Distribution and structure of glandular tissue in the oropharynx and proximal esophagus of the emu (Dromaius novaehollandiae)

Crole, M.R., Soley, J.T. 2011. Distribution and structure of glandular tissue in the oropharynx and proximal esophagus of the emu (Dromaius novaehollandiae). —Acta Zoologica (Stockholm) 92 : 206–215. The glandular regions of the upper digestive tract in the emu were non‐pigmented (except for the tongue in most specimens) and invested by a non‐keratinised stratified squamous epithelium. The glands found in these regions were exclusively simple in nature and composed of tubular secretory units lined by Periodic Acid Schiff Stain‐positive mucus‐secreting cells. The naming of the various glandular fields was based on previously identified anatomical features and on nomenclature modified from previous studies on birds. The glands were classified into two main types, namely, simple tubular and simple branched tubular mucus‐secreting glands. Simple branched tubular glands were a feature of the regions exposed to the greatest amount of friction during feeding, whereas simple tubular glands were a feature of regions exposed to less friction. The saliva produced by the salivary glands in birds functions to moisturize and lubricate food boli. Mucins in saliva also protect mucosal surfaces from desiccation and mechanical damage, assist in maintaining cellular water balance, provide lubrication and have an antimicrobial action. This study suggests that, in addition to the role of specific gross anatomical features, the type and distribution of glandular tissue in the emu upper digestive tract supports the cranio‐inertial feeding method employed by this species.     

Histology and ultrastructure of the salivary glands and salivary pumps in the scorpionfly Panorpa obtusa (Mecoptera: Panorpidae)

Liu, S. and Hua, B. 2009. Histology and ultrastructure of the salivary glands and salivary pumps in the scorpionfly Panorpa obtusa (Mecoptera: Panorpidae). —Acta Zoologica (Stockholm) 91 : 457–465. The morphology, histology and ultrastructure of the salivary glands and salivary pumps in the scorpionfly Panorpa obtusa Cheng 1949 were investigated using light microscopy and scanning and transmission electron microscopy. The salivary glands display a distinct sexual dimorphism. The female has only two small sac‐like glands located in the prothorax, while the male possesses six long tubular glands extending into the sixth abdominal segment. The male salivary glands can be divided into five distinct regions. The apical long, thin secretory region possesses numerous secretory cells containing large secretory vesicles; the salivary reservoir expands in diameter, accumulating and temporarily storing the saliva in addition to secreting saliva; the constricted region contains prismatic cells with complex infolded plasma membrane; the sac has an internal brush border to absorb water and ions; the common salivary duct contains longitudinal muscles in the male, but not in the female. The salivary pump possesses independent strong dorsal muscles and abundant internal palm spines near its orifice. The anatomy and ultrastructure of the salivary glands and the salivary pump of scorpionflies as well as their possible functions are briefly discussed.     

Studies on silk secretion in the trichoptera (F. Limnephilidae): I. Histology,histochemistry, and ultrastructure of the silk glands

As part of a study on trichopteran silk secretion, the histology, histochemistry, and ultrastructure of the silk glands of two species of limnephilid trichopteran larvae, Pycnopsyche guttifer (Walk.) and Neophylax concinnus McL., were investigated. The silk glands consist of three anatomically distinct regions: a long, posterior silk-secreting region; a shorter, anterior conducting tube; and a terminal press/common duct. In Pycnopsyche, there is also a modified bulbous region between the secreting and conducting areas. Each anatomical region has a distinct cell type. There are two structurally and histochemically different components of the secretion in the glandular lumen: a core and a peripheral layer. Both components are produced all along the gland and are principally proteinaceous. However, the peripheral layer is also PAS and alcian blue (pH. 2.5) positive and shows β-metachromasia with toluidine blue (pH 3.5), indicating the presence of both neutral and acidic polysaccharides.     

