Thrombin induces production of growth factors from aortic smooth muscle cells

Background. Myointimal hyperplasia is a common complication of arterial rec ontructive surgery. The serine protease thrombin has a major role in vessel wall healing and eventual myointimal hyperplasia formation. The aim of thi s study was to determine the effect of thrombin on the production of PDGF A A and bFGF by arterial smooth muscle cells. Materials and methods. Bovine smooth muscle cells were stimulated with thro mbin in a serum-free culture. The release of PDGF AA and bFGF was assessed by ELISA. The effect of thrombin on the proliferation of confluent monolaye rs of bovine smooth muscle cells was determined by tritiated thymidine upta ke. Results. Smooth muscle cells stimulated with thrombin released more PDGF AA (P < 0.001) and bFGF (P < 0.001) than the control. Addition of anti-PDGF AA and anti-bFGF antibodies to the medium of smooth muscle cell cultures neut ralized the mitogenic effect of thrombin (P < 0.001). Conclusions. The findings of our study suggest that thrombin may lead to my ointimal hyperplasia formation through induction of PDGF and bFGF productio n by smooth muscle cells. (C) 1999 Academic Press.