Changes Of VEGF And HIF-1 Expression And Their Correction In Rat Lung Tissue After Acute Pulmonary Thromboembolism

Purpose:Many studies suggest that hypoxia inducible factor-1 (HIF-1) is a hypoxia response play an important role in the transcription factor.Vascular endothelial growth factor (VEGF) is a key factor to promote angiogenesis.Both in myocardial ischemia disease, ischemic diseases, ischemia, hypoxia study of disease were highly expressed in the pathophysiology of these diseases play an important role.Pulmonary embolism (PE) leading to lung injury, oxygenation dysfunction, causing hypoxia. In acute pulmonary thromboembolism, HIF-1, VEGF expression is high?The existence of two related mechanisms?China reports no clear.In this study, right heart catheterization using modified autologous blood clots prepared rat model of pulmonary embolism, pulmonary embolism in lung tissue of rat vascular endothelial growth factor (VEGF), hypoxia inducible factor 1 (HIF-1) expression, and to explore after PTE and VEGF, HIF-1a relevance and possible mechanism.Methods:Selected 40 Wistar adult rats, weighing 250-300g, male.Randomly divided into 5 groups, normal control group,1 h after embolization group,6 h after embolization group 12 h after embolization group 24 h after embolization group, n= 8.1. A rat model of acute pulmonary embolism Sterile conditions, blood made of carotid emboli.Along the front midline incision into the right external jugular vein cannulation has been prepared thrombosis. So 1,6,12,24 h, respectively thoracotomy the lung.Note the normal control group at corresponding time points, the same amount of saline injection,24h thoracotomy the lung.Fixed, plus wax-embedded.Conventional refrigerator.2. Immunohistochemical detection of lung HIF-1 a, VEGF expressionSections, the conventional lost-wax to water H2O2 block,5%BSA serum closed, plus one anti-4℃overnight after, followed the next day plus biotin-labeled second antibody and SABC, color by DAB, hematoxylin, transparent, Fengpian, color under the microscope results.The results determine the HIF-la-positive form over the nuclei and cytoplasm appeared brown particles, according to staining intensity and percentage of positive cells multiplied into (-)-(+++)。VEGF-positive cells determined by reference Takaha shi VEGF expression and other methods will be divided into a total of four (-)-(+++) to the cytoplasm or membrane of brown yellow as positive.Statistical analysis using statistical software SPSS13.0, HIF-la and VEGF expression was analyzed by rank sum test, HIF-la and VEGF using Spearman correlation between correlation analysis.Results:1, all the embolization group into the thrombus emboli, the rats were immediately shortness of breath, RR= 35±5 times/min, heart rate, HR= 115±10 times/min; lips and toes are clearly brought out cyanotic; activities decreased more for the prone position; loss of appetite,24h did not take the initiative to eat inside.After injection of saline control group breathing steady, RR= 20±3 times/min, heart rate normal, HR= 75±5 times/min; not appear cyanotic; activities as usual; active feeding. 2, lung embolism and bronchial tissue with HE staining showed that pulmonary artery line, and other small vessels of different sizes of memory in the emboli, pulmonary embolism showed diffuse lesions, and embolization with pathological changes in time gradually increased. Control group, no lung tissue 24 hours after embolization, with normal structure.3, control group without lung tissue expression of HIF-la.Embolization group lung tissue of rats at different time points cell nucleus, the cytoplasm appeared in both the expression of HIF-1 a, the positive rate was 100%expression intensity between the "++"-"+++", and over time extended, high expression increased,12h of peak, remained stable until 24h.HIF-1 expression in the embolization group at different time inter-group differences were statistically significant (H= 17.20, P= 0.016<0.05).Control group, lung tissue cells, vascular endothelial cells VEGF expression was 37.5%, but was light color, expression of"+" main; embolization of the lung tissue expression of positive rate of VEGF increased with time increased expression to 12 h for high, mostly "++","+++", remained stable until 24h.VEGF in the embolization group between different time groups was statistically significant difference in expression (H= 17.57, P= 0.004 <0.05).4, through the different time points after embolization in the lung tissue of HIF-1 a and VEGF expression in the dynamic observation, found that changes in expression between the two have the same trend, a positive correlation (r= 0.600, P<0.05).Conclusion:1.In this study, adult Wistar rats, right heart catheterization through the improvement of pulmonary embolism model was prepared, with thrombosis rates, strong controllability, and good survival advantage, is pulmonary embolism an ideal animal model for basic research. 2. HIF-1α, VEGF PTE in the rat lung tissue was overexpressed, and the positive correlation between the two.Tips HIF-1αas the upstream gene, may regulate its downstream genes to increase expression of VEGF, HIF-1αconfirmed pulmonary embolism in the pathophysiological process in the play "start" effect on the clinical to HIF-1αas a target gene to provide treatment of pulmonary a new idea.