棉铃虫幼虫唾液腺cDNA文库的构建及EST分析

棉铃虫Helicoverpa armigera (Hübner)幼虫唾液中的各种酶类及各种生化组分在棉铃虫与植物相互作用及协同进化中起到重要作用; 唾液腺是棉铃虫唾液成分的合成器官。本研究通过构建棉铃虫幼虫唾液腺全长cDNA文库, 测序得到1 502条EST序列, 聚类分析后获得821个unigenes, 为筛选棉铃虫与寄主互作信号因子提供基因信息资源。使用Blast2 GO软件对821个unigenes进行了比对和功能注释, 初步获得棉铃虫幼虫唾液腺中mRNA的构成特征。结果显示, 在棉铃虫唾液腺ESTs文库中, 鉴定得到脂类相关消化酶基因17个, 糖类相关消化酶基因5个, 半胱氨酸蛋白酶基因1个, 丝氨酸蛋白酶基因20个（其中16个为新发现）, 提示唾液腺的主要功能是分泌消化酶进行预消化; 还发现在棉铃虫幼虫唾液腺中存在表皮蛋白、 气味结合蛋白和化学感受蛋白基因。结果为研究棉铃虫预消化系统打下基础。     

Effect of translocator protein (18 kDa)-ligand binding on neurotransmitter-induced salivary secretion in rat submandibular glands

Background information. TSPO (translocator protein), previously known as PBR (peripheral‐type benzodiazepine receptor), is a ubiquitous 18 kDa transmembrane protein that participates in diverse cell functions. High‐affinity TSPO ligands are best known for their ability to stimulate cholesterol transport in organs synthesizing steroids and bile salts, although they modulate other physiological functions, including cell proliferation, apoptosis and calcium‐dependent transepithelial ion secretion. In present study, we investigated the localization and function of TSPO in salivary glands. Results. Immunohistochemical analysis of TSPO in rat salivary glands revealed that TSPO and its endogenous ligand, DBI (diazepam‐binding inhibitor), were present in duct and mucous acinar cells. TSPO was localized to the mitochondria of these cells, whereas DBI was cytosolic. As expected, mitochondrial membrane preparations, which were enriched in TSPO, exhibited a high affinity for the TSPO drug ligand, ³H‐labelled PK 11195, as shown by B_max and K_d values of 10.0±0.5 pmol/mg and 4.0±1.0 nM respectively. Intravenous perfusion of PK 11195 increased the salivary flow rate that was induced by muscarinic and α‐adrenergic agonists, whereas it had no effect when administered alone. Addition of PK 11195 also increased the K⁺, Na⁺, Cl⁻ and protein content of saliva, indicating that this ligand modulated secretion by acini and duct cells. Conclusions. High‐affinity ligand binding to mitochondrial TSPO modulates neurotransmitter‐induced salivary secretion by duct and mucous acinar cells of rat submandibular glands.     

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.     

Observations on the gastric epithelium of ascidians with special reference to Styela clava

Summary Transmission electron microscopy shows the gastric epithelium of Styela clava to comprise at least three distinct cell types. Ciliated mucous cells which form the crest of each stomach ridge produce mucus by an unexpected route. Vacuolated cells lining the ridge sides appear to be absorptive in function. Gastric enzymes are produced by typical protein secreting cells scattered amongst the vacuolated cells. Undifferentiated cells are found in the crypts between ridges. The structure and function of the gastric epithelium in Styela is discussed with special reference to the wider concepts of ascidian gut organization.The author is grateful to Mrs. L. Rolph for technical help with scanning electron microscopy and Mr. J. Calvert and Mr. R. Jones for assistance with the transmission electron microscopy. Animals were collected through the kind offices of Mr. J. Sturges and other staff of the Admiralty Marine Trials Station, Portsmouth. This research was carried out during the tenure of SRC grant No. B/RG 82919 -The localization of polypeptide hormones in the pharynx and gut of Protochordates     

Localization of somatostatin-like immunoreactivity in the pancreatic islets of the hagfish,Myxine glutinosa and the lamprey Lampetra fluviatilis

Summary Somatostatin-like immunofluorescence has been found by immunostaining in cells of the bile duct mucosa and pancreatic islet parenchyma of the hagfish, Myxine glutinosa, and the islet lobules of the lamprey, Lampetra fluviatilis.We are grateful to Dr. Alan Thorpe, Queen Mary College, London University for the gift of antiteleost insulin serum     

The effects of dopamine receptor agonists and antagonists on the secretory rate of cockroach (Periplaneta americana) salivary glands

