Department of Cardiology, Chonnam National University Hospital, Gwangju, Korea.
Korean Circ J. 2013 Oct;43(10):686-93. doi: 10.4070/kcj.2013.43.10.686. Epub 2013 Oct 30.
It is widely known that angiotensin-II receptor blockers (ARBs) have reverse remodeling effects in atrium. Although atrial fibrillation is frequent in ischemic heart failure clinically, experiments to demonstrate ARB's effects on atrial remodeling in a heart failure model are rare.
A heart failure model and a sham-operated group were formed in 25 Sprague-Dawley male rats of roughly 260 g in weight. Ischemic heart failure models were obtained via ligation of the left anterior descending coronary artery. In the ARB group, 30 mg/kg of losartan was administrated over a day for 4 weeks. Echocardiography was performed to measure left ventricle ejection fraction and left atrial diameter (LAD) at the baseline and 4 weeks after the operation. 4 weeks later, histologic and immunohistochemical evaluation were performed.
Groups were divided into the sham group, heart failure group, and heart failure-ARB group. We maintained 5 rats in each group for 4 weeks after operation. The decrease of left ventricular ejection fraction in the heart failure-ARB group was less than that in the heart failure group (p=0.023). The increase of LAD in the heart failure-ARB group was less than that in the heart failure group (p=0.025). Masson's trichrome stain revealed less fibrosis in the heart failure-ARB group. Immunohistochemical stain and western blot for connexin 43 showed less expression in the heart failure-ARB group.
In the ischemic heart failure model of rats, structurally and histologically, the ARB, losartan, has atrial reverse-remodeling effects. However, electrically, its role as an electrical stabilizer should be studied further.
众所周知，血管紧张素Ⅱ受体阻滞剂（ARB）对心房具有逆重构作用。尽管临床上缺血性心力衰竭患者常发生心房颤动，但证明 ARB 在心力衰竭模型中对心房重构影响的实验却很少。
将 25 只体重约 260g 的雄性 Sprague-Dawley 大鼠分为心力衰竭模型组和假手术组。通过结扎左前降支冠状动脉构建心力衰竭模型。ARB 组大鼠每天给予 30mg/kg 氯沙坦，共 4 周。在术前和术后 4 周分别行超声心动图检查，测量左心室射血分数和左心房内径（LAD）。4 周后，进行组织学和免疫组织化学评估。
将各组分为假手术组、心力衰竭组和心力衰竭+ARB 组。每组各 5 只大鼠在术后 4 周内维持。心力衰竭+ARB 组左心室射血分数的下降幅度小于心力衰竭组（p=0.023）。心力衰竭+ARB 组 LAD 的增加幅度小于心力衰竭组（p=0.025）。Masson 三色染色显示心力衰竭+ARB 组的纤维化程度较轻。免疫组织化学染色和 Connexin 43 的 Western blot 显示心力衰竭+ARB 组的表达水平较低。
在大鼠缺血性心力衰竭模型中，ARB 氯沙坦在结构和组织学上具有心房逆重构作用。然而，其作为电稳定剂的作用还需要进一步研究。
