Pulmonary vascular remodeling after left lung pneumonectomy in rats / 中国实验动物学报

ABSTRACT

Objective To investigate the existence of pulmonary vascular remodeling after left pneumonectomy in rats and the role of hypoxia inducible factor-lα( HIF-1α) and vascular endothelial growth factor ( VEGF) in pulmonary vascular remodeling.Methods Twenty-four healthy male Sprague-Dawley rats were randomly divided into experimental and control groups, 12 in each group.The rat models of pulmonary vascular remodeling were created by open-chest left pneumonectomy.After 12 weeks of feeding, the mean pulmonary artery pressure ( mPAP) and partial pressure of arterial oxygen ( PaO2 ) of each rat were measured.The ultrastructure of small arteries in the lung specimens were examined by e-lectron microscopy.Muscularized degree of three kinds of small pulmonary vessels ( muscularized artery MA, partially mus-cularized artery PMA, and non-muscularized artery NMA) were observed by light microscopy, and the percentage of each kind of pulmonary arteries ( MA%, PMA%, NMA%) were calculated.Arterial external diameter, media thickness of ves-sel ( MTV) , total vascular area, media area of vessel ( MAV) , MTV%and MAV%were calculated as indicators of pul-monary vascular remodeling.The expressions of HIF-1αand VEGF in artery were detected by immunohistochemistry.Re-sults The values of mPAP, MA%, PMA%, MTV, MAV, MTV% and MAV% in the experimental group were signifi-cantly higher than those in the control group (P<0.01), but the value of PaO2 and NMA%were significantly lower than those in the control group (P<0.01).The IOD value of HIF-1αand VEGF expressed in the pulmonary arterial wall of the experimental group were 26.47 ±4.16 and 42.04 ±3.79, respectively, significantly higher than those in the control group (6.12 ±2.14 and 11.53 ±2.29, P<0.01).Linear correlation analysis showed that the expression of HIF-1αand VEGF was positively correlated with MTV% and MAV%, negatively correlated with PaO2 , and the HIF-1αexpression was posi-tively correlated with VEGF expression.Conclusions A rat model of pulmonary vascular remodeling can be successfully established by left pneumonectomy.Hypoxia is a key factor in the development of pulmonary vascular remodeling, HIF-1αand VEGF may play an important role in its pathogenesis.