Objective In order to study the important role of two specific VEGF receptors(Flt 1 and KDR) in angiogenesis, we design the experiment to detect the gene expression of Flt 1 and KDR in human umbilical vein endothelial cells cultured in hypoxium. Methods We cultured the human umbilical vein endothelial cells for different time and treated it with vascular activate factor, such as endothelin (ET), Nitric oxide (NO), LNNA (inhibitor of NO). The expressive level was analyzed by Northern blot or RT PCR. Results Hypoxia increases flt 1 mRNA in endothelial cells at 6 hours. Administration of ET stimulated an increase in flt 1 mRNA. NO inhibited expression of flt 1 mRNA. LNNA increased its expression. Hypoxia partly affected the expression of KDR. LNNA enhanced the VEGF transcripts. Conclusion Hypoxia up regulated flt 1 gene expression, partly KDR. ET enhanced and NO inhibited flt 1 gene expression.

Objective To investigate the regulation and expression of VEGF gene in human umbilical vein endothelial cells under hypoxia and the influence of vascular activators,such as endothelin(ET),nitric oxide(NO)and NO synthesis inhibitor N-nitro-L-Arginie(L-NNA),on the expression of VEGF.Methods Culture the human umbilical vein endothelial cells and then treat by hypoxia and vascular activators.The expression on VEGF mRNA level and protein level were assayed by northern blots,ELISA and computer figure analysis system respectively.Results When human umbilical vein endothelial cells were subjected to hypoxia for 6 hours,the expression of VEGF began to increase.ET could increase the expression and NO inhibited it,and LNNA affected the expression of the VEGF.VEGF protein concentration in the cell culture media matches the mRNA result.They are 6 hours hypoxia (8^2?1.1)?g/L,ET+6 hours hypoxia(9^37?1^02)?g/L,NO+6 hours hypoxia(2^86?0^91)?g/L,LNNA+6 hours hypoxia(14^75?1^87)?g/L respectively.Conclusion (1)Hypoxia can induce the expression of VEGF in human umbilical vein endothelial cells.(2)ET can increase the inducible effect of hypoxia,NO can inhibit it and LNNA stimulated the expression of VEGF in human umbilical vein endothelial cells.

BACKGROUND: Heme oxygenase-1 (HO-1) promotor region has a pair of dinucleotide(guanosine thymidine, GT) repeats with a lengthy polymorphism, also named microsatellite polymorphism. Experiments in vitro have shown that we can indirectly learn about the level of gene transcription by measuring the number of GT repeats.OBJECTIVE: To investigate if an association exists between restenosis after percutaneous coronary intervention(PCI) and microsatellite polymorphism in HO-1 gene promoter.DESIGN: A case-control study based on the observation of the patients with coronary heart disease after undergoing coronary stenting.SETTING: Wards of the department of cardiology of a university hospital.PARTICIPANTS: A total of 118 patients were admitted from April 1996 to May 2002 at the Department of Cardiology of the First Hospital of Peking University who underwent successful coronary stenting. Inclusion criteria: The patients with coronary heart disease who underwent coronary stent implantation for more than 3 months now came to perform coronary angiography in follow-up. Exclusion criteria: Angiography showed that the stenosis of lumen in diameter in the patients with coronary heart disease was less than 50%and the follow-up in angiography was less than three months. There were 92males and 26 females aged(62±10) years old and the informed consents were obtained. The patients were divided into two groups according to the criteria stipulated by American Heart,Lung and Blood Association: in-stent restenosis(68 cases) and non-restenosis (50 cases).METHODS: DNA of the peripheral blood was isolated from the whole blood. The length of GT repeat was confirmed by PCR amplification and Spreadex Gel electrophoresis. Selected samples were sequenced with Sanger's method.MAIN OUTCOME MEASURES: Microsatellite gene frequency of HO-1promoter and its relationship with restenosis RESULTS: Patients with GT repeats <25 GT in the HO-1 gene promoter on either allele had significantly less often restenosis than patients without (47.5% vs. 68.4% ,P<0.05). After controlling some possible confound ing factorsfor coronary heart diseases, multivariate analysis indicated that still there was a significant difference between the two groups in restenosis rate(odd ratio 0. 418,95% CI: 0. 197 to 0. 887,P<0.05).CONCLUSION: The present study indicated that short(GT) n repeats of HO-1 gene promoter is associated with reduced post-PCI restenosis, which suggests the genetic contribution to in-stent restenosis after stent implantation. It may have important meanings to prevent the occurrence of restenosis.