Nakamura Y, Nagata M, Mori H, Sakurai K, Takahashi M, Hattori S
Jpn Heart J. 1984 Sep;25(5):783-92. doi: 10.1536/ihj.25.783.
We investigated differences between ischemic and anoxic myocardium with respect to early mechanical and metabolic changes. Ischemia and anoxia were induced in the area perfused by the distal left anterior descending artery in 32 mongrel dogs. Since both the ischemia and the anoxia in this preparation resulted in very little change in global cardiac hemodynamics, indirect mechanical and metabolic effects on the involved myocardium were minimal. However, regional anoxia caused a later development of a myocardial systolic bulge than did regional ischemia (44.8 +/- 13.6 vs 26.8 +/- 9.9 sec). Myocardial ATP content was reduced to the same level 5 min after the onset of ischemia and anoxia. Anoxia with high K+ did not result in an earlier myocardial systolic bulge time, but myocardial ATP was maintained at a higher level than during ischemia. Anoxia with low pH also did not affect the time for development of a myocardial systolic bulge. We concluded that neither acidosis nor hyperpotassemia are more causally related to the earlier development of a myocardial systolic bulge during regional ischemia than during regional anoxia. Also the absolute value of myocardial ATP content is unlikely to be causally related to the determination of myocardial contraction, as reflected by the development of a myocardial systolic bulge.
我们研究了缺血性心肌和缺氧性心肌在早期机械和代谢变化方面的差异。对32只杂种犬左前降支远端灌注区域进行缺血和缺氧诱导。由于该实验准备中缺血和缺氧对整体心脏血流动力学的影响很小，对受累心肌的间接机械和代谢作用也微乎其微。然而，局部缺氧比局部缺血导致心肌收缩性膨出的出现时间更晚（44.8±13.6秒对26.8±9.9秒）。缺血和缺氧开始5分钟后，心肌ATP含量降至相同水平。高钾缺氧并未导致心肌收缩性膨出时间提前，但心肌ATP水平维持在高于缺血时的水平。低pH值缺氧也不影响心肌收缩性膨出的出现时间。我们得出结论，酸中毒和高钾血症与局部缺血期间心肌收缩性膨出的早期发生之间的因果关系并不比局部缺氧时更强。心肌ATP含量的绝对值也不太可能与心肌收缩的决定存在因果关系，这一点从心肌收缩性膨出的出现可以反映出来。
