Morphogenetic processes in cultured cells from integumentary glands of deer sambar (Cervus unicolor Kerr)

The present paper describes an attempt to maintain the metatarsal and caudal glands of deer sambar (Cervus unicolor Kerr) in diffusion chambers. Another purpose was to provide information on the secretory granule of these glands. Our results show that cultured gland cells have the capacity to reassociate into islet-like organoids in diffusion chambers. Competence in some epithelial cell types may probably be regulated as a function of growth. Scanning electron microscopy of secretory cells showed that the cells in the culture often had numerous short filopodia and blebs. The secretory granules of the caudal gland were spherical and uniform in size. Some of the secretory granules had pseudopodia-like protrusions. By means of SEM, the present study provides evidence of rapid structural changes in the surfaces of epithelial cells in the course of cultivation. It has been suggested that the structural organization in the cell colonies serves to "guide" the function of secretory cells.     

Fine structural studies of rat seminal vesicle in castrated and intact animals following estrogen treatment.

The effect of estradiol and/or testosterone upon secretion by seminal vesicle in castrated and intact rats was assessed in young adult Sprague-Dawley rats, using light microscopy (LM), transmission (TEM) and scanning (SEM)electron microscopy. Hormones were injected daily for ten days beginning ten days after castrations were performed. The normal rat seminal vesicle, as revealed by SEM, was characterized by a large saccular lumen with highly folded walls. Cell surfaces were covered with microvilli, or occasionally displayed a protruding, ruffled surface, sparsely covered with short microvilli. Cytology was normal in testosterone-treated animals. Estradiol treatment of castrated animals stimulated secretion by seminal vesicle epithelial cells as evidenced by the presence of normal secretory bodies, the presence of RER, and moderately hypertrophied Golgi complexes. These glands were not heavier than were glands from castrated, untreated animals, although the epithelial cells were significantly taller. Secretion was maintained in intact animals treated with estradiol, although glands were smaller and epithelial height was reduced. Estradiol and testosterone treatment in combination did not appear to have an additive effect on secretion, weight of the gland, or epithelial height. The following results support the hypothesis that estrogen-induced prolactin synthesis and release may be involved in the mechanism by which estradiol effected stimulation of seminal vesicle epithelium. Prolactin-treated, castrated animals exhibited focal areas of stimulated epithelium. In hypophysectomized animals (untreated controls), the seminal vesicle epithelium retained some secretory bodies and secretory fluid in the glandular lumen; epithelial height was taller than that in castrated controls. Estrogen treatment reduced the epithelial height to that of castrated controls; there was no evidence of secretion. This suggests that in the absence of anterior pituitary hormones, including prolactin, the stimulatory effect of estradiol on seminal vesicle epithelium was nullified. In adrenalectomized/castrated animals, estradiol treatment stimulated secretion in seminal vesicle epithelium just as in non-adrenalectomized/castrated animals. This indicates that the adrenal gland plays a non-essential role in the action of estrogen on seminal vesicle epithelium.     

Fine structure and chemical analysis of the metathoracic scent gland of Eurygaster maura (Linnaeus, 1758) (Heteroptera: Scutelleridae)

The morphology and ultrastructure of the metathoracic scent glands (MTG) of Eurygaster maura were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Also, extracts of the volatile fraction of the MTG secretion from males and females were analyzed by capillary gas chromatography-mass spectrometry (GC-MS). In SEM investigations, MTG are composed of a reservoir and a pair of lateral glands connected to the reservoir by a duct. MTG are open in between the meso- and the metacoxae. These areas, called evaporation areas, are composed of mushroom-like elements. In TEM investigations, the reservoir walls contained two types of cells. Generally, a reservoir is lined by a single layer of epithelial cells, type I cells, which have numerous organelles. Type II cells are found only in a certain area of the reservoir wall. These cells have large secretory ducts lined by a cuticular intima layer. The lateral glands are lined by secretory cells and a secretory duct found in their cytoplasm. Nuclei of secretory cells are closed to the basal region of the cells and circular-shaped. In GC-MS investigations, the MTG exhibited a typical scutellerid composition. In general, (E)-2-hexanal, (E)-2-hexenyl acetate, n-tridecane, n-hexanoic acid, octadecanoic acid, and n-dodecane compounds were present, while diisooctyl acetate and 14-Beta-H-Pregna were detected only in the male extracts of Eurygaster maura.     

