摘要目的 检测慢性快速左心房起搏心房颤动(房颤)犬左、右心房内皮素-1(endothelin-1,ET-1)表达和胶原纤维分布的变化,探讨ET-1与房颤心房纤维化间的关系. 方法 16只雄性实验杂种犬随机分为假手术组、房颤1周组、房颤2周组、房颤4周组(每组4只).快速左心房心外膜起搏构建慢性房颤犬模型.分别检测各组实验犬左、右心房ET-1和Ⅰ型胶原(COL1)mRNA和蛋白表达水平.Masson氏染色法检测各组犬左、右心房胶原纤维沉积情况. 结果 (1)随着房颤时间的延长,实验犬左、右心房ET-1、COL1表达水平及胶原容积分数(CVF)逐渐增加(P＜0.05).假手术组与房颤1、2、4周组犬胶原容积分数分别为左心房(3.25±0.51)％、(5.64±0.63)％、(11.45±1.98)％、(16.71±1.59)％,右心房(2.72±0.70)％、(6.46±0.73)％、(15.01±2.11)％、(20.70±2.37)％.(2)房颤2周后,实验犬右心房COL1表达和CVF高于左心房(P＜0.05),但左、右心房ET-1表达差异无统计学意义(P＞0.05). 结论 慢性房颤犬左、右心房纤维化程度不均一,ET-1可能通过促进心房纤维化而在房颤发病中起着重要作用.

abstractsObjective To detect the expression of endothelin-1 (ET-1)and the changes in collagen fiber distribution in left and right atrium in a canine model of chronic atrial fibrillation(AF),in order to investigate the relationship of ET-1 and atrial fibrosis in atrial fibrillation.Methods A total of 16 male canines were randomized into 4 groups:Sham group,AF lasting 1 week group(1W group),AF lasting 2 weeks group (2W group) and AF lasting 4 weeks group (4W group) (n =4,each).A canine model of chronic AF was made by rapid left atrial pacing.The mRNA and protein expression levels of ET-1 and collagen type Ⅰ(COL1)in left and right atrium of canines were measured by real-time quantitative polymerase chain reaction(PCR) and Western Blotting respectively in each group.Collagen fiber deposit in left and right atrium of canines in each group was assessed by Masson's staining.Results Along with prolonged AF duration,the mRNA and protein expression levels of COL1 and ET-1 as well as collagen volume fraction(CVF)in left and right atriums were gradually increased in chronic AF groups of 1-,2-,4-weeks duration versus the sham group.CVF:left atrium (5.64 ±0.63)％,(11.45±1.98)％,(16.71±1.59)％ vs.(3.25±0.51)％,right atrium(6.46±0.73)％,(15.01± 2.11) ％,(20.70 ± 2.37) ％ vs.(2.72±0.70)％,all P＜0.05.The mRNA and protein expression levels of COL1 and CVF in canine AF groups were higher in right atrium than in left atrium after two weeks of AF (all P ＜ 0.05),while ET-1 mRNA and protein expressions showed no differences between left atrium and right atrium (P＞ 0.05).Conclusions The distribution of collagen fibers in left and right atriums is anisotropic in a canine model of chronic AF.ET-1 may play an important role in the development of AF by promoting atrial fibrosis.