Thrombin and collagen induced the release of a growth factor from washed rabbit platelets which requires a serum factor derived from platelet poor plasma for maximum proliferation of the smooth muscle cells. The release of the platelet-derived growth factor by thrombin and collagen parallels the release of serotonin from these platelets. Therefore it is possible to use rabbit smooth muscle cells and rabbit platelets and 3H-thymidine to examine the effect of factors governing the release of the platelet-derived growth factor and the factors governing its effect on smooth muscle cell proliferation. These results show that it is possible to examine the effect of collagen, which is the principal stimulus to platelet release in the vessel wall, in an in vitro system to rapidly study its effect on the release of the platelet-derived growth factor.
Read full abstract