RESUMO
<p><b>OBJECTIVE</b>To investigate the role of substance P in the formation of hypertrophic scar.</p><p><b>METHODS</b>Dermal fibroblasts derived from human normal skin were cultured with substance P alone or together with selective non-peptide NK-1 tachykinin antagonist, L-703, 606 oxalate salt. The effect of substance P on proliferation of fibroblasts was measured by MTT assay. Furthermore, the TGF-beta 1 mRNA expression in the fibroblasts was determined by in situ hybridization and image analysis.</p><p><b>RESULTS</b>Substance P enhanced fibroblast proliferation dose-dependently, which showed the maximum rate when the concentration of substance P was 25 ng/ml or higher in the culture media. By 48 hours cultured with 25 ng/ml of substance P, the fibroblasts expressed TGF-beta 1 mRNA more significantly than the fibroblasts without substance P. The effects of substance P on both fibroblast proliferation and TGF-beta 1 mRNA expression could be antagonized by L-703, 606 oxalate salt.</p><p><b>CONCLUSION</b>The results suggest that substance P may play an important role in phenotype changes of fibroblasts in skin scarring.</p>