EXPRESSION OF TENASCIN, FIBRONECTIN, AND LAMININ IN RAT-LIVER FIBROGENESIS - A COMPARATIVE IMMUNOHISTOCHEMICAL STUDY WITH 2 MODELS OF LIVER-INJURY

The aim of this study was to follow semiquantitatively by immunohistoc hemical means the alterations of the expression of the hepatic glycopr oteins tenascin, fibronectin, and laminin in two different models of c hronic liver injury, i.e. thioacetamide-induced liver cirrhosis and fi brosis after bile duct ligation. The tenascin distribution pattern obs erved during cholostasis-induced liver fibrosis showed some similariti es, but also some differences in comparison with the results obtained after TAA intoxication. Most importantly, the data show that tenascin staining was detectable in almost all areas of the chronically injured livers up to 3 and 6 months in bile duct-ligated and chemically-injur ed livers, respectively. Thus, tenascin does not seem to play only a t ransient role in the fibrogenetic process as previously suggested. Lam inin was strongly stained in proliferating ductules, whereas only a we ak continuous distribution was observed along the sinusoidal wall. Fur thermore, our findings confirm the role of fibronectin as a pacemaker of fibrosis. Regional differences in the kinetics of the expression of the glycoproteins may reflect local differences in their production b y parenchymal or non parenchymal cells or regional patterns of proteol ytic activity.