Role of growth factors in the contraction and maintenance of collagen lattices made with arterial smooth muscle cells

The contraction of collagen lattices made with arterial smooth muscle cells was studied in medium MCDB 107 without serum or supplemented with 1% fetal bovine serum, plus insulin, transferrin, and low‐density lipoprotein. Under these conditions, smooth muscle cell mitogens including HBGF‐1 (aFGF), PDGF, and EGF stimulated contraction. Stimulation by HBGF‐1 was more profound than with other factors tested. HBGF‐1 stimulation of lattice contraction was blocked by protein synthesis inhibitors, but not by inhibitors of DNA synthesis. Histological observations indicated that HBGF‐1 also enhanced the maintenance of healthy cells in the lattice. Taken together, these observations suggest that HBGF‐1 stimulates lattice contraction, not by a mitogenic effect, but by stimulating synthesis of specific cellular proteins. Since the greatest effects of HBGF‐1 on lattice contraction were seen during the first 72 h following casting, the effects on maintenance of cell viability are probably less important in promoting lattice contraction.