超声对活鼠胚胎心肌细胞凋亡影响的研究

目的 观察诊断级超声波对活鼠胚胎心肌细胞Bcl-2及Bax表达及其凋亡的影响。方法 采用孕14d的Wistar大鼠36只,分为6组,分别为2.5MHz照射10 min、7MHz照射10 min、10 min对照组、2.5MHz照射40 min、7MHz照射40 min、40 min对照组(7MHz探头,Isppa=227W/cm²,Ispta=385mW/cm²;2.5MHz探头,Isppa=94.5W/cm²,Ispta=15.6mW/cm2)。采用免疫组化检测胎鼠心肌Bax及Bcl-2的表达,用TUNEL法及电镜检测胎鼠心肌细胞的凋亡情况。结果 统计显示同一样本不同胚胎间差异无显著性(P>0.05)。7MHz照射40 min组胎鼠心肌组织Bcl-2(+),Bax蛋白阳性(+),2.5MHz照射40min组胎鼠心肌组织Bcl-2阳性(+),Bax阳性(-),7MHz照射10min组胎鼠心肌组织Bcl-2(+),Bax蛋白阴性(-),2.5MHz照射10 min组胎鼠心肌组织Bcl-2阳性(+),Bax阳性(-),两组对照组两者均为(-);TUNEL试验及电镜显示7MHz照射40 min组较其他组凋亡差异有显著性(P<0.05),其余各组与对照组之间差异无显著性(P>0.05)。结论 较高强度诊断级超声波较长时间辐照可导致胎鼠心肌细胞凋亡,Bcl-2及Bax在该过程中起调节作用,小剂量的超声波可以促进Bcl-2表达来抑制细胞凋亡。

Ultrasound affects Apoptosis of living fetal Rat' Cardiomyocytes

Objective To study the effect of diagnostic ultrasound to living rat's embryonic cardiomyocytes on the expression of Bcl-2 and Bax protein and it's apoptosis.Methods To divided the mice which had been pregnant for 14 days into six groups: the 10 min irradiation with 2.5MHz ultrasound the 10 min irradiation with 7MHz ultrasound,the control group of 10 min,the 40 min irradiation with 2.5MHz ultrasound,the 40 min irradiation with 7MHz ultrasound and the control group of 40 min(7MHz probe: Isppa=227W/cm2;Ispta=385mW/cm2;2.5MHz probe: Isppa=94.5W/cm2,Ispta=15.6mW/cm2).Immunohistochemistry test was used to detect Bax and Bcl-2 protein's expression on fetal cardiomyocytes and TUNEL method was used to detect apoptosis.At last,TEM observation was used to observe the morphology of apoptotic cells.Results According to statistics,there had no significant difference in different embryos of the same sample(P> 0.05).Bcl-2 was weakly positive( ) and Bax was weakly positive( ) in 40 min irradiation with 7MHz ultrasound group;Bcl-2 was weakly positive( ) and Bax was negative(-) in 10 min irradiation with 7MHz ultrasound group;Bcl-2 was weakly positive( ) and Bax was negative(-) in 10 min irradiation with 2.5MHz ultrasound group;Bcl-2 was weakly positive( ) and Bax was negative(-) in 40 min irradiation with 2.5MHz ultrasound group;Two control groups were both negative(-) in Bcl-2 and Bax.TUNEL test and TEM demonstrated that 40 min irradiation with 7MHz ultrasound group was more significant than other groups in apoptosis(P<0.05).The rest of the experimental groups had no significant difference than the control groups(P<0.05).Conclusion High intensity diagnostic ultrasound can lead to apoptosis of fetal cardiomyocyte by long irradiation;Bcl-2 and Bax regulated play a regulating role in the process;Small dose of ultrasound can promote the expression of Bcl-2 protein.