PDGF-BB reduces rVSMC adhesion on laminin-5 adhesion in vitro. The presence of laminin-5 supported greater adhesion of rVSMC over naked plastic, and this increase in adhesion was reduced by the addition of PDGF-BB. Inhibition of MEK1, using PD98059 restored rVSMC adhesion to laminin-5 in the presence of PDGF-BB. Although fibronectin also supported rVSMC adhesion, the effect of adding PDGF-BB was less pronounced and was not restored using PD98059. The addition of TGF-β1, however, completely restored rVSMC adhesion to both fibronectin and laminin-5 in the presence of PDGF-BB.