Objective: To explore the role and mechanism of Wenyang Yiqi decoction on regulating lung structure remodeling in rats with heart failure after myocardial infarction.Method: The heart failure rat model was set up and the rats were divided into 6 groups:Wenyang Yiqi decoction high

middle

and low (2.0

1.0

0.5 g · kg-1 · d-1)dose groups

positive control group (prednisone 0.1 g · kg-1 · d-1)

model group and sham operation group (gavage administration of the same volume of distilled water).All the groups were treated for eight weeks. After gavage administration

the color Doppler ultrasonic diagnostic instrument was used to measure left ventricular end-diastolic diameter (LVIDd)

left ventricular end systolic diameter (LVIDs)

short axial shortening fraction (FS) and ejection fraction (EF). The wet lung/body weight

dry lung/body weight were determined

and HE staining was used for lung tissue slice. The enzyme-linked immunosorbent assay (ELISA)was used to determinate the tissue growth factor-β1 (TGF-β1)

Collagen and α-smooth muscle actin (α-SMA)

p-Smad3 protein family (p-Smad3) protein expression.Result: As compared with the model group

the LVIDd and LVIDs of Wenyang Yiqi decoction high dose group and medium dose group were significantly increased; the FS and EF levels were significantly decreased(P<0.05); the wet lung/body weight and dry lung/body weight were significantly increased(P<0.05). The alveolar was seriously damaged and the wall of alveolar was thickened in the model group. There was no obvious alveolar rupture

no lymphocytic infiltration

and no collagen deposition in the sham operation group and prednisone group. There was light alveolar rupture and less collagen deposition in Wenyang Yiqi decoction high dose group and middle dose group; while in low dose group

there was obvious lymphocyte infiltration and thickened alveolar wall. As compared with the model group

the expression levels of α-SMA

Collagen

TGF-β1

and p-Smad3 of Wenyang Yiqi decoction high dose group and middle dose group were significantly decreased(P<0.05); and the mRNA of TGF-β1 and mRNA of p-Smad3 were also significantly decreased in the high dose and middle dose group (P<0.05). As compared with the sham operation group and prednisone group

the α-SMA

Collagen

TGF-β1

and p-Smad3 levels were significantly increased in Wenyang Yiqi decoction low dose group(P<0.05)

and there was an positive relationship between TGF-β1 mRNA and TGF-β1

p-Smad3 mRNA

α-SMA

Collagen(P<0.05).Conclusion: Wenyang Yiqi decoction can block TGF-β1/Smad3 pathway signal transduction

inhibit the expression of protein including α-SMA

Collagen

TGF-β1 and p-Smad3

and then inhibit the activation of fibroblast proliferation

reduce the sedimentation of lung Collagen

and finally reach the role of inhibition of lung tissue remodeling.