Complex carbohydrates in the secretory epithelium of the goat prostate

Summary The complex carbohydrates in the epithelium of the goat prostate were studied with a battery of light microscopical histochemical methods that included peroxidase-labelled lectin-diaminobenzidine (PO-LT-DAB) procedures. The secretory epithelial cells were found to be of three types: (a) mucus-producing cells, (b) protein-secreting cells, and (c) cells intermediate between (a) and (b). All these cell types contained variable amounts of neutral and acidic complex carbohydrates. The histophysiological significances of these substances in the glandular cells are discussed with special reference to the function of the accessory sex glands.     

The histochemistry of complex carbohydrates in the scrotum of the boar

Summary In the scrotal skin of the boar, the histochemistry of complex carbohydrates has been studied by means of a series of selected methods of light microscopy. The epidermis of the scrotal skin was found to contain neutral and acidic complex carbohydrates with different saccharide residues. The secretory epithelial cells and secretory substances of the saccular apocrine sweat glands contained sulfated, other acidic and neutral complex carbohydrates, whereas the secretory epithelial cells and secretory substances of the tubular apocrine sweat glands involved largely neutral complex carbohydrates. The two types of complex carbohydrates from the both glands were shown to contain commonly substantial amounts of various saccharide residues but were devoid of notable amounts of sialic acid residues. In addition, complex carbohydrates in the smooth muscle cells were reacted for relatively small amounts of saccharide residues. From the present results, the histophysiological significanses of complex carbohydrates in the particular histologic structures of the scrotum have been discussed with special reference to the functions of the skin in the boar.A major part of this work has been presented at the 6th International Histochemistry and Cytochemistry Congress, Brighton, United Kingdom, in 1980     

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 Siaα2-3Gal1-4GlcNAc 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 observations on the apocrine glands of the scrotal skin of the cat and dog

Enzyme and carbohydrate histochemical methods were used to study the secretory activity of the apocrine glands of the scrotal skin of the cat and dog. The typical activity spectra of the different oxidative and hydrolytic enzymes investigated indicated high metabolic rates within the secretory cells. The carbohydrate histochemical differentiation revealed mostly neutral and partly acidic glycoproteins, with only small amounts of sialic acid, in the secretory cells and the luminal secretion of the glands. The PO-lectin-DAB procedures applied demonstrated that the following saccharide residues were dominant within the neutral glycoproteins present: alpha-D-glucose, alpha-D-mannose, beta-D-galactose, N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine.     

Cutaneous eccrine glands of the foot pads of the small Madagascan tenrec (<Emphasis Type="Italic">Echinops telfairi,</Emphasis> Insectivora,Tenrecidae): skin glands in a primitive mammal

In order to find correlations between skin gland morphology and specific ethological features, the cutaneous glands of the foot pads of the primitive mammal the Madagascan tenrec, Echinops telfairi, were studied by histological and various histochemical methods as well as by electron microscopy. In the foot pads specific eccrine skin glands occurred consisting of coiled ducts and tubular secretory portions, the lumina of which were considerably wider than in primate sweat glands. The secretory tubules were composed of branched myoepithelial cells and glandular cells. The latter contained abundant mitochondria, large amounts of glycogen particles and few secretory granules as well as individual heterolysosomes and myelin bodies. The lateral cell membrane was marked by extensive interdigitations. The apical membranes of all glandular cells contained proteoglycans with sulfated and carboxylated groups containing N-acetyl-glucosamine, N-acetyl-galactosamine, galactose and mannose. The expression pattern of cytokeratins of the glandular epithelium was variable and showed similarities to that of the human eccrine glands. Tubulin, vinculin and actin were expressed in the glandular epithelium. The secretory cells showed positive reactions with antibodies against antimicrobial peptides and IgA. A positive reaction was observed with antibodies against the androgen receptor. The PCNA and TUNEL reactions indicated that the tubular skin glands of Echinops are made up of a slowly renewing tissue. We conclude that the glands fulfill several functions: production of a fluid-rich secretory product, which may prevent slipping of the foot pads on the substrate during running or climbing, secretion of antimicrobial peptides and proteins, and playing a role in thermoregulation.We thank the Fendt Foundation for financial support     

Cultivation of epithelia from the secretory coil of the ovine apocrine gland: Evidence of secretory cell function and ductal morphogenesis In vitro

