ALPHA-SMOOTH-MUSCLE ACTIN EXPRESSION IN NORMAL AND FIBROTIC HUMAN LIVERS

To determine the significance of the expression of alpha-smooth-muscle actin in the fibrotic human liver, normal and diseased livers were st ained with anti-alpha-smooth-muscle-actin antibody by an immunoperoxid ase method. Vitamin A-containing lipocytes were also identified by the modified Kupffer's gold chloride method. In the normal human liver, l ipocytes as well as vascular smooth muscle cells expressed alpha-smoot h-muscle actin. In alcoholic liver disease, there was an increase in t he cells positive for alpha-smooth-muscle actin adjacent to the fibrot ic areas, but the response of lipocytes to the gold chloride reaction diminished. In chronic hepatitis, the cells positive for alpha-smooth- muscle actin increased around the enlarged portal areas, and the respo nse to the gold chloride reaction did not change appreciably. An incre ase in the cells positive for alpha-smooth-muscle actin was associated with the progression of hepatic fibrosis in the liver of patients wit h alcoholic liver disease and chronic hepatitis.