Glycoconjugate Histochemistry Research Articles

Glycoconjugate histochemistry of Xenopus laevis fundic gland with special reference to mucous neck cells during development

Mucous neck cells (MNCs) of the fundic gland are phylogenetically thought to have first appeared in amphibians. We studied the origin and differentiation of MNCs in fundic glands of Xenopus laevis. By means of lectin histochemical methods using Griffonia simplicifolia agglutinin-II (GSA-II), MNCs were detected specifically in fundic glands of adult X. laevis. Mucous granules of MNCs were labeled by GSA-II-colloidal gold (CG) staining. Other cells such as surface mucous cells (SMCs), oxynticopeptic cells (OPCs), and endocrine cells did not react to GSA-II. Ulex europaeus agglutinin-I specifically stained OPCs, but not MNCs and SMCs. During the morphogenetic period of the stomach in metamorphosing larvae, GSA-II reactive cells randomly appeared in various portions of the underdeveloped fundic glands and then rapidly localized in the neck portion. At this time, newly appearing mucous granules of MNC type were labeled by GSA-II-CG. Two types of cells intermediate to MNCs and SMCs and intermediate to MNCs and OPCs were observed in the larval gastric region. Cells intermediate to MNCs and OPCs were also found in adults. In these cells, mucous granules of MNC type were labeled by GSA-II-CG, but mucous granules of SMC type and zymogen-like granules did not react to GSA-II. These observations suggest that GSA-II is a useful marker in studying the differentiation of MNCs and their precursors regardless of species differentiation.

Glycoconjugate histochemistry of the prostate gland in the pig

In the porcine prostate, glycoconjugates elaborated and released by the glandular cells have been studied by means of a series of histochemical methods of light microscopy. The employed methods included several routine procedures in combination with digestion by carbohydrate-degrading enzymes and peroxidase-labelled lectin diaminobenzidine procedures. In the glandular tissues, the particular glycoconjugates were shown to be secretory glycoproteins which contained vicinal diol, sulphate, and carboxyl groups and were provided with different saccharide residues such as alpha-D-mannose, alpha-D-glucose, lactose, N-acetyl-D-galactosamine, beta-D-galactose, alpha-L-fucose, N-acetyl-D-glucosamine, and N-acetyl-neuraminic acid. These glycoconjugates were, likewise, found to exhibit positive reaction for proteins. The present histochemical results have been discussed with special reference to the histophysiological functions performed by the prostate gland in the pig.

Histochemistry of glycoconjugates in ovarian follicles of the adult house musk shrew, Suncus murinus.

In ovarian follicles of the adult house musk shrew, Suncus murinus, glycoconjugates have been studied by means of light- and electron-microscopic histochemistry. The results obtained are that: (1) glycoconjugates of the zona pellucida of oocytes are provided with vicinal diol and acidic groupings, and sialic acid-galactose dimer, alpha-D-mannose, alpha-D-glucose, beta-D-galactose, N-acetyl-D-glucosamine and alpha-L-fucose residues; (2) glycoconjugates of the intercellular matrix of the granulosa and theca folliculi are comparable in histochemical properties to those of the zona pellucida, except for the relatively smaller amount of vicinal diol and acidic groupings, and (3) the zona pellucida can be divided into outer and inner layers by the binding degrees of the lectins used. The possible histophysiological significances of all these glycoconjugates are discussed with special reference to the particular ovarian follicular structures.

Histochemistry of glycoconjugates in the gallbladder epithelium of ten animal species.

A battery of seven lectins and several conventional mucin histochemical techniques were used to identify the epithelial mucins of the gallbladder of ten species: man, rabbit (Oryctolagus cuniculus, mammalia), hamster (Mesocricetus auratus, mammalia), chicken (Gallus gallus, bird), sparrow (Passer domesticus, bird), moorish gecko (Tarentola mauritanica, reptilia), ladder snake (Elaphe scalaris, reptilia), lake frog (Rana perezi, amphibia), natterjack toad (Bufo calamita, amphibia) and gilthead sea bream (Sparus auratus, fish). Glycogen was found in the epithelial lining of the reptilian and amphibian gallbladders. Sulphate and carboxyl groups were frequently found in the same species, except in the ladder snake and natterjack toad gallbladders where only sulphate groups were identified. Sialic acid residues were detected in man, rabbit, bird, T. mauritanica, R. perezi and fish gallbladders. ConA binding pattern was similar in the ten species studied. In the human gallbladder only PNA failed to label the luminal surface, while the glands were only unreactive to DBA. The human gallbladder showed a large variety of saccharides. The present results suggest that no relation exists between the composition of the gallbladder mucins and the situation of the species in the phylogenetic scale.

Histochemistry of glycoconjugates in the skin of the bovine muzzle, with special reference to glandular structures.

The distribution of glycoconjugates in the muzzle of young adult Holstein cows has been studied by means of selected light-microscopic histochemical methods, including lectin histochemistry. In the skin layers, strong reactions were confined to intercellular substances in between the cells of the vital epidermis, exhibiting neutral glycoconjugates mainly with alpha-D-galactosyl and N-acetyl-D-galactosaminyl residues. In the nasolabial glands, distinctly positive staining for neutral glycoproteins with various saccharide residues (alpha-D-galactose, alpha-N-acetylgalactosamine, D-galactose-beta(1----3)D-N-acetylgalactosamine, beta-D-galactose), and for smaller amounts of acidic glycoconjugates, was found in the secretory cells and the luminal secretion. The cells of the excretory duct system showed weak to moderate reactions (alpha-D-galactose, beta-D-galactose), only the collecting ducts reacted positively for acidic glycoproteins with sialyl residues. The results obtained are discussed in view of muzzle function, with special reference to the salivary nature of the secretion of bovine nasolabial glands.

