Maekawa K, Saito D, Obayashi N, Uchida S, Haraoka S
Department of Cardiovascular Medicine, Okayama University Medical School, Japan.
Am J Physiol. 1994 Jul;267(1 Pt 2):H166-73. doi: 10.1152/ajpheart.1994.267.1.H166.
To investigate the role of endothelium-derived nitric oxide (EDNO) and adenosine in functional myocardial hyperemia, we examined the effect of NG-nitro-L-arginine (L-NNA) and 8-p-sulfophenyltheophylline (8-SPT) on coronary vasodilation in response to increased myocardial oxygen consumption in pentobarbital sodium-anesthetized dogs. L-NNA significantly attenuated the increase in coronary conductance from 28 +/- 6 to 16 +/- 2% with atrial pacing, from 69 +/- 5 to 36 +/- 6% with isoproterenol, and from 25 +/- 6 to 9 +/- 4% with constriction of the aorta. 8-SPT given alone attenuated the increase in coronary conductance to the same extent as L-NNA. The combined administration of L-NNA and 8-SPT did not further change coronary conductance. These findings suggest that EDNO and adenosine play an important role in functional hyperemia. EDNO-induced functional hyperemia appears to be dependent on adenosine receptor activation.
为研究内皮源性一氧化氮（EDNO）和腺苷在功能性心肌充血中的作用，我们在戊巴比妥钠麻醉的犬中，检测了NG-硝基-L-精氨酸（L-NNA）和8-对磺基苯甲基黄嘌呤（8-SPT）对因心肌耗氧量增加引起的冠状动脉舒张的影响。L-NNA显著减弱了心房起搏时冠状动脉传导率从28±6%增加到16±2%、异丙肾上腺素作用时从69±5%增加到36±6%以及主动脉缩窄时从25±6%增加到9±4%的幅度。单独给予8-SPT减弱冠状动脉传导率增加的程度与L-NNA相同。联合给予L-NNA和8-SPT并未进一步改变冠状动脉传导率。这些发现提示EDNO和腺苷在功能性充血中起重要作用。EDNO诱导的功能性充血似乎依赖于腺苷受体激活。
