Lectin histochemical localization of galactose, N-acetylgalactosamine, and N-acetylglucosamine in glycoconjugates of the rat vomeronasal organ, with comparison to the olfactory and septal mucosae.

The localization of alpha-D-galactose, N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine sugar residues of glycoconjugates in the vomeronasal organ, olfactory mucosa, and septal organ in the nasal mucosae of rats was investigated using lectinohistochemical techniques combined with bright-field, epifluorescence, and confocal laser scanning microscopy. Glycoconjugates in the mucomicrovillar complex of the vomeronasal organ contained all the sugar residues investigated, whereas glycoconjugates in the mucociliary complex of the olfactory mucosa and septal organ contained only N-acetyl-D-glucosamine. Vomeronasal receptor neurons expressed glycoconjugates with terminal alpha-D-galactose and beta-N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine residues, whereas olfactory and septal receptor neurons expressed glycoconjugates with only N-acetyl-D-glucosamine residues. Secretory granules of glands of the vomeronasal organ contained glycoconjugates with terminal alpha-D-galactose and N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine, whereas those of the Bowman's glands and glands of septal organ contained glycoconjugates with only internal N-acetyl-D-glucosamine residues. The results demonstrate that the glycoconjugates expressed by vomeronasal receptor neurons and glands contain terminal alpha-D-galactose and beta-N-acetyl-D-galactosamine sugar residues that are not expressed by analogous cells in the olfactory mucosa and septal organ.