Hyperosmolar saline induces reflex nasal secretions, evincing neural hyperresponsiveness in allergic rhinitis.

We investigated whether hyperosmolar saline (HS), applied via paper disk onto the septum of one nostril, induces a nasal secretory response. Furthermore, we examined whether this response is accentuated in patients with active allergic rhinitis (AR) compared with healthy volunteers. Unilateral HS produced significant nasal secretions both ipsilateral and contralateral to the site of challenge in the AR group and only ipsilaterally in the healthy group. The HS-induced nasal secretions were significantly greater in the AR vs. the healthy subjects. In a separate study, we ascertained that the nasal response to HS is neurally mediated and found that ipsilateral nerve blockade with lidocaine significantly attenuates the HS-induced secretions bilaterally. In another group of AR subjects, we determined whether nociceptive fibers were involved in this response and found that sensory nerve desensitization with repeated application of capsaicin attenuated the HS-induced nasal secretions. Finally, we determined whether the secretory hyperresponsiveness in AR is attributable to increased reactivity of submucosal glands rather than of nerves. We found that the dose response to methacholine, which directly stimulates the glands, was identical among AR and healthy subjects. We conclude that, in AR, nasal challenge with HS induces significantly greater reflex secretions involving capsaicin-sensitive nerve fibers, consistent with the notion of neural hyperresponsiveness in this disease.     

New ways to go—nasal floor structures as channelling system for vomeronasal stimuli in the shrew (<Emphasis Type="Italic">Sorex araneus</Emphasis>, Mammalia)

The mammalian lateral nasal gland (LNG, also called Steno’s gland) is known to be one source of so-called odorant-binding proteins, which are suggested to work as vehicles to carry chemosensory stimuli within the nasal cavity in order to guide them to olfactory and vomeronasal sensory neurons. Up to now, a largely unattended and unanswered question is how the secretions of the LNG migrate between the glandular opening at the upper edge of the anterior lateral nasal wall and the more caudally located vomeronasal organ. In order to address this issue, the functional morphology of the rostral nasal cavity of Sorex araneus was investigated histologically. Special interest was laid on the opening region of the LNG in the vestibular region of the nose and its topological connection to a hitherto largely unnoticed nasal concha, the atrioturbinate. It appears that the atrioturbinate serves as a specialised channel that directs the secretions of the LNG pointedly towards the entrance of the vomeronasal organ. In addition, it was observed that—contrary to previous reports—the LNG in Sorex araneus is anatomically clearly separated from the maxillary sinus gland and does not invade the maxillary sinus.     

Lateral nasal gland secretion in the anesthetized ferret

In anesthetized ferrets, we cannulated the duct of the lateral nasal gland for direct collection of glandular liquid. Administration of methacholine and substance P into the internal carotid artery via a retrograde cannulation of the lingual artery produced a dose-dependent increase in glandular output. The dose-response curve to methacholine was significantly shifted to the right by atropine. The secretory response to substance P was only partially inhibited by atropine at the dose that completely blocked secretion produced by methacholine (51 nmol/kg), suggesting the involvement of noncholinergic as well as cholinergic pathways. Phosphoramidon, an inhibitor of neutral endopeptidase, significantly potentiated the action of substance P. The analyses of electrolyte contents in glandular secretion revealed the presence of Na+, K+, and Cl-. The sum of the electrolyte concentrations indicated that the secretion was close to isotonic. The anesthetized ferret is a useful in vivo model for the study of physiology and pathophysiology of nasal secretion.     

Nasal glandular secretory response to cholinergic stimulation in humans and guinea pigs.

A guinea pig model of nasal secretory responses was developed to assess the contributions of vascular permeability and glandular secretion responsible for the production of cholinergically stimulated nasal secretions. The nasal secretory responses to provocation with saline, methacholine, and atropine on the ipsilateral (challenged) side and contralateral (reflex) side were analyzed by measurement of total protein (Lowry method), guinea pig albumin (enzyme-linked immunosorbent assay), 125I-labeled bovine serum albumin after intravenous injection, and alkaline phosphatase enzyme activity in nasal fluid. Alkaline phosphatase was found to be localized to submucosal glands by zymography. Topical methacholine challenge increased the secretion of total protein, alkaline phosphatase activity, and albumin on the ipsilateral challenged side, whereas the percentage of total protein represented by albumin was not increased. This response was totally prevented by atropine pretreatment. Serial provocation with methacholine resulted in progressively reduced amounts of both the total protein and alkaline phosphatase in secretions. The observation that repeated challenges produced progressively smaller responses was also examined employing human nasal provocation. Repeating methacholine (25 mg) challenges four times at 10-min intervals in six human volunteers revealed that the initial challenge produced the largest response as reflected in total protein, albumin, lysozyme, lactoferrin, immunoglobulin (Ig) G, IgA, and secretory IgA secretion. When the constituents in secretions were analyzed in relationship to the total protein, the two vascular proteins, IgG and albumin, demonstrated the greatest decrements with repeated methacholine challenges. The glandular proteins, lactoferrin, lysozyme, and secretory IgA, either remained constant or increased in their relative proportion to total protein. Thus, cholinergic stimulation causes glandular secretion from both the guinea pig and human nasal mucosa.(ABSTRACT TRUNCATED AT 250 WORDS)     

