Formation and disintegration of lipid droplets associated with cell organelles, especially smooth-surfaced endoplasmic reticulum in the white adipose cell

1978 ◽  
Vol 36 (2) ◽  
pp. 260-261
Author(s):  
G. Usuku ◽  
K. Iyama ◽  
K. Ohzono ◽  
M. Hirashima
Keyword(s):  
Endoplasmic Reticulum ◽  
Lipid Droplets ◽  
Epididymal Adipose Tissue ◽  
Cell Organelles ◽  
Adult Rats ◽  
Adipose Cell ◽  
Ultrastructural Studies ◽  
Functional Relationships ◽  
Lipid Mass ◽  
Electron Microscopical

Although a number of ultrastructural studies on the white adipose cell have been reported, not a few unsolved problems still remain on the morphological and functional relationships between formation or disintegration of lipid droplets and cell organelles in those cells. In order to re-examine such the points, we have made electron microscopical studies on the epididymal adipose cells from normal and starved Wistar adult rats, and on these cells from rats refed ordinary animal food or given only lipid without carbohydrate after a period of starvation. Additionally, for the same purpose we have observed the ultrastructure of developing and differentiating fat cells in the epididymal adipose tissue of rats ranging from newborn to 5 weeks old.The adipose cell from normal adult rats shows that the peripheral cytoplasm which envelopes a central large lipid mass contains well-developed cell organelles and occasionally small lipid droplets. These lipid droplets have no limiting membrane, but are often observed to be closely encircled by fenestrated profiles of smooth-surfaced endoplasmic reticulum (SER) which connects with a part of rough-surfaced endoplasmic reticulum (RER) in places (Fig. 1).

scholarly journals Ultrastructural studies of the hemocytes of Panstrongylus megistus (Hemiptera: Reduvidae)

1989 ◽  
Vol 84 (2) ◽  
pp. 171-188 ◽  
Author(s):  
Margherita A. Barracco ◽  
Clarice T. Loch
Keyword(s):  
Endoplasmic Reticulum ◽  
Light Microscopy ◽  
Rough Endoplasmic Reticulum ◽  
Lipid Droplets ◽  
Panstrongylus Megistus ◽  
Ultrastructural Studies ◽  
Hemocyte Count

Ultrastructural analyses revealed the presence of six hemocyte types in the hemolymph of Panstrogylus megistus, partially confirming our previous results obtained through light microscopy. Prohemocytes: small, round hemocytes with a thin cytoplasm layer, espcieally rich in free ribosomes and poor in membranous systems. Plasmatocytes: polymorphic cells, whose cytoplasm contains many lysosomes and a well developed rough endoplasmic reticulum (RER).They are extremely phagocytic. Sometimes, they show a large vacuolation. Granulocytes: granular hemocytes whose granules show different degrees of electrondensity. Most of them, have an internal structuration. Coagulocytes: oval or elongated hemocytes, which show pronounced perinuclear cisternae as normally observed in coagulocytes. The cytoplasm is usually electrondense, poor in membranous systems and contains many labile granules. Oenocytoids: large and very stable hemocytes, whose homogeneous cytoplasme is rich in loose ribosomes and poor in membranous systems. Adipohemocytes: large cells, containing several characteristic lipid droplets. The cytoplasm is also rich in glycogen, RER and large mitochondria. The total and differential hemocyte count (THC and DHC) were also calculated for this reduviid. THC increases from 2,900 hemocytes/cubic millimeter of hemolymph in the 4th intar to 4,350 in the 5th and then, decreases to 1,950 in the adults. Plasmatocytes and coagulocytes are the predominant hemocyte types.

Ultrastructural Studies on the Effects of Korean Panax Ginseng on the Theca Interna of Rat Ovary

1979 ◽  
Vol 07 (04) ◽  
pp. 333-344 ◽  
Author(s):  
Moo Rim Byung
Keyword(s):  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Golgi Apparatus ◽  
Panax Ginseng ◽  
Lipid Droplets ◽  
Ultrastructural Studies ◽  
Dense Bodies ◽  
Rat Ovary ◽  
Theca Interna ◽  
Morphologic Changes

