Arterial and venous smooth muscle cell proliferation in response to co-culture with arterial and venous endothelial cells

PURPOSE: To determine whether definable differences exist between arterial and venous smooth muscle cells (SMCs), as measured by proliferative response to co-culture with arterial or venous endothelial cells (ECs), MATERIALS AND METHODS: Human aortic ECs (A-ECs) and saphenous vein ECs (V-ECs) were cultured opposite either aortic SMCs (A-SMCs) or saphenous vein SMCs (V-SMCs). At selected time intervals, SMCs were counted by fluorescence microscopy, RESULTS: In the presence of an intact EC monolayer, A-ECs induced a 9%-31% increase in A-SMC (P less than or equal to .001) and a 15%-37% increase in V-SMC (P less than or equal to .001) proliferation. Saphenous vein ECs induced a 50%-71% increase in A-SMC (P less than or equal to .001) and a 40%-62% increase in V-SMC (P less than or equal to .001) proliferation, The small proliferative difference between A-SMCs and V-SMCs was significant for co-culture with A-ECs (P less than or equal to .001) and V-ECs (P less than or equal to .001), Of note, compared to A-ECs, V-ECs induced a significantly greater A-SMC (P less than or equal to .001) and V-SMC (P less than or equal to .001) proliferative response, CONCLUSION: A small, but definable, difference exists between A-SMCs and V-SMCs, as measured by proliferative response in coculture with A-ECs and V-ECs.