Lectin studies of surface carbohydrates and induction of gland secretion in the free-living stages ofSchistosoma mansoni.

Secretion from glands was observed when cercariae ofSchistosoma mansoni were exposed to certain lectins. Lectins fromMaclura pomifera, Pisum sativum, andTriticum vulgaris, were effective at 7.5 μ/ml. The effects of cercarial gland secretion caused byT. vulgaris agglutinin andArachis hypogaea agglutinin were blocked by pretreatment with the inhibiting glycan. Discharge of glands was not visualized after exposure of miracidia to lectins. The distribution of five labeled lectins was determined on live miracidia and cercariae. OnlyT. vulgaris agglutinin generally labeled the cercarial and miracidial bodies. Specific labeling occurred with the other lectins on the anterior, in glands or on their secretions, in flame cells in both stages, and on an unidentified ring of cells in miracidia. The possible mechanisms involved in changes caused by the lectins are discussed.