Stewart J M, Xu X, Ochoa M, Hintze T H
Department of Physiology, New York Medical College, Valhalla 10595, USA.
Med Sci Sports Exerc. 1998 Feb;30(2):220-8. doi: 10.1097/00005768-199802000-00008.
Exercise enhances the dilation of the epicardial coronary arteries by vasodilator drugs and blood flow. Our goal was to determine whether coronary artery elastic properties were affected by brief exercise training.
Arterial pressure and left circumflex coronary artery diameter were measured in dogs. Venous bolus injections of acetylcholine 5 microg x kg(-1) (ACH) and nitroglycerin 25 microg x kg(-1) (NTG) or infusions of adenosine 0.5 microM/kg/min (ADO) were given. Fifteen-second coronary artery occlusions were performed. Dogs exercised 2 h x d(-1) for 7 d at 10.9 km x h(-1). Experiments were repeated. Pressure and coronary radius data were used to calculate vessel wall stress and incremental wall modulus, Einc.
Baseline Einc and radius were not changed by exercise. Before exercise Einc increased similarly from baseline for all vasodilators. After exercise, the increase in Einc with ADO was unchanged. However, the increase was attenuated during ACH, abolished with occlusion, and reversed with NTG despite enhanced dilation.
Data suggest that functional remodeling of epicardial arteries begins soon after starting exercise training, before changes in resting vessel diameter, is mediated by cGMP, and contributes to increased vascular dilation. Brief exercise training enhances the vasodilating capability and elastic properties of large coronary arteries.
运动可增强血管扩张剂和血流对心外膜冠状动脉的扩张作用。我们的目标是确定短暂运动训练是否会影响冠状动脉弹性特性。
测量犬的动脉压和左旋冠状动脉直径。静脉推注5微克/千克（乙酰胆碱）（ACH）和25微克/千克（硝酸甘油）（NTG），或输注0.5微摩尔/千克/分钟（腺苷）（ADO）。进行15秒的冠状动脉闭塞。犬以10.9千米/小时的速度每天运动2小时，持续7天。重复实验。压力和冠状动脉半径数据用于计算血管壁应力和增量壁模量Einc。
运动后基线Einc和半径未改变。运动前，所有血管扩张剂的Einc从基线开始均有类似增加。运动后，ADO引起的Einc增加未变。然而，ACH期间增加减弱，闭塞时消失，NTG时尽管扩张增强但增加逆转。
数据表明，心外膜动脉的功能重塑在开始运动训练后不久即开始，在静息血管直径改变之前，由cGMP介导，并有助于增加血管扩张。短暂运动训练可增强大冠状动脉的血管舒张能力和弹性特性。
