During fibrosis the extracellular matrix (ECM) is continuously being remodeled and increases in volume due to the production of various proteins. In dogs we studied the distribution of Tenascin-C (TN-C). Also, the correlation of TN-C with the necro-inflammatory activity, α-SMA, CK7 and CD3+ T-lymphocytes was analyzed by using a semi-quantitative scoring system. Three groups (n=19) of dogs were used: group-1 (n=5) with neonatal hepatitis/lobular dissecting hepatitis (NH/LDH), group-2 (n=8) with chronic hepatitis/cirrhosis (CH/CIRR) and group-3 (n=6) of healthy animals.

In the normal livers TN-C was localized mainly in the Disse's space and around the walls of bile ducts and blood vessels. In CH/CIRR livers TN-C was localized at the rim of the regenerating nodules and conspicuous in the bridging fibrous bands. In the NH/LDH, however, TN-C was diffusely distributed along with the reticular fibers that dissect single cells or groups of hepatocytes. α-SMA in the normal hepatic parenchyma showed a slightly irregular signal distributed along the perisinusoidal linings. However, in other groups, α-SMA was increased in fibrotic septa and perisinusoidal linings. CK7 in normal livers was positive in bile ducts. In other groups, however, CK7+ cells were conspicuous in the portal-parenchymal interface, rim of the regenerative nodules and in the degenerated parenchyma. The pattern and distributions of CD3 + lymphocytes were found to oppose that of TN-C. The present result also showed that TN- C is strongly correlated with increased fibrotic stage, inflammatory activity, bile duct proliferation and α-SMA indicating its role in the progression of hepatic fibrosis.