心房颤动患者心房纤维化与缝隙连接重构的关系

目的：探讨心房颤动患者心房肌胶原纤维与缝隙连接重构在房颤发病机制中的可能作用以及它们之间的关系。 方法： 取44例心脏病患者的右心耳标本（房颤26例,为AF组；窦性心律18例，为SR组）,（1）行天狼猩红染色，偏光显微镜下观察AF组与SR组心房肌Ⅰ型胶原并通过图像分析系统分析统计2组间Ⅰ型胶原含量分数（collagen volume fraction of collagen Ⅰ,CVF-Ⅰ）的差异；（2）超微病理切片，透射电镜下观察闰盘并统计闰盘组数及闰盘重构分数（remodeled intercalated disc fraction, RIDF）；（3）连接蛋白43（connexin 43,Cx43）免疫组化染色，普通显微镜下观察分析缝隙连接蛋白Cx43的含量分数（volume fraction of Cx43,Cx43VF），统计2组间的差异；（4）CVF-I与Cx43VF、RIDF分别进行Pearson相关分析。 结果： （1）AF组CVF-I高于SR组（1.26 vs 0.57, P＜0.01）；(2)2组间闰盘组数无显著差异(9.54 vs 10.11, P>0.05), AF组闰盘重构分数大于SR组(39.48 vs 15.61, P＜0.01)；(3)AF组Cx43VF低于SR组(3.45 vs 5.22, P＜0.01)；(4)CVF-I与闰盘重构比例正相关(r＝0.96,P＜0.01)；(5)CVF-I与Cx43VF负相关(r＝－0.98,P＜0.01)。 结论： 房颤患者Ⅰ型胶原纤维化程度增加，闰盘与连接蛋白发生重构。纤维化可能分离心肌，使闰盘重构,进而影响到缝隙连接蛋白的分布，参与房颤发生发展的过程。

Relationship between fibrosis and remodeling of gap junction in atrium of patients with atrial fibrillation

AIM:To examine fibrosis and remodeling of gap junction in atrial myocardium of patients with or without atrial fibrillation and to investigate the relationship between them.METHODS:Right atrial appendage(RAA)samples were collected from 44 patients with rheumatic heart disease during heart operation,28 of which were clinically diagnosed as atrial fibrillation(AF),the left remained sinus rhythm(SR).Fibrosis and remodeling of connexin 43 were examined by polarization microscope and microscopy respectively,and analyzed with an image analyzer.Meanwhile,intercalated disc was counted under transmission electron microscope.The collagen volume fraction of type I(CVF-I)and the volume fraction of Cx43(Cx43VF)were studied between groups of atrial fibrillation and sinus rhythm.The relationship between CVF-I and fraction of remodeled intercalated disc was studied as well.RESULTS:(1)Polarization microscope demonstrated that CVF-I collagen increased(P<0.01)in atrial fibrillation group.(2)The ratio of remodeled of intercalated disc in patients with AF was higher(P<0.01)than that in SR group whereas the number of intercalated disc was not different(P>0.05)between the two groups.(3)Cx43VF decreased(P<0.01)in the AF patients compared to those with SR.(4)A positive correlation between fibrosis and the remodeling of intercalated disc(r=0.96,P<0.01)was observed.The CVF-I was negatively correlated with the Cx43VF(r=-0.98,P<0.01).CONCLUSION:These results suggest that both fibrosis of atrial muscle and remodeling of intercalated disc are involved in the pathogenesis of human atrial fibrillation.Fibrosis of atrial muscle may play an important role in the process of atrial fibrillation by interfering with remodeling of intercalated disc and thereby involves in the remodeling of connexins.