Separation of arterial smooth muscle cell subpopulations with different growth patterns.

Smooth muscle cell (smc) cultures of arterial intima and media have been fractionated into two subpopulations of smc depending upon the capacity for adhesion. The cells of the subpopulations were different structurally and displayed different patterns of growth. The high-adhesive cells (A-cells) grew as monolayer while the low-adhesive (I-cells) had a marked tendency to multilayered growth. Upon continued cultivation the I-cells showed excessive mound-formation and even formation of macroscopically visible tissue-like pieces, some of which detached spontaneously from the substratum. It is suggested that the dual nature of arterial smooth muscle cells may reflect specialized subpopulations of cells with one variety, the I-cell, possibly involved in repair and remodelling of the artery.