Alpha 2u-globulin in modified sebaceous glands with pheromonal functions: localization of the protein and its mRNA in preputial, meibomian, and perianal glands

alpha 2u-Globulin, the principal urinary protein of the male rat, has extensive sequence homology with many lipid binding proteins. The highest concentration of alpha 2u-globulin is found in the preputial gland, a holocrine secretory organ with pheromonal function. Meibomian and perianal glands are two other modified sebaceous glands with holocrine secretory cycles and pleiomorphic peroxisomes capable of synthesizing pheromonal lipids. Immunocytochemical examination shows the presence of alpha 2u-globulin in the acinar cells of all three of these modified sebaceous glands. Whereas in the preputial gland all of the acinar cells exhibit immunoreactivity, in the meibomian and perianal glands only selective cells contain alpha 2u-globulin. In the case of the preputial gland, in addition to the acinar cells some stratified epithelial cells also were immunoreactive. In the perianal and meibomian glands, keratinocytes lining nearby hair shafts and select cells of accessory oil glands stained for alpha 2u-globulin. In situ hybridization with a cloned cRNA probe confirmed the immunocytochemical data. Presence of the alpha 2u-globulin mRNA in these glands was also established by Northern blot analysis. Immunoelectron microscopic examination of preputial alpha 2u-globulin showed the presence of this protein in secretory granules of various maturational stages. Immunolabeled alpha 2u was also found in attached vesicles containing protein and lipid inclusions. The lytic cells were not only loaded with alpha 2u-globulin but also contained sharp-edged, irregularly shaped electron-dense granules which stained heavily for this protein. Specific localization of alpha 2u-globulin and its mRNA in three pheromone-producing sebaceous glands and its structural homology with known lipid binding proteins indicate a pheromone carrier role of alpha 2u-globulin.     

Intraspinal organ in man]

In the ependymal zone of the spinal cord at the LI-SIII level an ependymal glandular organ has been described. Its highest secretory activity coincides with the period of the greatest functional activity of the human reproductive system functioning. Certain stages in development of the organ, its cell composition, blood supply, afferent and efferent innervation have been studied. In secretory cells of the organ peptide with cardio- and vasotonic properties has been identified immunochemically. The action of the organ is considered in connection with role, which the ependymal glands of the brain play in regulation of the organism's function.     

Electron microscope studies of Fasciola hepatica. 13. Fine structure of newly excysted juvenile

The gross morphology and fine structure of the newly excysted juvenile fluke are described. The tegument is organized as in the adult, with a spine-containing surface syncytium connected to a perinuclear region lying below the muscle layers. It differs from the adult, however, in having only one type of perinuclear region and one type of secretory body. The digestive system has all the morphological characteristics of a secretory epithelium, rather than an absorptive one. It has numerous dense secretory bodies, ribosomes, and GER, an irregular apical surface due to eccrine secretion, and a lumen filled with a moderately dense material derived from the dispersed secretory granules.The excretory system closely resembles that of the adult, but has, in addition, part of its ascending ducts ciliated and concretions as well as lipid droplets as visible excretory products. The muscle is identical with that of the adult and the parenchyma is also very similar to the adult, although it has more lipid droplets and is associated in a less complex way with cells of other organ systems. Groups of embryonic cells are present and are characterized by a dense, invaginated nucleus surrounded by a very thin layer of cytoplasm.     

珊瑚菜植株分泌道发育和分布的解剖学观察

利用植物解剖学方法对珊瑚菜（Glehnia littoralis Fr．Schmidt ex Miq．）体内分泌道的发育和分布进行了观察。结果表明,珊瑚菜的分泌道有分枝,为溶生型,由1层分泌细胞围绕腔道而成。珊瑚菜叶片的分泌道发育较早,在幼叶阶段即发育成形。在根的次生韧皮部、根状茎的皮层和靠近初生木质部的髓部、叶脉的薄壁组织、叶柄维管束周围和厚角组织内侧的薄壁组织、花序轴正对维管束的皮层薄壁组织中以及果实的果壁维管束内外侧的薄壁组织中均分布有分泌道,分泌道在珊瑚菜体内分布广泛。     

The effect of dehydration on the ultrastructure and cholinesterase activity of the subcommissural organ in the rat

Summary Dehydration affected certain cytological features of the subcommissural organ in the albino rat suggesting a strong secretory stimulation of the ependymal and hypendymal cells of this organ in dehydrated animals.The cytoplasm of the secretory cells of the subcommissural organ in the dehydrated rats was filled with dilated and empty sacs and vacuoles of endoplasmic reticulum. The membrane system of the Golgi apparatus was also dilated, and more numerous vesicles and vacuoles of the Golgi complex were noticed after dehydration.In brains of the dehydrated animals, Reissner's fibre was not found in the lumen of the third ventricle, and only a few vesicles containing homogeneous secretory material were seen in the cytoplasm of the subcommissural secretory cells.In control animals, the activities of the specific and non-specific cholinesterases were localized in the cytoplasmic and nuclear membranes as well as in the rough and smooth endoplasmic reticulum. After dehydration, the activities of the specific and non-specific cholinesterases were strongly decreased.     

