Abstract: This study was designed to unravel if arterial grafts treated with phosphate buffered saline or 10Gy irradiation to induce endothelial cell loss, still contain enough biological information to drive proper endothelial regeneration. To demonstrate that damage to donor arteries retains the biological information needed to drive proper differentiation of circulating endothelial precursor cells, arteries were either irradiated (n=10) (10Gy) or stored for 30 min in PBS (n=10) at 20 C. After treatment the arteries were grafted end to end in the aorta descendens of GFP transgenic rats. Three weeks after implantation 5 grafts were recovered and the remaining 5 after 6 weeks and were analyzed immuno histochemically using antibodies to endothelial cell lineage markers (CD31 and von Willebrand factor), Griffiona simplicifolia lectin and Green Fluorescent Protein (GFP). Arteries processed immediately after surgery served as control. Grafted arteries had an intact endothelial layer. Three weeks after graft implantation the arteries were totally denuded for both treatment protocols, while cells attach to the fibroelastic layer. Six weeks after grafting the grafts showed neointima formation and were totally reendothelialized with recipient cells. The fibroelastic layer and adventitia also contained green recipient cells. These results provide compelling evidence that mild treated arteries loose their endothelial lining but still contain the biological information to drive endothelial differentiation of recipient circulating endothelial precursor cells resulting in a intact endothelial layer six weeks after surgery. This in contrast to harsh treated grafts.
R. Torensma , Rene H.J. Brouwer , Karin Van Ginkel , Carl G. Figdor and Sandeep K. Singh , 2007. Total Reendothelialization of Vascular Grafts by Circulating Recipient Endothelial Stem Cells in a Transgenic Green Rat. Research Journal of Medical Sciences, 1: 234-241.