CONTRIBUTION OF NITRIC OXIDE RELEASED TO METABOLIC VASODILATION IN THE HEART

血管内层（内皮）释放物质， 内层平滑肌的松弛。 放宽 在维持正常的血管张力中是必不可少的 从而控制血流。 氮释放不足 氧化物会导致血管不适当的扩张， 限制血流量的增加。 为了检查松弛是否 伴随着心率增加的血管， 我们研究了L-NMMA的作用，L-NMMA是一种释放 一氧化氮，对快速起搏产生的血流量增加的影响。 心 正常情况下，心脏起搏会增加33%的血流量， 但在阻断一氧化氮的释放后， L-NMMA 这表明，一氧化氮的释放从衬里 心脏血管的收缩对于放松动脉很重要， 控制心脏的血液流动 因素可导致 心脏内膜功能的异常， 减少血流，导致心绞痛恶化。

The lining of blood vessels (endothelium) releases substances that cause relaxation of smooth muscle that underlies the lining. The relaxation of the smooth muscle is essential in maintaining normal blood vessel tone and thus the control of blood flow. Deficiency in the release of nitric oxide would lead to inappropriate dilation of blood vessels and thus to limitation of the blood flow increase. To examine whether the relaxation of blood vessels that accompanies periods when the heart rate increases, we studied the effect of L-NMMA, which is an inhibitor of release of nitric oxide, on the blood flow increase produced by rapidly pacing the heart. Normally, pacing the heart produces a 33% increase in blood flow, but this was reduced to 9% after blocking the release of nitric oxide with L-NMMA. This suggests that release of nitric oxide from the lining of blood vessels in the heart is important in relaxing arteries and thus controlling blood flow in the heart. Conditions that lead to abnormalities of the function of the lining of the heart could, by reducing blood flow, lead to worsening of angina.