A light microscopic and ultrastructural study on the presence and location of oxytocin in the equine endometrium

It has been reported that oxytocin is produced not only in the hypothalamus and posterior pituitary but also in outside the classical hypothalamo-neurohypophyseal axis such as the ovary, testis, placenta and in some nonreproductive sites. In the mare, oxytocin-mRNA has been identified in the endometrium, and oxytocin and its neurophysin have been identified in the uterus. In the present study, oxytocin was localised in the endometrium of the mare at the light microscopic and ultrastructural level by immunostaining and immunogold labelling of endometrial biopsy specimens collected during estrus.Strong positive immunostaining for oxytocin was found in the secretory vesicles of the secretory (nonciliated) epithelial cells of the uterine lumen and of the superficial glands. Using immunogold labelling, oxytocin was detected in the secretory vesicles of secretory epithelial cells. The vesicles containing immunoreactive oxytocin were present on the luminal surface suggesting that oxytocin is secreted into the uterine lumen by apical exocytosis. There was no positive immunostaining in ciliated epithelial cells of the uterine lumen and endometrial glands, in the stromal cells, or in the basal endometrial glands. To our knowledge, this is the first report of the location of oxytocin in specific secretory cells in the endometrium of any domestic species. This locally synthesised uterine oxytocin may have an important role in the autocrine/paracrine control of uterine contractility and luteolysis in the mare.     

Distribution of entactin in the basement membrane of the rat mammary gland. Evidence for a non-epithelial origin

Entactin, a sulfated glycoprotein with a molecular weight (MW) of about 150 kD, is present in vascular basement membranes and in the interstitial connective tissue of the mammary glands of virgin rats. It does not appear to be present in the basement membrane surrounding the mammary ductal system. However, in lactating mammary glands entactin is also present in the basement membrane region surrounding the secretory alveoli. Ultrastructural localisation of entactin reveals that it is present on the basal surface of epithelial cells, with patchy staining in the lamina lucida and lamina densa. Entactin also appears to be associated with interstitial collagen fibres. Mammary fibroblastic cells in culture are able to produce entactin, whereas mammary epithelial and myoepithelial cells, which synthesise the basement membrane proteins laminin and type IV collagen, fail to synthesise entactin.     

Mammary epithelial stem cells: transplantation and self-renewal analysis

Abstract.  An entire mammary epithelial outgrowth, capable of full secretory differentiation, may be comprised of the progeny of a single cellular antecedent. This conclusion is based upon the maintenance of retroviral insertion sites within the somatic DNA of successive transplant generations derived from a single mammary fragment. In addition, dissociation of these clonal dominant glands and implantation of dispersed cells at limiting dilution demonstrated that both duct-limited and lobule-limited outgrowths were developed, as well as complete, fully differentiated glands. Thus, transplantation has revealed three distinct mammary epithelial progenitors in the mouse. Similar studies have extended this observation to rat mammary tissue. Recently, using cre-lox conditional activation of reporter genes, a new epithelial progenitor, specific for mammary secretory epithelium in postlactation females has been uncovered. In situ , these cells were shown to regenerate secretory lobules upon successive pregnancies. In transplant studies, they demonstrated the capacity for self-renewal and contributed to the new generation of all of the known epithelial cell types among mammary epithelium. In limiting dilution, the parity-induced progenitors were capable of engendering lobule-limited and duct-limited outgrowths in their entirety, but not completely developed glands. Serial transplant studies indicate that these progenitors have a significant but limited capacity for self-renewal.     