Neuropeptide Y is a vasoconstrictor in human nasal mucosa.

Neuropeptide Y (NPY) is a neurotransmitter in sympathetic nerve fibers in human nasal mucosa. Like norepinephrine, NPY acts as a vasoconstrictor. An established method of nasal provocation was used to determine the effects of topically applied NPY on nasal resistance to airflow measured by anterior rhinomanometry, the protein content of nasal secretions, and the protein content of bradykinin-induced secretions. NPY (2.3 nmol) reduced the resistance to inspiratory airflow by 57 +/- 18% (P < 0.001) in 10 normal subjects and by 50 +/- 17% (P < 0.05) in 12 subjects with perennial rhinitis. In nasal provocations, NPY in doses of 0.1-10 nmol had no effect on vascular (albumin), glandular (lysozyme, glycoconjugate), or total proteins present in lavaged nasal secretions. Because the vasoconstrictor properties of NPY may only be apparent in the presence of increased vascular permeability and albumin exudation, bradykinin (BK) nasal provocation was performed. BK (500 nmol) significantly increase total protein (10- to 20-fold), albumin (10- to 30-fold), and glycoconjugate (2- to 5-fold) in lavage fluid. NPY (2.3 nmol) reduced BK-induced total protein by 59 +/- 15% (P < 0.05) and albumin by 63 +/- 17% (P < 0.02) but had no significant effect on glandular secretion. Therefore exogenous administration of NPY to the human nasal mucosa reduced nasal airflow resistance and albumin exudation without affecting submucosal gland secretion. NPY agonists may be useful for the treatment of mucosal diseases characterized by vasodilation, vascular permeability, and plasma exudation.     

Fine Structure of Female Accessory Reproductive Gland in the Mealworm Beetle, Tenebrio molitor

ABSTRACT The fine structure of female accessory reproductive gland (FARG) of the adult mealworm beetle, Tenebrio molitor is studied with light and electron microscopes. The FARG is a simple tubular organ that composed of two kinds of cells-secretory epithelial cells and duct forming cells. The lumen of FARG is lined with a thin cuticle and filled with secretory materials. Each secretory epithelial cell has its peculiar end apparatus in addition to well-developed rough endoplasmic reticulum (rER), mitochondria, and secretory vesicles. They are forming basal infolding along the plasma membrane. Along the inner surface of the plasma membrane, numerous secretory vesicles are seen. The glandular secretions of the epithelial secretory cells are synthesized via rER to Golgi apparatus, and are stored in the extracellular cavity in the epithelial cell. These secretions are drained to the lumen through the end apparatus and this type of glandular secretion in the insects is type III. Histochemical reactions reveal the major component of these glandular secretions is an acid mucopolysaccharide.     

Fine structure of the external nasal gland of two lizards (Podarcis sicula campestris and Chalcides chalcides)

In this study, we describe the ultrastructural features of the external nasal gland in two lizards: ruin lizard (Podarcis sicula campestris) and seps (Chalcides chalcides). Two secretory cell types, which differ interspecifically, have been found in the secretory endpieces of the glandular tubules in both species examined. An unusual morphological observation was the presence of paracrystalline structures in the secretory granules of the seromucous cells of the external nasal gland of the seps. These structures may be related to the packaging mechanism of glycoproteins or to their macromolecular structure. They may also reflect segregation of heterogeneous subcomponents within the same secretory granule. The striated cells are located in the distal segment of the glandular tubules, and have the typical ultrastructural features of the cells which in some species of reptiles, but not in these two lizards, are known to be capable of elaborating a hyperosmotic saline solution.     

