长期微波辐射致大鼠心脏损伤远后效应的定量研究

Quantitative studies on the biological long-term effects of heart injury in rats induced by microwave radiation

目的探讨不同剂量长期微波辐射对大鼠心脏损伤远后效应的影响,为微波辐射损伤防治奠定基础。方法采用0 mW/cm^2、2.5 mW/cm^2、5 mW/cm^2、10 mW/cm^2微波连续辐射220只雄性Wistar大鼠(1次×6 min/d,5次/周,共30 d),于辐射后6 h、7 d、14 d、1 m、3 m、6 m、9 m、12 m和18m,采用全自动血生化检测仪检测大鼠外周血清中Ca^(2+)、AST、CK和LDH含量,采用多导生理记录及分析系统,记录标准II导联的心电图,并运用光镜及电镜观察大鼠心脏组织结构。结果 (1)2.5 mW/cm^2组大鼠心脏功能和组织结构于辐射后18 m内均未见明显异常。(2)5 mW/cm^2组大鼠于辐射后6 h和7 d,大鼠外周血清中Ca^(2+)浓度和LDH含量明显升高(P<0.01);心肌纤维波浪状排列、线粒体空化、肿胀。(3)10 mW/cm^2组辐射后6 h、7 d和14 d,大鼠外周血清中Ca^(2+)浓度、CK和LDH含量明显升高(P<0.01),心率和心电图P-H明显降低(P<0.05或0.01),心肌纤维波浪状排列、线粒体空化、肿胀。结论 2.5 mW/cm^2长期微波辐射后大鼠心脏功能、组织结构及超微结构未见显著改变;5 mW/cm^2和10 mW/cm^2微波辐射可致大鼠心脏功能、组织结构及超微结构损伤,上述改变与辐射剂量呈正相关。

Objective This study was to explore long term effects of heart damage and to lay the foundation for finding prevention and treatment with different doses of microwave radiation. Methods 220 male Wistar rats were exposed to the different average power densities of 0 mW/cm^2 , 2.5 mW/cm^2 , 5 mW/cm^2 and 10 mW/cm^2 （6 min per day, 5 times/week, a total of 30d）. Rats were sacrificed at 6 h, 7 d, 14 d, 1 m, 3 m, 6 m, 9 m, 12 m and 18 m after microwave radiation respectively. The contents of Ca^2＋, AST, CK, LDH were test by automatic biochemical detector. The electrocardiogram （ECG） was detested by multiple physiological recorder. The changes of tissues tructure and ultrastructure in rat＇s heart were observed by light microscopy and electron microscopy at 6 h, 7 d, 1 m, 3 m, 6 m, 9 m and 18 m after microwave radiation. Results ①The contents of Ca^2＋, AST, CK, LDH, the ECG, tissue structure and ultrastructurehadno differences in 2.5 mW/cm^2group within 18 m compared with the sham group after microwave exposure. ②The contents of Ca^2＋ and LDH were significant increased at 6 h and 7 d after microwave exposure in rats of 5 mW/cm^2group （P 〈0.01）, at the same time the myocardial fibers were arranged in a wavy shape and the myocardial ceils swell. ③The contents of Ca^2＋ , CK, LDH were significant increased （P 〈0.01）, the heart rate and ECG P-H lowered significantly （P 〈0.05 or 0.01 ）, the cardiac muscle fibers showed focallysis and breakage, the mitochondria of the myocardial cells were cavitationat 6 h, 7 d and 14 d after microwave exposure in rats of 10 mW/cm^2group. Conclusions 2.5 mW/cm^2 mierowave radiation could not cause the changes of heart function and structure in rats, while 5 mW/cm^2 and 10 mW/cm^2 microwave radiation caused the damages of heart function and structure, and the damages were positively correlated with the dose of microwave radiation.