The Infundibular Organ of Branchiostoma lanceolatum

The infundibular organ of adult and larval Branchiostoma was studied by means of the electron microscope. The secretion produced by the infundibular cells is released into the ventricular fluid from secretory vacuoles, fusing with the apical plasmalemma and forming a Reissner's fiber in the ventricle. The basal cell processes reach the external limiting membrane but no basal release of secretory material has been observed. No synapses are in contact with the infundibular cells. The organ seems to function autonomously with neither nervous control from the brain tissue nor chemical regulation from the ventricular fluid.     

Histochemical and electron probe analysis of secretory ameloblasts of developing rat molar teeth

Calcium was not found in secretory ameloblasts and stratum intermedium cells when treated with OsO4-pyroantimonate or when surfaces prepared by fracturing fresh, rapidly frozen, developing molar tooth germs were subject to electron probe X-ray analysis. Pyroantimonate reaction product, considered to be calcium, was found in mitochondria of enamel organ cells which were first placed in a bath containing calcium and potassium. The plasma membrane was disrupted in cells ehich showed mitochondrial localization of reaction product. The results provide no data which indicates that enamel organ cells have a direct, active role in the movement of calcium into the enamel. Rather, it is suggested that the secretory enamel organ might serve as a selective barrier in regulating the initial mineralization of enamel.     

Fluorescence histochemical observations on catecholamine-containing cell bodies in Auerbach's plexus

Summary The nature and distribution of cell contacts have been examined in the human enamel organ in bell stage. The lateral cell surfaces of secretory ameloblasts are linked at their distal (apical) and proximal (basal) parts by junctional complexes consisting of tight junctions, large intermediate junctions (zonulae adherentes), occasional gap junctions and one or more series of desmosomes. Scattered desmosomes and large gap junctions link epithelial cells of the external enamel epithelium, stellate reticulum, stratum intermedium and internal enamel epithelium including secretory ameloblasts. Furthermore the above-mentioned layers are also linked together by desmosomes and gap junctions.With increasing maturation of the enamel organ an increase in size and number of gap junctions is observed. Some possible implications of the role of the different junctions are considered. The gap junctions probably participate in cell differentiation in the normal morphogenesis of the teeth as well as in metabolic and ionic coupling of the cells of the enamel organ. By means of tight junctions, adjacent secretory ameloblasts cooperate to form a physical barrier which might prevent the diffusion of some types of molecules or substances (e.g. secretory material distally and acid mucopolysaccharides proximally) through the interspaces between the cells. Adhering junctions might assist in regulation of the mechanical properties of the enamel organ as a whole.This work was supported by grants from Statens almindelige Videnskabsfond, Copenhagen, and the Association for the Aid of the Crippled Children, New York.     

Activity of specific and non-specific cholinesterases in the subcommissural organ of guinea pig and albino rat

Summary The localizations of specific and non-specific cholinesterases were demonstrated by light and electron microscopical methods in the secretory cells of the subcommissural organ of the guinea pig and albino rat.The activity of non-specific cholinesterase at light microscopical level appeared slightly stronger compared to the activity of the specific cholinesterase. No differences in the localizations of the both enzymes could be noticed.In electron microscopic specimens no differences could be observed between the localization or intensity of the specific and non-specific cholinesterase reactions except some nerve fibres round the secretory hypendymal cells in which only a specific cholinesterase reaction product was noticed. The reaction product was found mainly in the cytoplasmic and nuclear membranes, in the rough and smooth surfaced endoplasmic reticulum and around some secretory granules in the ependymal and hypendymal secretory cells of the subcommissural organ in guinea pig and albino rat.The possible role of cholinesterases in the secretory cells of the subcommissural organ is further discussed. Their participation in the metabolism and/or secretion of the hormonal end products is suggested.     

