Possibilities of the prophylaxis of arterial restenoses with dexamethasone - an in-vitro study of human aortic smooth muscle cells

Purpose: To evaluate the effect of dexamethasone on the growth of cultured human aortic smooth muscle cells in an in-vitro model depending on the dose applied. Materials and Methods: Commercially available human aortic smooth muscle cells (haSMC) were incubated with different doses of dexamethasone (10-6, 10-8, 10-10 mol/l). For 20 days, the dose-depending effects of dexamethasone on cell growth were studied by analyzing cell proliferation, clonogenic activity as well as cell cycle distribution. In addition, the migratory ability of haSMC was evaluated using a two compartment in-vitro model. Results: Cell growth was reduced in a dose dependent manner. An applied dose of 10-6 M dexamethasone effectively inhibited cell growth for the follow-up period of 20 days. Cell cycle analysis revealed a G1-phase block which was dose dependent and significant for a dose of 10-6M. Also a reduction of haSMC clonogenic activity could be found in the colony formation assays. Finally, dexamethasone reduced the migratory ability of the treated cells significantly for doses of 10-6 and 10-8 M. Conclusion: Depending on the dose applied, incubation with dexamethasone results in a significant growth reduction of cultured haSMC, which may be due to a drug induced G1-phase block. Dexamethasone also reduces the clonogenic activity as well as the migratory ability of cultured haSMC. (orig.)