Changes in expression of hepatocyte growth factor and c-met in lungs in a rat model of pulmonary hypertension

Objective To investgate the changes in the expression of hepatocyte growth factor (HGF)and c-met in the lungs in a rat model of pulmonary hypertension.Methods Eighty 7 week old male SD rats weighing 180-250 g were randomly divided into 2 groups ( n =40 each ):control group (group C) and pulmonary hypertension group (group PH).Pulmonary hypertension was induced by left pneumonectomy and subcutaneous monocrotaline (MCT) 60 mg/kg 2 weeks later.Pulmonary artery pressure and the ratio between the weight of right ventricle and left ventricle + interventricular septum ( RV/LV + S) were measured at 7,14,21 and 28 d after MCT administration.HGF and c-met protein and mRNA expression and TGF-β content in the lung tissue were determined.Results Pulmonary hypertension and right ventricular hypertrophy associated with hypertrophy of pulmonary artery tunica media and muscularization of small pulmonary arteries developed after MCT administration in PH group.In PH group HGF protein and mRNA expression in the lungs was significantly down-regulated as compared with group C.There were no significant differences in c-met protein and mRNA expression in the lungs between the 2 groups.The TGF-β content in the lungs was significantly increased in group PH as compared with group C.Conclusion Decrease in HGF production in the lungs plays an important role in the pulmonary hypertension.Increasing of pulmonary TGF-β may play an important role in the down-regulation of pulmonary HGF expression during pulmonary hypertension. Key words: Hepatocyte growth factor;  Proto-oncogene proteins c-met;  Hypertension, pulmonary