scholarly journals OBSERVATIONS ON THE FINE STRUCTURE OF LUTEIN CELLS

1964 ◽  
Vol 22 (1) ◽  
pp. 127-141 ◽  
Author(s):  
Allen C. Enders ◽  
W. R. Lyons
Keyword(s):  
Endoplasmic Reticulum ◽  
Lipid Droplets ◽  
Normal Pregnancy ◽  
Perivascular Space ◽  
Limiting Factor ◽  
Corpora Lutea ◽  
General Effect ◽  
Multiple Characteristics ◽  
Old Rats ◽  
Dense Matrices

Corpus luteum formation was induced in 26-day-old rats which were subsequently hypophysectomized and injected with mammotrophic hormone (MH, LTH). Sections of corpora lutea from these animals were examined with the electron microscope and compared with similarly prepared (Caulfield's fixed, Araldite embedded) corpora from normal pregnancy and from controls, the latter consisting of corpora prior to hypophysectomy and corpora from uninjected rats 7 to 14 days after hypophysectomy. Lutein cells from corpora lutea of injected animals and of normal pregnancy are characterized by abundant, tortuous, tubular agranular endoplasmic reticulum and by mitochondria, many of which are disc-shaped with dense matrices and both villiform and lamelliform cristae. The endoplasmic reticulum is most abundant in lutein cells from pregnant animals, in which cells it is in the form of thin, highly tortuous tubules. The form of the lipid droplets seen in cells of stimulated animals varies greatly. Marginal foldings of the lutein cells on the perivascular space were found in all instances. Lutein cells from hypophysectomized animals have a less highly developed agranular endoplasmic reticulum. The mitochondria have irregular outlines and a relatively lucid matrix. The lipid droplets in these cells show less tendency to be extracted, but are not so large or abundant as in the cells of onset controls. Granules believed to contain lipid pigments are common in the lutein cells of these control animals. It is suggested that lutein cells from corpora lutea which are actively secreting progesterone may be readily distinguished from lutein cells from non-active corpora by means of the multiple characteristics enumerated. It is further suggested that mammotrophic hormone has a general effect on the metabolism of lutein cells rather than solely affecting a specific organelle, the abundance or composition of which may be the limiting factor in the production of progesterone.

scholarly journals Ultrastructure of cells after reversible dark-induced blocking of mitotic divisions in antheridial filaments of Chara vulgaris L.

2014 ◽  
Vol 49 (3) ◽  
pp. 169-186 ◽  
Author(s):  
Maria Kwiatkowska ◽  
Janusz Maszewski ◽  
Maria M. Maszewska
Keyword(s):  
Cell Cycle ◽  
Endoplasmic Reticulum ◽  
Spatial Distribution ◽  
Cell Growth ◽  
Golgi Apparatus ◽  
Lipid Droplets ◽  
Continuous Darkness ◽  
Mean Size ◽  
Dense Matrices ◽  
The Mean

As compared with the control plants cultured under photoperiodic L : D = =14 : 10 conditions (K w i a t k o w s k a, M a s z e w s k i, 1978), the ultrastructure of nuclei -in cells blocked by a 5 day exposure to continuous darkness is characterized by homogenous arrangement. This homogeneity is maintained in all generations of antheridial filaments irrespective of cell length, which in the controls, being directly correlated with particular type of nuclear structure, may serve as a precise indicator of a given stage of interphase. From similarities in both the spatial distribution and content of condensed chromatin in is concluded that the block of the cell cycle is imposed at the beginning of the G<sub>2</sub> phase. On comparing these cells with the early G<sub>2</sub> period (stage VII) in the control plants, marked changes in the structure of nucleoli were found. They decrease in size by half owing to the complete decline of granular component. The area occupied by endoplasmic reticulum undergoes a 50% reduction. The decrease in the activity of Golgi apparatus expressed by a drop in number of smooth vesicles surrounding a single dictyosome is found to parallel the limited rate of cell growth. The number of coated vesicles and cisterns of dictyosome slightly increases. Mitochondria show typical condensed configuration with dense matrices and swollen cristae, while in the control orthodox forms are prevailing. The mean size of mitochondria is smaller, but their number exceeds that of the control plants. The surface area of mitochondrial profiles is found to remain constant proportion of the cytoplasm section, e.g., about 3%. Dark-cultured antheridial filaments show absolute decline of lipid droplets. No differences were found in structure of plastids and vacuols, as well as in number of ribosomes in cytoplasm surface unit.