Glycoconjugate histochemistry of the rat fundic gland using Griffonia simplicifolia agglutinin-II during the development.

The development and maturation of fundic glands of Wistar rats were studied using Griffonia simplicifolia agglutinin-II (GSA-II) histochemistry at the light microscopic and electron microscopic levels. In adult rats, mucous neck cells and cells intermediate between mucous neck cells and chief cells were specifically labeled with GSA-II, whereas other fundic gland cells were virtually negative. Ontogenetic studies revealed that GSA-II positive cells appeared at the bottom of the gland by 21 days of gestation. With differentiation and aging, the elongation of the fundic gland continued, and the labeling intensity of the mucous neck cells increased by 3 weeks after birth. Cells intermediate between mucous neck cells and chief cells were discernible from 3 days after birth. Typical mucous neck cells appeared at 3 weeks after birth, when their labeling intensity with colloidal gold (CG) particles approximated that of adults. On the other hand, the reactive cell population gradually moved from the bottom toward the middle portion of the gland. Finally, the reactive cells were localized at the neck portion of the fundic gland. These results suggest that GSA-II is a valuable marker for studying mucous neck cells and both their precursor cells and their derivatives.

Histochemistry of Glycoconjugates in the Goat Nasolabial Skin with Special Reference to Eccrine Glands

The histochemistry of glycoconjugates in the nasolabial skin of the goat has been studied by means of a series of selected methods of light microscopy. The epidermis of the nasolabial skin was found to contain neutral and acid glycoconjugates with different saccharide residues. The secretory epithelial cells and secretory substances of the sebaceous glands contained primarily neutral glycoconjugates, whereas those of the apocrine glands involved largely strongly acidic and neutral glycoconjugates. In the epithelial cells and secretory substances of the nasolabial eccrine glands, glycoconjugates involved were characteristically strongly neutral but weakly acidic in nature. From the present results, the histophysiological significance of glycoconjugates in the particular histologic structures of the nasolabial skin has been discussed with special reference to the functions of this particular skin type in the goat.

The histochemistry of glycoconjugates in the colonic epithelium of the chicken.

In the colonic epithelium of the chicken, glycoconjugates have been studied by means of selected histochemical methods of light and electron microscopy. According to the results obtained, most of the colonic goblet cells contained acidic and neutral glycoconjugates with sulphate and vicinal diol groupings, alpha-D-mannose and alpha-D-glucose residues and sialic acid-galactose dimers. These goblet cells were found to undergo changes in histochemical reactivity during upward migration along the crypts; alpha-D-mannose and alpha-D-glucose residues and terminal sialic acid-galactose dimers increased in amount. The striated border of the colonic columnar cells has, likewise, been found to contain such glycoconjugates as were similar in reactivity to those of the goblet cells. The histophysiological significances of glycoconjugates involved in the chicken colonic epithelium have been discussed with special reference to the functional activities of the carbohydrates.

Lectin histochemistry of secretory and cell-surface glycoconjugates in the ovine submandibular gland.

Information about the chemical structure of ovine submandibular glycoconjugates was obtained in situ by means of a battery of peroxidase-conjugated lectins with affinity for specific terminal or internal sugars or sugar sequences in conjunction with neuraminidase digestion and periodate oxidation. Stored secretions in all mucous acinar cells contained disaccharide side chains consisting of N-acetylneuraminic acid linked to penultimate alpha-N-acetylgalactosamine localizing the predominant disaccharide demonstrated biochemically. A previously unrecognized disaccharide consisting of terminal N-acetylneuraminic acid and penultimate beta-galactose was found in 20-30% of mucous acinar cells. Occasional clusters of acini composed purely of serous cells contained an additional unrecognized glyco-conjugate with oligosaccharides terminated by sialic acid with O-acetylated polyhydroxyl side chains and penultimate beta-galactose. Serous demilunes, however, lacked detectable complex carbohydrate other than glycogen. Terminal sialic acid-beta-galactose dimers were present on the apical surface of all ducts except for intercalated ducts coated only with neutral glycoconjugate. Fucose assayed biochemically as a minor component occurred in abundance in glycoconjugates at the apical surface of all intercalated and most striated duct cells and within some striated duct cells. Terminal alpha-galactose not previously detected biochemically was localized at the apex of all duct cells. These results provide new knowledge concerning the structure of ovine submandibular glycoconjugates. They also illustrate the value of histochemical methods for elucidating the diversity of complex carbohydrates in an organ, locating different glycoconjugates in different types or subtypes of epithelial cells and demonstrating intracellular sites that contain complex carbohydrate.

Histochemistry of glycoconjugates of pleomorphic adenomas of minor salivary glands, with special reference to glycocalyx of tubular areas.

Histochemical characterization of glycoconjugates elaborated by palatal pleomorphic adenomas showed that glycoproteins, glycosaminoglycans, and perhaps glycolipids were present in both the "epithelial" and "connective tissue" components of these tumors, as well as in the distinct glycocalyx present in the luminal surface of tubular and cystic areas.