Objective  To study the effect of platelet-derived growth factor-BB (PDGF-BB) and SDZ RAD on the promoter activity of p27 gene and p27 mRNA expression in rat vascular smooth muscle cells (VSMCs).   Methods  The deletion constructs

pXp27

containing region of p27 gene promoter ligated to the chloramphenicol acetyltransferase (CAT) reporter gene

were transiently transfected into VSMCs. The transfected VSMCs were subsequently treated with PDGF-BB or SDZ RAD. Twenty-four hours later

the CAT activity and the expression level of p27 mRNA were detected by CAT enzymelinked immunosorbent assay and RT-PCR

respectively.   Results  PDGF-BB (10 ng/ml) decreased the CAT activity of pXp27 and significantly decreased p27 mRNA expression level

while SDZ RAD (10 ng/ml) increased the CAT activity of pXp27 and significantly decreased p27 mRNA expression level.   Conclusion  PDGF-BB inhibits and SDZ RAD increases the promoter activity of p27 gene in rat VSMCs

then both further act on the mRNA expression of p27 gene.