Electron microscopic and cytochemical study on the role of Golgi elements and plasma membrane of enterocytes in the intestinal lipid transport

Histochemie ◽  
1971 ◽  
Vol 28 (4) ◽  
pp. 276-287 ◽  
Author(s):  
H. Oledzka-Słotwińka ◽  
V. J. Desmet
Keyword(s):  
Plasma Membrane ◽  
Lipid Transport ◽  
Electron Microscopic ◽  
Cytochemical Study

Microtubules and associated microfilaments in the tentacles of the suctorian Heliophrya erhardi Matthes

1976 ◽  
Vol 20 (3) ◽  
pp. 589-617
Author(s):  
M. Hauser ◽  
H. Van Eys
Keyword(s):  
Plasma Membrane ◽  
Resting State ◽  
Close Association ◽  
Ultrastructural Level ◽  
Peritrophic Membrane ◽  
Electron Microscopic ◽  
Helical Wave ◽  
Length Changes ◽  
Microscopic Findings

At the ultrastructural level length changes accompanying linear movements of resting (non-feeding) tentacles of the suctorian Heliophrya involve not only altered microtubule numbers, but also marked changes in the specific microtubule pattern of cross-sectioned tentacles. These changes in number and pattern indicate a sliding between axonemal microtubules. The visualization of microfilaments in the cytoplasm at the tentacle base and in the knob region could shed new light on the problem of whether microtubular sliding is an active or passive process. At the tentacle base, microfilaments are either arranged in a ring-shaped configuration around the axoneme, or they run parallel to the axonemal microtubules, whereas at the tentacle tip during the resting state, microfilaments are closely associated with the plasma membrane of the knob. They form a filamentous reticular layer, which is continuous at the anchorage site of axonemal microtubules with the dense epiplasmic layer of the tentacle shaft. Obiously, this filamentous layer is engaged in positioning the haptocysts at the plasma membrane and in holding the membrane itself under tension. The putative contractile nature of microfilaments and the epiplasmic layer is argued from ATP-sensitive glycerol models of tentacles and from the results of halothane treatment of native tentacles. Halothane treatment of resting tentacles also gave indications of the presence of differentially stable intermicrotubule-bridges. The role of micro-filaments and halothane-resistant dynein-like inter-row bridges in tentacle movement is discussed. As soon as the plasma membrane of the knob is ‘sealed’ with the prey pellicle during feeding, the microtubules of the sleeve region slide into the knob where they bend back and outwards. The microtubules now appear decorated and sometimes cross-connected by microfilaments which adhere closely to the plasma membrane- now acting as a peritrophic membrane-lining the prey cytoplasm against the microtubules of the inner tube. These microfilaments which show a close association with the microtubules of the active knob area, are thought to be engaged in microtubular bending and stretching during feeding. They may also be involved in the transport of the peritrophic membrane in distal tentacle regions. Microinematographically recorded oscillations in tentacle diameter in these regions are in agreement with the electron-microscopic findings of various states of collapsed tentacle axonemes. These observations, as well as the occurrence of helically twisted tentacles during feeding, suggest microfilament mediated sequential back and forth movements of sleeve microtubules in the knob region which generate a proximally migrating helical wave.

Dystrophin is localized to the plasma membrane of human skeletal muscle fibers by electron-microscopic cytochemical study

1990 ◽  
Vol 13 (5) ◽  
pp. 376-380 ◽  
Author(s):  
Stirling Carpenter ◽  
George Karpati ◽  
Elizabeth Zubrzycka-Gaarn ◽  
Dennis E. Bulman ◽  
Peter N. Ray ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Human Skeletal Muscle ◽  
Muscle Fibers ◽  
Electron Microscopic ◽  
Cytochemical Study ◽  
Skeletal Muscle Fibers

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.

scholarly journals Essential role of non-vesicular lipid transport in microtubule-controlled cell polarisation

2020 ◽  
Author(s):  
M. Hersberger-Trost ◽  
D. Dreher ◽  
S.M. Huisman ◽  
A.R. Kijowski ◽  
M. Gemünden ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Molecular Basis ◽  
De Novo ◽  
Lipid Transport ◽  
Membrane Domains ◽  
Fundamental Biological Process ◽  
Dependent Cell ◽  
Plasma Membrane Domains ◽  
Dependent Pathway