An investigation was conducted to delineate the fine structure of steroid-producing ovarian theca interna cells following administration of Korean Panax ginseng to rats for 60 days. The cytoplasmic changes were observed in the ginseng-treated theca interna cells, increased number, size and density of the mitochondria, and increased size of the smooth surfaced endoplasmic reticulum, the rough surfaced endoplasmic reticulum and the Golgi apparatus. The nucleus and nucleolus were slightly enlarged and increased numbers of dense bodies were seen whereas lipid droplets were decreased in number. The changes may result from hyperfunction of the steroid-producing cells. Morphologic changes seen may represent stimulating effects on the steroid-producing cells of the theca interna in ginseng-treated animals.

scholarly journals STRATIFICATION AND SUBSEQUENT BEHAVIOR OF PLANT CELL ORGANELLES

1963 ◽  
Vol 18 (2) ◽  
pp. 441-457 ◽  
Author(s):  
G. Benjamin Bouck
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Lipid Droplets ◽  
Smooth Endoplasmic Reticulum ◽  
The Other ◽  
Cell Organelles ◽  
Large Unit ◽  
Original Length ◽  
Subsequent Behavior

Living excised roots of pea were centrifuged at 20,000 g for 24 hours, and the behavior of organelles was followed by electron microscopy at various intervals after centrifugation. With these forces, organelles are not perceptibly or irreversibly damaged, nor is the viability of the whole root destroyed. Organelles stratify generally in the order of lipid (centripetal pole), vacuoles, smooth endoplasmic reticulum and dictyosomes, proplastids (without starch), mitochondria, rough endoplasmic reticulum, proplastids with starch. The nucleus distends from the vacuolar region to the extreme centrifugal pole of the cell, while the chromatin and nucleolus seek the centrifugal pole of the nucleus. During the redistribution of organelles the rough endoplasmic reticulum is among the first to reorient, and possible explanations for this are discussed. Mitochondria can be stretched elastically many times their original length, but proplastids seem fairly rigid. Small vacuoles, forced together during centrifugation, apparently may fuse to form a large unit. Lipid droplets, on the other hand, tend to remain separate. Dictyosomes and smooth endoplasmic reticulum layer in the same region of the centrifuged cell, indicating a density similarity between these two organelles.

Electron microscopical study to assess thein vitroeffects of the synthetic trioxolane OZ78 against the liver fluke,Fasciola hepatica

Parasitology ◽  
2009 ◽  
Vol 136 (11) ◽  
pp. 1325-1337 ◽  
Author(s):  
L. HALFERTY ◽  
J. F. O'NEILL ◽  
G. P. BRENNAN ◽  
J. KEISER ◽  
I. FAIRWEATHER
Keyword(s):  
Endoplasmic Reticulum ◽  
Lipid Droplets ◽  
Fasciola Hepatica ◽  
Microscopical Study ◽  
Granular Endoplasmic Reticulum ◽  
Autophagic Vacuoles ◽  
Transmission Electron ◽  
Electron Microscopical ◽  
Tegumental Syncytium

SUMMARYAdultFasciola hepaticawere incubated for 48 hin vitroin the synthetic peroxide, OZ78 at a concentration of 100 μg/ml and then prepared for scanning and transmission electron microscopy. There was limited disruption to the external fluke surface, with only slight swelling and blebbing of the interspinal tegument in the midbody and ventral tail regions. By contrast, significant disruption was observed to the ultrastructure of the tegument and subtegumental tissues. There was severe swelling of the basal infolds in the tegumental syncytium and the flooding spread internally to affect the subtegumental tissues. In the tegumental system, there was swelling of the cisternae of granular endoplasmic reticulum and of the mitochondria, with the latter showing signs of breaking down. Autophagic vacuoles and lipid droplets were present and the synthesis of tegumental secretory bodies was much reduced. The gastrodermal cells were severely affected, with swelling and degeneration of the mitochondria and the presence of autophagic vacuoles and lipid droplets. The granular endoplasmic reticulum was swollen and vesiculated and the cells contained few secretory bodies. Both the vitelline and testis follicles showed evidence of extensive cellular disruption and degeneration. This study confirms previous data indicating the potential flukicidal activity of OZ78.

