Vascular Endothelial Grow Factor₁₆₅ And Angiopoitin-1 Augment Revascularization In A Rat Hindlimb Ischemia Model

Objectives To study the angiogenic effects of adnovirus-mediated human vascular endothelial growth factor 165 and human angiopoietin-1 (Ad5-VEGF165, Ad5-Ang-1) in a rat model of hindlimb ischemia. Methods Rat model of hindlimb ischemia was induced by ligation and peeling off rat's femoral. Ad-VEGF165 and Ad-Angl were intramuscularly transferred into the rat ischemic hindlimb. The expression of VEGF165 and Angl were examined by Western blotting. Immunohistochemistry was performed to illustrate the effects on rat ischemic muscles after gene transferring. Results (1) Western blotting showed a high expression of VEGF165 and Angl in the ischemic hindlimb muscle transferred with Ad5-VEGF165 and Ad5-Ang-1 VEGF165 respectively (2) There was no significant difference between groups on 7 days after transfection. The capillary to muscle fiber ratio were significantly higher in treating groups than those in control groups and were significantly higher inVEGF165+Angl group than in VEGF165 or in Angl groups on day 14th and day 21st. (3)Many structured vessels surrounded by a layer of smooth muscle cells were found in Ad-VEGF165 and Ad-VEGF165+Ad-Angl groups ,the number of SMA+ vessel per muscle fiber was obviously higher than those in control groups.(4)Enormous cells positive for BrdU appeared in treated muscles in Angl, VEGF165, VEGF165+Angl groups and many of them were positive for C-Kit, an antigen expressed by pluripotent marrow stem cells.Some C-Kit+ cells were incorporated in sites of neovascularization. Conclusion (1) Vascular endothelial growth factor165 and angiopoietin-1 can promote neovascularization in rat model of hindlimb ischemia and the angiogenic effect is much more significant in Ad-VEGF+Ad-Angl group. (2) VEGF165 can increase the number of vessles that are coated with smooth muscle cells and whose shapes are similar to arterioles (3) Not only angiogenic effect but perhaps vasculogenic effect also contributed to the neovascularization.