Summary The secretory coil of the ovine apocrine gland is composed predominantly of two cell types, secretory cells lining the lumen and myoepithelial cells adjacent to the basement membrane. The glands synthesize a number of hormones and growth factors, but analysis of the functions of these molecules may be hampered by the mixing of apocrine and sebaceous secretions in the pilary canal. The purpose of this study was to isolate the glands and devise simple culture procedures to facilitate investigations of secretory cell function. The most successful approach involved microdissection of the secretory coils individually from skin biopsies and culture in Dulbecco’s modified Eagle’s medium. After 1–2 wk in medium, cell outgrowths were seen from explants. These consisted predominantly of populations of epithelial cells, many containing granules. Smaller granules were usually concentrated around the cell nuclei and accumulated lipophilic dyes. Large granules were unreactive. Western analysis showed that cells in culture synthesized nerve growth factor-like peptides, a feature consistent with one of the functions of the gland in vivo. When isolated secretory coils were explanted to culture dishes coated with matrigel, highly compact, multilayered masses of cells grew out. Subsequently, tubular structures formed. The observations suggest that some differentiated functions of gland cells were retained in vitro and that the procedures described provide a system for the study of apocrine secretions in isolation from those of other skin glands.     

Cytochemistry of the skin of patients with mucopolysaccharidoses.

The distribution of complex carbohydrates has been investigated at the light and electron microscope levels in sweat glands of normal subjects and patients with Hurler's or Hunter's disease. Normal sweat glands examined with a battery of light microscopic histochemical methods revealed sulphated complex carbohydrate in secretory granules of the dark cells. These granules lacked affinity for dialysed iron (DI) at the light and electron microscope levels. The DI method demonstrated acid complex carbohydrates ultrastructurally on the surface of the intercellular canaliculi and central lumen in normal sweat glands. DI-reactive acidic material, presumably of mucopolysaccharide nature, surrounded and extended between collagen bundles in the stroma of normal skin, but was absent from the band which ensheathed the sweat gland and consisted of individual rather than bundled collagen fibrils. DI-reactive mucopolysaccharide lined and partially filled vacuoles of dark cells showing a laminar distribution in vacuoles of clear cells in sweat glands of a Hunter patient. The DI method also visualized mucopolysaccharide distributed throughout vacuoles in fibroblasts of this patient. DI-reactive acid material covered the luminal surface of the sweat gland, coated collagen bundles in the stroma and spared the periglandular collagenous sheath in skin from Hurler and Hunter patients as in that from normal controls. Acid phosphatase was localized ultrastructually in vacuoles and nearby cytoplasm and on plasmalemmae of clear cells, dark cells and myoepithelial cells of sweat glands from Hurler and Hunter patients. Vacuoles of dermal fibroblasts and Schwann cells in these specimens also exhibited strong acid phosphatase activity.     

Morphological, histochemical and immunohistochemical characterization of secretory production of the ciliary glands in the porcine eyelid

In addition to performing general histology and cytology of the ciliary glands of the miniature pig, we studied the localization of glycoconjugates and beta-defensins in these glands with the use of carbohydrate histochemical and immunohistochemical methods. The secretory cells of the glands were equipped with non-homogeneous secretory granules, a well-developed Golgi apparatus and rough endoplasmic reticulum. The secretory epithelium and luminal secretion of the glands contained large amounts of neutral and acidic glycoconjugates with various saccharide residues (alpha-L-Fuc, beta-D-Gal, alpha-D-GalNAc and sialic acid). The sebaceous glands and tarsal glands also exhibited positive reactions to most of the histochemical methods. Additionally, the antimicrobial peptide group of beta-defensins was demonstrated to be products of the ciliary glands, as well as the sebaceous glands and tarsal glands. The results obtained are discussed with regard to the specific function of the ciliary glandular secretions. These secretory products may be related to the moistening and general protection of the skin surface of the eyelid and ocular surface.     

Histochemical study on the eccrine glands in the foot pad of the cat

Enzyme and carbohydrate histochemical methods were used to study the secretory activities and secretion properties of the eccrine tubular glands in the foot pad of the cat. The activity spectra of the different oxidative and hydrolytic enzymes investigated indicate high metabolic rates within the secretory epithelium. Additionally the enzyme reactions emphasize a double innervation of the glands by cholinergic and adrenergic nerve fibres. The carbohydrate histochemical differentiation reveals mostly neutral and very few acidic glycoproteins in the secretory cells and the secretion, respectively. Clear (basal) cells contain distinct amounts of glycogen, and dark (superficial) cells show neutral glycoproteins, which reveal after PO-lectin-DAB procedures the following saccharide residues: alpha-D-mannose, alpha-D-galactose, N-acetyl-alpha-D-glucosamine, alpha-L-fucose, beta-D-galactose-D-N-galactosamine, beta-D-galactose, and sialic acid. The results obtained confirm the view that the normal biological functions of the eccrine glands of the feline foot pad are to improve the frictional capacities of the paw and to leave typical scent marks.     