The acinar salivary glands of the cockroach, Periplaneta americana, are innervated by dopaminergic and serotonergic nerve fibers. Serotonin stimulates the secretion of protein-rich saliva, whereas dopamine causes the production of protein-free saliva. This suggests that dopamine acts selectively on ion-transporting peripheral cells within the acini and the duct cells, and that serotonin acts on the protein-producing central cells of the acini. We have investigated the pharmacology of the dopamine-induced secretory activity of the salivary gland of Periplaneta americana by testing several dopamine receptor agonists and antagonists. The effects of dopamine can be mimicked by the non-selective dopamine receptor agonist 6,7-ADTN and, less effectively, by the vertebrate D1 receptor-selective agonist chloro-APB. The vertebrate D1 receptor-selective agonist SKF 38393 and vertebrate D2 receptor-selective agonist R(-)-TNPA were ineffective. R(+)-Lisuride induces a secretory response with a slower onset and a lower maximal response compared with dopamine-induced secretion. However, lisuride-stimulated glands continue secreting saliva, even after lisuride-washout. Dopamine-induced secretions can be blocked by the vertebrate dopamine receptor antagonists cis(Z)-flupenthixol, chlorpromazine, and S(+)-butaclamol. Our pharmacological data do not unequivocally indicate whether the dopamine receptors on the Periplaneta salivary glands belong to the D1 or D2 subfamily of dopamine receptors, but we can confirm that the pharmacology of invertebrate dopamine receptors is remarkably different from that of their vertebrate counterparts.     

The wax glands and wax secretion of Matsucoccus matsumurae at different development stages

In this paper, the wax secretions and wax glands of Matsucoccus matsumurae (Kuwana) at different instars were investigated using light microscopy, scanning electron microscopy and transmission electron microscopy. The first and second instar nymphs were found to secrete wax filaments via the wax glands located in the atrium of the abdominal spiracles, which have a center open and a series of outer ring pores. The wax gland of the abdominal spiracle possesses a large central wax reservoir and several wax-secreting cells. Third-instar male nymphs secreted long and translucent wax filaments from monolocular, biolocular, trilocular and quadrilocular pores to form twine into cocoons. The adult male secreted long and straight wax filaments in bundles from a group of 18–19 wax-secreting tubular ducts on the abdominal segment VII. Each tube duct contained five or six wax pores. The adult female has dorsal cicatrices distributed in rows, many biolocular tubular ducts and multilocular disc pores with 8–12 loculi secreting wax filaments that form the egg sac, and a rare type wax pores with 10 loculi secreting 10 straight, hollow wax filaments. The ultrastructure and cytological characteristics of the wax glands include wax-secreting cells with a large nucleus, multiple mitochondria and several rough endoplasmic reticulum. The functions of the wax glands and wax secretions are discussed.     

Monoclonal antibodies against rat saliva and salivary gland antigens

Hybridomas were produced by the fusion of NS1 myeloma cells with spleen cells of a BALB/c mouse immunized with rat submandibular saliva. Growth of hybridomas was evident in 60/96 wells, and colonies secreting antibodies against saliva components were identified in 20 wells by using a solid phase enzyme-linked immunoassay. Cloning of cells from 12 wells yielded originally 43 hybridoma cell lines secreting anti-saliva antibodies. After recloning, one hybridoma (4Cl3) was selected for further studies. The hybridoma (4Cl3) cells were grown as ascites tumors, and the antibodies were purified from the ascitic fluid by diethylaminoethyl Affi-gel Blue chromatography. The purified antibody (MA4), immunoglobulin G1, immunoprecipitated a 39K dalton protein from submandibular saliva, and also reacted with a protein of the same electrophoretic mobility on immunoblots. From extracts of submandibular gland slices, incubated with [3H]leucine, the antibody again immunoprecipitated a 39K protein, indicating that this protein is synthesized in the gland. MA4 was used for immunocytochemical stainings of submandibular glands of rats of different ages. In general, immunostaining was seen only in acinar cells. Thus, there was no staining in the glands of 1-day-old rats that lack differentiated acinar cells. In the glands of 1- to 4-week-old rats the number of immunoreactive cells and the extent of immunostaining paralleled the differentiation of the acinar cells. In the glands of adult rats a uniform staining of the secretory granules of the acinar cells was observed. The immunoreactive 39K protein seemed to be restricted to the acinar cells in the submandibular gland; there was no immunostaining in the parotid, sublingual, or lingual salivary glands, or in the pancreas, colon, and duodenum. Stimulation of saliva secretion by isoproterenol resulted in a virtual depletion of the antigen from the acinar cells. These results indicate the feasibility of producing mouse hybridomas that secrete antibodies against rat saliva components. The monoclonal antibody at hand will be useful in analyzing the differentiation of the acinar cells, and the factors that influence this differentiation process.     

