高功率微波辐射对大鼠心肌超微结构和caspase-3表达的影响

A study of the ultrastructure and expression of caspase-3 in rat heart after high power microwave radiation

目的探讨高功率微波(HPM)辐射后大鼠心肌超微结构和caspase-3表达的改变及其机制。方法采用平均功率密度为2,10,50mW/cm2的S波段HPM辐射60只Wistar雄性大鼠,应用电镜、PAS染色、免疫组织化学分析和图像分析技术,定量研究HPM辐射后大鼠心肌超微结构、糖原颗粒的改变及caspase-3表达的变化规律。结果均率密度为10,15mW/cm2的HPM辐射可造成大鼠心肌细胞核染色质边集、浓缩,肌原纤维排列紊乱、肌丝断裂、溶解,线粒体肿胀、空化,肌浆网扩张,糖原颗粒减少;HPM辐射后1d心肌细胞PAS阳性颗粒明显减少,28d恢复,且呈一定的剂量-效应关系;HPM辐射后1d,左心室心内膜下及肌层心肌细胞浆caspase-3表达增强(P<0.01),28d恢复。结论一定功率密度的HPM辐射可造成心肌细胞超微结构损伤,心肌细胞caspase-3表达增强,与HPM辐射所致心脏损伤的病理生理过程有关。

Objective To investigate the effect of high power microwave （HPM） radiation on the ultrastructure and caspase-3 expression of rat myocardial cells. Methods S-band HPM with mean power density of 2 - 50 mW/cm^2 was used to radiate 60 healthy Wistar male rats. Transmission electron microscopy, PAS staining,immunohistoehemistry techniques and image analysis were used to study the uhrastructural changes of myocardial cells and the expression of caspase-3. Results The HPM radiation of a power of over 10 mW/cm^2 caused myocardial cells chromatin condensation, cardiomyofilaments derangement, mitochondria swelling and hepatin loss.PAS positive granules were decreased to the minimum on the 1st day （P 〈 0.01 ） and recovered on the 28th day after radiation in a dose-dependent manner. Caspase-3 was increased in endocardium of the left ventricle and muscular layer at 1 st day, and recovered on the 28th day after radiation. Conclusion HPM radiation may cause the ultrastructural alterations of myocardial cells. The expression of caspase-3 was increased significantly and played an important role in the pathophysiological process of heart injury induced by HPM.