A HISTOCHEMICAL-STUDY ON GLYCOCONJUGATES IN EPITHELIAL-CELLS IN THE DISTAL COLONIC MUCOSA OF ADULT AND DEVELOPING MICE

Glycoconjugates were histochemically studied in the distal colon of developing ICR mice in view of the presence of goblet and vacuolated cells. Alcian blue, high iron diamine and periodic acid-Schiff stainings were performed to characterize glycoconjugates. In addition, two lectins, Ulex europeus agglutinin I and Limax fiavus agglutinin, were applied to detect fucosyl and sialyl residues, respectively. The reactivities to these stainings, noted from day 18 of gestation, did not seem to undergo any major change throughout their development. The present results suggest that: 1) goblet cells secrete sulfated glycoconjugates containing fucosyl and sialyl residues as terminal sugars; 2) vacuolated cells have glycoconjugates containing sialyl residues but no or few fucosyl residues nor sulfonic groups, and certain sialyl residues in the glycoconjugates are probably O-acetylated or O-acylated at least in part; and 3) the brush border of absorptive cells contains glycoconjugates sialylated and fucosylated to some extent but rarely sulfated. Since glycoconjugates elaborated by goblet and vacuolated cells differ from each other, one should be fully aware of the presence of these two types of mucin-producing cells in the distal colon.