Fibrogenesis along the hepatic sinusoids in carbon tetrachloride-induced cirrhosis. An electron microscopic study

Abstract

An ultrastructural investigation of CCl 4-induced cirrhotic and control livers has indicated that fibroblastic proliferation and new collagen formation were the significant factors in the development of fibrosis in the livers of the CCl 4-treated rats. There was no evidence that collapse or condensation of pre-existing hepatic stroma contributed to the formation of the fibrous bands. The newly formed collagen fibers could be distinguished from those of the pre-existing hepatic reticulum by morphologic features and structural associations. If these distinguishing characteristics pertain in human disease, the pathogenesis of hepatic fibrosis in the various forms of human cirrhosis could be assessed in terms of these structural parameters. In the CCl 4-induced cirrhosis, certain sinusoids were widened and appeared as sites of intense fibroblastic proliferation and new collagen formation. In general, the new fibers were deposited in direct apposition to the flanking hepatic parenchymal cells, without the intervention of a recognizable basement membrane or space devoid of newly formed collagen. The fibers tended toward deposition in cross-orientated layers. The widened sinusoids invariably included proliferated biliary ductules.