Role of adenosine in local metabolic coronary vasodilation.
Role of adenosine in local metabolic coronary vasodilation.
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腺苷在局部代谢性冠状血管舒张中的作用。
DOI：
10.1152/ajpheart.1999.276.5.h1425
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Feigl,EO
中科院分区：
文献类型：
--
作者：
Yada,T;Richmond,KN;VanBibber,R;Kroll,K;Feigl,EO
当心肌耗氧量增加时，腺苷被认为是冠脉血流量增加的中介。本研究的目的是评估腺苷在不使用儿茶酚胺的情况下通过心脏双脉冲刺激增加心肌耗氧量的作用。在10只麻醉开胸犬上，测量冠状动脉左回旋支的冠脉血流量，并用动静脉氧分压差计算心肌耗氧量。心脏间质腺苷浓度根据冠状动脉静脉和动脉血浆腺苷测量，使用前面描述的多室轴向分布的数学模型来估计。成对刺激使心率从55次/分钟增加到120次/分钟，心肌耗氧量增加104%，冠状动脉血流量增加92%，但估计的间质腺苷浓度仍低于冠状动脉血管扩张的阈值。用8-苯茶碱(8-PT)阻断腺苷受体后，冠脉血流量和心肌耗氧量与对照组无显著差异。腺苷受体阻断期间的双脉冲起搏导致心肌耗氧量和冠脉血流量增加，与8-PT前的反应相似。冠脉静脉和间质腺苷浓度并未增加以克服8-PT对腺苷的阻断作用。这些结果表明，在起搏引起的心肌耗氧量增加期间，腺苷不是冠脉血流局部代谢控制所必需的。
Adenosine has been postulated to mediate the increase in coronary blood flow when myocardial oxygen consumption is increased. The aim of this study was to evaluate the role of adenosine when myocardial oxygen consumption was augmented by cardiac paired-pulse stimulation without the use of catecholamines. In 10 anesthetized closed-chest dogs, coronary blood flow was measured in the left circumflex coronary artery, and myocardial oxygen consumption was calculated using the arteriovenous oxygen difference. Cardiac interstitial adenosine concentration was estimated from coronary venous and arterial plasma adenosine measurements using a previously described multicompartmental, axially distributed mathematical model. Paired stimulation increased heart rate from 55 to 120 beats/min, increased myocardial oxygen consumption 104%, and increased coronary blood flow 92%, but the estimated interstitial adenosine concentration remained below the threshold for coronary vasodilation. After adenosine-receptor blockade with 8-phenyltheophylline (8-PT), coronary blood flow and myocardial oxygen consumption were not significantly different from control values. Paired-pulse pacing during adenosine-receptor blockade resulted in increases in myocardial oxygen consumption and coronary blood flow similar to the response before 8-PT. Coronary venous and estimated interstitial adenosine concentration did not increase to overcome the adenosine blockade by 8-PT. These results demonstrate that adenosine is not required for the local metabolic control of coronary blood flow during pacing-induced increases in myocardial oxygen consumption.