ABSTRACT
BACKGROUND: Cigarette smoking has been directly linked to atherosclerosis formation and vascular graft failures but the role of nicotine in these processes is not yet completely understood. We investigated the release of platelet-derived growth factor BB (PDGF BB) by the bovine aortic endothelial cell (EC) after nicotine administration at concentrations similar to those found in plasma of active and passive smokers and the role of PDGF BB, autocrinally released, in EC cytoskeletal modification. METHODS: EC were stimulated in a serum-free medium for 72 h with (-)-nicotine (from 6 x 10(-4) to 6 x 10(-8) M). The release of PDGF BB was assessed by inhibition antibody-binding assay and confirmed by Western blotting. Mitogenic activity of nicotine on EC was also determined. The EC cytoskeleton was studied with specific antibodies anti-alpha-actin fibers and anti-vimentin and the modification induced by PDGF BB was assessed by blocking PDGF BB activity with specific antibodies. RESULTS: The greatest PDGF BB release was noted at a (-)-nicotine concentration of 6 x 10(-6) M (P < 0.001). The addition of antibody anti-PDGF BB to EC exposed to (-)-nicotine decreased tritiated thymidine uptake by 20% (P < 0.001). EC exposed to (-)-nicotine concentrations of 6 x 10(-6) and 6 x 10(-8) M had a significant alteration in the expression of alpha-actin fibers and vimentin as compared with control. Administration of the antibody anti-PDGF BB in the culture medium reversed cytoskeletal alteration. CONCLUSIONS: Nicotine enhanced the release of PDGF BB by EC which in turn caused an alteration in cytoskeletal organization.
