Novikova E B, Tskitishvili O V
Biull Eksp Biol Med. 1983 Jan;95(1):3-5.
Experiments on anesthetized dogs were made to examine oxygen extraction from coronary blood during increase and decrease in cardiac rhythm frequency under varying conditions of vasomotor regulation. With an initially high tone of the coronary vessels both increase and reduction of myocardial oxygen supply occurred at the expense of vasomotor reactions. Under these conditions the coronary blood flow velocity and systolic rhythm correlated well. At the same time the oxygen level in coronary blood did not experience noticeable changes. As the initial tone of the coronary vessels dropped, vasomotor reactions were attenuated and oxygen extraction from coronary blood underwent alterations which had occurred prior to depletion of the coronary expanding reserves. The data obtained suggest that reduction of the initial tone of the coronary vessels proceeds non-uniformly, leading to a decrease in vascular sensitivity to the tissue oxygen level.
对麻醉犬进行实验，以研究在血管运动调节的不同条件下，心律频率增加和降低时冠状动脉血液中的氧摄取情况。在冠状动脉血管最初处于高张力状态时，心肌氧供应的增加和减少均以血管运动反应为代价。在这些条件下，冠状动脉血流速度与收缩期节律密切相关。与此同时，冠状动脉血液中的氧水平没有明显变化。随着冠状动脉血管初始张力的降低，血管运动反应减弱，冠状动脉血液中的氧摄取发生改变，这种改变发生在冠状动脉扩张储备耗尽之前。所获得的数据表明，冠状动脉血管初始张力的降低是不均匀的，导致血管对组织氧水平的敏感性降低。