High-voltage EM description of the types and distribution of sensory endings in the inner conical body of the rat vibrissal follicle-sinus complex

1990 ◽  
Vol 48 (3) ◽  
pp. 410-411
Author(s):  
Tony M. Mosconi ◽  
Min J. Song ◽  
Frank L. Rice
Keyword(s):  
Mammalian Species ◽  
Dorsal Side ◽  
Hair Shaft ◽  
Sensory Innervation ◽  
Conical Body ◽  
Adult Rats ◽  
Perpendicular Plane ◽  
Ultrastructural Studies ◽  
Unmyelinated Axons ◽  
Sensory Endings

Whiskers or vibrissal follicle-sinus complexes (F-SCs) on the snouts of many mammalian species are structures that have complex, dense sensory innervation. The innervation of F-SCs is remarkably similar in all species with the exception of one site - the inner conical body (ICB). The ICB is an elongated cylindrical structure that encircles the hair shaft near the neck of the follicle. This site has received only cursory attention in ultrastructural studies of the F-SCAdult rats were perfused after the method of Renehan and Munger2. F-SCs were quartered longitudinally and embedded separately in Epon-Araldite. Serial 0.25 μm sections were cut in either the longitudinal or perpendicular plane through the ICB and examined with an AEI EM7 1.2 MV HVEM (Albany, NY) at 1000 KV. Sensory endings were reconstructed from serial micrographs through at least 20 μm in the longitudinal plane and through 10 μm in the perpendicular plane.From two to six small superficial vibrissal nerves converge upon the neck of the F-SC and descend into the ICB. The nerves branch into smaller bundles of myelinated and unmyelinated axons along the dorsal side of the hair shaft.

scholarly journals STUDIES ON MICROPEROXISOMES II. A CYTOCHEMICAL METHOD FOR LIGHT AND ELECTRON MICROSCOPY

1972 ◽  
Vol 20 (12) ◽  
pp. 1006-1023 ◽  
Author(s):  
ALEX B. NOVIKOFF ◽  
PHYLLIS M. NOVIKOFF ◽  
CLEVELAND DAVIS ◽  
NELSON QUINTANA
Keyword(s):  
Endoplasmic Reticulum ◽  
Guinea Pig ◽  
Lipid Droplets ◽  
Smooth Endoplasmic Reticulum ◽  
Light And Electron Microscopy ◽  
Distal Tubule ◽  
Striking Difference ◽  
High Concentration ◽  
Electron Microscopic ◽  
Pig Kidney

A modification of the Novikoff-Goldfischer alkaline 3,3'-diaminobenzidine medium for visualizing peroxisomes is described. It makes possible light microscopic as well as electron microscopic studies of a recently described class of peroxisomes, the microperoxisomes. Potassium cyanide (5 x 10–3 M) is included in the medium to inhibit mitochondrial staining, the pH is 9.7 and there is a high concentration of H2O2 (0.05%). Two cell types have been chosen to illustrate the advantages of the new procedure for demonstrating the microperoxisomes: the absorptive cells in the human jejunum and the distal tubule cells in the guinea pig kidney. Suggestive relations of microperoxisomes and lipid are described in the human jejunum. The microperoxisomes are strategically located between smooth endoplasmic reticulum that radiates toward the organelles and contains lipid droplets and "central domains" of highly specialized endoplasmic reticulum which do not show the lipid droplets. The microperoxisomes are also present at the periphery of large lipid-like drops. In the guinea pig kidney tubule there is a striking difference between the thick limb of Henle and distal tubule. The distal tubule has a population of cells with large numbers of microperoxisomes readily visible by light microscopy; these cells are not present in the thick limb of Henle. Other differences between the two are also described.

scholarly journals Septin-dependent compartmentalization of the endoplasmic reticulum during yeast polarized growth

2005 ◽  
Vol 169 (6) ◽  
pp. 897-908 ◽  
Author(s):  
Cosima Luedeke ◽  
Stéphanie Buvelot Frei ◽  
Ivo Sbalzarini ◽  
Heinz Schwarz ◽  
Anne Spang ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Membrane Proteins ◽  
Diffusion Barriers ◽  
Yeast Cells ◽  
Dependent Manner ◽  
Protein Diffusion ◽  
Ultrastructural Studies ◽  
Bud Neck ◽  
Er Membrane

Polarized cells frequently use diffusion barriers to separate plasma membrane domains. It is unknown whether diffusion barriers also compartmentalize intracellular organelles. We used photobleaching techniques to characterize protein diffusion in the yeast endoplasmic reticulum (ER). Although a soluble protein diffused rapidly throughout the ER lumen, diffusion of ER membrane proteins was restricted at the bud neck. Ultrastructural studies and fluorescence microscopy revealed the presence of a ring of smooth ER at the bud neck. This ER domain and the restriction of diffusion for ER membrane proteins through the bud neck depended on septin function. The membrane-associated protein Bud6 localized to the bud neck in a septin-dependent manner and was required to restrict the diffusion of ER membrane proteins. Our results indicate that Bud6 acts downstream of septins to assemble a fence in the ER membrane at the bud neck. Thus, in polarized yeast cells, diffusion barriers compartmentalize the ER and the plasma membrane along parallel lines.