The perforation organ of Thais lapillus L. (Gasteropodes, Prosobranches). Optical and electron microscopic study]

The histologic and cytologic structure of the boring organ of Thais lapillus has been studied with both light and electron microscopy. The organ evaginates from the foot and has a dome-like form. It has a spongy center which contain nerves, muscles and blood vessels, these originate in the foot and continue into the boring organ via a short stalk. The organ is invested externally by a continuous simple epithelium constituted of extremely elongated cells (150 to 300 mu). There are three radial zones from the basal to the apical aspect of the cells : basally the cells are overlapping, here are located the nuclei, the Golgi apparatus, the rough endoplasmic reticulum and secretory granules; organelles which in their character suggest a secretory function for these cells. In the middle zone cells are separated into "groups" by large spaces occupied by blood sinuses; at this level are located numerous elongated mitochondria with closely apposed, angulated cristae. In addition there are microtubules arranged parallel to the main cellular axis, whose role may be to facilitate rapid transit of secretory granules from the basal to the apical zone of the epithelium. In the apical zone the cells expand in tightly interdigitating folds, having a height of 2 mu, which are joined together by junctions of various types. This zone is the only junctional area between the epithelial cells of this expanding and contracting boring organ. A network of microfilaments which penetrates the cellular folds at this level, probably plays an important role in the invagination of the organ. Finally at the apex, the epithelial cells have a high "brush border" of long microvilli whose plasmalemma is coated internally by particulate subunits of 30 A. This peculiarity may be an other fact to support the hypothesis that hydrogen ions are emited by these cells, by the action of carbonic anhydrase located perhaps in these subunits.     

Histochemical and electron probe analysis of secretory ameloblasts of developing rat molar teeth

Summary Calcium was not found in secretory ameloblasts and stratum intermedium cells when treated with OsO₄-pyroantimonate or when surfaces prepared by fracturing fresh, rapidly frozen, developing molar tooth germs were subject to electron probe X-ray analysis.Pyroantimonate reaction product, considered to be calcium, was found in mitochondria of enamel organ cells which were first placed in a bath containing calcium and potassium. The plasma membrane was disrupted in cells which showed mitochondrial localization of reaction product.The results provide no data which indicates that enamel organ cells have a direct, active role in the movement of calcium into the enamel. Rather, it is suggested that the secretory enamel organ might serve as a selective barrier in regulating the initial mineralization of enamel.     

The pallial organ of Atrina pectinata (Bivalvia: Pinnidae): its structure and function

Hitherto, the unique pallial organ of the Pinnidae has been considered to fulfil a cleansing role, removing sediment and shell fragments from the mantle cavity. This study of the pallial organ of Atrina pectinata describes structure in greater detail than before but was unable to demonstrate a cleansing function. Rather, the organ is thigmotropic and massively secretory. Study of the pallial organ head demonstrates it to have a pH of between 2 and 4 and that tall, apparently empty cells in the head epithelium contain sulphuric acid which can be precipitated as barium sulphate crystals following irrigation with barium chloride.
Acid-secreting cells are recorded from a number of animal groups, notably opisthobranch gastropods, where they are concluded to possess a defensive function. Such a structure has not hitherto been recorded from the Bivalvia.     

Gelsolin immunoreactivity and development of the tectorial membrane in the cochlea of normal and hypothyroid rats

Summary Gelsolin was localized by immunocytochemistry in the developing cochlea of the rat. In normal animals, the protein appeared at 18 th day in utero in cells of the Kölliker's organ, which are involved in the secretion of the tectorial membrane. The Kölliker's organ cells were not immunoreactive after the first postnatal week, which is when they cease their secretory activity. Gelsolin immunoreactivity was similar in thyroid-deficient rats until the second postnatal week but, at this age, Kölliker's organ did not transform and its gelsolin immunoreactivity persisted, together with its secretory activity. As a result, the tectorial membrane was greatly distorted and out of contact with the hair cells, which dramatically impaired the mechanical properties of the organ of Corti. The developing cochlea thus provides an example of the involvement of gelsolin in a secretory process that is of importance in the development of hearing.     

Influence of thyrotropin releasing hormone and dibutyryl cyclic adenosine 3',5'-monophosphate on ultrastructure of adenohypophysis in organ culture.

Ultrastructure of adenohypophysis in organ culture exposed to thyrotropin releasing hormone or dibutyryl cyclic adenosine 3',5'-monophosphate has been investigated. The features of increased secretory activity of glandular cells as well as the occurrence of a strongly osmiophilic substance in the intercellular spaces was observed in cultures exposed to both investigated factors.     