Morphology of the nasal fossae and associated structures of the hamster (Mesocricetus auratus)

The hamster nasal cavity consists of vestibular, non-olfactory and olfactory portions. Much of the non-olfactory nasal cavity surface is lined by cuboidal, stratified cuboidal, and low columnar epithelia, devoid of cilia. Goblet cells and ciliated respiratory epithelium are present over only a small portion of the nasal cavity surface. The largest glandular masses in the hamster nose are the maxillary recess glands, the vomeronasal glands and the lateral nasal gland 1; these three glands contain neutral mucopolysaccharides (PAS-positive). Other nasal glands contain both acidic and neutral mucopolysaccharides; the staining reaction for acidic mucopolysaccharide is stronger in goblet cells and olfactory glands than in the other nasal glands. The ducts which open into the nasal vestibule are the excretory ducts of compound tubuloacinar serous glands. The one major PAS-positive gland whose duct opens into the nasal vestibule is the lateral nasal gland 1. The ducts of the compound tubuloacinar vomeronasal glands open into the lumen of the vomeronasal organ, which is connected to the ventral nasal meatus by means of the vomeronasal duct. The ducts of the branched tubuloacinar maxillary recess glands open into the maxillary recess. Few ducts open into the caudal half of the nasal cavity.     

THE DEVELOPMENT OF SURFACE SPECIALIZATION IN THE SECRETORY EPITHELIUM OF THE AVIAN SALT GLAND IN RESPONSE TO OSMOTIC STRESS

Cell surface specialization, a characteristic common to most ion-transporting epithelia, was studied in the salt (nasal) gland of the domestic duck in relation to osmotic stress. Three days after hatching, experimental ducklings were given 1% NaCl to drink for 12 hr and freshwater for the remainder of each day. Control ducklings were maintained exclusively on freshwater. The fine structure of the secretory epithelium was examined on various days of the regimen. The nasal gland epithelium of the secretory lobule is composed of several types of cells. Peripheral cells, lying at the blind ends of the branched secretory tubules, are similar in both control and experimental animals at all stages of glandular development. These generative cells contain few mitochondria and have nearly smooth cell surfaces. Partially specialized secretory cells predominate in the secretory tubules of control animals and appear as transitional cells in the tubular epithelium of salt-stressed animals. These cells contain few mitochondria and bear short folds along their lateral cell surfaces. Fully specialized cells dominate the secretory epithelium of osmotically stressed ducklings. The lateral and basal surfaces of these cells are deeply folded, forming complex intra- and extracellular compartments. This vast increase in absorptive surface area is paralleled by an increase in the number of mitochondria that pack the basal compartments. The development of this fully specialized cell is correlated with the marked increase in (Na⁺-K⁺)-ATPase activity in the glands of osmotically stressed birds.     

Peculiar salivary glands in a silk‐producing mite Bakericheyla chanayi (Cheyletidae)

This is the first ultrastructural investigation of salivary glands in the family Cheyletidae. In both sexes of Bakericheyla chanayi, paired acinous salivary glands and tubular coxal glands were shown to be united into the common podocephalic system. The secretory portion of the salivary gland includes medial and lateral lobes composed of the five and two cells, respectively, with clearly distinct ultrastructure. The cytoplasm of the cells is occupied by the secretory granules containing fine fibrous material. The fine structure of both cell types suggest a proteinaceous nature of their secretions. A single central process extending from the apical face of each secretory cell passes through the common acinar cavity to enter the conducting duct. A pair of intercalary cells at the base of the conducting duct links it with the secretory portion of the gland. Extending towards the acinar cavity, protrusions of intercalary cells alternate the apical regions of the secretory cells and form with them highly‐specialized contacts characterized by the apical network of microtubules and microfilaments. Two possible ways of secretion are suggested: 1) exocytosis into the acinar cavity and 2) direct passage via the central processes. The detection of axon profiles in the gland body suggests a neural control for the glandular cell function. In tritonymphs, neither secretion nor large lateral lobe cells were observed up to the pharate stage when the lateral lobe undergoes rapid differentiation. The arrangement of the acinous gland is compared to that of other arthropods. Its composition appears to be close to the class three of insect glands. The involvement of the lateral lobe cells in silk production is discussed. J. Morphol. 276:772–786, 2015. © 2015 Wiley Periodicals, Inc.     