Proteomic analysis of secretion from human transplanted submandibular gland replacing lacrimal gland with severe keratoconjunctivitis sicca

Purpose: Proteomic analysis of secretions from transplanted or non-transplanted submandibular glands in patients with severe keratoconjunctivitis sicca and tears from normal eyes. Experimental design: Secretions from submandibular glands transplanted to replace lacrimal glands and non-transplanted submandibular glands were collected at 1 year from 5 patients with severe keratoconjunctivitis sicca undergoing transplantation, and tears were collected from 3 normal subjects. 2-D electrophoresis (2-DE), then mass spectrometry was used to identify proteins. Western blot analysis was used to confirm protein expression. Results: We identified 34 and 11 distinct proteins in the saliva from transplanted submandibular glands and tears, respectively. The saliva from transplanted submandibular glands contained almost all the proteins abundant in tear fluid. The functions of identified proteins in the saliva from transplanted submandibular gland were mainly immune response and anti-bacterial. In total, 7 proteins showed differential expression between the saliva of transplanted and non-transplanted submandibular glands. The upregulation of short palate, lung and nasal epithelium carcinoma-associated protein 2 and carbonic anhydrase VI was confirmed by Western blot analysis. Conclusions: Identified proteins in saliva from transplanted submandibular glands may protect ocular structures. These findings can help in understanding the functional status of transplanted submandibular glands.     

The innervation of the salivary gland of the moth,Manduca sexta

Summary The salivary glands of the moth, Manduca sexta (Insecta: Sphingidae), are unlike most other salivary glands in that they are innervated from one source only. Vital staining of nerves with methylene-blue reveals numerous fine nerves extending to the glands from the oesophageal nerve, a part of the stomatogastric or visceral nervous system. Light and electron microscopy confirm that only the fluid-secreting cells, confined to a discrete region in these glands, are innervated. Axons with or without glial wrappings are found in intercellular spaces between fluid-secreting cells. Axons lacking a glial sheath contain, after glutaraldehyde-osmium tetroxide fixation, large granular and small agranular vesicles. In nerve endings in glands fixed with permanganate these smaller vesicles are granular, having the electron-dense cores characteristic of monoamine-containing neurons. These nerve endings with synaptoid areas are in close (direct) contact with the fluid-secreting cells.I am grateful to Professor T. Weis-Fogh for accommodation in the department of Zoology and to Dr. Nancy Lane for use of A.R.C. facilities and advice. Thanks are also due to Drs. M. J. Berridge, S.H.P. Maddrell, and W. T. Prince and Mr. R. A. Leslie for helpful discussion. Financial assistance from Clare College, Cambridge is gratefully acknowledged.     

Proteomic analysis of secretion from human transplanted submandibular gland replacing lacrimal gland with severe keratoconjunctivitis sicca

Purpose: Proteomic analysis of secretions from transplanted or non-transplanted submandibular glands in patients with severe keratoconjunctivitis sicca and tears from normal eyes. Experimental design: Secretions from submandibular glands transplanted to replace lacrimal glands and non-transplanted submandibular glands were collected at 1year from 5 patients with severe keratoconjunctivitis sicca undergoing transplantation, and tears were collected from 3 normal subjects. 2-D electrophoresis (2-DE), then mass spectrometry was used to identify proteins. Western blot analysis was used to confirm protein expression. Results: We identified 34 and 11 distinct proteins in the saliva from transplanted submandibular glands and tears, respectively. The saliva from transplanted submandibular glands contained almost all the proteins abundant in tear fluid. The functions of identified proteins in the saliva from transplanted submandibular gland were mainly immune response and anti-bacterial. In total, 7 proteins showed differential expression between the saliva of transplanted and non-transplanted submandibular glands. The upregulation of short palate, lung and nasal epithelium carcinoma-associated protein 2 and carbonic anhydrase VI was confirmed by Western blot analysis. Conclusions: Identified proteins in saliva from transplanted submandibular glands may protect ocular structures. These findings can help in understanding the functional status of transplanted submandibular glands.     

