Characterization of glycoconjugates in an embryonic human epithelial line and changes consequent to adaptation to a hyperosmotic medium.
Cell surface and cytoplasmic glycoconjugates were characterized in embryonic human explant cells (a transformed heteroploid line) cultured in iso-osmotic medium (0.137 M NaCl) and in hyperosmotic medium (0.274 M NaCl) for 10 days in order to study the changes induced in these compounds by hyperosmoticity. Cytochemical and ultracytochemical staining selective for glycoconjugates was carried out. The following results were obtained: (1) glycoproteins, glycosaminoglycans and glycolipids are present on the cell surface and in the cytoplasm of the explant cells; (2) lectin histochemistry combined with glycosidase digestion demonstrated the presence of the disaccharides fucose-N-acetylglucosamine and sialic acid-beta-galactose as terminal sequences; (3) histophotometric evaluation of lectin labelling showed a noticeable decrease in histochemical reactivity of adapted cells; (4) plasma membrane cell coat decreased in adapted cells, which was emphasized by ultracytochemical reactions and a rearrangement of glycolipids in the cytoplasm.
Bolognani Fantin
A M
AM
Department of Animal Biology, University of Modena, Italy.
Menghi
G
G
Franchini
A
A
Bondi
A M
AM
Accili
D
D
Fuhrman Conti
A M
AM
D002478:Cells, Cultured; D003470:Culture Media; D004622:Embryo, Mammalian; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D006001:Glycoconjugates / Q000378:metabolism*; D006801:Humans; D007124:Immunoenzyme Techniques; D009994:Osmolar Concentration
D003470:Culture Media; D006001:Glycoconjugates