Western blot showing effects of PDGFRα and PDGFRβ neutralising antibodies. (a) Dermal fibroblasts were treated with neutralising antibodies to anit-PDGFRα, anti-PDGFRβ or vehicle for 1 h at room temperature and then stimulated with either PDGF-AA or PDGF-BB or vehicle for 15 min. Cells were then washed in ice-cold PBS and lysed. Cell lysates were Western blotted for PDGFRα, pPDGFRα, PDGFRβ, pPDGFRβ, ERK, pERK and GAPDH. The relative amount of pPDGFRα, pPDGFRβ, as measure by densitometry, is shown in (b) and (c). (d) Lung fibroblasts were treated and analysed in the same manner (e) and (f).