Hormonal and pharmacologic agents affecting choline uptake and incorporation in Schistosoma mansoni adults

Initial uptake of choline by Schistosoma mansoni (2-min uptake) revealed no differences between male, female or paired worms for any of the control or experimental groups. After a 30-min uptake period, however, males showed significantly higher uptake of choline in the presence of mitomycin C, cytochalasin B and calcium ionophore A23187, while paired worms showed significantly reduced uptake in the presence of actinomycin D, puromycin, mitomycin C, cytochalasin B, colchicine, insulin, thyroxine and lysine. Choline uptake by females was elevated, in the presence of cytochalasin B at 30 min, although not significantly. Significantly increased incorporation of choline into phosphatidylcholine was observed following a 30-min incubation with 5-hydroxytryptamine (males), puromycin and thyroxine (females) and calcium ionophore A23187 (males, females and pairs). These effects on phosphatidylcholine synthesis are discussed in relation to the uptake data and to previous work concerning the outer membrane complex of the parasite as an important facet of parasite resistance to the host immune response.