scholarly journals THE FINE STRUCTURE AND DEVELOPMENT OF THE COMPANION CELL OF THE PHLOEM OF ACER PSEUDOPLATANUS

1965 ◽  
Vol 24 (1) ◽  
pp. 117-128 ◽  
Author(s):  
F. B. P. Wooding ◽  
D. H. Northcote
Keyword(s):  
Endoplasmic Reticulum ◽  
Sieve Tube ◽  
Acer Pseudoplatanus ◽  
Sieve Plate ◽  
Wheat Grain ◽  
Companion Cell ◽  
Large Nucleus ◽  
Cell Organelles ◽  
Phloem Tissue ◽  
Aleurone Cells

At maturity the companion cell of the phloem of the sycamore Acer pseudoplatanus has a large nucleus, simple plastids closely sheathed with rough endoplasmic reticulum, and numerous mitochondria. The cytoplasm contains numerous ribosomes, resulting in a very electron-opaque cytoplasm after permanganate fixation. Bodies similar to the spherosomes of Frey-Wyssling et al. (4) are collected in clusters and these also contain bodies of an unidentified nature similar to those found by Buttrose (1) in the aleurone cells of the wheat grain. The pores through the wall between the companion cell and sieve tube are complex and develop from a single plasmodesma. Eight to fifteen plasmodesmata on the companion cell side communicate individually with a cavity in the centre of the wall which is linked to the sieve tube by a single pore about twice the diameter of an individual plasmodesma. This pore is lined with material of an electron opacity equivalent to that of material bounding the sieve plate pores. The development of the cell organelles, the possible role played in the phloem tissue by the companion cell, and the function of the complex pores contained in its wall are discussed.

scholarly journals The Torsin/ NEP1R1-CTDNEP1/ Lipin axis regulates nuclear envelope lipid metabolism for nuclear pore complex insertion

2020 ◽  
Author(s):  
Julie Jacquemyn ◽  
Joyce Foroozandeh ◽  
Katlijn Vints ◽  
Jef Swerts ◽  
Patrik Verstreken ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Nuclear Pore Complex ◽  
Lipid Droplets ◽  
Nuclear Pore ◽  
List Type ◽  
Unknown Mechanism ◽  
Structure Lipid ◽  
Cellular Events ◽  
Upstream Regulator

AbstractTorsin ATPases of the endoplasmic reticulum (ER) and nuclear envelope (NE) lumen inhibit Lipin-mediated phosphatidate (PA) to diacylglycerol (DAG) conversion by an unknown mechanism. This excess PA metabolism is implicated in TOR1A/TorsinA diseases, but it is unclear whether it explains why Torsin concomitantly affects nuclear structure, lipid droplets (LD), organelle and cell growth. Here a fly miniscreen identified that Torsins affect these events via the NEP1R1-CTDNEP1 phosphatase complex. Further, Torsin homo-oligomerization rather than ATPase activity was key to function. NEP1R1-CTDNEP1 activates Lipin by dephosphorylation. We show that Torsin prevents CTDNEP1 from accumulating in the NE and excludes Lipin from the nucleus. Moreover, this repression of nuclear PA metabolism is required for interphase nuclear pore biogenesis. We conclude that Torsin is an upstream regulator of the NEP1R1-CTDNEP1/ Lipin pathway. This connects the ER/NE lumen with PA metabolism, and affects numerous cellular events including it has a previously unrecognized role in nuclear pore biogenesis.HighlightsNuclear envelope PA-DAG-TAG synthesis is independently regulated by Torsin and Torip/LAP1Torsin removes CTDNEP1 from the nuclear envelope and excludes Lipin from the nucleusExcess nuclear envelope NEP1R1-CTDNEP1/ Lipin activity impairs multiple aspects of NPC biogenesisNEP1R1-CTDNEP1/ Lipin inhibition prevents cellular defects associated with TOR1A and TOR1AIP1 / LAP1 disease

Sign in / Sign up

Export Citation Format

Share Document