| Autologous vein graft and percutaneous transluminal angioplasty(PTA) are the key treatmental methods of peripheral arterial oblitarens diseases. Recent years, with maturing of treatment strategy and rapid growth of newer technologies, the early outcome has been advancing significantly. But intimal hyperplasia(IH) and vascular remodeling account for 20% to 40% of restenosis, which seriously hampers distant outcome. Therefore it is imperative to elucidate the pathogenesis of restenosis and develop new strategy for the precaution and treatment of restenosis.The cellular and molecular mechanisms that lead to the formation of IH lesions have not been clearly defined. Smooth muscle cell proliferation and migration are pivotal events in the development of IH. Abundant evidence is available to support roles for growth factors as key signaling molecules in the accelerated vascular injury following angioplasty. Many features of the lesions can be readily explained by known properties of growth factors and cytokines. Among the growth factors, it is remarkable that bFGF alone as a potent mitogen and chemoattractant together with its ability to transform cells is a leading candidate to play a major role.Basic Fibroblast growth factor(bFGF) is one of the important members of FGF family, distributes diffusely and have mutiple biological activities. In normal, VSMC and endothelium are major cells of vascular wall that synthesize bFGF. Because of different translational initiation, there are four bFGF isoforms. The low molecular weight 18-KDa form is a result of translational initiation at 5' AUG start codon, localized in cytosolic; while the others area result of translation beginning at upstream CUG codons, the high molecular weight 22-KDa, 22. 5-KDa and 24-KDa forms are targeted to the nucleus.Up to date, there are only a small number of reports about the relationships of bFGF and VSMC proliferation in native. In view of this fact, the aim of the present study is to explore systematically and comprehensively the relationships of bFGF and VSMC proliferation in vitro, througth seni-quantitive and qualitative methods.Chapter I : The construction and identification of primary culture of the rat VSMCVSMCs were isolated from thoracic explants of the Wistar rat. Cells were cultured in DMEM containing 10%FBS. Cells of passage 4~7 were used for experiments. Morphology of VSMCs were was verified routinely by phase-contrast light microscopy. When seeded and maintained at low population density, the SMC resemble the less well differentiated SMC in embryonic development(synthetic phenotype), their appearance is broader and flatter. When cultured SMCs were seeded at high density to achieve confluence , they were fusiform or ribbon shaped, and they exhibited a typical "hill-valley" pattern. VSMCs were identified by immunocytochemical staining for a -actin. So when SMCs were cultured in the presence of appropriate factors, the phenotypes of the cells used to establish the culture remained the same as they were in vivo.Chapter II: The gene expression of bFGF and its receptor in VSMCIn the present study, passage VSMC using as material, bFGF mRNA and its specific receptor FGFR-1 mRNA were detected by in situ hybridization. The result demonstrated that Rat VSMC could expressbFGF and its relevant receptor FGFR-1 in a high level. bFGF protein was evaluated by immunocytochemistry. The outcome show that the expression of bFGF protein is positive in VSMC. From the above study, it is found that Rat VSMC express both bFGF and its receptor, which suggest that bFGF is an autocrine factor, bFGF exerts its cellular activity partially through interacting with its specific cell surface receptors in autocrine patern.ChapterIII:The inhibitory effect of bFGF antisense oligoneucleotides on proliferation of vascular smooth muscle cells in vitroFrom the above mentioned study, it was known that Rat VSMC expressed bFGF and its specific receptor and that the cell activity of bFGF was achieved by autocrine and intracrine. The evi...
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