AbstractCell polarisation is a fundamental biological process. Fission yeast is a key model system to study the molecular basis of microtubule-controlled cell polarisation. In this process, cells define prospective growth sites by generating distinct plasma membrane domains enriched in de novo synthesised sterols. Microtubules restrict the number and location of these domains by depositing factors at the cell poles. The mechanisms underlying such sterol-rich membrane domain formation and polarisation are largely unknown. We found that the oxysterol-binding proteins kes1p, osh2p and kes3p define three independent sterol delivery pathways to the plasma membrane. These mediate different phases of cell polarisation in a phosphoinositide-dependent fashion and differ in their requirement for vesicular trafficking steps. The redundant, kes1p- and osh2p-dependent pathways are vital and prime cell polarisation by mediating the formation of randomly distributed sterol-rich plasma membrane domains. Subsequent microtubule-controlled polarisation of these domains preferentially employs kes1p that directly delivers sterols to the plasma membrane independent of cdc42p. In cells lacking kes1p, polarisation becomes cdc42p-dependent, utilising mainly the kes3p-dependent pathway. Our study uncovers an essential biological function for non-vesicular lipid transport and establishes a molecular basis for different sterol-delivery pathways acting in cdc42p-independent and cdc42p-dependent cell polarisation.

scholarly journals Ca(2+)-ATPase and Mg(2+)-ATPase in Aplysia glial and interstitial cells: an EM cytochemical study.

1991 ◽  
Vol 39 (12) ◽  
pp. 1645-1658 ◽  
Author(s):  
K Maggio ◽  
A Watrin ◽  
E Keicher ◽  
G Nicaise ◽  
M L Hernandez-Nicaise
Keyword(s):  
Nervous System ◽  
Plasma Membrane ◽  
Atpase Activity ◽  
Peripheral Nervous System ◽  
Glial Cells ◽  
Neuronal Cell ◽  
Calcium Atpase ◽  
Electron Microscopic ◽  
Cytochemical Study ◽  
Neuronal Cell Bodies

The localization of Ca(2+)- and Mg(2+)-ATPases was determined in Aplysia central and peripheral nervous system, using an electron microscopic cytochemical method. The enzyme activity appeared localized to the membrane of glial granules (gliagrana), particularly in the peripheral nervous system of the esophagus, and on the plasma membrane of central glial cells adjacent to neuronal cell bodies. No calcium- and/or magnesium-ATPase activity was detectable on the plasma membrane of glial cells surrounding nerve axons in the pleuro-visceral connectives. These findings are discussed along two main lines: (a) the calcium-ATPase of the gliagrana coincides with a high intragranular calcium and/or proton concentration; and (b) the presence of a calcium-ATPase activity at the glio-neuronal interface around the neuronal cell bodies coincides with the use of calcium ions as charge carriers of the action potential, and its absence at the level of the axon with the concurrent functional use of sodium ions.

Stannous fluoride treatment of acid-etched caries-like lesions of enamel: A scanning electron microscopic study

1984 ◽  
Vol 42 ◽  
pp. 720-721
Author(s):  
M. John Hicks ◽  
Leon M. Silverstone ◽  
David G. Gantt ◽  
Catherine M. Flaitz
Keyword(s):  
Acid Etching ◽  
Surface Zone ◽  
Electron Microscopic ◽  
Fluoride Treatment ◽  
Stannous Fluoride ◽  
Scanning Electron Microscopic Study ◽  
Demineralized Enamel ◽  
Intact Surface ◽  
Topical Fluoride

Although fluoride levels become elevated in sound enamel following a topical fluoride treatment, the caries-preventive effect of fluoride is thought to be due primarily to the role of fluoride in remineralization of clinically undetectable enamel lesions and hypomineralized enamel. During lesion formation, redistribution of fluoride from the enamel surface to the subsurface demineralized enamel occurs. This results in a surface zone with a relatively low fluoride content. In order to maintain an intact surface zone over a carious lesion, it may be necessary to replenish the fluoride levels with an exogenous fluoride source. By acid-etching the lesion surface, a more reactive surface is made available for fluoride interaction. In addition, porosities and etching patterns may be created, allowing for bonding of a caries-resistant resin material to the lesion surface. The purpose of this study was to determine the integrity of the caries-like lesion surface following acid-etching and subsequent stannous fluoride treatment (SnF2).

Scanning electron microscopic study of collagen fibrillogenesis and extracellular compartmentalization in the chick embryo tendon

1986 ◽  
Vol 44 ◽  
pp. 208-209
Author(s):  
Grace C.H. Yang
Keyword(s):  
Chick Embryo ◽  
Extracellular Space ◽  
Fibroblast Cell ◽  
Collagen Fibrils ◽  
Electron Microscopic ◽  
Voltage Electron ◽  
Scanning Electron Microscopic Study ◽  
Microscopic Studies ◽  
And Function

The size and organization of collagen fibrils in the extracellular matrix is an important determinant of tissue structure and function. The synthesis and deposition of collagen involves multiple steps which begin within the cell and continue in the extracellular space. High-voltage electron microscopic studies of the chick embryo cornea and tendon suggested that the extracellular space is compartmentalized by the fibroblasts for the regulation of collagen fibril, bundle, and tissue specific macroaggregate formation. The purpose of this study is to gather direct evidence regarding the association of the fibroblast cell surface with newly formed collagen fibrils, and to define the role of the fibroblast in the control and the precise positioning of collagen fibrils, bundles, and macroaggregates during chick tendon development.

