Structural Differences of the Harderian Gland between Common Pheasants (Phasianus Colchicus Talischensis) and Hybrids of Italian Amber and Common Pheasants

Abstract

The aim of the present study was to demonstrate the histological and histochemical structure of the Harderian gland in wild and hybrid of wild and domestic birds. The samples were stained with haematoxylin-eosin, methyl green-pyronin Y, periodic acid-Schiff, alcian blue pH 2.5, aldehyde fuchsin and Hale's dialyzed iron staining's. In both species, the glands had multilobar tubuloacinar structure type I. The Harderian gland was located in the orbit near the inter-orbital septum, between the medial rectus muscle, the pyramidal muscle of the third eyelid, and the ventral oblique muscle. In the common pheasant, the gland was wider in the proximal and distal part. The common pheasant had more elongated lobes of the Harderian gland than in the hybrid. In the common pheasant, the glandular cells presented darkly-stained serous secretion and lightly-stained mucous secretion. In the hybrid, the glandular cells presented seromucous secretion. The central lobar space, interacinar space, and apical parts of the acini of the Harderian glands were filled with many lymphocytes and plasma cells, particularly in the common pheasant, where centers of all large lobes were abundantly filled with plasma cells. The plasma cells dominated in common pheasant's Harderian gland, while in the hybrid, lymphocytes and plasma cells were present at similar quantities. The cells positive for periodic acid of Schiff staining were dominant in hybrid. Periodic acid-Schiff, Hale's dialyzed iron and alcian blue pH 2.5 stainings demonstrated acid-carboxylated mucopolysaccharides in the glandular cells cytoplasm of the examined birds.