Tretinoin in-hibited the mRNA expression of VEGF i n keratinocytes after 4hours,and had no inhibition in keratinocytes aft er 24hours and in COLO16cells after 4hour s and 24hours.

• 维A酸作用于正常人角质形成细胞4h后可抑制VEGFmRNA的表达,作用于正常角质形成细胞24h后及作用于COLO16细胞4h和24h均无抑制作用。