The expression and significance of heparinase, MMP‐9 in lung tissue of rat pulmonary hypertension model

Abstract

Objective To investigate the relationship between heparinase and matrix metalloproteinase (MMP 9) and pulmonary hypertension by comparing their expression characteristics in pulmonary hypertension model rats and normal rats, and to study their possible mechanisms in pulmonary hypertension and pulmonary vascular structure reconstruction in rats. Methods Pulmonary hypertension model was established by single intraperitoneal injection of Monocrotaline. Twenty rats were randomly divided into normal control group and pulmonary hypertension model group (model group) with 10 rats in each group. Color Doppler ultrasonography was used to measure the changes of pulmonary artery peak velocity and inner diameter of pulmonary artery root. The changes of mean pulmonary artery pressure (mPAP), right ventricular hypertrophy index and mean carotid artery pressure (mCAP) were measured. HE staining was used to observe the pathological morphological changes of pulmonary vessels. The expression of heparinase and MMP 9 in the lung tissues of rats in the two groups was determined by immunohistochemical SABC method. Results The peak velocity of pulmonary artery, inner diameter of pulmonary artery root, mPAP, MMP 9 and right ventricular hypertrophy index in model group were significantly higher than those in control group (P<0.01). There was no significant difference in mean carotid pressure and heparinase expression between the two groups (P>0.05). Conclusion The establishment of pulmonary hypertension model by single intraperitoneal injection of Lilipine has the characteristics of simple operation, low damage to animals and high success rate. Inhibition of MMP 9 synthesis or reduction of MMP 9 activity may be one of the mechanisms by which MMP 9 inhibits wilylin-induced pulmonary hypertension and pulmonary vascular structural reconstruction in rats.