Action of metoprolol, enalapril, diltiazem, verapamil, and nifedipine on cell growth of vascular smooth muscle cells.

The influence of nifedipine, verapamil, diltiazem, metoprolol, and enalapril on the basal and angiotensin II (Ang II)-induced elevation of [3H]thymidine incorporation into vascular smooth muscle cell (VSMC) DNA was examined. Our results from four independent experiments, each performed in triplicate, are summarized by calculating the half-maximal inhibitory concentration (IC50) of the drugs. Nifedipine, verapamil, and diltiazem had IC50 values of 2.3 +/- 0.7 x 10(-6), 3.5 +/- 0.3 x 10(-6), and 6.6 +/- 2.8 x 10(-6) M, respectively. Metoprolol had an IC50 value of 49 +/- 16 x 10(-6) M, whereas enalapril was completely ineffective. All drugs used had no influence on the basal cell [3H]thymidine incorporation. This in vitro study allows one to conclude that the calcium-entry blockers can inhibit the Ang II-induced cell growth and thus may have beneficial effects on the development and regression of vascular growth, which is associated with the pathogenesis of cardiovascular diseases.