Retinoic acid enhances the proliferation of smooth muscle cells

Summary Retinoic acid (RA, 10^–5–10^–7 M) is shown to enhance the proliferation of cultured rat aortic smooth muscle cells (SMC). This effect is not connected with a synergistic action of RA together with serum mitogens. Moreover, the expression of L1, a surface antigen specific for modulated SMC entering the cell cycle, is amplified by RA treatment.