Platelet factor 4 blocks the binding of basic fibroblast growth factor to the receptor and inhibits the spontaneous migration of vascular endothelial cells.

Platelet factor 4 (PF-4) blocked the binding of basic fibroblast growth factor (bFGF) to the plasma membrane receptor. Five micrograms/ml of PF-4 completely blocked the specific binding of bFGF to the receptor of NIH 3T3 cells. Endogenously produced bFGF regulates the spontaneous migration of bovine aortic endothelial (BAE) cells as an autocrine factor (Sato and Rifkin, 1988). PF-4 inhibited the spontaneous migration of BAE cells in a reversible and dose dependent manner. The inhibition reached maximum at 5 micrograms/ml of PF-4, where the binding of bFGF to the receptor was completely blocked.