Light and Electron Microscopic Studies of the Seminal Vesicular Glands of the African Straw-coloured Fruit Bat, Eidolon helvum

2020 ◽  
Author(s):  
C.N. Abiaezute ◽  
I.C. Nwaogu ◽  
I.R. Obidike ◽  
U.M. Igwebuike
Keyword(s):  
Abiotic Factors ◽  
Secretory Cells ◽  
Basal Cells ◽  
Reproductive Structure ◽  
Electron Microscopic ◽  
Dense Granules ◽  
Fruit Bat ◽  
Microscopic Studies ◽  
Eidolon Helvum ◽  
Near Threatened

Background: Secretions from the seminal vesicular gland enhance the survival and reproductive functions of the spermatozoa. The order Chiroptera has evolved great diversity in their reproductive structure influenced by location, abiotic factors and availability of food. Eidolon helvum is a near threatened tropical African fruit bat and little is known of its reproductive biology. The aim of this study was to highlight the structure, histochemistry and ultrastructure of the seminal vesicular glands of Eidolon helvum. Methods: The paired seminal vesicular glands of 16 adult male Eidolon helvum were obtained in May during the early rainy season in tropical Nigeria. The glands were evaluated grossly, histological and ultrastructurally.Result: The spirally coiled tubular organs were divided into numerous lobules of tubular-alveolar glandular acini lined by simple cuboidal epithelium made up of basal cells and mono or bi-nucleated cuboidal secretory cells. PAS positive secretions projected from the apical surfaces. Principal secretory cells contained numerous rough endoplasmic reticulum, mitochondria, Golgi complexes, electron lucid secretory vesicles, electron dense granules and lysosomes. The unique merocrine and apocrine secretions contributed to the formation of vaginal plugs.

Correlative transmission and high-resolution scanning electron microscopic studies on pituitary cells

1990 ◽  
Vol 48 (3) ◽  
pp. 20-21
Author(s):  
S. Tai
Keyword(s):  
Cell Types ◽  
Depth Of Field ◽  
Secretory Cells ◽  
Specific Cell ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
3 Dimensional ◽  
Microscopic Studies ◽  
Structure And Activity ◽  
Intracellular Structure

Extensive cytological and histological research, correlated with physiological experimental analysis, have been done on the anterior pituitaries of many different vertebrates which have provided the knowledge to create the concept that specific cell types synthesize, store and release their specific hormones. These hormones are stored in or associated with granules. Nevertheless, there are still many doubts - that need further studies, specially on the ultrastructure and physiology of these endocrine cells during the process of synthesis, transport and secretion, whereas some new methods may provide the information about the intracellular structure and activity in detail.In the present work, ultrastructural study of the hormone-secretory cells of chicken pituitaries have been done by using TEM as well as HR-SEM, to correlate the informations obtained from 2-dimensional TEM micrography with the 3-dimensional SEM topographic images, which have a continous surface with larger depth of field that - offers the adventage to interpretate some intracellular structures which were not possible to see using TEM.

Zymogen Secreting Cells in the Hepatopancreatic Duct of Pagurus Bernhardus (Linnaeus, 1758) and Clibanarius Longitarsus (De Haan, 1849) (Anomura)

Crustaceana ◽  
1995 ◽  
Vol 68 (5) ◽  
pp. 616-628
Author(s):  
C. Manjulatha ◽  
D. Erri Babu
Keyword(s):  
Connective Tissue ◽  
Secretory Activity ◽  
Secretory Cells ◽  
Main Duct ◽  
Zymogen Granules ◽  
Electron Microscopic ◽  
Food Material ◽  
Acidic Polysaccharide ◽  
Microscopic Studies ◽  
Pagurus Bernhardus

AbstractHistological and histochemical observations reveal that there are two clusters of acidic polysaccharide secreting glands at the opening of the mouth into the oesophagus in Pagurus bernhardus and Clibanarius longitarsus. Below these there are structurally similar glands in the connective tissue of the oesophagus. The epithelial cells lining the hepatopancreatic main duct show secretory activity and they secrete acidophilic granular secretions, which are chemically similar to vertebrate pancreatic zymogen granules. Electron microscopic studies reveal the presence of secretory cells in the hepatopancreatic duct and the synthesis of zymogens within these cells. The time of release of these granular secretions synchronizes with the release of the food material into the midgut.

scholarly journals EFFECT OF ACTIVE ACCUMULATION OF CALCIUM AND PHOSPHATE IONS ON THE STRUCTURE OF RAT LIVER MITOCHONDRIA

