Glycoprofile of the different cell types present in the mucosa of the horse guttural pouches

Diabetes affects hepatic and renal glycoproteins: effect of Boswellia ovalifoliolata on glycoproteins proportions in diabetes induced hepatic and renal injury

Purpose

Chronic hyperglycemia and deficiency of insulin are peculiar features of diabetes mellitus alters glycoprotein levels in various tissues leads to impaired metabolism of glycoproteins which play a major role in the pathogenesis of diabetic complications. Boswellia ovalifoliolata is a medicinal plant known for its many medicinal properties including diabetes. In this background our study was aimed to evaluate the effect of aqueous extract of stem bark of Boswellia ovalifoliolata (AESBBO) on antidiabetic and glycoprotein metabolism.

Methods

Diabetes was induced in rats by intraperitoneal administration of streptozotocin at a dose of 50 mg/kg bw. After induction of diabetes rats were treated with AESBBO at dosage of 200 mg/kg for a long term treatment of 40 days. Finally, by the end of study all the rats were dissected blood, liver, and kidney tissue samples were collected to investigate the long term effects of AESBBO on diabetes and glycoprotein metabolism.

Results

Treatment with AESBBO significantly reduced the fasting blood glucose levels whereas the levels of insulin and hemoglobin were increased with decreased levels of glycosylated hemoglobin. The long term treatment of AESBBO significantly decreased the levels of plasma, liver and kidney tissue glycoproteins such as fucose, hexose, hexosamine and sialic acid.

Conclusions

This study concludes that the aqueous extract of stem bark of Boswellia ovalifoliolata possesses a protective role on abnormal glycoprotein metabolism in addition to its antihyperglycemic activity.

Histochemical Characterization of Oocytes in the Pink Cuskeel (Genypterus blacodes)

In the present study we histochemically and lectinhistochemically characterized the growing oocytes of the pink cuskeel (Genypterus blacodes). We used histochemical methods for the localization and characterization of glycoconjugates (GCs) and lectin histochemical techniques for the identification of specific sugar residues. We analyzed presence and distribution of GCs in the different structures of the growing follicles (cortical alveoli, globules, yolk granules and zona radiata). During the initial stage of vitellogenesis, the oocytes presented small yolk granules composed of GCs that gradually increased during exogenous vitellogenesis. These GCs contained moderate quantities of α-D-mannose, D-glucose, N-acetylglucosamine and N-acetyl-neuraminic acid. The cortical alveoli contained both neutral and carboxylated GCs, and lectin techniques detected N-acetylgalactosamine, galactose and L-fucose. The zona radiata showed a strong positive reaction to PAS and it reacted weakly with more specific techniques, such as KOH/PA*S and PA/Bh/KOH/PAS. This structure showed GCs with oxidizable vicinal diols, O-acyl sugars and sialic acid residues with different substitution types and presented N-acetylgalactosamine and L-fucose specific residues. The oocytes follicular envelope evidenced neutral and acidic non-sulfated GCs and high concentrations of α-D-mannose, D-glucose, galactose and N-acetylgalactosamine. The intergranular cytoplasmic GCs were mainly rich in α-D-mannose, D-glucose, N-acetylgalactosamine, N-acetylglucosamine and N-acetyl-neuraminic acid. These results enhance the comprehension of the structure and functionality of the pink cuskeel ovarian follicles, and provide a useful tool for the study of this tissue in other teleost species.

Cytochemistry of sialoglycoconjugates and lysozyme in canine anal glands as studied by electron microscopic methods

The distribution of sialoglycoconjugates and lysozyme in the secretory cells of canine anal glands was studied by means of electron microscopic cytochemical methods, particularly lectin cytochemistry and immunocytochemistry. Sialic acids were predominantly present in the secretory granules, Golgi bodies, surface coat of the plasma membrane and luminal secretions. In addition, within these structures, the secretory granules, Golgi bodies and luminal secretions exhibited high levels of sialoglycoconjugates that terminated in Siaα2-6Gal/GalNAc or Siaα2-3Galβ1-4GlcNAc. In the secretory cells, reactive gold particles representing lysozyme were mainly detectable in the secretory granules and Golgi bodies. Sialic acids possess diverging functional properties, whereas lysozyme contributes to the non-specific defense against microorganisms. Therefore, their presence and secretion are suggestive of protective effects of both secretory products at the anal mucosa.

Cytochemistry of sialoglycoconjugates, lysozyme, and β-defensin in eccrine glands of porcine snout skin as studied by electron microscopy

In most mammals except for humanoid primates, eccrine glands are confined to the skin of a series of specific body regions. Sialic acids and antimicrobial substances exhibit various functional properties and serve as a component of nonspecific defense against micro-organisms, respectively. In this study, the distribution of these moieties was studied by electron microscopic histochemical methods. The eccrine glandular acini consisted of two types of dark cells as well as clear cells. The secretory granules and Golgi apparatus of both types of dark cells contained sialic acid residues linked to α2-6Gal/GalNAc. On the other hand, sialoglycoconjugates with Siα2-3Galβ1-4GlcNAc sequence were confined to those of the Type II dark cells. In addition, lysozyme and β-defensin were mainly detected in the secretory granules of the Type II dark cells. These secretory products may create a defensive barrier against microbial invasion and play an essential role in preservation of the integrity of porcine snout skin as a sensory organ.

