Fasciola hepatica: collagen deposition and other histopathology in the rat host's bile duct caused by the parasite and by proline infusion.

Bile ducts were examined histochemically to compare the effects of proline infusion with Fasciola hepatica implantation in rats. After 3 weeks of infusion or implantation, both proline and F. hepatica produced increases in the luminal perimeter and collagen content of the bile duct. However, the effect of the parasite was significantly greater than that of proline, and the parasite produced significant increases in the bile duct wall. These results corroborate earlier biochemical and histological studies indicating the important role of proline in the enlargement of the bile duct in fascioliasis.