| Objective:The objection of present study is to compare the morphology, function and the level of endothelial cells growth factor receptor-2 (vascular endothelial growth factor receptor, VEGFR-2)in the vascular endothelial cells (Endothelial cells, ECS), which grow on the expanded polytetrafluoroethylene (expanded polytetrafluoroethylene, e-PTFE). To investigate the role of e-PTFE in pulmonary artery and provide experimental data and theoretical basis for the clinical application of artificial blood vessels in the pulmonary artery reconstruction, the artificial blood vessel, reconstructed to replace the pulmonary artery, thoracic aorta and inferior vena cava, were employed in the present study.Method 27 healthy Dian Nan small ear pigs (25-35Kg, male or female) were used in the present study. They were randomly divided into three groups:e-PTFE artificial vascular replacement pulmonary artery group (pulmonary artery group), e-PTFE artificial vascular replacement thoracic aorta group (thoracic aorta group) and e-PTFE artificial vascular reconstruction of inferior vena cava group (inferior vena cava group). The expression of e-PTFE in the transplantation of artificial blood vessel hemodynamic, alterations of endothelial cell structure, vascular diameter and function were determined by using light microscopy, echocardiography and electron microscopy. The distribution and expression of VEGFR-2 protein in the transplantation of artificial blood vessel were also detected by immunohistochemistry, quantitive Real-time poly merasechain reaction (qRT-PCR) and Western blot, at each time point after reconstruction operation. In order to evaluate the value of the e-PTFE artificial blood vessel which was replaced the pulmonary artery, we also analyzed the results and compared differences among groups.Result1. Vascular color Doppler ultrasound:we have not found the thrombosis neither in pulmonary artery group nor in thoracic aorta group. However, we can find thrombosisin the inferior vena cava group. Besides, we also found portal vein widened and peritoneal effusion in the inferior vena cava group.2. Direct observation of thrombus:the diameter of the pulmonary artery and thoracic aorta group were measured after two weeks of operation. The visible thrombosis was observed in these two groups, but the diameter stenos of artificial blood vessel were not more than 50% compared with that of the normal group. We also found that the visible thrombosis in the inferior vena cava group at the end of 2 weeks,3 months and 6 months after operation. The diameter stenos of inferior vena cava group were more than 50% at each time point (vs.normal group). However, the visible thrombosis was observed in the artificial vascular of inferior vena cava group.3. The rate of Endothelial cell coverage:the rate of pulmonary artery group VS thoracic aorta group had no statistical significance (P> 0.05);either pulmonary artery group or thoracic aorta group VS inferior vena cava group showed statistical significance (P<0.05), respectively.4. Changes of Molecular biology:(1) the level of VEGFR-2 gene detected by qRT-PCR:Pulmonary artery group VS thoracic aorta group showed no statistical significance (P>0.05); either pulmonary artery group or thoracic aorta group VS inferior vena cava group showed statistical significance (P<0.05), respectively. (2) the level of VEGFR-2 protein expression evaluated by Western Blot:either Pulmonary artery group or thoracic aorta group VS inferior vena cava group showed statistical significance on 2 week and 3 month after operation (P<0.05), respectively; either Pulmonary artery group or thoracic aorta group VS inferior vena cava group showed no statistical significance (P>0.05) on 6 month point.Conclusion1. There is no significant difference of patency between pulmonary artery group and thoracic aorta group after being replaced by artificial blood vessel. However, compared with that of inferior vena cava group, all groups descr-ibed above showed poor patency of artificial blood vessel.2. The morphology of ECs grows on artificial blood vessels replaced by pulmonary artery or thoracic aorta was consistent. However, the morphology of ECs was significant difference compared with that of the inferior vena cav-a group.3. We found that the level of VEGFR-2 either in pulmonary artery group or thoracic aorta group is higher than that of the inferior vena cava group. At 2 week and 3 months after operation, VEGFR-2 in vascular ECs of pulmonary artery showed no difference compared with that of thoracic aorta group. However, compared with that of the inferior vena cava group, VEGFR-2 in vascular ECs of pulmonary artery significantly increased at 2 week and 3 months after operation. At 6 months following of operation, the level of VEGFR-2 secretedby implanted artificial blood vessel ECs showed no significant different among these three groups and even closed to the normal level. |
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