Hearse D J, Stewart D A
Recent Adv Stud Cardiac Struct Metab. 1975;10:277-89.
Isolated perfused working rat hearts were subjected to elective cardiac arrest for 20 or 30 min. Various methods of arrest were studied, either singly or in combination and with or without coronary perfusion. The functional recovery of the heart following the termination of arrest was found to be related to the concentration of ATP and creatine phosphate in the myocardium at the end of the period of arrest. In turn, these concentrations were dependent upon the method used to induce arrest. Normothermic ischemic arrest led to a marked reduction in high energy phosphates and a poor functional recovery. In contrast, coronary perfusion with hypothermic solutions or solutions containing high concentrations of potassium, induced arrest without depleting ATP or creatine phosphate. These procedures conferred considerable protection on the myocardium and thus permitted good recoveries. The energy status and recovery associated with ischemic arrest could be improved by combining the ischemia with hypothermia or potassium arrest. The latter, while increasing recovery significantly, still failed to afford complete protection to the myocardium. Potassium chloride gave greater protection than potassium citrate. When topical hypothermia was combined with ischemia, a time and temperature relationship was demonstrated but effective protection could only be obtained with severe topical hypothermia over a relatively short time period. The results stress the importance of maintaining high energy phosphates during arrest, and this requires the provision of a continuous supply of oxygen and nutrient, which may perhaps be best achieved by ensuring continuous and adequate coronary perfusion.
将离体灌注的正常工作大鼠心脏进行选择性心脏停搏20或30分钟。研究了各种停搏方法，单独或联合使用，以及有无冠状动脉灌注的情况。发现停搏终止后心脏的功能恢复与停搏期末心肌中三磷酸腺苷（ATP）和磷酸肌酸的浓度有关。反过来，这些浓度又取决于诱导停搏所使用的方法。常温缺血性停搏导致高能磷酸盐显著减少，功能恢复较差。相比之下，用低温溶液或含高浓度钾的溶液进行冠状动脉灌注诱导停搏时，不会耗尽ATP或磷酸肌酸。这些方法对心肌有相当大的保护作用，因此能实现良好的恢复。将缺血与低温或钾停搏相结合，可以改善与缺血性停搏相关的能量状态和恢复情况。后者虽然能显著提高恢复率，但仍未能为心肌提供完全保护。氯化钾比柠檬酸钾提供的保护作用更大。当局部低温与缺血相结合时，呈现出时间和温度的关系，但只有在相对短的时间段内采用严重的局部低温才能获得有效的保护。结果强调了在停搏期间维持高能磷酸盐的重要性，而这需要持续供应氧气和营养物质，这或许通过确保持续且充足的冠状动脉灌注才能最好地实现。
