Light and electron microscopic studies on the effect of praziquantel onSchistosoma mansoni, Dicrocoelium dendriticum, andFasciola hepatica (trematoda) in vitro

Abstract
The fine structure of the tegument of three trematode species,Schistosoma mansoni, Dicrocoelium dendriticum, andFasciola hepatica, was studied by means of light scanning (SEM) and transmission electron microscopy (TEM) after in vitro exposure to 0, 1,10, and 100 μg/ml of the anthelmintic praziquantel for 5, 15, 30, and 60 min. InS. mansoni andD. dendriticum the resulting vacuolization of the tegument was confined to numerous small areas scattered all over the surface of the parasites and this finally led to the disruption of the apical tegumental layer. No changes were found in the tegument ofF. hepatica after treatment with praziquantel.