EFFECT OF PERFUSION MEDIA ON MYOCARDIAL OXYGEN TENSION IN ISOLATED RAT HEARTS

在许多关于“孤立的心脏”的实验中，通常情况下 用95%氧气平衡的晶体介质灌流，以确保 充足的心肌氧分压，常用于研究心脏 为新陈代谢需求提供足够的氧气。 然而，当血红蛋白可用于氧气运输时， 用21%的氧气平衡足以满足代谢需求。这 应用EPR血氧仪测定大鼠心肌血氧分压的研究 用红细胞悬浮液灌流离体心。基线 红细胞灌流心脏的心肌氧分压为16.4q3.5 毫米汞柱(平均qS.E.)。与以前的心肌组织测量结果相比 PO2在晶体介质灌流的离体心中的应用 红血球悬浮液导致血液中的 心肌氧分压，同时避免过低和过高的数值。标准 使用95%的氧气与晶体导致心肌水平 氧气远远高于通常存在的血红蛋白和 室内空气，同时仍不能消除潜在的非常低的PO2 发生在心肌中。极端的pO2可能会导致生理性的 异常和损坏。

In many experiments with "the isolated heart", typically it is perfused with crystalloid media equilibrated with 95% O2 to ensure adequate myocardial oxygen tension, is commonly used to study cardiac function in order to provide sufficient oxygen for metabolic demands. When hemoglobin is available for oxygen transport, however, equilibration with 21% O2 is adequate to meet metabolic demands. This study uses EPR oximetry forthe measurement of myocardial pO2 in isolated hearts perfused with an erythrocyte suspension. Baseline myocardial pO2 in erythrocyte-perfused hearts was 16.4q3.5 mmHg(meanqS.E.). When compared to previous measurements of myocardial pO2 in isolated hearts perfused with crystalloid media the use of erythrocyte suspensions resulted in a tenfold lower level of myocardial pO2 while avoiding very low and high values. The standard use of 95% oxygen with crystalloid results in myocardial levels of oxygen far above those usually found in the presence of hemoglobin and room air, while still not eliminating the potential for very low pO2 to occur in the heart muscle. Extremes of pO2 may cause physiological abnormalities and damage.