Cytochemistry of sialoglycoconjugates and lysozyme in canine anal glands as studied by electron microscopic methods

The distribution of sialoglycoconjugates and lysozyme in the secretory cells of canine anal glands was studied by means of electron microscopic cytochemical methods, particularly lectin cytochemistry and immunocytochemistry. Sialic acids were predominantly present in the secretory granules, Golgi bodies, surface coat of the plasma membrane and luminal secretions. In addition, within these structures, the secretory granules, Golgi bodies and luminal secretions exhibited high levels of sialoglycoconjugates that terminated in Siaα2-6Gal/GalNAc or Siaα2-3Galβ1-4GlcNAc. In the secretory cells, reactive gold particles representing lysozyme were mainly detectable in the secretory granules and Golgi bodies. Sialic acids possess diverging functional properties, whereas lysozyme contributes to the non-specific defense against microorganisms. Therefore, their presence and secretion are suggestive of protective effects of both secretory products at the anal mucosa.