BACKGROUND: The current study was performed to investigate the effect of adenosine monophosphate (AMP) – activated protein kinase (AMPK) activation on the extracellular matrix (ECM) remodeling of pulmonary arteries in pulmonary arterial hypertension (PAH) and to address its potential mechanisms.

MATERIAL AND METHODS: PAH was induced by a single intraperitoneal injection of monocrotaline (MCT) into Sprague-Dawley rats. Metformin (MET) was administered to activate AMPK. Immunoblotting was used to determine the phosphorylation and expression of AMPK and expression of tissue inhibitor of metalloproteinase-1 (TIMP-1). Gelatin zymography was performed to determine the activity of matrix metalloproteinase-2 (MMP-2) and MMP-9.

RESULTS: Activation of AMPK by MET significantly reduced the right ventricle systolic pressure and the right ventricular hypertrophy in MCT-induced rat PAH model, and partially inhibited the ECM remodeling of pulmonary arteries. These effects were coupled with the decrease of MMP-2/9 activity and TIMP-1 expression.

CONCLUSIONS: This study suggests that activation of AMPK benefits PAH by inhibiting ECM remodeling of pulmonary arteries. Enhancing AMPK activity might have potential value in clinical treatment of PAH.

Keywords: AMP-Activated Protein Kinases - metabolism, Enzyme Activation - drug effects, Extracellular Matrix - pathology, Hypertension, Pulmonary - pathology, Matrix Metalloproteinase 2 - metabolism, Metformin - pharmacology, Monocrotaline - pharmacology, Pulmonary Artery - enzymology, Random Allocation, Tissue Inhibitor of Metalloproteinase-1 - metabolism, Vascular Remodeling - drug effects