The interaction between the deacetylated (amine) metabolite of diamphenethide (DAMD) and cytochemically demonstrable Na+/K+-ATPase activity in the tegument of Fasciola hepatica.

The relative effects on tegumental Na+/K+-ATPase activity in Fasciola hepatica of the deacetylated (amine) metabolite of diamphenethide (DAMD) (10 micrograms/ml, 18 h) and the Na+/K+-ATPase inhibitor ouabain (0.1 mM, 0.5 h) have been assessed cytochemically. In the normal tegument, Na+/K+-ATPase activity is particularly concentrated along the invaginations of the apical plasma membrane and the infoldings of the basal plasma membrane. Ouabain pretreatment significantly reduces the overall level of Na+/K+-ATPase activity, but does not induce swelling of the basal infolds. In contrast, DAMD does not significantly reduce either the level or distribution of Na+/K+-ATPase activity, but does cause a pronounced swelling of the basal infolds. The results are discussed in relation to the postulated action of diamphenethide as an inhibitor of Na+/K+-ATPase activity.