Résumé
Objective To evaluate the production and regulation of platelet derived growth factor (PDGF) in the skin. Methods Normal human keratinocytes (NHKs) and human dermal fibroblasts (HDFs) were cultured, PDGF peptides were measured by ELISA and PDGF B chain mRNA was detected by Northern hybridization. Results The results showed that NHKs constitutively produced PDGF molecules, phorbol 12 myristate 13 acetate (PMA) inhibited PDGF production, while 1, 25 dihydroxyvitamin D 3 enhanced its production. TNF alpha, interferon ? and interleukin 1 alpha all failed to affect PDGF production. On the other hand, HDFs produced no PDGF molecule in spite of a low level of PDGF B chain mRNA expression in Northern hybridization, suggestting a post transcriptional blocking of PDGF production in HDFs. Conclusion The results obtained above indicate that epidermal keratinocytes may be the major PDGF generating cells, whereas dermal fibroblasts the PDGF responsive cells in the skin.