心房颤动患者心房组织血管紧张素Ⅱ受体表达的研究

Regulation of atrial angiotensin Ⅱ receptor subtypes in human atrial fibrillation

目的 探讨心房颤动 (房颤 )患者心房组织血管紧张素Ⅱ受体 (AT R)基因转录和蛋白质表达的变化。方法 33例风湿性心脏瓣膜病患者 ,心脏外科手术时取右心耳组织。通过逆转录 聚合酶链反应和免疫组织化学 ,测量血管紧张素Ⅱ受体 1(AT1 R)和血管紧张素Ⅱ受体 2 (AT2 R)的mRNA和蛋白的相对表达量。结果 窦性心律患者、阵发性房颤及慢性房颤患者之间的心房组织AT1 R和AT2 R的mRNA水平差别均无显著性 (P均 >0 0 5 ) ;AT1 R和AT2 R在各组患者心房组织中主要表达在心房肌细胞 ;与窦性心律患者相比 ,阵发性房颤和慢性房颤患者的心房组织AT1 R的蛋白表达均明显减少 (P <0 0 5 ;P <0 0 1) ,而AT2 R的蛋白表达均明显增高 (P <0 0 1;P <0 0 5 )。结论 心房在房颤时AT1 R表达下调而AT2 R表达上调 。

Objective To determine the atrial expression of angiotensin Ⅱ type 1 and type 2 receptors(AT 1 R and AT 2 R)in human atrial fibrillation(AF).Methods A total of 33 patients with rheumatic heart disease were included.Atrial tissue was obtained from the right atrial appendage during open heart surgery.AT 1 R and AT 2 R were semi quantified at the mRNA and protein level by reverse transcription polymerase chain reaction and immunohistochemistry.Results AT 1 R or AT 2 R mRNA content was similar in all three groups ( P all>0 05).Both types of AT R were predominantly expressed in atrial myocytes in all three groups.The proteins of AT 1 R in patients with paroxysmal AF and chronic AF were significantly decreased compared with patients in sinus rhythm(0 257±0 074 vs 0 345±0 041, P <0 05;0 213±0 053 vs 0 345±0 041, P <0 01). In contrast,AT 2 R in patients with paroxysmal AF and chronic AF significantly increased(0 288±0 069 vs 0 183±0 043, P <0 01;0 236±0 065 vs 0 183±0 043, P <0 05).Conclusions AF is associated with the down regulation of atrial AT 1 R and the up regulation of AT 2 R proteins.These findings may help define the pathophysiological role of the angiotensin system in the structural remodeling of the fibrillating atria.