ABSTRACT
Pulmonary arterial hypertension (PAH) is a chronic progressive disease which leads to elevated pulmonary arterial pressure and right heart failure. 3,7-Bis(2-hydroxyethyl)icaritin (ICT), an icariin derivatives, was reported to have potent inhibitory activity on phosphodiesterase type 5 (PDE5) which plays a crucial role in the pathogenesis of PAH. The present study was designed to investigate the effects of ICT on monocrotaline (MCT)-induced PAH rat model and reveal the underlying mechanism. MCT-induced PAH rat models were established with intragastric administration of ICT (10, 20, 40â¯mg/kg/d), Icariin (ICA) (40â¯mg/kg/d) and Sildenafil (25â¯mg/kg/d). The mean pulmonary arterial pressure (mPAP) and right ventricle hypertrophy index (RVHI) were measured. Pulmonary artery remodeling was assessed by H&E staining. Blood and lung tissue were collected to evaluate the level of endothelin 1 (ET-1), nitric oxide (NO), and cyclic guanosine monophosphate (cGMP). The expressions endothelial nitric oxide synthase (eNOS) and PDE5A in lung tissues were determined by Western blot analysis. The results showed that ICT reduced RVHI and mPAP, and reversed lung vascular remodeling in rats with MCT-induced PAH. ICT also reversed MCT-induced ET-1 elevation, NO and cGMP reduction in serum or lung tissue. Moreover, ICT administration significantly induced eNOS activation and PDE5A inhibition. ICT with lower dose had better effects than ICA. In summary, ICT is more effective in preventing MCT-induced PAH in rats via NO/cGMP activation compared with ICA. These findings demonstrate a novel mechanism of the action of ICT that may have value in prevention of PAH.
Subject(s)
Cyclic GMP/metabolism , Cyclic Nucleotide Phosphodiesterases, Type 5/metabolism , Flavonoids/pharmacology , Hypertension, Pulmonary/metabolism , Hypertension, Pulmonary/prevention & control , Monocrotaline/adverse effects , Nitric Oxide/metabolism , Animals , Cyclic GMP/blood , Endothelin-1/blood , Endothelin-1/metabolism , Hypertension, Pulmonary/chemically induced , Lung/drug effects , Lung/metabolism , Lung/physiopathology , Male , Nitric Oxide/blood , Phosphodiesterase 5 Inhibitors/pharmacology , Rats , Rats, Sprague-Dawley , Vascular Remodeling/drug effectsABSTRACT
BACKGROUND: Myocardial infarction (MI) is the main cause of global mortality and morbidity despite the development of therapeutic approaches. ShenZhuGuanXin granules (SG) have been shown to possess cardioprotective effects against coronary heart disease (CHD). However, little is known about its specific mechanism. The present study aimed to investigate the therapeutic effect of SG in cardiac dysfunction and to demonstrate whether SG can promote myocardium angiogenesis by establishing a rat model of myocardial infarction with left anterior descending ligating. METHODS AND RESULTS: Three days after MI, rats were randomly divided into six groups: sham group (sham), MI group (MI), MI + low dose SG (SG-L) group, MI + middle dose SG (SG-M) group, MI + high dose SG (SG-H) group, and MI + compound Danshen dropping pills (CDDP) group as a positive control. Four weeks after administration, rats underwent hemodynamics and echocardiography study. Ventricle tissues were processed for histology and immunohistochemistry studies. Compared with MI group, SG treatment dose-dependently improved cardiac hemodynamic function, attenuated infarct size, increased microvessel density, and increased the expression of PECAM-1/CD31 and VEGF. CONCLUSIONS: SG dose-dependently improved cardiac hemodynamic function and attenuated infarct size by promoting angiogenesis through upregulating PECAM-1/CD31 and VEGF expression.
