Variations in growth and cell cycle time of arterial smooth muscle cells cultured at low density.

The population kinetics of cultured rat arterial smooth muscle cells replated at various low densities were studied by direct counting and observation of the cells. Population doubling time decreases with increasing initial density of the culture. These variations in population doubling times depend on both the variation in the percentage of quiescent cells and on the variation of the mean cell cycle time of non-quiescent cells.