Cardiovascular effects of dobutamine during exercise in dogs.
Cardiovascular effects of dobutamine during exercise in dogs.
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多巴酚丁胺在狗运动过程中对心血管的影响。
DOI：
10.1152/ajpheart.1989.257.3.h954
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Ordway,GA
中科院分区：
文献类型：
--
作者：
Haidet,GC;Musch,TI;Friedman,DB;Ordway,GA
为了检验在最大强度运动期间心脏中肾上腺素能受体的刺激最大的假设，并确定在剧烈运动期间肾上腺素能受体的全身刺激是否在运动期间发生的血流的正常区域分布中产生显著改变，我们评估了在跑台跑步期间在杂种狗中输注多巴酚丁胺（40微克·kg-1·min-1）的心血管效应。在极量运动时，多巴酚丁胺输注导致心率显著增加（P <0.05）。然而，运动能力、全身耗氧量（VO 2）和最大动静脉氧差在输注该药物期间均降低。运动性骨骼肌的最大血流量随之减少。多巴酚丁胺的输注也导致了在剧烈的次极量运动水平下心率的增加。然而，与最大运动期间不同，VO 2没有变化。运动骨骼肌的血流量增加，动静脉氧差随之减少。在剧烈运动和最大运动期间，通常发生在内脏循环中的血流量减少在输注本药物期间通常有所减弱。因此，多巴酚丁胺，一种拟交感神经药物，在运动期间以高剂量输注时产生显著的心血管效应。我们的研究结果表明，β-肾上腺素能受体储备存在于狗在最大运动期间的心脏。此外，药物输注期间发生的外周反应提供了额外的证据，表明在剧烈运动和最大运动期间，不同程度的肾上腺素能受体储备通常似乎存在于不同的局部循环中。
To test the hypothesis that stimulation of adrenergic receptors in the heart is maximal during maximal exercise, and to determine whether generalized stimulation of adrenergic receptors during strenuous exercise produces significant alterations in the normal regional distribution of blood flow that occurs during exercise, we evaluated the cardiovascular effects of the infusion of dobutamine (40 micrograms.kg-1.min-1) in mongrel dogs during treadmill running. During maximal exercise, the dobutamine infusion resulted in a significant (P less than 0.05) increase in heart rate. Exercise capacity, total body O2 consumption (VO2), and maximal arteriovenous O2 difference, however, each were reduced during the infusion of this drug. A concomitant reduction in maximal blood flow to locomotive skeletal muscle occurred. The infusion of dobutamine also resulted in an increase in heart rate at a strenuous level of submaximal exercise. However, unlike during maximal exercise, VO2 was unchanged. Blood flow to locomotive skeletal muscle increased, and there was a concomitant reduction in arteriovenous O2 difference. Blood flow reductions that normally occur in splanchnic circulations during strenuous and during maximal exercise were generally somewhat attenuated during the infusion of this drug. Thus, dobutamine, a sympathomimetic agent, produces significant cardiovascular effects when infused in high doses during exercise. Our results demonstrate that beta-adrenergic receptor reserve exists in the heart during maximal exercise in dogs. In addition, the peripheral responses that occur during the infusion of the drug provide additional evidence that different degrees of adrenergic receptor reserve normally appear to be present within different regional circulations during strenuous and during maximal exercise.