Dynamics of Collagen Accumulation and Activity of Collagen-Degrading Enzymes in the Liver of Rats with Carbon Tetrachloride-Induced Hepatic Fibrosis

Abstract

Liver fibrosis in rats was induced by repeated subcutaneous injections of carbon tetrachloride. Total collagen, soluble and insoluble collagen fractions as well as type I and type III collagen content in the liver were subsequently measured over a 3—18 week period. Liver collagen was found to increase exponentially during this time. Insoluble collagen accumulated more rapidly than soluble forms, and the accumulation of type III collagen was relatively greater than type I collagen. Changes in specific liver enzymes were also observed. Collagenase, collagenolytic cathepsin and collagen peptidase activities all increased. Levels of collagen-degrading enzymes increased rapidly during the first weeks of fibrosis-induction, and were followed by a more gradual increase during the remainder of the study.