[Effects of Qili Qiangxin Capsule on Lung Structural Remodeling in Heart Failure Rats after Myocardial Infarction and Its Mechanism].

ABSTRACT

Objective To observe the effect of Qili Qiangxin Capsule (QQC) in improving lung struc- tural remodeling on heart failure (HF) rats after myocardial infarction (Ml) and to study its possible mecha- nism. Methods The proximal left anterior descending branch of coronary artery was ligated using a terylene suture to establish acute myocardial infarction (AMI) rat model. After successful AMI modeling rats were ran- domly divided into the model group (intragastrically administered with distilled water at 1 mL/100 g, n =13) and the QQC group (intragastrically administered with QQC at the daily dose of 1 g/kg, n =9). And the sham-opera- tion group (intragastrically administered with distilled water at 1 mL/100 g, n =10) was also set up. After four weeks intervention heart functions of rats were detected using echocardiography. The pathological changes of lung structures were observed by HE and Masson staining method. Protein expressions of lung α-SMA, Collagen I, TGF-ß1, and p-Smad3 of the lung tissue were detected by immunohistochemistry and Western blot. Re- sults Compared with the sham-operation group, ejection fraction (EF) and fraction shortening (FS) decreased (P <0. 05) , protein expressions of lung left ventricular internal diastolic diameter (LVIDd), left ventric- ular internal systolic diameter (LVIDs), end diastolic volume (EDV), end systolic volume (ESV), α-smooth muscle actin (a-SMA), Collagen I, tumor growth factor-ß1 (TGF-ß1), and p-Smad3 increased (P <0.05) in the model group. The muscularized small arteries ratio and collagen area of the lung tissue increased in the model group (P <0. 05). Compared with the model group, EF and FS increased (P <0. 05), protein expressions of LVIDs, ESV, α-SMA, Collagen I, TGF-ß, , and p-Smad3 decreased (P <0.05) in the QQC group. The muscular- ized small arteries ratio and collagen area of the lung tissue decreased in the QQC group (P <0. 05). Conclusion QQC could improve lung structural remodeling degree of HF rats after MI, and its possible mechanism might be achieved by regulating TGF-beta,/Smad3 signaling pathways.