Structure of the male reproductive accessory glands of Pterostichus nigrita (Coleoptera: Carabidae), their role in spermatophore formation

Accessory gland secretions of male insects have many important functions including the formation of spermatophores. We used light and electron microscopy to investigate the structure of the accessory glands and posterior vasa deferentia of the carabid beetle Pterostichus nigrita to try to determine where spermatophore material is produced. Each accessory gland and posterior vas deferens had an outer layer of longitudinal muscle, beneath which was a layer of connective tissue and a thin band of circular muscle, all of which surrounded a layer of epithelial cells lining the lumen of the ducts. Based on the ultrastructure of the epithelial cells, and their secretory products, we identified two epithelial cell types in each region (distal and proximal) of the accessory glands and four types in the posterior vas deferens. Most secretory products, which stained positively for proteins and some mucins, were released into the lumen of the ducts by apocrine secretion. The accessory glands produced one type of secretory product whereas in posterior vasa deferentia, four types of secretory products were found layered in the lumen. Our results suggest that most of the structural material used to construct a spermatophore is produced by the cells of the posterior vasa deferentia.     

中华补血草盐腺发育的解剖学研究

采用叶表皮印痕、扫描电镜以及石蜡切片法对中华补血草的叶片进行解剖研究,观察其成熟盐腺的结构、盐腺的发育与盐腺的密度。结果表明:(1)上表皮的盐腺密度比下表皮的略小。(2)成熟的盐腺由20个细胞构成,中央有4个分泌细胞,每一个分泌细胞外侧又伴有一个长方形的毗邻细胞;向外由2层杯状细胞包围,每一层分别有4个杯状细胞,使盐腺呈近似圆形;盐腺内部靠近叶肉细胞处有4个收集细胞;中央4个分泌细胞顶端的角质层各有一小孔,是盐分泌出的通道。(3)中华补血草盐腺是由一个单独的表皮细胞发育而成,分别经历单细胞时期、2细胞时期、4细胞时期、8细胞时期、16细胞时期和20细胞时期的不同发育阶段。     

Xanthine oxidase,an indicator of secretory differentiation in mammary cells

Elevated levels of xanthine oxidase were found in (1) lactating mouse mammary glands, compared with virgin and midpregnant glands; and (2) primary mouse mammary cells cultured on floating collagen gels, compared with non-secretory cells on attached gels. In primary culture, increase in xanthine oxidase activity above a basal level coincided with secretory activity as measured by casein production; intracellular levels of casein and xanthine oxidase showed a high degree of correspondence. It is suggested that xanthine oxidase levels can be used as an indicator of in vivo and in vitro secretory differentiation in mammary epithelial cells.     

Dorsal galnds of Alligator mississippiensis: a histological and histochemical study

Several investigators have described in some crocodilians a row of round or oval organs, called dorsal glands, lying under scutes on each side of the dorsal midline. The function of these glands is unknown, but they are hypothesized to produce skin-conditioning secretions. We investigated the anatomy and histochemistry of the dorsal glands of adult American alligators ( Alligator mississippiensis ). Twenty to 22 pairs of glands containing a viscous, often black, material were observed lying from the mid-cervical to the anterior caudal regions in the axial musculature or on the inner surface of the dermis. The capsule of each gland consists of dense collagenous fibres and numerous short elastic fibres, and is surrounded by skeletal muscle. The single lumen is lined by one to several layers of cuboidal to columnar epithelium in varying stages of degeneration, indicating a holocrine secretory mode. The epithelial cell membranes often interdigitate and tight junctions and desmosomes occasionally are observed between them. The epithelial cells and secretory product contain slight to considerable amounts of lipid; glycoproteins may be present. Crystals exhibiting a dense core and/or layering occur in the epithelial cells and secretory product. Energy-dispersive X-ray analysis demonstrates calcium, copper, iron, lead, potassium, and zinc in the crystals. Mitochondria, vacuoles, and short segments of rough endoplasmic reticulum also occur in the cells.     