Histology and ultrastructure of the caudal courtship glands of the red‐backed salamander,Plethodon cinereus (Amphibia: Plethodontidae)

Caudal courtship glands (CCGs) are sexually dimorphic glands described in the skin of the dorsal tail base of some male salamanders in the genera Desmognathus, Eurycea, and Plethodon in the family Plethodontidae. These glands are believed to deliver pheromones to females during courtship, when the female rests her chin on the dorsal tail base during the stereotypic tail straddling walk unique to plethodontids. Although CCGs have been studied histologically, no investigations of their ultrastructure have been made. This article presents the first study on the fine structure and seasonal variation of CCGs, using the plethodontid Plethodon cinereus. The CCGs vary seasonally in height and secretory activity. The mature secretory granules observed in males collected in October and April consist of oval, biphasic granules that are eosinophilic and give positive reactions to periodic acid‐Schiff for neutral carbohydrates but do not stain for acidic mucosusbtances or proteins with alcian blue and bromphenol blue, respectively. Granular glands, some of which contain mucous demilunes, are twice as large as CCGs, are syncytial (unlike CCGs), and stain for proteins. Mucous glands are similar in size to CCGs, but are basophilic, show no seasonal variation in secretory activity, and stain positive for acidic mucosubstances. CCGs do not resemble cytologically the sexually dimorphic mental glands of some plethodontids, which contain round or oval granules filled with an electron‐dense amorphous substance. The CCGs are similar histologically to sexually dimorphic skin glands described in some anurans, but more comparative work is needed. J. Morphol. 276:319–330, 2015. © 2014 Wiley Periodicals, Inc.     

Localization of prolactin receptor in the dorsal and ventral skin of the frog (Rana ridibunda)

The dorsal and ventral skin in amphibians plays an important role in osmoregulation. Prolactin hormone is involved in regulation of amphibian skin functions, such as water and electrolyte balance. Therefore, amphibians may be useful as a model for determining the sites of the prolactin receptor. In this study, prolactin receptor was detected in frog dorsal and ventral skin using immunohistochemical staining method. Prolactin receptor immunoreactivity was localized in all epidermal layers except stratum corneum of dorsal skin epidermis, stratum germinativum layer of ventral skin epidermis, myoepithelial cells, secretory epithelium and secretory channel cells of granular glands in both skin regions. The mucous glands and secretory granules of granular glands did not show immunoreactivity for the prolactin receptor. According to our immunohistochemical results, the more widespread detection of prolactin receptor in dorsal skin epidermis indicates that prolactin is more effective in dorsal skin. Presence of prolactin receptors in epidermis points out its possible osmoregulatory effect. Moreover, detection of receptor immunoreactivity in various elements of poison glands in the dermis of both dorsal and ventral skin regions suggests that prolactin has a regulatory effect in gland functions.     

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.     

Ultracytochemistry of glycoproteins in the eccrine nasolabial glands of the North American raccoon (Procyon lotor)

The distribution and quality of glycoproteins was studied by means of electron microscopic cytochemical methods, particularly lectin cytochemistry, in the secretory cells of the eccrine nasolabial glands of the North American raccoon (Procyon lotor). In the dark and clear glandular cells, complex glycoconjugates were demonstrable, predominantly, in secretory granules, the cisternae of the Golgi apparatus, the surface coat of the plasma membrane, and as glycogen particles. Secretory granules found in the dark cells contained a variety of saccharide residues, such as α-d-mannose, β-d-galactose, β-N-acetyl-d-glucosamine and sialic acid. Several sugars were also detectable in the surface coat of the plasma membrane and the Golgi apparatus.The results obtained may be helpful to understand the specific functions of the glandular secretions of the raccoon nasolabial glands. These could be, particularly, binding of water on the snout surface and protection against microbial hazards, to maintain the structural and functional integrity of the relatively thin snout epidermis in carnivores.     

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.     

Morphology of the exocrine glands of the frog skin

Frog skin contains three distinct types of exocrine glands: granular (poison), mucous, and seromucous. The granular gland forms a syncytial secretory compartment within the acinus, which is surrounded by smooth muscle cells. The mucous and seromucous glands are easily identifiable as distinct glands. The serous and mucous secretory cells are arranged in a semilunar configuration opposite the ductal end and are filled with granules. Within the acinus, located at the ductal pole of the gland, are distinct groups of cells with few or no granules in the cytoplasm. In both the mucous and seromucous gland there is a cell type with abundant mitochondria; the one in the mucous gland is located in the region adjacent to the secretory cells. The duct of these glands is two-layered, with the individual cells appearing morphologically similar to the layers of the skin epithelium as the duct traverses the skin. The duct appears to be patent throughout its length. The morphological heterogeneity and distinct distribution of the cell types within the gland acinus may be indicative of a functional heterogeneity that allows the production of distinctly different types of secretion from the same gland type, depending on the type of stimulus.     

