心房颤动犬心肌组织中血小板源生长因子受体β的表达

摘要

Aim: To detect the expression and the effects of PDGFR-β on myocardial remodeling during atrial fibrillation. Methods:Ten dogs underwent continuous rapid atrial pacing(500 beats/min) to create persistent atrial fibrillation. In five rapidly-paced dogs,mibefradil dihydrochloride was given beginning 2 days after pacemaker implantation,continuing until the twenty-fourth week. A group of size-match dogs(n =5) without given mibefradil was used as pure atrial fibrillation group. Another group of size-matched dogs(n =5) without pacemaker implantation was used as control group. RT-PCR was used to detect the expression of PDGFR-β mRNA. Immunohistochemistry was used to detect the expressions of PDGFR-β and cardiac collagen subtype Ⅲ. Van-Cieson( V-G) method was used to detect total cardiac collagen. Results:The expressions of PDGFR-β mRNA in atrial tissue were different among the 3 groups( F = 10. 017 ,P =0. 004) ,which was lower in mibefradil group than that of atrial fibrillation group( P <0.05). The expressions of PDGFR-β,cardiac collagen subtype Ⅲ , and total cardiac collagen in atrial tissue were different among the 3 groups (F = 111.015,39. 358, and 174. 805, P < 0.001) ,which was different between each 2 groups( P < 0.05 ) . Conclusion: There is fibrosis in atrial myocyte during atrial fibrillation, which is not associated with PDGFR-p signaling pathway.%目的:探讨心房颤动(房颤)时心房肌成纤维细胞血小板源生长因子受体β(PDGFR-β)的表达及在心肌重塑中的作用.方法:杂种犬10条,植入起搏器进行右心房快速起搏(520次/min),制作持续房颤模型.5条在起搏术后第2天开始给米贝地尔,共24周,为房颤+米贝地尔组;5条未服药的为单纯房颤组.另取5条未植入起搏器犬作正常对照组.观察24周后取心房肌组织,用RT-PCR检测PDGFR-β mRNA的表达,用免疫组织化学法检测PDGFR-β及Ⅲ型胶原蛋白的表达,用Van-Gieson(V-G)法检测心肌组织总胶原.结果:3组犬心肌组织中PDGFR-β mRNA的表达差异有统计学意义(F=10.017,P=0.004),房颤+米贝地尔组较单纯房颤组降低(P＜0.05).3组犬心肌组织PDGFR-β、Ⅲ型胶原和总胶原表达差异均有统计学意义(F=111.015、39.358和174.805,P均＜0.001),3组间两两比较,差异均有统计学意义(P均＜0.05).结论:房颤时心房肌存在纤维化;心房肌纤维化可能与PDGFR-β信号通路无关.