Lectin binding of surface epithelia and concomitant glands of gallbladder and biliary ducts in the guinea pig

Complex carbohydrate components of secretory granules and the glycocalix were analysed in surface epithelia, endoepithelial glands and exoepithelial tubuloalveolar glands of the biliary-ductular system (guinea pig). Brunner glands and pyloric glands were studied for comparison. The columnar epithelial cells of the gallbladder and biliary ducts displayed a well-developed PAS-positive apical glycocalix. These materials strongly bound Ricinus communis A I, Ulex europaeus I, Lotus tetragonolobus A and wheat-germ-A lectins. With the exception of Lotus A lectin which did not bind at all, the same lectins stained the basolateral cell surface. The secretory granules in the supranuclear regions of surface epithelia and in the exoepithelial glands strongly bound Ricinus A I, Ulex europaeus I, wheat-germ-A and Helix pomatia lectins. Concanavalin A was less intensively bound by the secretions of tubuloalveolar glands than by the secretory granules in surface epithelia. The luminal and basolateral cell surfaces of glandular cells in the exoepithelial glands were stained by the same spectrum of lectins as were the columnar cells of surface epithelia, but the staining was less distinct. In the guinea pig, the lectin-binding patterns of tubuloalveolar glands in the biliary ducts closely resembled those of Brunner glands and pyloric glands. The secretions of the tubuloalveolar glands were different from the secretion of surface epithelia, as they bound Concanavalin A less intensively.     

Light microscopic detection of sugar residues in glycoconjugates of salivary glands and the pancreas with lectin-horseradish peroxidase conjugates. II. Rat

Summary Salivary glands and pancreases from male rats were stained with a battery of ten different lectin-horseradish peroxidase conjugates. Qualitative and quantitative differences were observed in the content of terminal sugar residues in stored secretory glycoproteins in parenchymal cells of glands having a similar histological structure. Heterogeneity in the content of secretory glycoconjugates was also found between cells in the same exocrine glands, which were previously thought to be identical on the basis of classical morphological and histochemical staining studies. Similar differences were observed in the structure of glycoconjugates associated with the apical surface of epithelial cells lining glandular excretory ducts. Intercalated ducts presented a gland specific staining pattern different from that of the glandular secretory cell population, whereas striated duct and interlobular duct epithelial cells stained similarly in all major rat exocrine glands. A comparison of lectin binding patterns in identical histological sites in the mouse, reported in a companion paper, is provided, and the similarities and differences between these two rodent species are discussed. In addition to providing valuable information concerning the localization and structure of tissue complex carbohydrates, a comparison of staining in the same tissue sites with labelled lectins reported biochemically to have similar binding specificity has revealed interesting differences in the binding specificity of these macromolecules.     

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     

Lectin binding of surface epithelia and concomitant glands of gallbladder and biliary ducts in the guinea pig

Summary Complex carbohydrate components of secretory granules and the glycocalix were analysed in surface epithelia, endoepithelial glands and exoepithelial tubuloalveolar glands of the biliary-ductular system (guinea pig). Brunner glands and pyloric glands were studied for comparison. The columnar epithelial cells of the gallbladder and biliary ducts displayed a well-developed PAS-positive apical glycocalix. These materials strongly bound Ricinus communis AI, Ulex europaeus I, Lotus tetragonolobus A and wheat-germ-A lectins. With the exception of Lotus A lectin which did not bind at all, the same lectins stained the basolateral cell surface. The secretory granules in the supranuclear regions of surface epithelia and in the exoepithelial glands strongly bound Ricinus A I, Ulex europaeus I, wheat-germ-A and Helix pomatia lectins. Concanavalin A was less intensively bound by the secretions of tubuloalveolar glands than by the secretory granules in surface epithelia. The luminal and basolateral cell surfaces of glandular cells in the exoepithelial glands were stained by the same spectrum of lectins as were the less distinct. In the guinea pig, the lectin-binding patterns of tubuloalveolar glands in the biliary ducts closely resembled those of Brunner glands and pyloric glands. The secretions of the tubuloalveolar glands were different from the secretion of surface epithelia, as they bound Concanavalin A less intensively.     

