Subcellular distribution of basic fibroblast growth factor-like molecules ın fibroblasts and extracellular matrix

Basic fibroblast growth factor (bFGF) is thought to play an important role in normal tissue repair and wound healing. It is a potent mitogenic and chemotactic factor for fibroblasts. To some degree bFGF regulates proliferation and extracellular matrix (ECM) production by these cells. In this study we investigate (i) the distribution of bFGF in fibroblasts and ECM of supporting tissues (ii) the subcellular location of this protein in vivo and, (iii) mechanisms for release of this growth factor from fibroblasts. Spurr's resin embedded ultrathin sections from adult rat sciatic nerve, adrenal gland, kidney; and from normal human lung and skin were labeled with either polyclonal (F3393-Sigma) or monoclonal antibodies (F6162-Sigma, C3316-ZymoGenetics Inc.) specific for bFGF using a two-step immunogold labeling method. Controls were incubated with either an equivalent volume of blocking solution (omitting the primary antibody) or an irrelevant antibody (Factor VIII, anti-Histamine)(Fig. 4).