Thrombomodulin expression in pulmonary hypertensive rats

Objective To evaluate the role of thrombomodulin (TM) in the pulmonary vascular remodeling in pulmonary hypertensive rats. Methods The pulmonary hypertension animal model was induced by monocrotaline (MCT), and the pulmonary arterial pressure was measured by catherization. The pulmonary TM mRNA expression was studied by RT-PCR and plasma levels of TM were determined by enzyme-linked immunosorbent assay.Results The pulmonary arterial pressure increased significantly on the 21st day after injection of MCT and reached at the peak on the 28th day. The plasma levels of TM increased during the first two weeks,and then decreased significantly. The pulmonary TM mRNA expression began to reduce on the 7th day after injection of MCT. TM mRNA expression in the lungs was significantly lower in test rats than that in the control on the 14th day and was the lowest on the 28th day after injection. Conclusion Decreased thrombomodulin expression may reflect in situ thrombosis due to endothelial injury,which might play an important role in the pathogenesis of pulmonary hypertension.Anticoagulation therapy may be required in the pulmonary hypertersives.