Lamers J M, Post J A, Verkleij A J, Ten Cate F J, van der Giessen W J, Verdouw P D
Department of Biochemistry, Erasmus University Rotterdam, The Netherlands.
Biomed Biochim Acta. 1987;46(8-9):S517-21.
The purpose of this study was to explore the relationship between the extent of sarcolemmal damage observed 2 h after reperfusion of myocardium which had been ischemic for either 0.5 or 1 h and the long-term recovery of function of that same myocardium. For this purpose we studied the Ca2+ pumping ATPase activity and protein phosphorylation of sarcolemmal vesicles isolated after 2 h reperfusion. Both activities declined depending on the duration of ischemia, which suggests the development of sarcolemmal Ca2+ pump failure. Morphological examination of the sarcolemma by thin-section and freeze-fracture electronmicroscopy, in biopsies obtained after 2 h of reperfusion, showed severe clustering of intramembranous particles and formation and extrusion of lipidic liposomal structures which also depended on the duration of ischemia. Except for the occurrence of minor particle aggregation in the samples which had been ischemic for 0.5 h, sarcolemmal disruption was only seen in those myocardial segments which had been subjected to 1 h of coronary artery ligation. Recovery of regional myocardial function, assessed by 2-D-echocardiography after 2 weeks of reperfusion, was closely related to the degree to which sarcolemmal integrity was maintained after 2 h reperfusion.
本研究的目的是探讨心肌缺血0.5小时或1小时后再灌注2小时所观察到的肌膜损伤程度与同一心肌长期功能恢复之间的关系。为此，我们研究了再灌注2小时后分离的肌膜囊泡的Ca2+泵ATP酶活性和蛋白质磷酸化。这两种活性均随缺血时间的延长而下降，这表明肌膜Ca2+泵功能衰竭的发生。对再灌注2小时后获取的活检组织进行超薄切片和冷冻断裂电子显微镜检查，结果显示膜内颗粒严重聚集，脂质体结构形成并挤出，这也取决于缺血时间。除了缺血0.5小时的样本中出现轻微颗粒聚集外，仅在冠状动脉结扎1小时的心肌节段中观察到肌膜破坏。再灌注2周后通过二维超声心动图评估的局部心肌功能恢复与再灌注2小时后肌膜完整性的维持程度密切相关。
