^(60)Coγ射线照射对心肌细胞蛋白表达的影响

Effects of gamma-ray radiation on protein synthesis of rat cardiomyocytes in vitro

目的研究60Coγ射线照射对体外培养的大鼠心肌细胞蛋白表达的影响。方法体外培养新生大鼠心肌细胞,分为未照射组(0 Gy组)5、Gy1、0 Gy2、0 Gy照射组,分别用60Coγ射线0 Gy5、Gy1、0 Gy2、0 Gy单剂量照射心肌,在照射后48 h:(1)用蛋白检测试剂盒检测各组心肌细胞中的总蛋白含量;(2)用流式细胞仪检测检测各组细胞的细胞周期变化;(3)用带绿色荧光蛋白基因的腺病毒(AdGFP)感染各组心肌细胞,感染后48 h用流式细胞仪检测各组心肌细胞中所含的绿色荧光蛋白的平均荧光强度(MFI),间接比较各组心肌细胞中绿色荧光蛋白的生成量。结果照射后48 h,各照射组心肌细胞中的总蛋白含量较未照射组减低,照射组心肌细胞的绿色荧光强度明显弱于未照射组(P<0.01),抑制程度与照射剂量呈正相关。结论60Coγ射线单剂量照射抑制体外培养的心肌细胞的蛋白合成。

Objective The aim of the present study was to investigate direct effect of gamma ray radiation on protein synthesis of cultured rat cardiomyocytes in vitro. Methods The study was perfomed using primary cell cultures of cardiomyecytes isolated from hearts of now-born rats.After cultured for 72 h in vitro,primary cell cultures of cardiomyocytes were irradiated with single dose of 0 Gy,5 Gy,10 Gy,20 Gy of gamma ray respectively.At 48 h post-irradiation, total protein was measured by total protein measurement and cell cycle by flow cytometry. Furthermore, cardiomyoctes were infected with AdGFP at 48 h post-irradiation.Mean fluorescence intensity （MFI）Of GFP in cardiomyocytes were determined with flow cytometry at 48 h after inftected. Results The results show that the protein synthesis was decreased significantly in irradiated cardiomyocytes compared to un-irradiated group （ P 〈 0.05 or P 〈 0.01）. Flow cytometry confirmed the fluorescence intensity of GFP in irradiated cardiomycytes was much lower than in unirradiated cells（ P 〈 0.01）. Duse-effeet relationship was demonstrated between total protein, fluorescence intensity of GFP and irradiation dose in the study. Conclusion The study demonstrates gamma ray radiation can directly inhibit protein synthesis of cultured cardiomyocytes, which shows dose effect relationship. The mechanism of it should be investigated further.