Vascular smooth Muscle cell (VSMC) proliferation remains a major cause of veno-arterial graft failure. We hypothesised that exposure of venous SMCS to arterial pressure would increase KLF5 expression and that of cell cycle genes Porcine jugular veins were perfused at arterial or venous pressure in the absence of growth factors. The KLF5, c-myc, cyclin-D and cyclin-E expression were elevated within 24 h of perfusion at arterial pressure but not at venous pressure Arterial pressure also reduced the decline in SM-myosin heavy chain expression. These data Suggest a role for KLF5 in initiating venous SMCs proliferation in response to arterial pressure. (C) 2009 Elsevier Inc. All rights reserved.