Experimental Study About VEGF Subcutaneous Injection Affects The Survial Of Autologous Fat Graft In Rat

Autolougous fat particles is made by liposuction from their own body fat tissue through the process of purification, 4～6mm in diameter, contain some part of free fat cells[1].autolougous fat particles are injected into body soft tissues depression by syringe in order to correct body deformity which be a conventionaltechnique in plastic surgery.autolougous fat particles have no rejection,can be conveniently collected ,slightly tissue damage,soft touch in keeping with surrounding tissue,the filling effect is natural.But fat graft havs a high resorption rate,the long term fat survival rate is not high.the most key point for keeping transplant effect is to promote the early revasculartion and preadipocyte differeniation.the domestic and foreign fat graft research have evinced that angiogenic factors such as Ang-1 and bFGF can promote the fat angiogensis,increase the survival rate of grafted fat.VEGF is the most effective,specific angiogenic factor in present findings,it can promote endothelial cell proliferation,increase the vessel permeability,degradate the extracellular matrix and accelerate the graft tissue neovascular.Objective: through applying the exogenous recombinant murine vegf165 local injection in autologous fat particle transplantation experiment,in order to observing the early period of angiogensesis in the recipient site after autolougous graft and if increase the survival rate of fat cell.Methods :the study comprised Thirty-six female Wistar rats weighing 250 g were randomly divided into three equal groups according to the treatment of free autolougous fat transplant into rat subcutaneous.each rat was take fat mass from bilateral inguinal areas after a normal surgery and cut the fat block into 1-2mm particles, use saline washing away the blood and anaesthetic ,the finale volume of the purified fat approximately to 1.5ml,then injected the fat into rat subcutaneous. Group 1 rats were treated with sterile saline (control group). Group 2 rats treated with 100ng/ml VEGF.Group 3 rats were treated with 200ng/ml VEGF .The half of transplanted fat in each group were taken out after 10 days were stained with hematoxylin-eosin and CD34 immunohistochemistry method.The microvessel density was measured by medical imagine analysis system.The remain rats in each group were taken out transplanted fat mass after 30 days,and their remain volumes were measured by cylinder.the data were process by SPSS stastic program.Results: vascular endothelial cell CD34 stained into pale brown in each group.The mean microvessel density in VEGF groups was significantly higher as compared with in saline groups in the same observing periods(P<0.01).There was no significant difference between the two VEGF difference concentration treated groups.Conclusions: A effected concentration VEGF local injection may promotes angiogenesis in fat particle auto-transplantation and improve the long term survival rate of fat particles.