Fine structure of the silk gland in the mite Ornithocheyletia sp. (Prostigmata,Cheyletidae)

Silk spinning is widely-spread in trombidiform mites, yet scarse information is available on the morphology of their silk glands. Thus this study describes the fine structure of the prosomal silk glands in a small parasitic mite, Ornithocheyletia sp. (Cheyletidae). These are paired acinous glands incorporated into the podocephalic system, as typical of the order. Combined secretion of the coxal and silk glands is released at the tip of the gnathosoma. Data obtained show Ornithocheyletia silk gland belonging to the class 3 arthropod exocrine gland. Each gland is composed of seven pyramidal secretory cells and one ring-folded intercalary cell, rich in microtubules. The fine structure of the secretory cells points to intensive protein synthesis resulted in the presence of abundant uniform secretory granules. Fibrous content of the granules is always subdivided into several zones of two electron densities. The granules periodically discharge into the acinar cavity by means of exocytosis. The intercalary cell extends from the base of the excretory duct and contributes the wall of the acinar cavity encircling the apical margins of the secretory cells. The distal apical surface of the intercalary cell is covered with a thin cuticle resembling that of the corresponding cells in some acarine and myriapod glands. Axon endings form regular synaptic structures on the body of the intercalary cell implying nerve regulation of the gland activity.     

Movement of neurosecretory product through the anatomical compartments of the neural lobe of the pituitary gland

Summary Electron microscopic studies of the carotid body of the domestic fowl (Gallus gallus domesticus) have shown Type I and Type II cells combined with axons into compact groups. The many Type I cells in the depths of the organ had a body, containing the nucleus, and an elongated, flared process. Some of the Type I cells in the superficial regions tended to be spindle-shaped. Type I cells were characterised by membrane-bound, dense-cored vesicles about 120 nm in diameter. Type II cells invested the Type I cells and had axons embedded in them as in Schwann cells.The fine structure of the carotid body in the domestic fowl resembles that of the Lovebird (Uroloncha domestica) and of various amphibia and mammals. The possibility is discussed that the Type I cells may have a chemoreceptor or a general secretory function, or even both pathway for functions together. The main role of the Type II cells seems to be to provide a of these axons leading to or from Type I cells.The authors are grateful to Mr. R. P. Gould of the Department of Anatomy, Middlesex Hospital Medical School for permission to use some of his and Dr. Hodges' original material in the illustrations. Dr. Hodges also wishes to thank the A.R.C. and the University of London Central Research Fund for financial assistance. We are also most appreciative of the photographic assistance of J. Geary.     

Localization of cells producing thyroid stimulating hormone in the pituitary gland of the domestic drake

Summary Cells binding anti-bovine TSH serum were found exclusively in the rostral lobe of the adenohypophysis of the drake using the peroxidase-antiperoxidase complex unlabelled antibody method. The specificity of the binding of the anti-serum to TSH cells was established by relating the morphology and relative abundance of immunochemically stained cells to the TSH content of the adenohypophysis after experimentally altering the activity of the pituitary-thyroid axis. The TSH activity of the adenohypophysis was assessed indirectly, by the weight of the thyroid glands, and directly, by bioassay. As determined by bioassay, the TSH content of the rostral lobe of the adenohypohysis was much greater than that of the caudal lobe. Compared with control drakes, immunochemically stained cells in birds fed a goitrogen, methimazole, seemed to be enlarged and were closer together, while the stained cells in drakes injected with thyroxine were shrunken and less intensely stained. The TSH content of the adenohypophysis was increased in drakes fed methimazole. Castration did not alter the TSH content of the adenohypophysis or change the morphology of immunochemically stained cells. These observations suggest that in the drake: 1) anti-bovine TSH serum binds specifically to TSH cells; 2) the TSH cells occur in the rostral and not in the caudal lobe of the adenohypophysis; and 3) the activity of TSH cells is not inhibited by the feedback effects of gonadal steroids.We thank Dr. L.E. Reichert Jr. and the National Institute of Arthritis, Metabolic and Digestive Diseases for the gift of ovine TSH and Mr. R. Wilkie for technical assistance. We are grateful to Dr. M.F. El Etreby, Professor B.K. Follett, Dr. C.G. Scanes, Dr. J. Seth and Dr. J.G. Pierce for gifts of immunochemicals