Yamahara Y, Asayama J, Ohta B, Matsumoto T, Miyazaki H, Tatsumi T, Kobara M, Inoue M, Inoue D, Nakagawa M
Second Department of Medicine, Kyoto Prefectural University of Medicine, Japan.
Basic Res Cardiol. 1993 Jul-Aug;88(4):307-13. doi: 10.1007/BF00800637.
Previously, we reported that cardiac troponin T (TnT) can be detected and measured in coronary effluent from isolated rat hearts during hypoxia. The present study was designed to evaluate the release kinetics of TnT from post-ischemic rat hearts. Using the Langendorff technique, the hearts were reperfused for 4 h after 20 min or 60 min of global ischemia. Coronary flow was measured by timing the collection of the coronary perfusate that dripped from the hearts, and left ventricular pressure (LVP) was monitored continuously during the experiments. The amount of TnT released in 1 min was compared with the release of creatine kinase (CK) and lactate dehydrogenase (LD). The release kinetics of CK and LD showed a monophasic pattern and the levels at 4 h after reperfusion returned to baseline levels. By contrast, the release kinetics of TnT showed a small peak followed by a larger and more sustained peak. There were good negative correlations between developed pressure of LVP and both sigma TnT and the amount of TnT released within 1 min at 4 h after reperfusion. These results indicate that the release kinetics of TnT is different from that of CK and LD during reperfusion, and further that cardiac TnT is a useful indicator of myocardial cell damage and can be used to evaluate the degree of myocardial cell damage in both the early and late phase of acute myocardial infarction.
此前，我们报道过在缺氧状态下可从离体大鼠心脏的冠脉流出液中检测和测量心肌肌钙蛋白T（TnT）。本研究旨在评估缺血后大鼠心脏中TnT的释放动力学。采用Langendorff技术，在全心缺血20分钟或60分钟后对心脏进行4小时的再灌注。通过对从心脏滴下的冠脉灌注液的收集计时来测量冠脉流量，并在实验过程中持续监测左心室压力（LVP）。将1分钟内释放的TnT量与肌酸激酶（CK）和乳酸脱氢酶（LD）的释放量进行比较。CK和LD的释放动力学呈单相模式，再灌注4小时后的水平恢复到基线水平。相比之下，TnT的释放动力学表现为一个小峰值后接着一个更大且更持久的峰值。再灌注4小时时，LVP的发展压力与总TnT以及1分钟内释放的TnT量之间均存在良好的负相关。这些结果表明，再灌注期间TnT的释放动力学与CK和LD不同，进一步表明心肌TnT是心肌细胞损伤的有用指标，可用于评估急性心肌梗死早期和晚期的心肌细胞损伤程度。
