Aim To understand the interaction of endothelial cells(EC)with arterial smooth muscle cells (SMC),the relationship between lipid peroxidation injury to cultured human umbilical vein EC and the proliferation of cultured arterial SMC was investigated.Methods The lipid peroxidation injury to cultured EC was induced by the treatment of diamide,and the content of terminal metabolite of cellular lipid peroxides malonaldehyde was determined by the method described by Hisayuki.The expression of both basic fibroblast growth factor(bFGF)and platelet derived growth factor BB(PDGF-BB)in EC after exposed to diamide was examined by immunohistochemistry using a mouse anti-human bFGF monoclonal antibody and a mouse anti-human PDGF-BB polyoclonal antibody,respectively,and the expression of bFGF in SMC after exposed to the medium conditioned by diamide stimulated EC(dsEC-CM )was examined by the same method as well.The incorporation of H thymidine into DNA in the cells was used to observe the mito genic effect of dsEC-CM on SMC.Results Diamide induces lipid peroxidation injury to cultured EC resulting in the increased expression of bFGF and PIX.F-BB in the cells.dsEC-CM could in duce the expression of bFGF in SMC, and was obviously proliferation for SMC.Conclusions The lipid peroxidation injury to EC may play a role in atherogenesis through inducing the production of some growth factors that stimulate the proliferation of SMC.