[Hepatic cell transformation changes in experimental opisthorchiasis]

Changes in the liver where Opisthorchis felines (Rivolta, 1884) parasitizes were traced by light and transmission electron microscopies on experimental models (gold hamsters) of acute and chronic opisthorchiasis. Regenerative processes, such as hepatic epithelial mitotic indices, binucleated, hypertrophic hepatocytes, were determined; the composition of infiltrates was identified; fibroplastic changes and hepatocytic apoptotic index were traced. The progression/regression (P/R) ratio was used to detect atrophy of a hepatic parenchymatous component (hepatocytes) in different periods (from 3 to 120 days) of invasion. In opisthorchiasis, proliferation of committed hepatocytes was first found on day 10 of invasion. Oval (committed) cells are differentiated mainly to cholangiocytes, followed by the formation of ductular structures; the committed cells of the liver may be simultaneously a source of programmed hepatocellular differentiation; however, the newly formed hepatocytes are solitary amongst them in opisthorchiasis.