The fine structure of ventral prostatic secretory epithelial cells in older rats

Summary The ventral prostatic secretory epithelial cells in older rats were studied by light and electron microscopy. The cells vary in height in different parts of the same organ, and ultrastructurally they show the presence of a developed secretory apparatus such as well-developed Golgi body and abundant rough endoplasmic reticulum. They also show signs of a depressed secretory activity, involving occasional emiocytosis of apical secretory vacuoles and a paucity of condensing vacuoles in the Golgi region and above it. Further, they are characterized by the frequent occurrence of supra and paranuclear pleomorphic lysosomes.     

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.     

Demonstration of secretory component in membrane structures of the human thymus

A large amount of secretory component (Sc) was demonstrated in human thymus by the immunofluorescence technique. The component was found to be contained by the membranes permeating the parenhuyma and surrounding numerous tubular formations in the cortical layer of the organ under discussion. It is suggested that like other heteroorgan antigens, secretory component is involved in the formation of natural immunological tolerance, informing organ lymphocytes of the structures of the host own antigens. It is possible that in addition Sc promotes the differentiation of lymphocytes which repopulate to the lymphoid organs where serum IgA is synthesized and secretory IgA is formed.     

Metabolic activities of the isolated perfused rat kidney

1. A technique for perfusing the isolated rat kidney is described. It is primarily designed for the study of renal metabolism but is also suitable for studying some aspects of the secretory function; this was normal with respect to minimal glucosuria. The glomerular filtration rate as measured by creatinine clearance was lower than in vivo and slowly decreased with time. 2. Gluconeogenesis from a variety of precursors was rapid and similar to that in kidney-cortex slices, in contrast with liver where the perfused organ is more effective than slices. Whereas the maximal rates of gluconeogenesis from glycerol and pyruvate were similar in liver and kidney, the rates from succinate, malate and fumarate were 14–20 times, and those from glutamate and aspartate about three times, as high in the kidney. 3. The oxygen consumption of the perfused organ was about twice that of cortex slices, presumably because of the secretory work done in the perfused organ but not in slices. 4. The rate of acetoacetate oxidation was about the same in the perfused organ and in slices but, because of the higher rate of oxygen consumption, the percentage contribution of acetoacetate to the fuel of respiration was lower in the perfused organ. The results suggest that acetoacetate can supply energy for the basal requirements and for gluconeogenesis but not for the secretory work. 5. Glutamine was formed at a high rate from glutamate and at a lower rate from aspartate. The high rates indicate that, in the rat, the kidney is a major source of body glutamine.     

The secretory function of adipocytes in the physiology of white adipose tissue

White adipose tissue, previously regarded as a passive lipid storage site, is now viewed as a dynamic tissue. It has the capacity to actively communicate by sending and receiving different types of signals. An overview of these signals, the external modulators that affect adipose tissue and the secreted signaling molecules, the adipokines, is presented. The secretory function is highlighted in relation to energy metabolism, inflammation and the extracellular matrix and placed in the context of adipose tissue biology. We observe that the endocrine function of adipocytes receives much attention, while its paracrine and autocrine functions are underestimated. Also, we provide examples that species specificity should not be neglected. We conclude that adipose tissue primarily is an energy storage organ, well supported by its secretory function.     

Autoradiographic study of the production of secretory material by the subcommissural organ of frogs (Rana temporaria) after injection of several radioactive precursors,with special reference to the glycosilation and turnover rate of the secretory material

The suitability of several radioactive precursors for studying the secretory processes in the cells of the subcommissural organ (SCO) of frogs (Rana temporaria) was tested by means of autoradiography. Special attention was paid to: the contributions made by different cellular compartments to the glycosilation of the secretory product, and the intracellular turnover rate of the secretory material. From the results it is concluded that: 3H-glucosamine excellently labels Reissner's fibre (RF) in autoradiographs, much better than any other of the radioactive precursors applied. 3H-glucosamine molecules are attached to the protein moiety of the secretory product within the peri- and subnuclear granular endoplasmic reticulum, whereas 3H-fucose and additional 3H-glucosamine molecules are added to the oligosaccharide moiety in the supranuclear Golgi apparatus, previous to apical release; consequently, the subnuclear secretory material and the material that is released into the brain ventricle are chemically different so far as the oligosaccharide moiety is concerned. The oligosaccharide portion of the apical secretory product belongs (at least partially) to the class of the N-linked complex type oligosaccharides. The intracellular half-life of the subnuclear secretory material is at least 5.5 days. The subnuclear secretory material in the ependymal SCO-cells presumably has to pass through the Golgi apparatus before it can be released; this release probably occurs at the apical cell border.