Glycoconjugates in the human fetal endolymphatic sac as detected by lectins

The distribution of glycoconjugates in the 11 to 16 weeks old human fetal endolymphatic sac (ES) was analyzed using six biotinylated lectins; Wheat germ agglutinin (WGA), Abrus precatorius agglutinin (APA), Ulex europaeus agglutinin I (UEA-I), Ricinus communis agglutinin 120 (RCA120), Helix pomatia agglutinin (HPA), Concanavalin A (ConA). In the 11 week old human fetus, fluorescent reactions with WGA, APA, RCA120 and ConA were detected in the ES. There was almost no reaction with HPA and UEA-I. In the 14 week old human fetus, however fluorescent reactions with HPA and UEA-I appeared. This result suggests that the presence of glycoconjugates changes during the maturation process of the ES. Glycoconjugates detected with HPA were related to the epithelial cell elements of the ES epithelium. The reaction with UEA-I suggests that the stainable substance present in the ES lumen may be secreted locally by the ES itself.