Ivanics T, Miklós Z, Dézsi L, Ikrényi K, Tóth A, Roemen T H, Van der Vusse G J, Ligeti L
Institute of Human Physiology and Clinical Experimental Research, Semmelweis University, Budapest, Hungary.
Mol Cell Biochem. 2001 Oct;226(1-2):119-28. doi: 10.1023/a:1012739722150.
This study was designed to elucidate the relationship between enhanced cytoplasmic calcium levels (Ca2+i) and membrane phospholipid degradation, a key step in the loss of cellular integrity during cardiac ischemia/reperfusion-induced damage. Isolated rat hearts were subjected to 15 min ischemia followed by 30 min reperfusion. Ca2+i was estimated by the Indo-1 fluorescence ratio technique. Degradation of membrane phospholipids as indicated by the increase of tissue arachidonic acid content was assessed in tissue samples taken from the myocardium at various points of the ischemia/reperfusion period. The hemodynamic parameters showed almost complete recovery during reperfusion. Fluorescence ratio increased significantly during ischemia, but showed a considerable heart-to-heart variation during reperfusion. Based upon the type of change of fluorescence ratio during reperfusion, the hearts were allotted to two separate subgroups. Normalization of fluorescence ratio was associated with low post-ischemic arachidonic acid levels. In contrast, elevated fluorescence ratio coincided with enhanced arachidonic acid levels. This observation is suggestive for a relationship between the Ca2+-related fluorescence ratio and arachidonic acid accumulation probably due to a calcium-mediated stimulation of phospholipase A2.
本研究旨在阐明细胞质钙水平升高（Ca2+i）与膜磷脂降解之间的关系，膜磷脂降解是心脏缺血/再灌注诱导损伤期间细胞完整性丧失的关键步骤。将离体大鼠心脏进行15分钟缺血，然后再灌注30分钟。通过Indo-1荧光比率技术估算Ca2+i。在缺血/再灌注期的不同时间点从心肌采集组织样本，评估组织花生四烯酸含量增加所表明的膜磷脂降解情况。血流动力学参数在再灌注期间几乎完全恢复。荧光比率在缺血期间显著增加，但在再灌注期间心脏之间存在相当大的差异。根据再灌注期间荧光比率的变化类型，将心脏分为两个不同的亚组。荧光比率的正常化与缺血后低花生四烯酸水平相关。相反，荧光比率升高与花生四烯酸水平升高同时出现。这一观察结果提示Ca2+相关荧光比率与花生四烯酸积累之间可能存在关系，这可能是由于钙介导的磷脂酶A2刺激所致。
