ABSTRACT
AIM:To study the expression of Jagged 2/Notch3 signaling molecules in pulmonary vascular wall of pulmonary hypertensive rats induced by monocrotaline .METHODS: SD rats were randomly divided into normal control group (C group,n=15), solvent control group (S group,n=15) and monocrotaline model groups (M group,n=15).The model of pulmonary hypertension was established by a single subcutaneous injection of monocrotaline (50 mg/kg).The rats in S group were given a single subcutaneous injection of the same dose of solvent .After 4 weeks, the pulmonary vascular remodeling was assessed by HE staining , and the mean pulmonary artery pressure ( mPAP) and right ventricular systolic pressure (RVSP) were determined by right heart catheterization .The expression of Jagged2/Notch3 /Hes5 molecules in the pulmonary vascular wall was detected by immunohistochemical method and real -time PCR.RESULTS:Compared with S group and C group , the percentage of medial wall thickness of smaller arteries in model group increased significantly (P<0.01).The levels of mPAP and RVSP in M group were significantly higher than those in S group and C groups (P<0.01).The results of real-time PCR showed that the expression of Jagged 2, Notch3 and Hes5 was significantly increased in M group compared with S group and C group .The data from immunohistochemical detection indicated that Jagged 2 mainly expressed in the intima of small lung artery , Notch3 and Hes5 mainly expressed in the medial smooth muscle cells .Com-pared with S group and C group , the expression of Jagged 2 and Notch3 was significantly increased in the lung small arteries of M group.CONCLUSION:The activation of Jagged2/Notch3 signaling pathway might play an important role in the for-mation of pulmonary hypertension .