Plasma extravasation through neuronal stimulation in human nasal mucosa in the setting of allergic rhinitis

Sanico, Alvin M., Satsuki Atsuta, David Proud, and AlkisTogias. Plasma extravasation through neuronal stimulation in humannasal mucosa in the setting of allergic rhinitis. J. Appl. Physiol. 84(2): 537-543, 1998.We havepreviously shown that capsaicin nasal challenge in subjects withallergic rhinitis produces a dose-dependent increase in the albumincontent of nasal lavage fluids. In the present set of studies, wedetermined whether this observation represents plasma extravasationthat is neuronally mediated. To evaluate whether glandular secretionscontribute to the albumin increase in nasal lavage fluids, volunteerswith allergic rhinitis were pretreated with atropine or placebo before capsaicin challenge. Atropine significantly reduced the volume ofreturned lavage fluids and their lysozyme content but increased theiralbumin and fibrinogen content. To assess the contribution of sensorynerve stimulation, subjects with allergic rhinitis were pretreated in asecond study with lidocaine or placebo before capsaicin challenge.Lidocaine significantly attenuated the capsaicin-induced increases inthe volume of nasal lavage fluids, as well as their lysozyme andalbumin content. To rule out the possibility of a direct effect oflidocaine on blood vessels rather than on nerves, healthy subjects werepretreated in a third study with lidocaine or placebo before bradykininnasal challenge. Lidocaine did not affect the bradykinin-inducedincrease in the albumin content of nasal fluids. We conclude that, inallergic rhinitis, high-dose capsaicin induces plasma extravasation inthe human nose and that this effect is neuronally mediated. Thisprovides more definitive evidence that neurogenic inflammation canoccur in vivo in the human upper airway.

     

Configuration of the medial and lateral segments of duck (Anas platyrhynchos) salt glands

Salt glands of the domestic duck Anas platyrhynchos differ from those of the herring gull Larus argentatus and other birds. In ducks, each salt gland consists of distinct medial and lateral segments. Centrally located drainage ducts that extend along the entire length of these medial and lateral segments collect hypertonic fluid secreted by an array of lobules. Each lobule is formed by a single mass of branched tubules in which the direction of capillary blood flow is opposite to that of the secreted fluid. This fluid drains from the medial segment through an external duct that opens into the nasal cavity at the base of the vestibular fold. A duct from the lateral segment loops and opens onto the surface of the nasal septum. The structure and function of the secretory cells is reviewed briefly within the context of our study of the configuration of duck nasal salt glands.     

Structure and function of the glandular vas deferens in Ascaris suum (Nematoda).

The glandular vas deferens in the linearly arranged male reproductive tract in Ascaris suum produces substances which cause marked morphological and physiological changes in the spermatozoa. The glandular secretions, presumably formed by the rough endoplasmic reticulum and Golgi saccules, are extruded from the cells and coalesce to form homogeneous masses in the gland lumen. In sexually inactive worms the secretory material is separated from the spermatozoa by a sphincter comprised of neuro-muscular-like cells. During copulation the sphincter lumen enlarges and the spermatozoa and sperm-activating glandular material are mixed and simultaneously transferred to the female worm.     

Natural killer cells regulate murine cytomegalovirus-induced sialadenitis and salivary gland disease

The transmission of herpesviruses depends on viral shedding at mucosal surfaces. The salivary gland represents a major site of persistent viral replication for many viruses, including cytomegalovirus. We established a mouse model of salivary gland dysfunction after acute viral infection and investigated the cellular requirements for the loss of secretion. Murine cytomegalovirus (MCMV) infection severely impaired saliva secretion independently of salivary gland virus levels. Lymphocytes or circulating monocytes/macrophages were not required for secretory dysfunction. Dysfunction occurred before glandular inflammation, suggesting that a soluble mediator initiated the disruption of acinar cell function. Despite genetic differences in innate resistance to MCMV, NK cells protected the host against acinar atrophy and the loss of secretions under conditions of an exceedingly low virus inoculum. NK cells also modulated the type of glandular inflammation after infection, as they prevented an influx of Siglec-F(+) polymorphonuclear leukocytes (PMNs). Therefore, beyond their recognized role in controlling MCMV replication, NK cells preserve organ integrity and function and regulate the innate inflammatory response within the gland.     

Aquaporins in complex tissues. II. Subcellular distribution in respiratory and glandular tissues of rat

The molecular pathways for fluid transport in pulmonary, oral,and nasal tissues are still unresolved. Here we use immunocytochemistry and immunoelectron microscopy to define the sites of expression of fouraquaporins in the respiratory tract and glandular epithelia, where theyreside in distinct, nonoverlapping sites. Aquaporin-1 (AQP1) is presentin apical and basolateral membranes of bronchial, tracheal, andnasopharyngeal vascular endothelium and fibroblasts. AQP5 is localizedto the apical plasma membrane of type I pneumocytes and the apicalplasma membranes of secretory epithelium in upper airway and salivaryglands. In contrast, AQP3 is present in basal cells of tracheal andnasopharyngeal epithelium and is abundant in basolateral membranes ofsurface epithelial cells of nasal conchus. AQP4 resides in basolateralmembranes of columnar cells of bronchial, tracheal, and nasopharyngealepithelium; in nasal conchus AQP4 is restricted to basolateralmembranes of a subset of intra- and subepithelial glands. These sitesof expression suggest that transalveolar water movement, modulation ofairway surface liquid, air humidification, and generation ofnasopharyngeal secretions involve a coordinated network of aquaporinwater channels.

