Collagen metabolism in the liver of normal and carbon tetrachloride treated rats.

A significant increase in the activity of prolyl hydroxylase, in the relative collagen synthesis and in the hydroxyproline content was observed in the liver of rats treated for five weeks with CCl4 when compared to control liver. Five weeks after the suspension of the treatment, the activity of prolyl hydroxylase and the relative collagen synthesis returned to normal, but the hydroxyproline content of the liver of the CCl4-treated animals remained significantly higher than that of the controls. These findings suggest that an impairment in the mechanisms responsible for the resorption of the scar tissue could account for the accumulation of collagen within the parenchyma in liver fibrosis.