Histochemistry of carbohydrates in the epithelium lining the bulbourethral gland of the rat

The histochemistry of carbohydrates has been studied in the epithelium lining the bulbourethral gland of the rat by means of light- and electron-microscopic methods. The results obtained show that the cytoplasms of the epithelial cells contain neutral and acidic carbohydrates. The neutral carbohydrates exhibited positive reactions with periodic acid-Schiff and periodic acid-thiosemicarbazide-silver proteinate, whereas the acidic carbohydrates reacted positively with alcian blue (AB; pH 1.0 and 2.5) and dialyzed iron. Most neutral carbohydrates were found to be glycoproteins localized within the secretory granules. The acidic carbohydrates consist of at least two types, AB (pH 1.0)-reactive sulfated and AB (pH 2.5)-reactive nonsulfated carbohydrates; most nonsulfated carbohydrates were determined to be sialic acid. The acidic carbohydrates were also localized within the secretory granules.     

Seasonal lectin binding variations of thumb pad in the frog (Pelophylax ridibundus)

The thumb pad is one of the most common secondary sexual characteristics in frogs. Although it is known that amphibian skin has affinity for several lectins, there is no report regarding lectin‐binding affinity of the thumb pad or its structural components. This study investigated localization and seasonal variation of specific carbohydrate moieties of glycoconjugates in both the epidermal and dermal components of the frog thumb pad at the light microscopic level using lectin histochemistry. The study consisted of four seasonal groups of the frog species, Pelophylax ridibundus (Synonym of Rana ridibunda): active, prehibernating, hibernating and posthibernating. Four horseradish peroxidase conjugated lectins were employed. It was found that dolichos biflorus agglutinin (DBA), wheat germ agglutinin (WGA), and ulex europaeus (UEAI) gave positive reactions in both epidermal layers and breeding glands. These three lectins bound specific secretory cells in the breeding glands, and the distribution of the cells and epithelial lectin reactions exhibited seasonal changes. In addition, UEA‐I and peanut agglutinin (PNA) showed an affinity in granular glands and the granular zone of mixed glands. Generally, epidermal lectin binding showed dense affinity during the posthibernation period. DBA, UEA‐I, and WGA‐specific cells in the mucous gland decreased gradually until the posthibernation period. These findings suggest that differences of lectin binding in the thumb pad may be related to functional activities and, thus, seasonal adaptations. Moreover, the presence of specific lectin‐binding cells in the breeding glands indicated that they consisted of heterogeneous secretory cell composition or that the cells were at different secretory stages. J. Morphol. 275:76–86, 2014. © 2013 Wiley Periodicals, Inc.     

Distribution of prolactin receptor in frog (Rana ridibunda) dorsal skin during hibernation

The role of prolactin in the regulation of frog skin functions is still unclear particularly during environmental changes. In this study, prolactin receptor (PRLR) was detected in active and hibernating frog dorsal skin using immunohistochemical method. PRLR immunoreactivity in active frogs was observed in the epidermis, in the secretory epithelium of granular glands and the secretory channel cells of the glands. Myoepithelial cells of granular glands that started accumulating secretory material or those with a full lumen were PRLR immunoreactive, while some myoepithelial cells of empty granular glands were negative for PRLR. In hibernating frogs, this immunoreactivity was observed in the same regions; however, immunoreactivity was more intense than that in active frogs. PCNA was employed for detection of proliferative activity of PRL in the dorsal skin, and immunoreactivity was detected in the nuclei of a few epidermis cells and in the duct of glands of active frogs. The number of immunoreactive nuclei in these regions increased in hibernating and in prolactin injected groups. We conclude that prolactin provides morphological and functional integrity of skin stimulating the proliferation and regulating the function of granular glands and plays an important role in the adaptation of amphibians to the long winter period.     

The histological and histochemical characteristics of the hepatoid circumanal glands in the dog: the features of similarity and difference with the skin glands of other types

Three types of skin glands, the derivatives of the outer root sheath of the hair follicle, have been compared, which are represented by hepatoid, sebaceous and apocrine sweat glands. There are three characteristic properties inherent to hepatoid glands, existence of a network of intercellular secretory tubules, lysis of some secretory cells during the duct formation which is not the fatty transformation and cyst formation.     

Histochemical demonstration of 5-hydroxytryptamine in poison glands of amphibian skin

Summary The aim of this project was to see whether 5-hydroxytryptamine (5-HT) believed to be present in the skin glands of anuran amphibians can be demonstrated histochemically. The Periodic acid-Schiff technique (P.A.S.) and three histochemical methods known to demonstrate 5-HT in enterochromaffin cells (Pontana's, diazonium and Schmorl's) were applied to the dorsal skin of three species—Xenopus laevis, Rana angolensis and Bufo regularis.Mucous glands were identified by their P.A.S. reactivity in all three species. Poison glands were identifiable in Bufo regularis and Xenopus laevis only. The secretory granules of the latter glands have strong positive reactions with all three histochemical techniques used.It is concluded that the poison glands of anuran amphibians contain 5-HT demonstrable by histochemical means.