INCREASE IN TYPE-1 AND TYPE-3 COLLAGENS IN HUMAN ALCOHOLIC LIVER CIRRHOSIS

Collagen in bulk was isolated in about 30% yield from the livers of normal human beings and from livers of persons with alcoholic cirrhosis. Analyzed chemically and examined by electron microscopy, the collagen in each case consisted of 2 types identical with, or resembling closely, type I and type III collagens of skin. The collagen from normal liver was predominantly type I, whereas that from cirrhotic livers consisted of approximately equal amounts of the 2 types. Using carboxymethyl-cellulose chromatography, the type I collagen from the cirrhotic livers showed one .alpha.2 chain and two .alpha.1 chains. chains. The .alpha.1 chains were separable from one another, but gel electrophoretic patterns of peptides obtained from them after treatment with CNBr were almost identical, and resembled the pattern obtained with CNBr peptides of the .alpha.1 chain of rat skin type I collagen. The increased collagen of both types was responsible in part for the observed distortion of the architecture of the cirrhotic livers associated with increased rigidity of the stroma. The predominance of type III collagen in the areas of collapse of architecture where, as shown by others, few fibroblasts are present, suggests that hepatocytes might have an important function in fibrogenesis during the course of liver cirrhosis.