ABSTRACT
The innervation of normal hamster gall bladders and those that had been infected with Opisthorchis viverrini was visualized by histochemical staining for acetylcholinesterase (AchE) on whole mount preparations. In the uninfected animals, the gall bladder walls were innervated by nonganglionised cholinergic nerve fibers. The nerve fibers ran along the cystic arteries and their smaller branches in the gall bladder walls. A few smaller fibers were also observed that were not associated with the blood vessels, and these ramified irregularly throughout the walls. In contrast, gall bladders from infected animals were dilated ad hyperemic. The vascular trees in the walls were also dilated. In some infected animals the AchE-positive fibers were reduced in number and staining intensity, but in the majority of these animals, AchE-positive nerve plexuses were totally absent. Te loss of AchE-positive nerve fibers may be important in the pathogenesis of gall bladder and biliary tract disease associated with liver fluke infection.