Histology, histochemistry and fine structure of the Harderian gland, lacrimal gland and superficial gland of the third eyelid of the European bison, Bison bonasus bonasus (Artiodactyla: Bovidae)

Renata Nowaczyk,Tomasz Szara,Karolina Gozdźiewska-Harła,Joanna Klećkowska-Nawrot,Katarzyna Olbrych

doi:10.1590/s1984-46702015000500007

Abstract

The macroscopic anatomy and the microscopic and ultrastructural features of the Harderian gland (HG), lacrimal gland (LG) and superficial gland of the third eyelid (SGTE) of the adult European bison are described. In addition, morphometric studies were conducted and were followed by statistical analysis of the results. Tissue sections were stained with hematoxylin and eosin, methyl green-pyronin Y, periodic acid-Schiff, Alcian blue pH 2.5, aldehyde fuchsin and Hale's dialysed iron. Analysis of the staining showed that the HG has a multilobular tubuloalveolar structure with mixed secretion. The LG and the SGTE have a multilobar tubuloacinar structure with serous secretion in the LG and mucoserous in the SGTE. The TEM study demonstrates that the secretory cells of the HG, LG and SGTE have similar ultrastructural appearance, with two types of secretory vesicles in the cytoplasm of all studied glands. The histochemical staining methods and the TEM study revealed the secretory activity in the HG, LG and SGTE ducts. The structural studies can be important for establishing relations between morphological structure and functions of these glands. It can have clinical implications especially when taking into consideration the protective mechanisms of the eye.

Highlights

The orbital glands, mainly lacrimal and Harderian glands (LG and HG), are important for normal eye physiology
We describe the normal anatomical, histological and fine structures of the orbital glands of female and male European bisons to determine the histochemical profile of their HG, lacrimal gland (LG) and superficial gland of the third eyelid (SGTE) glands
The HG was located on the ventral straight muscle in the medioventral part of the periorbita

Summary

Introduction

The orbital glands, mainly lacrimal and Harderian glands (LG and HG), are important for normal eye physiology. The SGTE is a cluster of glandular tissue within the TE, while the LG is part of the lacrimal apparatus and is responsible for the production of the aqueous layer of the tear film (PAYNE 1994, SHADKHAST et al 2008). The SGTE has a similar structure to the LG and is a compound tubuloacinar gland, which produces a mucoserous secretion by merocrine process and supplies the aqueous fraction of the tear film. The aqueous layer of the tear film has an active role in the lubrication and protection of the ocular surface (conjunctiva and cornea). It contains antibacterial factors, including immunoglobulins, and is involved in the regeneration of the damaged cornea (KLEKOWSKA-NAWROT et al 2013)

Methods

Results

Conclusion