| Objective: This paper describes effects of postinterventional therapy and human cord blood stem cells transplantation（HCBSCT） of rabbits` left hind limb artery on serum vascular endothelial growth factor（VEGF） and transforming growth factor beta-1（TGF-β1） levels and the pathological changes of blood vessel, to explore the mechanism of the prevention of postangioplasty restenosis by HCBSCT.Methods:1 18 healthy New Zealand white rabbits were divided into Control group（group A, n=6）, Balloon injury group（group B, n=6） and Balloon injury + HCBSCT group（group C, n=6） randomly. The mononuclear cells were isolated by ficoll density gradient centrifugation from human cord blood, and the concentration of the cells was adjusted and used up within 2 hours.2 Every rabbits` left hind limb artery was exposed and labeled in aseptic operation being general anesthesia respectively. The Control group was injected with 0.5ml phosphate buffer solution（PBS） in hind limb arteries and directly sutured after the femoral artery was labeled. When C group`s vessels were separated, clipped the both ends to block the blood by vascular clamps. Then pierced the vessel which was to be expanded and pulled by 3.0mm×40mm balloon, 30 sec, a total of 3 times. Then the arterial endothlia ischemic damage model was completed. Injected umbilical cord blood stem cell suspension 0.5ml（2.0×106） trans-catheter in the hind limb arteries injury and pulled out of the balloon slowly and sutured the puncture site, retreated vascular clamps about 20min`s later to restore blood supply. Group B after intervention operation by the same method, injected with the same volume of PBS in local damage of hind limb artery, sutured the puncture site. Each wound would be sutured well post operation.3 The blood 3.0ml from central artery of ear was collected before the operation start and postoperative 7d and 14 days, separation of the serum out and VEGF/TGF-β1 were measured by enzyme-linked immunosorbent adsorption assay（ELISA）. At the end of the experiment, the local vascular tissue was obtained and stained with H-E, the pathological changes were observed after intervention.4 SPSS13.0 statistical software and Graph Pad Prism 5.0 statistical graphics software were applicated for the results statistical analysis. Normal distribution quantitative data were expressed as means±s. Comparison between the groups were examined using paired samples t-test. One-way variance analysis was used to examine multigroup comparison, the relationship between two variables using linear correlation and regression analysis. Inspection level α = 0.05.Results:1 The preoperative VEGF levels of group A、B and C were no significant difference（F=0.000, P=0.978>0.05）; 7d after operation the level of group B was significantly higher than that of group A（t=2.286, P=0.045<0.05）, the C group`s VEGF level was higher than both group A and B（t=6.196, P=0.000<0.05; t=2.336, P=0.042<0.05）; Compared postoperative 14 d VEGF levels in group B with A, result showed no significant difference（t=1.294, P=0.225>0.05）, group C was significantly higher than that of group A and B（t=6.738, P=0.000<0.05; t =2.641, P=0.038<0.05）.2 The preoperative TGF-β1 levels in group A、B and C has no significant difference（F=0.003, P=0.997>0.05）; 7d after the operation the TGF-β1 levels of group B was significantly higher than that of A（t=9.052, P=0.000<0.05）, TGF-β1 level of group C was higher than group A, but significantly decreased compared with group B, the differences were statistically significant（t=2.675, P=0.023<0.05; t=3.104, P=0.011<0.05）; 14 d after operation group B TGF-β1 levels were higher compared with group A（t=3.443, P=0.006<0.05）, but group C was significantly lower than that of B group（t=2.932, P=0.020<0.05）, still higher than A group, but no statistically significant difference（t=1.262, P=0.236>0.05）.3 Post stem cells transplantation and balloon injury the rabbits` artery serum VEGF and TGF-beta 1 level changes at different time points were negatively correlated（r=-0.539, P=0.000）.4 14 d after operation, the group A stayed a continuous and complete intima, the size of lumen was normal, while there were different degree of vascular subintima hyperplasia, discontinuous elastic layer and smooth muscle cells arranged in disorder with group B, as the lumen narrowing. Compared with group B, subintimal hyperplasia of C was significantly lower and the stenosis of the lumen showed not obvious.Conclusions:1 After the arteries intimal were injuried the levels of serum VEGF and TGF-β1 both increased.2 After the umbilical cord blood stem cells transplantation serum VEGF increased significantly than that of group B, over the same period TGF-β1 remarkably decreased, a negative correlation appearing in the changes between the two factors.3 The umbilical cord blood stem cells transplantation could promote the impaired endothelia repair and inhibit the proliferation of smooth muscle cells and the increase of vascular subintima stroma, so that inhibit the remodeling of the vascular wall that could be effectively in preventing and controlling the occurrence of restenosis after interventional therapy. |
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