To investigate whether smooth muscle cell(SMC)derived fibroblast growth factor(FGF) plays a role in atherogenesis, this growth factor was purified, and some of its biological and biochemical properties were determined.Methods The rabbit aortic SMC were cultured using a substrateattached explant method. The SMC at the 3rd～5th passage which grew well were collected and sonicated. The sonicated was centrifuged at 10 000 r·min~(-1) and the FGF was extracted. The chemotactic activity of the extract for rabbit peripheral blood monocytes(MC) was assayed by using modified Boyden chamber, Subsequently, the extract was loaded on a column of heparin-Sepharose and agradient elution was performed. The effect of the eluate fractions on DNA synthesis of NIH 3T3 fibroblasts was assayed by using ~3H-thymidine( ~3H-TdR ) incorporation into DNA of the cells. To determin the molecular weight and reactivity to anti-bFGF polyclonal antibody, NaDodSO_4-polyacrylamide gel electrophoresis (SDSPAGE), immunoblotting and an image processing system were used.Results The FGF extract was significantly chemotactic for MC. The actions eluted in 1.4～1. 6 mol· L~(-1) NaCl from the heparin Sepharose were mitogenic for 3T3 cells, and the ~3H-TdR incorporation values were 2～3 times as much as the control. The purified molecule had a molecular weight of about 18.4 kDa as determined by SDS-PAGE. Immunoblot analysis showed that this purified protein was positively immunoreactive to an anti-bFGF polyclonal antibody.Conclusions The purified protein from the present experiment is bFGF. It suggests that the SMC which have migrated in the intima may release bFGF when injured. Basic FGF may play a role in atherogenesis through inducing cell migration and proliferation.