Fig. 2

Characterization of stented coronary arteries 3 months after placement. Sections of arteries implanted with polymer-only stents (control) or 6-MP-eluting stents (6-MP) were stained with H&E to assess general histology of the stented vessel wall (a, d). Masson trichrome staining visualized the adventitia (Adv), media (Med) and intima (Int) of the vessel wall as well as strut holes (s) (b, e). Lawson-Van Gieson staining was applied to stain the internal and external elastic lamina and thus quantification of the different layers of the vessel wall (c, f), enabling morphometric analysis. Endothelial cell coverage of the vessel wall was demonstrated by immunohistochemical staining with an antibody against vWF (g). The media largely consists of circumferentially aligned SMCs, whereas SMCs in the intima are oriented longitudinally in the vessel wall, as shown by staining with an antibody directed against αSMA (h). Most cells positive for the cell-cycle inhibitor p27^kip1 are localized in media and adventitia, whereas hardly any positive cells were found in the intima, indicating that especially in the intima cells are proliferating (i)