二氮嗪与1,6-二磷酸果糖心麻痹液对大鼠心肌细胞的保护作用

Effects of cardioplegic solution supplemented with diazoxide and fructose-1,6-diphosphate on myocardial apoptosis of cryopreserved rat hearts

提要:目的观察含二氮嗪(DZ)与1,6-二磷酸果糖(FDP)心麻痹液对冷保存大鼠心脏心肌细胞凋亡的影响。方法SD大鼠24只,分为3组(n=8):对照组、STH组和DF组。离体心脏在4℃条件下保存6h后,在Langendorff装置灌注20min,转为离体左心脏工作模型10min。实验终了取心肌组织,检测心肌细胞凋亡指数;心肌丙二醛(MDA)含量,心肌线粒体钙离子含量([Ca2+]m)、细胞质细胞色素C(Cytc)含量、细胞质caspase-3活性;部分心肌液氮保存,采用RT-PCR检测心肌细胞caspase-3 mRNA含量。结果与对照组比较,STH组与DF组再灌注后心肌细胞凋亡指数较明显升高(P<0.01),但DF组明显低于STH组(P<0.01)。STH组心肌MDA含量、[Ca2+]m、细胞质Cytc含量显著增高,细胞质caspase-3 mRNA表达增加,caspase-3活性明显高于对照组(P<0.01)。DF组较STH组各项指标显著改善(P<0.01)。结论含二氮嗪与1,6-二磷酸果糖心麻痹液能减少缺血再灌注引起的心肌细胞凋亡。

Objective To investigate the effects of St. Thomas Ⅱ solution supplemented with diazoxide （DZ） and fructose-1,6-diphosphate （FDP） on myocardial apoptosis in cryopreserved rat hearts. Methods Twenty-four SD rats were randomly divided into 3 groups： control, STH and DF. The isolated hearts were stored at 4 ℃ for 6 h except control group, STH group in St. Thomas Ⅱ solution and DF group in St. Thomas Ⅱ solution supplemented with DZ and FDP. All hearts were perfused by Langendorff model for 20 min, then changed into isolated working heart model for 10 min. The myocardial cell apoptosis was determined with terminal deoxynucleotidyl transferase-mediated nick end labeling （TUNEL） method. The content of cytosolic malondialdehyde （ MDA）, the mitochondrial Ca^2＋ concentration （ [ Ca^2＋ ] m ） were detected and the content of cytosolic Cytochrome c （ Cyt c） protein by Western blotting was evaluated. The expression of caspase-3 mRNA was evaluated by RT-PCR. The activity of cytosolic caspase-3 was determined with fluorescent assay. Results Compared with controls, the levels of apoptotic index, caspase-3 activity and its mRNA content, [ Ca^2＋] m, the content of cytosolic MDA and Cyt c protein were significantly increased in STH group. These parameters of DF group were lower significantly than STH group （P 〈 0.01 ）. Conclusion Cardioplegic solution supplemented with DZ and FDP could restrain apoptosis of myocardial cells caused by ischemical reperfusion injury.