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Ultrastructural characterization of normal Merkel cells in the dog
Author(s) -
Ramírez Gustavo A.,
Rodríguez Francisco,
Herráez Pedro,
CastroAlonso Ayoze,
Andrada Marisa,
EspinosadelosMonteros Antonio
Publication year - 2015
Publication title -
veterinary dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.744
H-Index - 60
eISSN - 1365-3164
pISSN - 0959-4493
DOI - 10.1111/vde.12230
Subject(s) - ultrastructure , osmium tetroxide , cytoplasm , anatomy , uranyl acetate , pathology , basal (medicine) , epidermis (zoology) , merkel cell , biology , paraformaldehyde , electron microscope , chemistry , microbiology and biotechnology , medicine , merkel cell carcinoma , carcinoma , physics , endocrinology , insulin , optics
Background Involvement of Merkel cells ( MK s) in different cutaneous diseases as well as in the growth, differentiation and homeostasis of the skin has been previously documented. Hypothesis/Objectives The aim was to assess the ultrastructural features of MK s in canine skin, including morphometrics, highlighting their similarities with and differences from those described for other mammals. Animals Hard palate, nasal planum, lower lip and whisker pad samples were taken from two healthy young dogs destined for academic purposes. Methods Ultrathin sections of samples fixed in osmium tetroxide and embedded in Epon 812 resin were stained with uranyl acetate and lead citrate and examined using a JEOL JEM 2010 transmission electron microscope. Results Ultrastructural characteristics included the following: (i) arrangement in clusters in the basal layer of the epidermis, oral mucosa and external follicular root sheath; (ii) inconstant link with nerve terminal; (iii) oval (10.27 ± 1.64 μm major axis) cell shape with large lobulated nuclei (5.98 ± 1.16 μm major axis); (iv) spine‐like and thick cytoplasmic processes interdigitating with surrounding keratinocytes; (v) presence of desmosomes in the cell body or at the base of spine‐like processes attaching to neighbouring keratinocytes; and (vi) cytoplasm containing loosely arranged intermediate filaments (10.04 ± 1.17 nm) and numerous dense‐core granules (100.1 ± 17.12 nm) arranged in the basal portion of the cytoplasm. Conclusions and clinical importance This study provides the first complete description of the ultrastructural characteristics of MK s in the dog, enhancing our knowledge of the skin structure in this species and providing a basis for future physiological and pathological studies of the role of these cells in normal and damaged canine tissues.