Smooth Muscular Cells in the Mammalian Ovary

1971 ◽  
Vol 29 ◽  
pp. 508-509
Author(s):  
Z. Fumagalli ◽  
P. Motta ◽  
S. Calvieri
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Electron Microscope ◽  
Small Groups ◽  
Cortical Area ◽  
Lipid Droplets ◽  
Corpora Lutea ◽  
Ovarian Stroma ◽  
Theca Interna ◽  
Glycogen Particles

The presence of smooth muscular cells was demonstrated with the electron microscope in different areas of the ovary of cats, mice and rabbits. The myocytes were arranged in fascicles, small groups, or most frequently appeared isolated. They were scattered in the ovarian stroma, related to the interstitial cells, in the periphery of the corpora lutea (rarely between luteal cells) in the middle of the gland. Smooth muscular cells were seldom observed between cells of the theca interna and externa of developing follicles and in the middle of atresic follicles. Some smooth muscular cells were found in the cortical area of the ovaries.Each smooth muscular cell showed typical filaments, free ribosomes, lipid droplets and at times glycogen particles. Mitochondria were vesicular; the (Golgi) vesicular complex was often related to two centrioles (frequently in a process of ciliogenesis). The granular endoplasmic reticulum was moderately developed. The plasma membrane presented invaginations and micropinocytotic vesicles as well as tight junctions between adjacent cells. The nucleus was elongated and its envelope formed wide perinuclear cisternae.

Ultrastructure of Luteal Cells in Fully Formed and Regressing Corpora Lutea During Pregnancy and Lactation in the Marsupials Isoodon Macrourus and Perameles Nasuta.

1980 ◽  
Vol 28 (2) ◽  
pp. 195 ◽  
Author(s):  
DE Hollis ◽  
AG Lyne
Keyword(s):  
Endoplasmic Reticulum ◽  
Lipid Droplets ◽  
Smooth Endoplasmic Reticulum ◽  
Cell Junction ◽  
Corpora Lutea ◽  
Cholesterol Crystals ◽  
Luteal Cells ◽  
Pregnancy And Lactation ◽  
Advanced Stages ◽  
Spherical Nuclei

Corpora lutea (CL) collected from 23 bandicoots (I. macrourus and P. nasuta), from day 5 of pregnancy (gestation 12.5 days) to day 53 of lactation (lactation c. 60 days), were examined with the electron microscope. The luteal cells of fully formed CL (from day 5 of pregnancy to day 44 of lactation) were large and contained spherical nuclei with distinct nucleoli. The amount of heterochromatin increased during the latter part of this period. The cytoplasm contained numerous lipid droplets and abundant smooth endoplasmic reticulum (SER). Granular endoplasmic reticulum (GER) was less common. Mitochondria were most numerous from day 16 to day 44 of lactation and some of them contained large osmiophilic inclusions. Several types of granules and inclusions were present in the cytoplasm. During pregnancy, small dense-cored granules were common in P. nasuta and sparse in I. macrourus. They were still present in small numbers during early lactation in P. nasuta but were absent throughout lactation in I. macrourus. A special type of cell junction associated with endoplasmic reticulum was present between the luteal cells in P. nasuta but not in I. macrourus. The luteal cells of regressing CL on days 48, 50 and 53 of lactation were markedly reduced in size, with small irregularly shaped nuclei containing clumps of heterochromatin and indistinct nucleoli. The cells still contained numerous lipid droplets, and osmiophilic inclusions were still present in some of the mitochondria, which were reduced in number (and absent in the animal at day 50). Lancet-shaped spaces, which probably initially contained cholesterol crystals extracted by solvents during processing, were present in some of the regressing luteal cells. Organelles, including SER and GER, were either sparse or unrecognizable in luteal cells at advanced stages of regression. In general, the ultrastructural features of the luteal cells in fully formed and regressing CL of bandicoots were similar to those described in active and regressing CL of eutherian mammals.

scholarly journals Microperoxisomes in the late pregnancy corpus luteum of rhesus monkeys (Macaca mulatta).

1975 ◽  
Vol 23 (5) ◽  
pp. 359-368 ◽  
Author(s):  
B J Gulys ◽  
L C Yuan
Keyword(s):  
Endoplasmic Reticulum ◽  
Lipid Droplet ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Lipid Droplets ◽  
Late Pregnancy ◽  
Corpora Lutea ◽  
Adjacent Area ◽  
Electron Lucent ◽  
Specific Inhibitors

Microperoxisomes were identified in the franulosa lutein cells from the corpora lutea of rhesus monkeys (Macaca mulatta). These organelles were histochemically visualized in aldehyde-fixed tissues icubated in alkaline 3,3'-diaminobenzidine (DAB). The DAB staining of the microperoxisomes was abolished when the tissues were preincubated in specific inhibitors for catalse or when the H2O2 was omitted from the DAB medium. Microperoxisomes were differentiated from primary lysosmes by the Gomori acid phosphatase staining. Tortuous undulating agranular endoplasmic reticulum (ER) was usually closely associated with microperoxisomes. Those regions of the granular ER which were closely associated with microperoxosomes lacked ribsomes. Micropersoxisomes were often contiguous with lipid droplets, and in some instances the limiting membrane of the moroperosisomes appeared discontinous at the point of contiguity, and the DAB staining substance diffused onto the surface of the lipid droplet. In these instances, the adjacent area of the lipid droplet showed electron-lucent staining.

