EXPRESSION OF α-SMA, DESMIN AND VIMENTIN IN CANINE LIVER WITH FIBROSIS

In this work, 36 canine livers with fibrosis were examined. Based on the degree of fibrosis, the livers were classified into three groups: 1- mild portal fibrosis; 2- moderate portal fibrosis with mild periportal and septal fibrosis; 3- severe portal fibrosis with marked periportal and septal fibrosis or cirrhosis. Normal liver sections obtained from five dogs with no evidence of infectious, neoplastic, or cardiovascular diseases were used as controls. The degree of fibrosis was evaluated on liver sections stained according to Masson's trichrome method. It was proved using an immunohistochemical method that HSC and periductal myofibroblasts are immunoreactive to desmin, vimentin and alpha-SMA. Desmin, vimentin and a-SMA positive cells in the portal triad were significantly more numerous in dogs with fibrosis of the third degree than in the controls or all other examined livers. The density of alpha-SMA, vimentin and desmin-positive cells in the portal triad was in correlation with the degree of fibrosis, which cannot be said for HSC. These results suggest that portal myofibroblasts have a significant role in the process of liver fibrosis in dogs.