Objective To investigate the long effect of nonpulsatile flow on changes of structure and function in pulmonary microcirculation and to identify the pulmonary reconstruction under this blood perfusion. Methods Canine models with nonpulsatile flow in the right lung was established, and sacrificed 6 months later. Compare endothelial nitric oxide synthase (eNOS) in vascular endothelium, apoptosis in smooth muscle cell with immunohistochemistry by streptavidinbioepidermmultienzyme complex methodes, and observe structural changes in pulmonary arterioles with optical microscope. Results The expression of eNOS in the right nonpulsatile flow perfusing lung was weaker as compared to the left lung （10 846.7±177.8 vs. 13 136.1±189.6;t＝2.240, P=0.040）, the fas was ber as compared to the left lung（14 254.1±217.1 vs. 11 976.7±195.7; t＝2.160, P=0.040）. The ratio of wall thichness/vessel diameter in the right lung（13.64%±12.80% vs. 14.96%±13.10%） and wall area/vessel area(46.40%±11.70% vs. 47.80%±12.20%) was lower as compared to the left lung(Plt;0.05). Conclusion Longterm nonpulsatile flow can decrease the expression of eNOS, contract the muscles in capillary net, and increase pulmonary vascular resistance. Moreover it canincrease the arteriole apoptosis, leading to vascular structure remodeling.
Objective To assess the variation and its significance of messenger ribonucleic acid(mRNA) expression of endothelial nitric oxide synthase (eNOS) in allografts of common carotid transplantation model in white rabbits. Methods To establish an animal model of common carotid transplantation in vivo, 30 rabbits were divided into four groups with random number table. Group A (n=3): autografts; group B (n=9): allografts with the least treated; group C (n=9): allografts treated by penicillin/streptomycin and preserved under room temperature; group D (n=9): allografts treated by penicillin/streptomycin and cryopreserved in liquid nitrogen. All the transplanted grafts were harvested 1-3 weeks later, then compared and evaluated the histomorphological variation and eNOS mRNA expression. Results The vascular structures of autografts in group A were kept approximately normal, only a few infiltration of inflammatory cells could be found. The structural variations of allografts in other trial groups behaved similarly as, intima proliferation in the 1st week, intima hyperplasia in the 2nd week, and both intima and media hypertrophy in the 3rd week. And also there seemed that luminal thrombosis could be found in all the allografts. Allografts in group B were destructed utmost the worst in all the groups. The expression of eNOS mRNA in allografts of group B was significantly less than that in other groups (Plt;0.05). Conclusion The down-regulation of eNOS mRNA expression might lead to intima hyperplasia and thrombosis of allografts.
Objective Observing the expressions of inducible nitric oxide synthase （iNOS） and endothelial nitric oxide synthase （eNOS） mRNA in lung tissues of rats with acute necrotizing pancreatitis （ANP） to explore the role of NOS in ANP associated-lung injury. Methods Forty Wistar rats were assigned into ANP group (n=30) and sham-operation group (SO group, n=10). ANP model was induced by retrograde injection of 5% sodium taurocholate into the bili-pancreatic duct. Pathological changes of the lung tissue were observed under light microscope at 3 h, 6 h and 12 h after the ANP-model operation, and the expressions of iNOS mRNA and eNOS mRNA in lung tissue were assayed by RT-PCR. Results Different degrees of pathological changes of the lung tissue, such as hyperemia, edema, inflammatory cells infiltration, hemorrhage and necrosis, were found in the ANP group. The pathologic injury scores of lung tissue in ANP group were higher than that in SO group (Plt;0.05), and gradually increased with the duration extension of ANP (Plt;0.05). Compared with the SO group, the expressions of iNOS and eNOS mRNA in ANP group were all higher at 3 h, 6 h, and 12 h (Plt;0.05). Conclusions The overexpressions of iNOS and eNOS mRNA may play important roles in lung injury of ANP. This provides us a theory basis that lung injury of ANP could be relieved by inhibiting the expressions of iNOS and eNOS mRNA.
ObjectiveTo compare the biological features of early and late endothelial progenitor cells (EPCs) by isolating and culturing early and late EPCs from the human peripheral blood so as to find some unique properties of EPCs and to propose a suitable strategy for EPCs identification. MethodsMononuclear cells were isolated from the human peripheral blood using density gradient centrifugation. Then, the cells were inoculated in human fibronectin-coated culture flasks and cultured in endothelial cell basal medium 2. After 4-7 days and 2-3 weeks culture, early and late EPCs were obtained respectively. The morphology, proliferation potential, surface markers, cytokine secretion, angiogenic ability, and nitric oxide (NO) release were compared between 2 types of EPCs. Meanwhile, the human aortic endothelial cells (HAECs) were used as positive control. ResultsThe morphology of early and late EPCs was different:early EPCs formed a cell cluster with a spindle shape after 4-7 days of culture, and late EPCs showed a cobblestone appearance. Late EPCs were characterized by high proliferation potential and were able to form capillary tubes on Matrigel, but early EPCs did not have this feature. Both types EPCs could ingest acetylated low density lipoprotein and combine with ulex europaeus Ⅰ. Flow cytometry analysis showed that early EPCs did not express CD34 and CD133, but expressed the CD14 and CD45 of the hematopoietic stem cell markers;however, late EPCs expressed CD31 and CD34 of the endothelial cell markers, but did not express CD14, CD45, and CD133. By RT-PCR analysis, the expressions of vascular endothelial growth receptor 2 and vascular endothelial cadherin in early EPCs were significantly lower than those in the late EPCs and HAECs (P<0.05), but no significant difference was found in the expression of von Willebrand factor and endothelial nitric oxide synthase (eNOS) between 2 type EPCs (P>0.05). The concentrations of vascular endothelial growth factor, granulocyte colony-stimulating factor, and interleukin 8 were significantly higher in the supernatant of early EPCs than late EPCs (P<0.05). Western blot assay indicated eNOS expressed in both types EPCs, while the expression of eNOS in late EPCs was significantly higher than early EPCs at 5 weeks (P<0.05). Both cell types could produce similar amount of NO (P>0.05). ConclusionThe expression of eNOS and the production of NO could be used as common biological features to identify EPCs, and the strategy of a combination of multiple methods for EPCs identification is more feasible.