Coronary nitric oxide production in response to exercise and endothelium-dependent agonists.
Coronary nitric oxide production in response to exercise and endothelium-dependent agonists.
复制标题
冠状动脉一氧化氮的产生响应运动和内皮依赖性激动剂。
DOI：
10.1161/01.cir.101.21.2526
复制
发表时间：
2000
期刊：
影响因子：
37.8
通讯作者：
Bache,RJ
中科院分区：
文献类型：
--
作者：
Traverse,JH;Wang,YL;Du,R;Nelson,D;Lindstrom,P;Archer,SL;Gong,G;Bache,RJ
背景：在运动过程中，内皮源性一氧化氮（NO）有助于心外膜冠状动脉血管扩张。然而，阻断NO的产生并不影响运动期间冠状动脉血流量（CBF）的增加，这表明NO不是运动诱导的冠状动脉阻力血管扩张所必需的。相比之下，内皮依赖性激动剂产生的CBF增加在NO阻断后减少。因此，本研究旨在确定激动剂对冠状动脉NO生成的增加是否大于运动时的增加。方法和结果：我们使用化学发光法测量了主动脉和冠状窦血浆中NO（硝酸盐+亚硝酸盐=NOx）的氧化产物，以评估长期使用器械的狗在3阶段跑步机运动方案中冠状动脉循环中NOx的产生，以及冠状动脉内给予内皮依赖性激动剂乙酰胆碱（37.5 μg/min）和缓激肽（3.0 μg/min）的反应。静止及运动前2阶段均未检测到冠状动脉一氧化氮生成；只有在最高水平的运动中，冠状动脉一氧化氮生成才有小幅增加。相比之下，冠状动脉一氧化氮的产生在内皮依赖性激动剂的作用下显著增加。结论：内皮依赖性激动剂对冠状动脉NO生成的影响大于对运动相关剪应力增加的影响。这些发现支持了先前的研究，即正常心脏在运动过程中发生的冠状动脉血管扩张不需要NO。
Background—Endothelium-derived nitric oxide (NO) contributes to epicardial coronary artery vasodilation during exercise. However, blockade of NO production does not impair the increase in coronary blood flow (CBF) during exercise, suggesting that NO is not obligatory for exercise-induced coronary resistance vessel dilation. In contrast, the increases in CBF produced by endothelium-dependent agonists are decreased after NO blockade. Consequently, this study was performed to determine whether the increase in coronary NO production in response to agonists is greater than that which occurs during exercise.Methods and Results—We measured the oxidation products of NO (nitrate+nitrite=NOx) in aortic and coronary sinus plasma using chemiluminescence to assess NOxproduction across the coronary circulation in chronically instrumented dogs during a 3-stage treadmill exercise protocol and in response to intracoronary administration of the endothelium-dependent agonists acetylcholine (37.5 μg/min) and bradykinin (3.0 μg/min). No coronary NOxproduction could be detected at rest or during the first 2 stages of exercise; only at the highest level of exercise was a small increase in coronary NOxproduction measured. In contrast, coronary production of NOxwas significantly increased in response to endothelium-dependent agonists.Conclusions—Coronary NO production in response to endothelium-dependent agonists is greater than in response to the increase in shear stress associated with exercise. These findings support previous studies suggesting that NO is not required for the coronary vasodilation that occurs in the normal heart during exercise.