去甲肾上腺素对原代培养大鼠心肌细胞的凋亡率及相关蛋白的影响

Effects of norepinephrine on apoptosis of cultured rat cardiomyocytes and expression of related apoptotic proteins

目的观察去甲肾上腺素(NE)对体外培养的原代新生大鼠心肌细胞凋亡率及相关凋亡蛋白的影响。方法选用出生1-3 d的SD大鼠建立原代培养新生大鼠心肌细胞模型。将培养72 h的心肌细胞随机分为对照组(未使用任何药物)与不同浓度NE组(分别采用10^(-8),10^(-7),10^(-6),10^(-5),10^(-4)mol/L NE),每组3孔(n=3)。加药后3 h采用流式细胞术测定心肌细胞凋亡率;采用Western blot检测Cry AB及Bcl-2、Bax及Bcl-2/Bax比值的变化。结果与对照组比较,10^(-8),10^(-7),10^(-6),10^(-5),10^(-4)mol/L NE作用下心肌细胞凋亡率均出现显著升高(均P<0.05);Cry AB表达下降(均P<0.05),Bcl-2表达下降(除10-8mol/L组外均P<0.05)、Bax表达升高(除10-7mol/L组外均P<0.05),Bcl-2/Bax比值下降(均P<0.05)。结论去甲肾上腺素可能通过降低Cry AB、Bcl-2表达,升高Bax表达,降低Bcl-2/Bax比值,诱导体外原代培养大鼠心肌细胞的凋亡率增加。

Objective To investigate the effects of norepinepherine（ NE） on the apoptosis rate of cultured rat cardiomyocytes and the changes of the related apoptotic proteins. Methods The neonatal cardiomyocytes from the new-born Sprague-Dawley rats（ 1-3 days of age） were isolated and cultured. The cardiomyocytes incubated for 72 h were used for further experiments. Eighteen wells of the cultured cardiomyocytes were randomly divided into 6 groups（ 3 wells in each group） ： control group（ without NE） and five NE groups（ treated with 10^-8,10^-7,10^-6,10^-5,10^-4 mol/L NE respectively）. The apoptosis rate of the cardiomyocytes were examined by flowcytometry（ FCM）. The expression of Bcl-2,Bax and αB-crystallin in cultured cardiomyocytes were detected by Western blot. Results The apoptosis rate of the cardiomyocytes in NE graups（ 10^-8-10^-4 mol/L） were significantly higher than that in control group（ all P〈0. 05）. The expressions of Bcl-2 and αB-crystallin were significantly decreased after treated with NE（ P〈0. 05）,while Bax was significantly increased（ P〈0. 05）,and the value of Bcl-2/Bax decreased significantly（ P〈0. 05）. Conclusion NE could induce the apoptosis by increasing the expression Bax,decreasing the level of Bcl-2,αB-crystallin and the ratio of Bcl-2 to Bax in cultured cardiomyocytes.