Regulation of proliferation of bovine aortic endothelial cells, smooth muscle cells, and adventitial fibroblasts in collagen lattices

We compared the proliferation of bovine aortic cells grown in collagen lattices. Smooth muscle cells continued to divide for 2 weeks while adventitial fibroblasts ceased to divide after 4-5 days. Endothelial cells did not proliferate within an untreated collagen lattice; however, if the lattice was covered with culture medium, endothelial cells populated its surface and proliferated to form a monolayer. We also found that both smooth muscle cells and endothelial cells, like fibroblasts, are able to contract a collagen lattice to a small fraction of its original volume, although endothelial cells are able to do so only if the lattice is covered with culture medium.