Attachment to collagen by isolated hepatocytes from rats with induced hepatic fibrosis

The attachment to and synthesis of collagen by hepatocytes isolated from rats with and without hepatic fibrosis were studied. Attachment of normal hepatocytes was enhanced fourfold in the presence of serum, whereas attachment of hepatocytes from CCl4-treated rats with severely fibrotic livers was enhanced only twofold by serum. Fibronectin promoted hepatocyte attachment to collagen to the same degree as serum, whereas serum from which the fibronectin had been removed did not. Thus hepatocytes adhere to collagen via fibronectin, a known adhesion protein for fibroblasts. In the absence of serum or fibronectin, hepatocytes attached best to basement membrane collagen (type IV). This enhanced attachment was abolished by periodate oxidation of the collagen, an observation which suggested that carbohydrate residues are involved in hepatocyte attachment to this collagen. Collagen synthesis was determined after hepatocytes were cultured for 24 hr. No difference was found in the amount of collagen synthesized by cultures of hepatocytes derived from control rats and from rats with hepatic fibrosis. By immunofluorescence, the cell responsible for the synthesis of collagen appeared to have a fibroblastic morphology.