Specific Features of Progression of the Parasitic Invasion, caused by Opisthorchis felineus, in Golden Hamsters

Abstract

The influence of Opisthorchis felineus invasion on the development of pathological changes in the hepatobiliary system was studied in 120 golden hamsters in a long-term experiment (42 weeks) after single infection per os in the dose of 50 metacercariae per animal. The animals were sacrificed on weeks 4, 8, 12, 16, 28 and 42. Chronic experimental infestation with O. felineus triggered a cascade of morphogenetic processes in both extrahepatic and intrahepatic biliary systems. At the early stages of the experiment, polyps and strictures of bile ducts were formed in the lobar bile ducts; in portal tracts, hyperplasia and adenomatous transformation of the newly formed epithelial structures were observed. At the later stages, third-degree biliary intraepithelial neoplasia developed in the lobar bile ducts; in the intrahepatic bile ducts, increased epitheliocyte hyperplasia and invasive growth of cell cords were observed, that impaired tissue architectonics. Progressing cell atypia can be classified as cholangiocellular cancer.