ABSTRACT
Objective In order to investigate the mechanism of the remodeling of pulmonary vascular in hypoxic pulmonary hypertension,normobaric hypoxic rat model (FIO 2=10%)was used to observe the changes of fibronectin(FN)and leminin(LN)within the pulmonary artery by morphological methods. Methods The normobaric hypoxic chamber was used to establish the hypoxic rat model. The lungs were taken off and stained with immunohistochemical method.Some specimens were examined by electromicroscopy. Results Immunohistochemical analysis revealed progressive increase in the deposition of FN and LN,which was most prominent in hypoxia 7d group.The content of FN was higher than LN.Electromicroscope revealed that the SMC of tunia media had transitted from a contractile to a synthetic phenotype. Conclusion Long term hypoxic exposure resulted in increasing of FN and LN in the wall of pulmonary artery.These increase not only raise the tension and make thickening of the vessels themselves,but also provide an environment for the transition of SMC from a contractile to a synthetic phenotype.FN and LN played an important role in the remodeling of pulmonary vascular directly and indirectly. [