Types of collagen in Opisthorchis viverrini infected hamster liver.

Levels and types of collagen from normal and Opisthorchis viverrini infected hamster livers were compared. Normal liver contained approximately twice as much type I collagen than type III collagen. Upon infection by O. viverrini, both type I and type III collagen were elevated, but the increase in type III was proportionately larger than type I collagen. Of the 3-fold increase in total collagen content of infected livers, type I and type III collagen increased 2- and 4-fold, respectively. As a result, the ratio of type I to type III collagen changed from 2 in normal liver to 1.1 in the livers of animals infected with O. viverrini. The extent of the increase in both type I and type III collagen was found to depend on the infection times and on the number of worms present. In livers infected with 50 metacercariae of O. viverrini, both collagen types increased gradually with duration of infection and reached plateau after 4 months of infection. In livers from 3 month infections, with 15 worms or less, both types of collagen increased directly with the number of worms recovered. Levels of type I and type III collagen did not increase in infections with more than 20 worms.