Histological and Histochemical Studies on the Lingual Tonsil of the Buffalo (Bubalus bubalis)

Abstract

The study was conducted on lingual tonsil of six adult buffaloes (5-6 years of age) of the local mixed breed to explore histomorphological characteristics with functional significance. The mucosal surface of the lingual tonsil lined by stratified squamous keratinized epithelium was comprised of strata basale, spinosum, granulosum and corneum whereas towards the deeper folds the epithelium was stratified squamous non-keratinized. The latter epithelium modified into reticular epithelium especially toward the deeper portion and was characterized by a reduced number of epithelial cells, loss of distinct strata and heavy infiltration of lymphoid cells. The propria submucosa had loose irregular connective tissue along with glandular and lymphoid tissue. The lymphoid tissue was mainly distributed in the form of lymphoid follicles and diffused arrangement. The follicles of varying shapes and size showed darkly stained corona and lightly stained germinal centre were surrounded by parafollicular areas. The parafollicular areas possessed high endothelial venules (HEVs) with large sized endothelial cells having round to oval nuclei with distinctly visible centric or eccentric nucleoli. These HEVs are involved in trafficking of lymphocytes by transendothelial and interendothelial migration. The mucous glandular acini presented strong reactions for glycogen, acidic mucopolysaccharides, weakly sulfated mucosubstances, hyaluronic acid, sialomucins and mucins as demonstrated by different histochemical techniques. The secretions of acini also showed the presence of more than 4% content of cysteine. The presence of modified reticular epithelium and associated lymphoid tissue suggested that the lingual tonsil may be involved in sampling of oral antigens and transporting them to the underlying mucosal lymphoid tissue for processing and initiation of immune responses. The future microbiological studies may exploit the tonsil as a targeted organ for improved delivery of existing mucosal vaccines and development of new strategies for oral vaccines.

Histoarchitecture and Histochemical Studies on the Lacrimal Gland of Pig (Sus scrofa)

“…The glandular tissue was consisted of serous acini and mucous acini and sero-mucous (mixed) secretory units ( Fig. 1a and 1b) which were in agreement with the findings in pigs (Kuhnel and Scheele, 1979;Gargiulo, et al, 1999), sheep (Singh et al, 2018) and buffaloes (Girgiri and Kumar, 2018). In contrast, canine lacrimal glands were reported as being purely mucus-secreting glands (Martin et al, 1988) and goat as serous (Alsafy, 2010).…”

“…The acini showed strong presence of acidic and neutral mucopolysaccharides with PAS-AB stain (Fig. 2b) as reported in buffalo (Girgiri and Kumar, 2018), whereas in sheep (Singh et al, 2018) showed presence of both acidic and neutral mucopolysaccharides with predominanace of neutral one. The strong alcianophilic activity was observed towards the Alcian blue (pH 2.5) showing presence of weakly acidic sulfated mucosubstances, sialomucins and hyaluronic acids in glandular parenchyma of the gland (Fig.…”

“…The strong alcianophilic activity was observed towards the Alcian blue (pH 2.5) showing presence of weakly acidic sulfated mucosubstances, sialomucins and hyaluronic acids in glandular parenchyma of the gland (Fig. 2c) as reported in buffalo (Girgiri and Kumar, 2018), whereas sheep (Singh et al, 2018) and small ruminants (Triveni et al, 2017) alcianophilic activity was moderately positive. The reaction towards Colloidal iron (Fig.…”

“…The secretory units were followed by a duct system. The excretory duct system was made up of intercalated, intralobular, interlobular and large excretory ducts (Fig 1a, 1b. ) as revealed in pigs (Kuhnel and Scheele, 1979) and other species like sheep (Singh et al, 2018) and buffaloes (Girgiri and Kumar, 2018). In contrast, the duct system of lacrimal gland of dog was started with intralobular (Shaker and AL-Obeady, 2016).…”

Scanning and Transmission Electron-Microscopic Studies on the Lingual Tonsil of the Buffalo (Bubalus bubalis)

“…Together, these components provided innate, cellular and humoral immunity at the local and systemic levels [5]. The histological and histochemical structure of lingual tonsil of the buffalo has been earlier described [6,7]. The present study elucidated in detail the ultrastructural features of the lingual tonsil in buffalo with emphasis on different types of epithelia, lymphoid tissue and high endothelial venules.…”