Effect of the nifedipine-atenolol association on arterial myocyte migration and proliferation

The in vitro effect of nifedipine and atenolol, either alone or in combination, on the proliferation and migration of rat aortic smooth muscle cells was investigated. Nifedipine inhibited the replication of arterial myocytes in concentrations ranging between 10 and 100 microM. The inhibition, evaluated as cell number, was dose- and time-dependent with an IC50 of 39 and 34 microM after 48 and 72 h, respectively; the cell doubling time increased with drug concentrations up to 118 h versus 28 h for controls. Atenolol alone failed to reduce arterial myocyte proliferation, and did not influence the effect of nifedipine on cell proliferation. Nifedipine and atenolol alone inhibited in a dose-dependent manner rat aortic myocytes migration induced by fibrinogen as chemotactic agent. When the combination nifedipine-atenolol was investigated, an additive inhibitory effect on cell migration was observed. These results provide in vitro support for a potential effect of this drug association on early steps of atherogenesis.