Fig. 1.

Effect of all-trans retinoic acid (atRA) on [³H]-thymidine incorporation is dependent on atRA concentration. [³H]-thymidine incorporation in vascular smooth muscle cells (VSMC) (A) and adventitial fibroblasts (AF) (B) was assessed following exposure to atRA (1–200 μmol/l) over 24 h (*P < 0.001 vs. control). We observed a maximum decrease in proliferation of 72% and 78% in VSMC and AF, respectively. Data are representative of 4–5 separate experiments (n = 8/treatment group). DMSO, dimethyl sulfoxide.