心房颤动患者心房肌盐皮质激素受体表达研究

目的探讨心房颤动（房颤）患者心房肌组织盐皮质激素受体（MR）mRNA和蛋白表达的改变。方法入选进行人工心脏瓣膜置换术的风湿性心脏病患者25例,其中窦性心律者（窦律组）12例,永久性房颤者（房颤组）13例（房颤时间≥6个月）。上述患者均于术前进行经胸超声心动图检查并留取有关资料,于手术时取左、右心房侧壁组织,用实时荧光定量聚合酶链反应和Westernblot分别测定MRmRNA及其蛋白在心房肌组织中的表达情况,用免疫组织化学染色检测MR在心房肌细胞中的分布。结果与窦律组比较,房颤组左房内径显著扩大（P〈0．01）;心房肌组织MRmRNA及其蛋白表达均明显增加（P〈0．01或0．05）,但在左、右心房之间无论是在窦律或房颤时MRmRNA及其蛋白表达差异均无统计学意义（P〉0．05）;免疫组织化学染色证明,MR主要分布在心房肌细胞胞质中,且在房颤时其染色密度明显增加。结论房颤时心房肌组织MR表达增加,醛固酮受体拮抗剂将可能对房颤发挥治疗作用。

Study on expression of mineralocorticoid receptor in human atria during atrial fibrillation

OBJECTIVE: To investigate the mRNA and protein expression of mineralocorticoid receptor (MR) in patients with atrial fibrillation. METHODS: Twenty-five patients with rheumatic heart valve disease, 12 in sinus rhythm and 13 in chronic atrial fibrillation (>or= 6 months), underwent transthoracic echocardiography and right and left atrial lateral wall tissue samples were obtained from these patients during mitral/aortic valve replacement operation. Realtime quantitative PCR and Western blot were used to determine the mRNA and protein expression of MR in atria specimens. The distribution of MR in human atria was analyzed by specific immunohistochemical staining. RESULTS: The left atrial diameters increased markedly in atrial fibrillation group compared with that in sinus rhythm group (P<0.01). And the results showed that the level of mRNA and protein of MR were increased significantly in atrial fibrillation group compared with those in sinus rhythm group (P<0.01 or 0.05), whereas the expression of mRNA and protein of MR were found to be no difference between left atria and right atria both in fibrillation and sinus groups (all P>0.05). The special immunohistochemical staining demonstrated that MR was abundant in the human atrial myocardium and MRs were located mainly in the cytoplasm of atrial cells, which were more evident in atrial fibrillation group than those in sinus rhythm group. CONCLUSION: These findings suggested that MRs were upregulated in atrial fibrillation and aldosterone antagonists may be effective in treating atrial fibrillation.