Aim To determine the effects of API0l34 on en-dothelin (ET)-stimulated proliferation of vascularsmooth muscle cells (VSMC ) and expression ofgrowth factor, such as platelet derived growth factor(PDGF-B ) and basic fibrob1ast growth factor(bFGF), and oncogene c-sis and c-myc.Methods The experimental models of proliferationof cultured porcine aortic smooth muscle cells inducedby ET were established, and 3H-thymidine (3H-TdR ) incorporation, flow cytometry, immunohistochemistry and Northern blot assaies were used.Results API0134 may drop 3H-TdR data in-creased by ET and hold-back VSMC from static phase(G,/G, ) to DNA synthetic phase (S) and mitoticphase (G2/M ). Furthermore, API0134 could re-verse the enhanced expression of antigen PDGF-B,bFGF and reduced expression of oncogene c-sis and c-myc induced by ET.Conclusion API0134 might inhibit DNA synthesisand proliferation of VSMC, related to the mechanismof molecular biology of controlling growth factors andoncogene.