The neointimal hyperplasia effect of erythropoietin on carotid artery injury model of rat

Background : Neointimal hyperplasia is major cause of instent restenosis in coronary artery and stenosis in arteriovenous fisula for hemodialysis. Erythropoietin is known to show proliferative effect on vascular smooth muscle cells in vitro study, but there is few in vivo study. This study investigated the effect of erythropoietin given subcutaneously to injured carotid arteries of rats on neointimal hyperplasia. Methods : Sprague-Dawley rat underwent common carotid artery (CCA) balloon injury. Erythropoietin was given subcutaneously to balloon-injured rats (n=6) in 100 U/Kg/week by dividing three times. The control group (n=6) was treated with normal saline only. Two weeks later, the lumen and the neointimal area were obtained and compaired. Actively proliferating cells of neointimal area were observed by microscopy using PCNA staining method. Results : Luminal area was 0.2330.073 , 0.1120.047 in the control and the erythropoietin treated group respectively. The area was significantly smaller in the treatment group(p0.029 , 0.2260.056 and 1.1690.146 min, 1.953>0.465 min in the control and the erythropoietin treated group respectively (p