Liu Li, Qu Xiu-Fen, Yu Yang, Bai Bing, Huang Yong-Lin
Department of Cardiology, First Affiliated Hospital of Harbin Medical University, Harbin 150001, China.
Zhonghua Yi Xue Za Zhi. 2009 Oct 20;89(38):2718-21.
To investigate the effect of benazepril on atrial cytoskeleton remodeling in atrial fibrillation (AF) canines induced by chronic rapid atrial pacing (RAP).
Twenty canines were randomly divided into 3 groups: (1) Sham-operated group without RAP; (2) AF group: AF established by RAP at 600 beats per minute for 6 weeks; (3) Benazepril group: benazepril was dosed from 1 week pre-pacing to 6 weeks post-pacing. The diameter of atrial cardiomyocyte was measured, collagen volume fraction (CVF) analyzed by Masson staining and the expression and distribution of desmin were assayed by immunohistochemistry. RT-PCR method was used to semi-quantify the mRNA expression of beta-tubulin and desmin.
The diameter of atrial cardiomyocyte increased in AF group [LA:(27.9 +/- 3.8) microm; RA: (26.8 +/- 3.2) microm] and benazepril group[LA: (25.1 +/- 3.4) microm; RA: (25.2 +/- 3.5) microm] than sham-operated group [LA: (19.6 +/- 2.9) microm; RA: (18.7 +/- 2.6) microm] (P < 0.01). CVF increased in AF group than sham-operated group [LA: (16.9 +/- 1.1)% vs (9.2 +/- 0.9)%, RA: (15.7 +/- 2.3)% vs (9.3 +/- 0.8)%, P < 0.01] and it decreased in benazepril group than AF group [LA: (11.3 +/- 0.8)% vs (16.9 +/- 1.1)%, RA: (10.9 +/- 0.8)% vs (15.7 +/- 2.3)%, P < 0.01]. Normal desmin cross-striations were lost in atrial cardiomyocyte and the desmin organization became irregular in AF group. The A values analyzed by immunohistochemistry of desmin increased in AF group than sham-operated group and they decreased in benazepril group than AF group (P < 0.01). The expression of mRNA level of desmin and beta-tubulin were up-regulated in AF group than sham-operated group, (LA:1.0 +/- 0.3 vs 0.6 +/- 0.3, 0.9 +/- 0.4 vs 0.6 +/- 0.3; RA: 1.0 +/- 0.6 vs 0.6 +/- 0.2, 1.1 +/- 0.3 vs 0.7 +/- 0.4, P < 0.01) and they were down-regulated in benazepril group than AF group (LA:0.8 +/- 0.4 vs 1.0 +/- 0.3, 0.7 +/- 0.3 vs 0.9 +/- 0.4; RA:0.7 +/- 0.3 vs 1.0 +/- 0.6, 0.7 +/- 0.3 vs 1.1 +/- 0.3, P < 0.01).
Benazepril can favorably improve atrial cytoskeleton remodeling in the canine atrial fibrillation model.
探讨贝那普利对慢性快速心房起搏（RAP）诱导的犬心房颤动（AF）模型心房细胞骨架重塑的影响。
将20只犬随机分为3组：（1）未行RAP的假手术组；（2）AF组：以每分钟600次的频率行RAP 6周建立AF模型；（3）贝那普利组：从起搏前1周开始至起搏后6周给予贝那普利。测量心房肌细胞直径，采用Masson染色分析胶原容积分数（CVF），免疫组织化学法检测结蛋白的表达及分布。采用RT-PCR法半定量β-微管蛋白和结蛋白的mRNA表达。
AF组[左心房：（27.9±3.8）μm；右心房：（26.8±3.2）μm]和贝那普利组[左心房：（25.1±3.4）μm；右心房：（25.2±3.5）μm]心房肌细胞直径大于假手术组[左心房：（19.6±2.9）μm；右心房：（18.7±2.6）μm]（P<0.01）。AF组CVF高于假手术组[左心房：（16.9±1.1）%对（9.2±0.9）%，右心房：（15.7±2.3）%对（9.3±0.8）%，P<0.01]，贝那普利组CVF低于AF组[左心房：（11.3±0.8）%对（16.9±1.1）%，右心房：（10.9±0.8）%对（15.7±2.3）%，P<0.01]。AF组心房肌细胞结蛋白正常横纹消失，结蛋白排列不规则。AF组结蛋白免疫组织化学分析A值高于假手术组，贝那普利组低于AF组（P<0.01）。AF组结蛋白和β-微管蛋白mRNA水平表达高于假手术组（左心房：1.0±0.3对0.6±0.3，0.9±0.4对0.6±0.3；右心房：1.0±0.6对0.6±0.2，1.1±0.3对0.7±0.4，P<0.01），贝那普利组低于AF组（左心房：0.8±0.4对1.0±0.3，0.7±0.3对0.9±0.4；右心房：0.7±0.3对1.0±0.6，0.7±0.3对1.1±0.3，P<0.01）。
贝那普利可有效改善犬心房颤动模型的心房细胞骨架重塑。
