Detection of ecdysteroids in the human trematode,Schistosoma mansoni

Abstract

SUMMARYFreeze fracture study ofSchistosoma mansonimembrane differentiation enabled us to describe the characteristic features of the tegumental membrane complex at various stages of development of this parasite. The observation of a membrane exuviation during the 10–20 day period of infection of the definitive host led us to search for possible hormonal control. The development of an appropriate radioimmunoassay has allowed the detection of significant production of ecdysteroids in a human platyhelminth. This hormonal material undergoes level variation during the development of post-cercarial stages ofS. mansoniand its precise chemical characterization is presently being investigated.