Some factors regulating collagen polymorphism in cultured porcine and bovine aortic endothelium.

The apparently random behaviour of the collagen profiles of cultured bovine and porcine aortic endothelium, both in the cells and the medium, has been studied. Despite the fact that these cells retain their normal cobblestone appearance, the collagen profile in each case changes over a period of 12 days in culture following confluence, the changes following distinct patterns. Varying the serum concentration from 2 to 20% in the culture medium has no effect on the collagen types produced. It thus appears that regulatory mechanisms do exist to control collagen polymorphism and that, in this system, the age of normal cobblestone cells in culture constitutes one factor whilst the occurrence of sprouting (angiogenesis), as reported previously, constitutes a second.