MIGRATION OF HUMAN VASCULAR ENDOTHELIAL AND SMOOTH-MUSCLE CELLS

Abstract

Migration of umbilical vein endothelial and smooth muscle cells was studied in vitro by measuring the increase in surface area at specific time intervals of confluent cell colonies advancing under agarose gels that contained both Morgan''s medium 199 and various types of human sera. First passage cultures of endothelial cells or 3-6 passage smooth muscle cells were plated into wells punched in agarose gels, at a seeding density of 50,000 cells/well. At zero time the size of the cell colonies was 35.4 mm 2.+-. SE 0.1. Irradiation (1500 rad) did not affect the expansion of the cell colonies although 3H-thymidine uptake was inhibited. Endothelial cells migrated under the agarose gels concentrically as contiguous sheets. When exposed to either 20% platelet-poor plasma platelet-rich plasma or whole blood serum, the average increase in surface area was approximately 9 mm 2/day. Arterial smooth muscle cell colonies expanded with an increment of approximately 9 mm 2/day when exposed to 10% platelet-poor plasma serum but 12 mm 2/day when exposed to 10% platelet-rich plasma serum (P < 0.001). Platelet factors also had stimulatory effects on the migration of venous smooth muscle cells. Cytochalasin B, dibutyryl cyclic AMP and theophylline inhibited the migration of both endothelial and smooth muscle cells but the latter responded more to the inhibitory effects of all 3 agents. Compared to vascular smooth muscle, endothelial cells do not require platelet factors for migration and are less responsive to specific inhibitors affecting cell movement.