自发性高血压大鼠细胞凋亡相关基因蛋白的研究

目的：研究自发性高血压大鼠(SHR)心肌细胞Bax和Bcl-2基因蛋白表达的变化及其与心肌细胞凋亡的关系。方法：采用免疫组化和末端脱氧核糖核苷酸转移酶介导的dUTP缺口末端标记(TUNEL)法检测Bax和Bcl-2基因蛋白及凋亡细胞。结果：(1)心肌细胞凋亡和Bax基因蛋白表达在1月龄SHR组(NLVH组)和18～20月龄SHR组(CHF组)显著增高且Bax基因蛋白表达与心肌细胞凋亡呈显著正相关(P均＜0.01)。(2)在10月龄SHR组(LVH组)，心肌细胞凋亡显著降低但Bcl-2基因蛋白表达显著增高且Bcl-2基因蛋白表达与心肌细胞凋亡呈显著负相关(P均＜0.01)。(3)NLVH组和CHF组Bcl-2/Bax比例显著降低，但LVH组Bcl-2/Bax比例显著增高且Bcl-2/Bax比例与心肌细胞凋亡呈显著负相关(P均＜0.01)。结论：SHR心肌细胞Bax和Bcl-2基因蛋白表达及心肌细胞凋亡存在动态变化，且Bax基因蛋白表达上调可能与SHR心肌细胞凋亡增加和CHF相关而Bcl-2基因蛋白表达上调则可能与SHR心肌细胞凋亡减少和LVH有关。因此，Bax和Bcl-2基因蛋白表达的动态变化可能在SHR心肌细胞凋亡和心脏重构中起重要作用。

The study of apoptosis-associated genes protein in spontaneously hypertensive rats

Objective :To study the dynamic changes of Bax and Bcl-2 genes protein expression in cardiomyocytes and the relationship between the changes and cardiomyocyte apoptosis in spontaneously hypertensive rats (SHR). Methods: Bax and Bcl-2 genes protein expression and cardiomyocyte apoptosis were tested by immunohistochemical method and in situ TdT-mediated dUTP nick end labeling(TUNEL). Results: (1)The cardiomyocyte apoptosis and Bax gene protein expression were notably increased in I-month-old SHR group (NLVH group) and 18～20-month-old SHR group (CHF group) and Bax gene protein expression was positively bound up with cardiomyocyte apoptosis(all P values less than 0.01). (2)The cardiomyocyte apoptosis was significantly decreased but Bcl-2 gene protein expression remarkably increased in 10-month-old SHR group (LVH group) and Bcl-2 gene protein expression was negatively related to cardiomyocyte apoptosis (all P values less than 0.01). (3)The ratio of Bcl-2 to Bax (an inverse index of cell susceptibility of apoptosis) was markedly lowered in NLVH group and CHF group but that was outstandingly raised in LVH group and the ratio of Bcl-2 to Bax was inversely correlated with cardiomyocyte apoptosis(all P values less than 0.01). Conclusion: The dynamic changes of Bax and Bcl-2 genes as well as cardiomyocyte apoptosis exist in SHR, moreover, upregulation of Bax gene protein expression may be associated with the increase of cardiomyocyte apoptosis and CHF of SHR,whereas upregulation of Bcl-2 gene protein expression may be bound up with the decrease of cardiomyocyte apoptosis and LVH of SHR. Therefore, the dynamic changes of Bax and Bcl-2 genes protein expression may play an important role in cardiomyocyte apoptosis and heart remodeling of SHR.