title: The shedding of the outer glycocalyx of juvenile Fasciola hepatica.
abstract: Freshly excysted Fasciola hepatica possess an outer glycocalyx which on incubation at 37 degrees C is rapidly shed. Using an ELISA technique the release of this parasite antigen was shown to be temperature-dependent and to occur in both normal bovine serum as well as in serum free conditions. The ELISA failed to detect the antibody--antigen complexes that occurred when flukes were incubated in immune serum. Release of specific parasite antigen fell slowly with in vitro cultured flukes, but increased with in vivo cultured flukes. Using a fluorescence inhibition assay, antigens with high ELISA titres inhibited surface fluorescence of the parasite suggesting that the ELISA was detecting surface antigens as well as other parasite metabolic products. Several metabolic blocking agents and commercial antihelminthics were titrated against juvenile F. hepatica to screen for inhibition of the surface--tegument shedding: there was little selective inhibition of surface shedding without a significant loss of motility.
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex / Q000276:immunology*; D002417:Cattle; D003429:Cross Reactions; D003513:Cycloheximide / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005210:Fasciola hepatica / Q000187:drug effects / Q000254:growth & development / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D051379:Mice; D011817:Rabbits
chemical_list: D000936:Antigen-Antibody Complex; D003513:Cycloheximide