Salivary epithelial cells: An unassuming target site for gene therapeutics

Salivary glands are classical exocrine glands whose external secretions result in the production of saliva. However, in addition to the secretion of exocrine proteins, salivary epithelial cells are also capable of secreting proteins internally, into the bloodstream. This brief review examines the potential for using salivary epithelial cells as a target site for in situ gene transfer, with an ultimate goal of producing therapeutic proteins for treating both systemic and upper gastrointestinal tract disorders. The review discusses the protein secretory pathways reported to be present in salivary epithelial cells, the viral gene transfer vectors shown useful for transducing these cells, model transgenic secretory proteins examined, and some clinical conditions that might benefit from such salivary gland gene transfer.     

Ultrastructural study of the mental body of Hydromantes genei (Amphibia: Plethodontidae)

The mental glands of Hydromantes genei are considered a specialized form of the urodele serous cutaneous glands. Use of a variety of techniques of maceration and digestion as well as transmission electron microscopy (TEM) and scanning electron microscopy (SEM) has shown the three-dimensional morphology of secretory and myoepithelial cells. Secretory cells are pyramidal and rest on an almost continuous layer of myoepithelial cells. The latter have a long ribbon-like body from which branch off transversal and longitudinal processes with swallow-tailed ends. Cytoplasmic processes of secretory cells, containing irregular dense vesicles, squeeze through clefts between myoepithelial cells and may reach, at some points, the basal lamina. The interstices between myoepithelium and secretory cells are extraordinarily rich in nerve endings with clear vesicles. The glandular outlets appear as elliptical stomata in the superficial layer of the epidermis and are lined by horny cells, which invaginate to circumscribe the excretory duct. The morphological results indicate that the myoepithelium of Plethodontidae mental glands differ in some respects from that of amphibian serous cutaneous glands. A double polarity for the secretory cells is also suggested. © 1993 Wiley-Liss, Inc.     

NADPH-diaphorase and NOS-1 Positive Ganglion Cells are Found in the Rat Vallate Papilla/von Ebner Gland Complex

The nervous system of the vallata papilla and von Ebner glands was investigated in the rat tongue. Cells involved in the production of nitric oxide were identified by immunohistochemical detection of neuronal nitric oxide synthase type-1 and by cytochemical detection of NADPH-diaphorase. The analysis of serial sections showed that a ganglion composed of about 180–190 neuronal cells was present between the vallata papilla and von Ebner glands. These cells were positive for nitric oxide synthase type-1 and NADPH-diaphorase. From the ganglion, we observed nitrergic fibres running: (a) in the lamina propria of the receptor-free mucosa; (b) just below the gustatory epithelium; (c) in the von Ebner glands; and (d) around the vascular system of the vallata papilla. Our study suggests that the nitrergic ganglion cells may mediate interactions between chemoreceptorial systems in the vallata papilla and secretory cells in the von Ebner glands and that nitric oxide could be involved in the regulation of the blood supply to the vallata papilla and in the regulation of the von Ebner glands.     

Effect of epithelium on mucus secretion from feline tracheal submucosal glands

We studied the effect of airway epithelium on mucus secretion by use of an isolated tracheal submucosal gland preparation reported previously (J. Appl. Physiol. 60: 1237-1247, 1986). Mucus glycoconjugate release from submucosal glands of feline trachea was examined using [3H]glucosamine as a mucus precursor. Isolated glands showed significantly higher secretory responses to cholinergic, alpha-, and beta-adrenergic agonists and dibutyryladenosine 3',5'-cyclic monophosphate (average 400% of control) than the conventional tracheal mucosal explants, which contained epithelium and submucosal tissues in addition to submucosal glands (average 160% of control). The addition of isolated epithelium depressed the secretory response of isolated glands to the same level as that of tracheal explants. However, the supernatant from isolated epithelium failed to inhibit secretory responses to methacholine in isolated glands, suggesting that the epithelium-derived inhibitory factor to secretion may be short-lived. Leukotriene D4 antagonist (FPL 55712), cyclooxygenase and/or lipoxygenase inhibitors (indomethacin or BW 755C) caused no significant change in the inhibitory action of epithelium, suggesting that the inhibition is not due to arachidonic acid metabolites. The newly found secretory inhibitory action of epithelium is of particular interest in the pathogenesis of hypersecretion associated with epithelial damage.