Distribution of hepatic stellate cells and their role in the development of parasitic fibrosis and liver cirrhosis in domestic animals

Increasing of the extracellular matrix in rats, as well as in humans, occurs as a consequence of hepatic stellate cells (HSCs) activity. The objective of this work was to investigation the role of these cells in the development of fibrosis and liver cirrhosis which occurs as a consequence of infection of sheep and goats with large (Fasciola hepatica) and small (Dicrocoelium dendriticum) fluke. Liver samples taken from 12 cattle and 10 sheep infected under natural conditions with large and small fluke were fixed in formalin and embedded in paraffin. Paraffin clips were stained with hematoxylin- eosin and masson trichrome method, and immunohistochemical method for α-smooth muscle actin (α-SMA). All tested samples were divided into three groups according to histological criteria: livers of infected animals with the first degree of fibrosis, livers of infected animals with the second degree of fibrosis, and livers of infected animals with cirrhosis. Distribution of HSCs depended on the degree of liver fibrosis. Immunohistochemically reactive HSCs were predominantly placed in perisinusoidal space. In liver samples with cirrhosis, HSCs were placed on the periphery of pseudolobulus. Cells of a different shape and size were positive to α-SMA. HSCs play an important role in synthesis of components of extracellular matrix during the development of parasitic fibrosis and liver cirrhosis in domestic animals