电磁脉冲辐照对大鼠左心室肌超微结构的影响

Effects of electromagnetic pulse on ultrastructure of left ventricular myocardia of rats

目的初步探讨电磁脉冲(EMP)辐照致大鼠左心室肌损伤的时效特点。方法 24只雄性SD大鼠均在锥形平板GTEM小室内接受相同能量的EMP辐照,EMP辐照参数为场强200 k V/m,脉冲前沿3.5 ns,脉宽14ns,重复频率1 Hz。分别于辐照后12、24、48和96 h活杀,每个时间点6只,取左心室肌制成电镜超薄切片,应用透射电镜观察心肌超微结构的改变。结果 EMP辐照后12 h心肌超微结构即发生改变,24 h变化最为明显,主要表现为肌浆网扩张,线粒体肿胀,嵴排列紊乱、减少甚至空泡化,闰盘间隙增宽及核内异染色质的边集。48 h较24 h明显好转,96 h已基本恢复正常。结论 EMP辐照可造成大鼠左心室肌组织的可恢复性损伤。

Objective To investigate the temporal characteristics of left ventricular myocardium injuries due to electromagnetic pulse （EMP） irradiation. Methods Twenty -four male SD rats received EMP irradiation of the same energy （200 kV/m intensity, 3.5 ns rise time, 14 ns width, 1 Hz frequency） in GTEM cells. They were later killed and left ventricular myocardia were collected at different time points （ 12, 24, 48 and 96 h after irradiation, 6 rats at each time point）. Ultrastruetural changes in the myocardium samples were observed under the transmission electron microscope. Re- suits Uhrastructural changes of left ventrieular myoeardium were evident 12 h after irradiation and peak changes emerged 24 h after the irradiation, which consisted of dilated sarcoplasmic reticulum, swollen mitochondria with irregular cristae, cristae loss or even vacuolization of cristae, increased space between intercalated discs, as well as gathering of heteroehro- matins under nucleus membranes. These changes diminished at 48 h and disappeared 96 h after the EMP irradiation. Conclusion EMP can cause reversible injury to left ventricular myoeardium in rats.