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Tight junctions in Gerbil von E bner's Gland: Horseradish peroxidase and freeze‐fracture studies
Author(s) -
Huang Anthony Y.,
Chen MingHuei,
Wu Sandy Y.,
Lu KuoShyan
Publication year - 2015
Publication title -
microscopy research and technique
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 118
eISSN - 1097-0029
pISSN - 1059-910X
DOI - 10.1002/jemt.22464
Subject(s) - horseradish peroxidase , tight junction , anatomy , chemistry , biophysics , cell junction , gerbil , connective tissue , serous fluid , electron microscope , biology , pathology , biochemistry , cell , medicine , physics , ischemia , optics , cardiology , enzyme
The permeability of tight junctions to horseradish peroxidase (HRP) and the freeze‐fracture appearance of junctional structures were investigated in the von Ebner's gland of gerbils. In the tracing study, HRP was either administered topically on the dorsal surface of tongues or injected subepithelially into the connective tissue of vallate papillae for 5–30 min. Lingual tissues containing the von Ebner's gland were sectioned and examined by light and electron microscopy. In von Ebner's glands, the reaction product for HRP was found in the intercellular and interstitial spaces, whereas HRP appeared to penetrate the tight junctions and the reaction product was localized in the lumina of serous acini. In contrast, the staining for HRP that delineated the boundary of epithelial cells was frequently observed in the superficial layers of the lingual epithelium but not the underlying tissues while applying HRP topically. Freeze‐fracture replicas of acinar cells revealed that the tight junction had a depth of 0.815 ± 0.023 μm, and 4–6 parallel strands on the protoplasmic fracture face, with a branching network of joining strands with interruptions, interconnections and high linear strand density apically, and corresponding grooves on the extracellular face. Quantitative analyses showed a greater number of strands (7.217 ± 0.326) in gerbils compared to those of acinar cells (3.86 ± 0.22) in mice. These results demonstrate that the tight junctions in the gerbil von Ebner's gland is permeable, and that specific species differences in tight junction structures may be associated with the mechanism for survival in an extremely dry environment. Microsc. Res. Tech. 78:213–219, 2015. © 2015 Wiley Periodicals, Inc.