THE ULTRASTRUCTURE OF THE HUMAN GRANULOSAL LUTEIN CELL OF THE FIRST TRIMESTER OF GESTATION

1968 ◽  
Vol 58 (3) ◽  
pp. 481-496 ◽  
Author(s):  
Poul Hjortkjær Pedersen ◽  
Jørgen Falck Larsen
Keyword(s):  
Endoplasmic Reticulum ◽  
Smooth Endoplasmic Reticulum ◽  
First Trimester ◽  
Corpora Lutea ◽  
Steroid Synthesis ◽  
Intracellular Location ◽  
Human Pregnancy ◽  
Subendothelial Space ◽  
Lutein Cell ◽  
Early Human

ABSTRACT The ultrastructure of granulosal lutein cells of 13 corpora lutea in early human pregnancy was studied. The predominant cytoplasmic element was the smooth endoplasmic reticulum. No convincing signs of degeneration of the lutein cells could be demonstrated within the first 14 weeks of pregnancy, as the mitochondria as well as the rough and smooth endoplasmic reticulum were well preserved. However, lysosomes may be slightly more numerous in older specimens and the subendothelial space increases with the age of gestation. A particular type of multilaminated structure one to five micron in diameter was observed, particularly in the earliest specimens. The possible intracellular location of steroid synthesis is discussed.

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 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.

scholarly journals Litter size components traits in two Algerian rabbit lines

2021 ◽  
Vol 29 (1) ◽  
pp. 51
Author(s):  
Rafik Belabbas ◽  
Maria de la Luz García ◽  
Hacina AinBaziz ◽  
Ali Berbar ◽  
Maria José Argente
Keyword(s):  
Body Weight ◽  
Litter Size ◽  
Principal Components ◽  
Local Population ◽  
The Body ◽  
Ovulation Rate ◽  
Phenotypic Correlation ◽  
Limiting Factor ◽  
Corpora Lutea ◽  
Synthetic Line

<p>The aim of this study was to estimate the limiting litter size components in rabbit females from a Synthetic line (n=32) and a Local population (n=34). Ovulation rate, number of implanted and live embryos were counted by laparoscopy at 12 d after mating. Prolificacy (total newborn, number born alive and mortality) and embryonic, foetal and prenatal survival at day of birth of the 3<sup>rd</sup> gestation were measured. The analysed traits were body weight of the female at mating, ovulation rate, implanted, live and resorbed embryos, embryonic, foetal and prenatal survival, as well as total newborn, number born alive and mortality at birth. Synthetic line females had a higher ovulation rate compared to the Local population (11.03±0.23 vs. 8.41±0.23 corpora lutea; <em>P</em>&lt;0.0001). Synthetic line displayed a higher number of implanted embryos (10.00±0.25 vs. 7.85±0.25 embryos; <em>P</em>&lt;0.0001). No difference was found between groups for number of resorbed embryos. Similar embryonic, foetal and prenatal survival rates were reported between the Synthetic line and the Local population. Additionally, total newborn was higher in the Synthetic line than in the Local population (+1.46 kits; <em>P</em>&lt;0.05). A principal components analysis was performed. The first four principal components (PC) explained more than 90% of the total variation in both lines. Total newborn, number born alive and live embryos were the main variables defining the 1<sup>st</sup> PC. Resorbed embryos and foetal survival were located in the 2<sup>nd</sup> PC. Ovulation rate and embryonic survival were the predominant variables defining the 3<sup>rd</sup> PC. The body weight of females was located in the 4<sup>th</sup> PC. The phenotypic correlation between total newborn and its components were high and positive in both lines, except for ovulation rate and total newborn, where it was moderate in Synthetic line. In conclusion, the females from Synthetic line have a higher total newborn than those from Local population, as a consequence of a higher number of released oocytes and embryos that successfully reach implantation. However, a higher uterine crowding in Synthetic line seems to limit survival of foetuses that reach term of gestation, while ovulation rate is the principal limiting factor of total newborn in Local population.</p>

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

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