     

Cationic polypeptides are required for antibacterial activity of human airway fluid

In a search for direct evidence leading to the biological relevance of airway secretions in innate host defense, we characterized the antibacterial function of cationic polypeptides within minimally manipulated nasal fluid. In this study, we show that cationic antimicrobial polypeptides are responsible for most of the bactericidal activity of whole nasal fluid. The removal of cationic polypeptides using a cation-exchange resin ablated the activity of nasal fluid against Escherichia coli, Listeria monocytogenes, and Pseudomonas aeruginosa. By using a novel proteomic approach, we identified a dozen cationic peptides and proteins within nasal fluid, all of which either are known antimicrobial polypeptides or have other proposed roles in host defense. Of the three most abundant cationic polypeptides in nasal fluid, lysozyme was more effective than either lactoferrin or secretory leukoprotease inhibitor in restoring the antibacterial activity of the cationic polypeptide-depleted fluid against a mucoid cystic fibrosis isolate of P. aeruginosa.     

Relationship and possible function of the nasal sacs and glands of the one-humped camel, camelus dromedarius.

The relationship between the lateral nasal gland and sacs of the maxillary recesses was investigated. The nasal sacs possess a well-defined aperture communicating with the nasal cavities. It was concluded that the sacs and not the body of the gland produce mucous secretions that moisten the inhaled dry air of the desert and may also act as reservoirs. A possible function of the body of the nasal gland is water economy by excretion of concentrated salts.     

A histological and ultrastructural comparison of the male accessory reproductive glands of diapausing and non-diapausing adults in Bruchidius atrolineatus (Pic) (Coleoptera : Bruchidae)

Cytological variations of the median and the 2 lateral accessory glands of Bruchidius atrolineatus Pic (Coleoptera : Bruchidae) were examined as a function of age and the reproduction of the male. In sexually active virgin males, the secretory epithelium is columnar at emergence, but progressively flattens, and the secretions formed and stored by its cells are expelled by exocytosis into the glandular lumen. After 10 days, the male accessory glands exhibit a stage of repletion, characteristic of glands temporarily storing their secretions in their lumen. In diapausing males, the genital tract is relatively undeveloped and the accessory glands are reduced to tubules, whose lumen, surrounded by an epithelium composed of narrow cells, contains little secreted material. The presence of secretion aggregates in the secretory epithelial cells, the abundance of rough endoplasmic reticulum in them, and the release of a part of their secretions into the glandular lumen, indicate that reproductive diapause in B. atrolineatus is characterized by a decrease in the reproductive function. and not its total arrest.     

SECRETORY VESICLE FORMATION IN GLANDULAR TRICHOMES OF CANNABIS SATIVA (CANNABACEAE)

Formation of secretory vesicles in the noncellular secretory cavity of glandular trichomes of Cannabis saliva L. was examined by transmission electron microscopy. Two patterns of vesicle formation occurred during gland morphogenesis. 1) During initial phases of cavity formation small hyaline areas arose in the wall near the plasma membrane of the disc cell. Hyaline areas of elongated shape and different sizes were distributed throughout the wall and adjacent to the secretory cavity. Hyaline areas increased in size, some possibly fusing with others. These hyaline areas, possessing a membrane, moved into the cavity where they formed vesicles. As membraned vesicles they developed a more or less round shape and their contents became electron-dense. 2) During development of the secretory cavity and when abundant secretions were present in the disc cells, these secretions passed through the wall to accumulate as membraned vesicles of different sizes in the cavity. As secretions emerged from the wall, a membrane of wall origin delimited the secretory material from cavity contents. Vesicles released from the wall migrated in the secretory cavity and contacted the sheath where their contents permeated into the subcuticular wall as large or diffused quantities of secretions. In the subcuticular wall these secretions migrated to the wall–cuticle interface where they contributed to structural thickening of the cuticle. This study demonstrates that the secretory process in glands of Cannabis involves not only secretion of materials from the disc cell, but that the disc cell somehow packages these secretions into membraned vesicles outside the cell wall prior to deposition into the secretory cavity for subsequent structural development of the sheath.