Correlations study between obstruction of collaterals and COPD with Pulmonary Hypertension

Objective:To explore the Correlations between obstruction of collaterals and COPD with Pulmonary Hypertension,we observed the changes in pathological and vascular endothelial function in rats with COPD and Pulmonary Hypertension. Methods:SD rats were given a single dose of MCT (60 mg/kg) to induce the model of COPD with Pulmonary Hypertension,collected serum and the lung tissue specimens after 4 weeks. The Pathological features of pulmonary arteries were observed and the expression of VEGF in pulmonary artery wall were measured by HE staining and immunohistochemistry technique. The levels of NO and Endothelin-1 (ET-1)in lung homogenate were measured by radio immunoassay (RIA) and nitrate reductase method; Vascular endothelial growth factor (VEGF) in serum was measured by euzymelinked immunosorbent assay respectively.Results:Compared with normal control group,pulmonary artery wall in model group was thicker and lumens was narrower and endothelial dysfunction obviously. The expression of VEGF in pulmonary artery wall of model group was higher than that of normal control group(P0.01). Compared with normal control group,the NO in model group decreased(P0.01) and the level of ET-1 in lung tissue increased obviously(P0.05),the expression of VEGF in serum of model group was significantly higher than that in normal control(P0.01).Conclusion:These results indicate that a single intraperitoneal injection of MCT could induce the pulmonary artery wall endothelial dysfunction ,pulmonary vascular remodeling,lead to increased pulmonary artery pressure which correspond to the pathology character of COPD developing Pulmonary Hypertension. The pulmonary vasomotor dysfunction in rats with COPD and Pulmonary Hypertension were closely related with invalidism result in either qi depression to blood stasis or diseases on pulmonary collaterals.