The migratory response to platelet-derived growth factor of smooth muscle cells isolated from synthetic vascular grafts in a canine model

Objective: Previous studies on smooth muscle cells (SMCs) harvested from im planted synthetic grafts demonstrate increased production of platelet-deriv ed growth factor (PDGF) hut decreased proliferative response compared with aortic SMCs. The purpose of this study was to determine the migratory respo nse of graft versus aortic SMCs. Method's: Thoracoabdominal grafts were implanted in beagles. The SMCs were harvested from the graft and infrarenal aorta. Migration was determined wit h the use of a razor-scrape assay and computerized image analysis. Results: The mean distance migrated and the number of cells that migrated w ere greater hi graft SMCs at baseline (185 +/- 18 mu m and 108 +/- 17 cells ) compared with aortic cells (110 +/- 10 mu m and 42 +/- 5 cells)(P < .05). Baseline differences persisted after treatment with antibodies to PDGF. Th e addition of PDGF (10 ng/mL) resulted in increased migration in both graft (229 +/- 23 mu m and 146 +/- 20 cells) and aortic SMCs (130 +/- 9 mu m and 70 +/- 5 cells) compared with baseline (P < .05). The relative increase in response to PDGF was similar between the two groups (P = not significant). Conclusions: Graft SMCs differ phenotypically from aortic SMCs; they exhibi t increased basal migration that is independent of autocrine stimulation by PDGF. In contrast to their blunted proliferative response, graft SMCs have a similar migratory response to PDGF compared with aortic SMCs.