Inhibition by verapamil of the medium change induced stimulation of cultured vascular smooth muscle cells.

Mitotic stimulation of vascular smooth muscle cells in confluent cultures as determined by increased thymidine incorporation is achieved by medium change, possibly by the action of serum derived factors. Results obtained by measuring 3H-thymidine incorporation, glucose uptake and lactate production of cultured smooth muscle cells show that application of verapamil, a calcium entry blocker, prevents the stimulating effect of medium change. It is concluded that this type of stimulation is triggered by an influx of calcium ions accessible to calcium antagonistic drugs. It seems possible that the antiatherosclerotic effect of verapamil is based at least to some extent on a similar mechanism.