Microlesion formation in myocardial cells by high-intensity electric field stimulation.
Microlesion formation in myocardial cells by high-intensity electric field stimulation.
复制标题
高强度电场刺激心肌细胞形成微损伤。
DOI：
10.1152/ajpheart.1987.253.2.h480
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Balasky,G
中科院分区：
文献类型：
--
作者：
Jones,JL;Jones,RE;Balasky,G
临床和实验性经胸除颤后经常观察到心律失常、S-T段改变、立即再纤颤和其他功能障碍体征。体外研究表明，休克诱导的功能障碍是由肌膜介电击穿并伴有肌膜中短暂的休克诱导的微损伤的离子交换引起的。为了验证这一假设，培养的鸡胚心肌细胞在含有异硫氰酸荧光素标记的葡聚糖（FITC-葡聚糖）的培养基中休克，分子量范围从4至70 kDa，使用电场刺激5 ms的持续时间和强度范围从0至200 V/cm。结果表明，掺入4- 20-kDa葡聚糖的细胞百分比以剂量依赖性方式增加。以50-100 V/cm的强度开始掺入4-和10-kDa葡聚糖。右旋糖酐掺入对应于休克强度，产生持续1分钟的自发收缩的休克诱导逮捕。20-kDa的右旋糖酐被纳入150-和200-V/cm的冲击。这些强度的冲击也产生了短暂的休克后挛缩。未掺入较大的葡聚糖（40和70 kDa）。这些结果表明，在高强度电场刺激过程中形成了直径为45-60 A的瞬时肌膜微损伤。
Arrhythmias, S-T segment changes, immediate refibrillation, and other signs of dysfunction are often observed after clinical and experimental transthoracic defibrillation. In vitro studies suggested that shock-induced dysfunction is induced by sarcolemmal dielectric breakdown accompanied by ionic exchanges through transient, shock-induced microlesions in the sarcolemma. To test this hypothesis, cultured chick embryo myocardial cells were shocked in media containing fluorescein isothiocyanate-labeled dextrans (FITC-dextrans) ranging in molecular mass from 4 to 70 kDa, using electric field stimulation 5 ms in duration and ranging in intensity from 0 to 200 V/cm. Results showed that the percentage of cells incorporating 4- to 20-kDa dextrans increased in a dose-dependent manner. The 4- and 10-kDa dextrans were incorporated beginning at intensities of 50–100 V/cm. Dextran incorporation corresponded with shock intensities which produced a shock-induced arrest of spontaneous contraction lasting 1 min. The 20-kDa dextrans were incorporated following 150- and 200-V/cm shocks. Shocks of these intensities also produced a transient postshock contracture. Larger dextrans (40 and 70 kDa) were not incorporated. These results suggest the formation of transient sarcolemmal microlesions having a diameter of 45-60 A during high-intensity electric field stimulation.