Open AccessMorphological and histochemical characterization of the secretory epithelium in the canine lacrimal gland
Author(s) -
Tadashi Yasui,
Kenya Miyata,
Chie Nakatsuka,
Azuma Tsukise,
Hiroshi Gomi
Publication year - 2021
Publication title -
european journal of histochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.754
H-Index - 42
eISSN - 2038-8306
pISSN - 1121-760X
DOI - 10.4081/ejh.2021.3320
Subject(s) - lactoferrin , lacrimal gland , secretory protein , biology , microbiology and biotechnology , epithelium , secretory component , secretion , secretory vesicle , syntaxin , exocytosis , cell type , cell , immunology , biochemistry , pathology , antibody , medicine , genetics
In the present study, the expression of secretory components and vesicular transport proteins in the canine lacrimal gland was examined and morphometric analysis was performed. The secretory epithelium consists of two types of secretory cells with different morphological features. The secretory cells constituting acinar units (type A cells) exhibited higher levels of glycoconjugates, including β-GlcNAc, than the other cell type constituting tubular units (type T cells). Immunoblot analysis revealed that antimicrobial proteins, such as lysozyme, lactoferrin and lactoperoxidase, Rab proteins (Rab3d, Rab27a and Rab27b) and soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor (SNARE) proteins (VAMP2, VAMP4, VAMP8, syntaxin-1, syntaxin-4 and syntaxin-6), were expressed at various levels. We immunohistochemically demonstrated that the expression patterns of lysozyme, lactoferrin, Raba27a, Rab27b, VAMP4, VAMP8 and syntaxin-6 differed depending on the secretory cell type. Additionally, in type T cells, VAMP4 was confined to a subpopulation of secretory granules, while VAMP8 was detected in almost all of them. The present study displayed the morphological and histochemical characteristics of the secretory epithelium in the canine lacrimal gland. These findings will help elucidate the species-specific properties of this gland.