Collagen polymorphism in cell cultures derived from guinea pig aortic smooth muscle: Comparison with three populations of fibroblasts

The collagens synthesized by cultured smooth muscle cells derived as outgrowths from the media of guinea pig aorta have been characterized. The results demonstrate that these cells synthesize Type I and Type III collagens. An additional collagenous peptide with an apparent molecular weight of 45,000 was also observed in the denaturation products of collagen synthesized by the smooth muscle cells. The latter peptide is designated CP45. A comparison of the results with collagens isolated from three populations of fibroblasts derived as outgrowths from dermis, striated muscle, and the adventitia of aorta shows that the smooth muscle cell in culture synthesizes a relatively higher proportion of Type III collagen when compared to Type I. Furthermore, no detectable synthesis of CP45 occurred in fibroblast populations which had been derived from dermis and striated muscle. The results demonstrate that phenotypic differences exist in collagen biosynthesis when smooth muscle cells are compared with fibroblast populations.