Collagen stimulating factors in hepatic fibrogenesis

Four factors which stimulate collagen synthesis and prolyl hydroxylase activity in cultures of human and mouse fibroblasts have been isolated by molecular sieve chromatography from animal and human fibrotic and cirrhotic livers. These factors do not stimulate protein or DNA synthesis or total DNA in these cultures. It has also been shown that these factors, designated collagen stimulating factors F1-F4, do not owe their activity to ascorbate or glutamine. Collagen stimulating factors are heat stable, and F1 and F2 have apparent molecular weights of about 4000 and 1000 respectively. Since these factors are not present in normal animal or human liver it is suggested that they may be responsible for increased collagen production in vivo in hepatic fibrosis and cirrhosis.