摘要
目的观察苯肾上腺素对腹主动脉缩窄导致心肌纤维化的作用及可能机制。方法雄性昆明（KM）小鼠42只,体重24-30 g,其中28只采用腹主动脉缩窄术（AAC）建立压力超负荷诱导心肌反应性纤维化的动物模型,8周后将模型小鼠随机分为4组,AAC组、苯肾上腺素（PE）组（AAC＋PE组）、哌唑嗪（Praz）组（AAC＋Praz组）和普萘洛尔（Prop）组（AAC＋Prop组）,每组7只,其中AAC＋PE组给予PE 0.65 mg/（kg·d）腹腔注射,AAC＋Praz组予Praz 5 mg/（kg·d）灌胃,AAC＋Prop组给予Prop 10 mg/（kg·d）灌胃,AAC组给等量生理盐水灌胃,连续4周;另设空白对照组及假手术组各7只,其中假手术组只分离腹主动脉而不结扎,二组均给予等量生理盐水持续灌胃。给药4周后处死动物,取左心室游离壁组织,HE染色观察组织细胞形态学变化,胶原容积分数（CVF）、羟脯氨酸（Hyp）含量测定及Ⅰ、Ⅲ型胶原蛋白免疫组化染色观察心肌胶原,Western blot方法测定α-平滑肌肌动蛋白（α-SMA）、转化生长因子β1（TGF-β1）、p-Smad2和p-Smad3蛋白表达。结果 ACC术后12周小鼠心脏均发生明显纤维化,与空白对照组相比,CVF、Hyp含量显著升高（P〈0.01）,Ⅰ、Ⅲ型胶原表达增多（P〈0.01）,α-SMA、TGF-β1、p-Smad2及p-Smad3蛋白表达增加（P〈0.01）,假手术组CVF、Hyp含量以及α-SMA、TGF-β1、p-Smad2、p-Smad3蛋白表达和Ⅰ、Ⅲ型胶原含量变化不明显。与AAC组比较,AAC＋PE组和AAC＋Prop组左心室CVF、Hyp含量及Ⅰ、Ⅲ型胶原表达均明显减少（P〈0.01）,α-SMA、TGF-β1、p-Smad2和p-Smad3的蛋白表达水平降低（P〈0.05）,而AAC＋Praz组上述各指标无明显变化（P〉0.05）;AAC＋PE组与AAC＋Prop组相比,上述指标均无统计学差异（P〉0.05）。结论苯肾上腺素可能通过TGF-β1/Smads信号通路改善压力超负荷介导的小鼠心肌间质纤维化,其作用与普萘洛尔相似。
Aim To explore the effect of phenylephrine（PE,α1-adrenergic receptor agonist） on myocardial fibrosis induced by abdominal aorta coarctation（AAC） in mice and to elucidate related mechanism. Methods In this study,mice model of myocardial fibrosis were established by abdominal aorta coarctation in 28 mice,and 14 mice were randomly taken as control group and sham group. Eight weeks after surgery,mice were divided into 4 groups： AAC group,AAC ＋ PE group（phenylephrine 0. 65 mg/（kg·d） intraperitoneal injection）,AAC ＋ Praz group（prazosin 5 mg/（kg·d） gavage） and AAC ＋ Prop group（propranolol 10 mg/（kg·d） gavage）. After administrated therapy for 4 weeks,the morphological changes of cardiac tissue were observed by hematoxylin-eosin（HE） staining,collagen volume fractions（CVF）of left ventricle were observed by Van-Gieson（VG） staining and hydroxyproline concentration were studied. The proteincontent of collagenⅠand collagen Ⅲ were examined by immunohistochemical analysis. Western blot was used to measure the myocardial protein expression of α-smooth muscle actin（ α-SMA）,transforming growth factor-β1（ TGF-β1）,phosphor-drosophila mothers against decapentaplegic protein 2（ p-Smad2） and phosphor-drosophila mothers against decapentaplegic protein 3（ p-Smad3）. Results Compared with control group,the heart of AAC group were developed fibrosis obviously.The CVF level and myocardial hydroxyproline concentration was significantly higher in AAC group as the same as protein level of collagenⅠand collagen Ⅲ（ all P〈0. 01）,and the protein expressions of α-SMA,TGF-β1,p-Smad2 and p-Smad3 were also elevated（ all P〈0. 01）. PE treatment significantly reduced the CVF,hydroxyproline concentration,decreased expression of collagenⅠand collagen Ⅲ and expressions of α-SMA,TGF-β1,p-Smad2 and p-Smad3 in myocardial tissue compared with the AAC group（ all P〈0. 05） as the same as propranolol treatment. However,prazosin had no effect on protein levels
出处
《中国动脉硬化杂志》
CAS
北大核心
2016年第11期1097-1103,共7页
Chinese Journal of Arteriosclerosis
基金
国家临床重点专科建设项目
