary vasodilatation in both young and aged rats. Urotensin 11 markedly increased the release of the vasodilating prostacyclin and PGE(2) into the coronary effluent. Production of these prostanoids was maintained even in the aged coronary arteries. These results indicate that the production of NO in the endothelium of coronary arteries is impaired in aged rats, and that prostacyclin and PGE2 may play an important role in regulating urotensin II-induced coronary vasodilatation. (c) 2005 Elsevier B.V. All rights reserved.