Mitochondrial matrix calcium ions regulate energy production in myocardium: A cytochemical study

1990 ◽  
Vol 48 (2) ◽  
pp. 166-167
Author(s):  
W.A. Jacob ◽  
R. Hertsens ◽  
A. Van Bogaert ◽  
M. De Smet
Keyword(s):  
Energy Metabolism ◽  
Calcium Ions ◽  
Energy Production ◽  
Regulation Of Respiration ◽  
Free Calcium ◽  
Mitochondrial Matrix ◽  
Cytochemical Study ◽  
Nmr Techniques

In the past most studies of the control of energy metabolism focus on the role of the phosphorylation potential ATP/ADP.Pi on the regulation of respiration. Studies using NMR techniques have demonstrated that the concentrations of these compounds for oxidation phosphorylation do not change appreciably throughout the cardiac cycle and during increases in cardiac work. Hence regulation of energy production by calcium ions, present in the mitochondrial matrix, has been the object of a number of recent studies.Three exclusively intramitochondnal dehydrogenases are key enzymes for the regulation of oxidative metabolism. They are activated by calcium ions in the low micromolar range. Since, however, earlier estimates of the intramitochondnal calcium, based on equilibrium thermodynamic considerations, were in the millimolar range, a physiological correlation was not evident. The introduction of calcium-sensitive probes fura-2 and indo-1 made monitoring of free calcium during changing energy metabolism possible. These studies were performed on isolated mitochondria and extrapolation to the in vivo situation is more or less speculative.

Ultrastructural Cytochemical Study of Human Gastric Cancer: Observation of AKP ase,ACP ase,G6P ase,TPP ase and CO ase

1990 ◽  
Vol 48 (3) ◽  
pp. 254-255
Author(s):  
Dong Yuming ◽  
Yang Guanglin ◽  
Du Wei Dong ◽  
Xu Ai Liam
Keyword(s):  
Gastric Cancer ◽  
Gastric Epithelium ◽  
Human Gastric Cancer ◽  
Electron Microscopic ◽  
Cytochemical Study ◽  
Electron Microscopic Cytochemistry ◽  
Cytochemical Reaction ◽  
Set Up ◽  
Cancer Tissues ◽  
Cytochemical Technique

The activities and distributions of AKPase ,ACPase,G6Pase,TPPase and COase in human normal gastric mucosa and gastric cancer tissues were studied histochemically at light microscopic level. These enzymes are the marker enzymes of cell membrane lysosome endoplasmic reticulum, Golgi apparatus and mitochondrion objectively. On the basis of the research we set up a special ultrastructural cytochemical technique and first researched into gastric cancer domesticly. Ultrastructural cytochemistry is also called electron microscopic cytochemistry. This new technique possesses both the sensitivity of cytochemical reaction andi the high resolution of electron microscope. It is characterized by direct observation,exact localization and the combination morphology with function.The distributions of AKPase,ACPase,G6Pase,TPPase and COase in 14 cases of gastric cancer and 1 case of gastric Denign lesion were studied ultrastructurally. The results showed: 1. normal gastric epithelium had no AKPase reaction. The reaction of ACPase,G6Pase,TPPase and Coase were found in the corresponding organella, which were consistent with their function.

Immunocytochemical localization of p65 with one-nanometer gold particles following silver development

1989 ◽  
Vol 47 ◽  
pp. 1042-1043
Author(s):  
Richard W. Burry ◽  
Diane M. Hayes
Keyword(s):  
Plasma Membrane ◽  
Bovine Serum Albumin ◽  
Calf Serum ◽  
Specific Protein ◽  
Immunocytochemical Localization ◽  
Electron Microscopic ◽  
Gold Particles ◽  
Pass Through ◽  
Label Distribution ◽  
Phosphate Buffered Saline

Electron microscopic (EM) immunocytochemistry localization of the neuron specific protein p65 could show which organelles contain this antigen. Antibodies (Ab) labeled with horseradish peroxidase (HRP) followed by chromogen development show a broad diffuse label distribution within cells and restricting identification of organelles. Particulate label (e.g. 10 nm colloidal gold) is highly desirable but not practical because penetration into cells requires destroying the plasma membrane. We report pre-embedding immunocytochemistry with a particulate marker, 1 nm gold, that will pass through membranes treated with saponin, a mild detergent.Cell cultures of the rat cerebellum were fixed in buffered 4% paraformaldehyde and 0.1% glutaraldehyde (Glut.). The buffer for all incubations and rinses was phosphate buffered saline with: 1% calf serum, 0.2% saponin, 0.1% gelatin, 50 mM glycine 1 mg/ml bovine serum albumin, and (not in the HRP labeled cultures) 0.02% sodium azide. The monoclonal #48 to p65 was used with three label systems: HRP, 1 nm avidin gold with IntenSE M development, and 1 nm avidin gold with Danscher development.

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