Interstitial collagen polymorphism in rat liver with CCl4-induced cirrhosis.

The hepatotoxin, CCl4, was used to develop cirrhosis in rats in an attempt to compare fibrosis of this experimental disease with the alcoholic liver disease in humans. Several observations noted were as follows: (1) Collagen synthesis was increased by as much as 5-fold during the experimental period. Removal of the hepatotoxin led to a dramatic reduction of collagen synthesis within 2 weeks. The increased collagen synthesis was more marked after 21 and 80 days of CCl4 administration as compared with the rate after 200 days of administration. (2) Type III collagen from liver from rats with fibrosis was purified and eight CNBr-derived peptides characterized by molecular weight and amino acid composition. (3) After CNBr digestion of whole livers, quantitation of alpha 1(I)-CB8 and alpha 1-(III)-CB8 revealed that both type I and type III interstitial collagens, were increased by the same amount when measured in terms of either net synthesis or total collagen in the liver. At all stages, rat liver contained 35--40% type III collagen when compared with the total quantity of type I and type III interstitial collagens.