Histochemical analyses of glycoconjugates and antimicrobial substances in goat labial glands

Saliva is known to protect the oral cavity and contains glycoproteins and antimicrobial substances. The distribution of these salivary secretions was studied in the labial glands of the Japanese miniature (Shiba) goat using lectin histochemical and immunohistochemical methods. The mucous acinar cells of the labial glands exhibited glycoconjugates with different saccharide residues, such as GalNAcα1-3GalNAc, Galβ1-4GalNAc, β-D-GlcNAc and sialic acid linked to α2-6Gal/GalNAc. Furthermore, α-D-Man, α-L-Fuc, α-D-GalNAc, β-D-Gal and sialic acid residues were present, in particular, in the serous demilunar cells. Antimicrobial substances (lysozyme, IgA, lactoferrin and β-defensin) were shown to be mainly immunolocalized in the serous demilunes and duct cells. The results obtained are discussed with regard to the functional role of labial glands. The secretory compounds demonstrated may play an important role in the maintenance of oral health with regard to saliva.

Histochemical demonstration of sialic acids and antimicrobial substances in the porcine anal glands

The distribution of sialic acids and antimicrobial products (lysozyme, β-defensin-1, lactoferrin, IgA) in the anal glands of miniature pig was studied by glycoconjugate histochemistry and immunohistochemistry. The glandular acini of these glands exhibited considerable amounts of sialoglycoconjugates that terminated in Siaα2-6Gal/GalNAc or Siaα2-3Gal1-4GlcNAc, including O-acetylated sialic acids. Additionally, all antimicrobial products examined could be demonstrated in the anal glands, especially in the serous cells. The results obtained are discussed with regard to the functional significance of the anal glands. Our observations corroborated the view that sialic acids closely interact with defense cells and antimicrobial substances in the innate immune response. Therefore, the anal glandular secretions may function as protective agents in order to preserve the integrity of the anal region.

Histochemical analyses of anti-microbial substances in canine perianal skin with special reference to glandular structures

Circumanal glands are prominent features of the canine perianal skin, which are often located near to the sebaceous glands and apocrine glands. As the functional relevance of circumanal glands is yet unknown, we studied the localisation of sialic acids and anti-microbial substances (lysozyme, immunoglobulin A, lactoferrin, β-defensin) in these glandular structures by lectin histochemistry and immunohistochemistry. The glands exhibited a number of sialic acids that were linked to α2-6Gal/GalNAc and α2-3Galβ1-4GlcNAc. Additionally, lysozyme, lactoferrin and β-defensin could be demonstrated in the three types of skin glands, whereas IgA was only detectable in the apocrine glands. The results of the study suggest the specific significance of the circumanal glands. Independent of a certain endocrine role, their products may mainly function as protective agents to preserve the integrity of the anal region, considering that sialic acids and anti-microbial substances are important in defence mechanisms.

Histochemical distribution of sialic acids and antimicrobial substances in porcine carpal glands

The localization of sialic acids and antimicrobial products (lysozyme, IgA, lactoferrin, β-defensin 2) as well as Rab3D in the carpal glands of pig was studied by sialoglycoconjugate histochemistry and immunohistochemistry. The secretory epithelium of the carpal glands consisted of dark and clear cells. The dark cells of these glands exhibited high levels of sialoglycoconjugates, including O-acetylated sialic acids, whereas the localization of sialic acids linked to α2-3Gal1-4GlcNAc was confined to a subpopulation of the dark cells. Furthermore, all antimicrobial substances and Rab3D were mainly detectable in a subpopulation of the dark cells. The results obtained are discussed with regard to the functional significance of these glands. Our findings suggested that Rab3D is involved in the secretory regulation of sialoglycoconjugates and antimicrobial substances. These secretory products may create a defensive barrier against microbial invasion and play an essential role in the preservation of skin integrity.

Histochemical localization of sialic acids and antimicrobial substances in eccrine glands of porcine snout skin

The distribution of sialic acids and antimicrobial products (lysozyme, IgA, lactoferrin, β-defensin 2) as well as Rab3D in the eccrine glands of porcine snout skin was studied by sialoglycoconjugate histochemistry and immunohistochemistry. The secretory epithelium consisted of two types of secretory cells: dark and clear cells. The dark cells exhibited considerable amounts of sialoglycoconjugates, which included O-acetylated sialic acids, whereas sialic acids in the sequence Siaα-2-3Gal1-4GlcNAc were confined to some of the dark cells. All antimicrobial substances and Rab3D were demonstrated to be also mainly present in some of the dark cells. Additionally, in the cytological and cytochemical features, the different characteristics were observed among the dark cells. The results obtained are discussed with regard to the functional significance of the eccrine glands. The secretory products elaborated by this gland type may function as protective agents in order to preserve the skin integrity of the snout region, considering that sialic acids and antimicrobial substances are important in general defense mechanisms.

Histochemical properties of sialic acids and antimicrobial substances in canine anal glands

The functional properties of sialic acids appear to be manifold. Additionally, antimicrobial substances serve as a non-specific defense against microorganisms. In this study, therefore, the localization of sialic acids and antimicrobial substances in the anal glands of dog was studied by sialoglycoconjugate histochemistry and immunohistochemistry. The secretory epithelium, luminal secretions and excretory ducts exhibited high levels of sialoglycoconjugates that terminated in Siaα2-6Gal/GalNAc or Siaα2-3Gal1-4GlcNAc. Additionally, O-acetylated sialic acids were detectable in these glandular structures. Antimicrobial substances, such as lysozyme, immunoglobulin A (IgA), lactoferrin and the peptide group of β-defensins, were also demonstrated as products of the anal glands. The results obtained are discussed with regard to the functional significance of the anal glands. These secretory products may create a defensive barrier against microbial invasion at the anal mucosa.