1964 ◽  
Vol 23 (1) ◽  
pp. 21-38 ◽  
Author(s):  
John W. Greenawalt ◽  
Carlo S. Rossi ◽  
Albert L. Lehninger
Keyword(s):  
Specific Gravity ◽  
Rat Liver ◽  
Cesium Chloride ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Electron Microscopic ◽  
Dense Granules ◽  
Phosphate Ions ◽  
Microscopic Studies

Rat liver mitochondria allowed to accumulate maximal amounts of Ca++ and HPO4= ions from the suspending medium in vitro during respiration have a considerably higher specific gravity than normal mitochondria and may be easily separated from the latter by isopycnic centrifugation in density gradients of sucrose or cesium chloride. When the mitochondria are allowed to accumulate less than maximal amounts of Ca++ and HPO4= from the medium, they have intermediate specific gravities which are roughly proportional to their content of calcium phosphate. Maximally "loaded" mitochondria are relatively homogeneous with respect to specific gravity. Correlated biochemical and electron microscopic studies show that Ca++-loaded mitochondria contain numerous dense granules, of which some 85 per cent are over 500 A in diameter. These granules are electron-opaque not only following fixation and staining with heavy metal reagents, but also following fixation with formaldehyde, demonstrating that the characteristic granules in Ca++-loaded mitochondria have intrinsic electron-opacity. The dense granules are almost always located within the inner compartment of the mitochondria and not in the space between the inner and outer membranes. They are frequently located at or near the cristae and they often show electron-transparent "cores." Such granules appear to be made up of clusters of smaller dense particles, but preliminary x-ray diffraction analysis and electron diffraction studies have revealed no evidence of crystallinity in the deposits. The electron-opaque granules decrease in number when the Ca++-loaded mitochondria are incubated with 2,4-dinitrophenol; simultaneously there is discharge of Ca++ and phosphate from the mitochondria into the medium.

Ultrastructural and Scanning Electron Microscopic Studies of Basal Cell Carcinoma

1980 ◽  
Vol 38 ◽  
pp. 728-729
Author(s):  
A. Lupulescu
Keyword(s):  
Electron Microscopy ◽  
Basal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Basal Cell ◽  
Basal Cells ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Microscopic Studies ◽  
And Migration ◽  
Scanning Electron

Previously it has been shown that long-term topical application of 3-methylcholanthrene (MCA) on the rat skin induced basal cell carcinoma. These tumors are very similar to that occurring in humans and they were studied only by light microscopy.1 Transmission electron microscopy (TEM) and Scanning electron microscopy (SEM) can provide more characteristic details for the neoplastic transformation of basal cells, their cytoarchitecture and migration.

Electron microscopic studies on developing cartilage

Development ◽  
1970 ◽  
Vol 23 (1) ◽  
pp. 169-184
Author(s):  
S. C. Goel
Keyword(s):  
Chondroitin Sulphate ◽  
Soluble Form ◽  
Ground Substance ◽  
Noncollagenous Proteins ◽  
Electron Microscopic ◽  
Dense Granules ◽  
Acid Mucopolysaccharides ◽  
Microscopic Studies ◽  
Extracellular Materials ◽  
Cellular Organelles

The present communication describes the changing developmental pattern of the cellular organelles concerned with the synthesis and transfer of the extracellular materials during the process of chondrogenesis in chick limb-buds. Cartilage consists of a large amount of extracellular phase interspersed with chondrocytes. Chemically it is well established (Eastoe, 1961) that the main constituents of the extracellular phase are collagen and protein-polysaccharides. The latter are made up of a non-collagenous protein and acid mucopolysaccharides. The acid mucopolysaccharides are chondroitin sulphate A and C (Godman & Porter, 1960; Jackson, 1964). In electron micrographs, the extracellular phase is seen as an amorphous electron-translucent ground substance interlaced by fibrous material overlaid with electron-dense granules. The chemical interpretation of this ultrastructure is still dubious (Matukas, Panner & Orbison, 1967). It is usually considered that the amorphous ground substance consists of the acid mucopolysaccharides, the noncollagenous proteins and tropocollagen, which is a soluble form of collagen (Godman & Porter, 1960).

scholarly journals Karyometric and electron microscopic studies of dark and light cells of the adrenal cortex in mammals

2018 ◽  
Vol 7 (3) ◽  
pp. 61-67 ◽  
Author(s):  
A. G. Ul'yanov ◽  
P. M. Torgun
Keyword(s):  
Electron Microscopy ◽  
Adrenal Cortex ◽  
Lipid Droplets ◽  
Adrenal Glands ◽  
Ovis Aries ◽  
Secretory Cells ◽  
Electron Microscopic ◽  
Dark Cells ◽  
Microscopic Studies ◽  
Light Cells

