Representative immunohistochemical photomicrographs for PCNA expression in common carotid arteries (magnification ×400). (A) Wistar rats control. (B) A large number of PCNA positive cells were observed in Wistar rats at day 7 after balloon injury. (C) GK rats control. (D) Strong PCNA immunostaining was seen in GK rats at day 7 after balloon injury. (E) The percentage of PCNA positive cells in Wistar and GK rats after balloon injury increased significantly as compared to Wistar and GK rats control respectively. The percentage of PCNA positive cells in Wistar rats was significantly less than in GK rats. Arrows in images sign PCNA positive cells and lums indicate luminal side of artery. * indicates Wistar control versus Wistar day 7, # indicates GK control versus GK day 7, $ indicates Wistar day 7 versus GK day 7. p<0.01.