The purpose of this study is a comparative study of dark and light cells of cortical parenchyma of the adrenal glands in mammals using light and electron microscopy. Material and methods. Cariometric and electron microscopic studies of the adrenal glands of 9 mammalian species have been carried out: Vulpes vulpes (fox), Vulpes lagopus (arctic fox), Canis familiaris (dog), Мartes zibellina (sable), Mustela vison (mink), Enhydra lutris (sea ape); Castor fiber (river beaver); Callorhinus ursinus (fur seal); Ovis aries (sheep). Serial paraffin sections were stained with hematoxylin and eosin, iron hematoxylin, Heidenheim azan, the PAS-reaction was used, the color of the trichrome-PAS and the tetrachromium-PAS. RNA was detected by the reaction of Brashe and gallocyanin by Einarsson. For the detection of lipids, frozen sections were stained with Sudan III + IV, Black Sudan. The number of dark and light cells in the cortex of the adrenal mink in different seasons was determined. On electron micrographs, the amount of lipid droplets and mitochondria in the fascicle of the adrenal cortex was counted. Results. In the cortex of the adrenal glands of mammals, dark and light cells are present. Dark cells, as far as accumulation of sudanophilic substances are converted into light cells, which with further accumulation of lipids undergo destructive changes. Also found are the dark dying cells of the adrenal cortex, characterized by densification of the cytoplasm, pycnosis of nuclei, accumulation of yellow-brown pigment. Dark cells have larger nuclei, give more intense reaction to RNA and ketosteroids and are more active secretory cells compared to light adrenocorticocytes. Electron microscopy in dark cells reveals a large number of mitochondria and a significant amount of lipid droplets are present. Light cells contain many lipid inclusions and few mitochondria.

Fine Structural Changes of the Porcine Oviductal Epithelium During Late and Term Pregnancy

1976 ◽  
Vol 34 ◽  
pp. 150-151
Author(s):  
R. K. Nayak ◽  
E. N. Albert
Keyword(s):  
Estrous Cycle ◽  
Early Pregnancy ◽  
Structural Changes ◽  
Ultrastructural Changes ◽  
Secretory Cells ◽  
Corpora Lutea ◽  
Term Pregnancy ◽  
Electron Microscopic ◽  
Uterine Tube ◽  
Microscopic Studies

The characteristic ultrastructural changes in the ciliated and secretory cells of the tubal epithelium of adult gilts during the estrous cycle have been described (1). Earlier light microscopic studies revealed that pregnancy inhibited the cyclic alterations in the tubes of the sow and the epithelium appeared to remain in the state which was found in the second week after ovulation, when the corpora lutea were full grown (2). Nayak and Zimmerman have presented limited electron microscopic studies of the porcine tubal epithelium during early pregnancy (3) . To the best of our knowledge, no electron microscopic studies of the porcine uterine tube epithelium during late and term pregnancy have been reported.

ATP is required in platelet serotonin exocytosis for protein phosphorylation and priming of secretory vesicles docked on the plasma membrane

1996 ◽  
Vol 109 (1) ◽  
pp. 113-118
Author(s):  
T. Morimoto ◽  
S. Ogihara
Keyword(s):  
Plasma Membrane ◽  
Protein Phosphatase ◽  
Secretory Activity ◽  
Electron Microscopic ◽  
Dense Granules ◽  
Granule Membrane ◽  
Microscopic Studies ◽  
Amorphous Structures ◽  
Gamma S

Calcium-evoked secretion generally requires the presence of millimolar concentrations of Mg-ATP. We investigated the role of Mg-ATP in the secretion of serotonin from electropermeabilized bovine platelets. The secretion of serotonin was lost within 5 minutes when the Mg-ATP concentration was diluted to less than 0.1 mM, but was maintained when ATP-gamma S (adenosine 5′-O-3-thiotriphosphate) was used instead of ATP. Okadaic acid, a potent inhibitor of protein phosphatase, could also maintain the exocytotic activity even when ATP was diluted. Decrease in the secretory activity was paralleled by a decrease in phosphorylation level of four proteins after dilution of ATP, but the activity was maintained when the thiophosphorylation level of these proteins was maintained. Two of these proteins were digested by a protease, calpain, which has been shown to lead to a loss in the exocytotic activity. Electron microscopic studies showed that calcium did not induce the formation of distinct bridge-like structures between the granule membrane and the plasma membrane in Mg-ATP-diluted cells, previously shown as the structure transiently formed prior to fusion of the two membranes. Anchorage of the secretory dense granules to the plasma membrane and the presence of the amorphous structures between the granules and the plasma membrane were unchanged by dilution of ATP. These results indicate that ATP is not required for the anchorage itself, but is required to prime anchored granules for calcium-triggered secretion. Maintenance of the phosphorylated state of proteins by ATP enables the calcium trigger to form the bridge-like structures preceding membrane fusion events.

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