scholarly journals Preservation of alveolar type II pneumocyte lamellar bodies for electron microscopic studies.

1979 ◽  
Vol 27 (5) ◽  
pp. 989-996 ◽  
Author(s):  
A J Collet
Keyword(s):  
Uranyl Acetate ◽  
Alkaline Solutions ◽  
Alveolar Type ◽  
Morphological Aspect ◽  
Type Ii ◽  
Lamellar Bodies ◽  
Electron Microscopic ◽  
Type Ii Pneumocyte ◽  
Microscopic Studies ◽  
Freeze Etching

Simultaneous fixation with glutaraldehyde and osmium tetroxide, followed by an uranyl acetate (UA) treatment before dehydration and embedding (Hirsch and Fedorko 1968) ensures a very good preservation of lamellar bodies (LB's) as well as of the cellular membranes in type II pneumocyte. The uranyl acetate treatment appeared to be the most efficient step of the procedure. The morphological aspect of lamellar bodies after such a preparation was similar to that observed after freeze-etching of lipid retaining methods. Moreover, the Hirsch-Fedorko procedure is very simple and can easily be used for routine ultrastructural and radioautographic studies. On the other hand, it appeared that the uranyl acetate phospholipid "complex" is very sensitive to the pH of chemical solutions used after sectioning. The "complex" is variously dissolved by alkaline solutions, photographic developers or stains. The best preservation of ultrastructure was obtained with neutral or acidic developers and acidic stains.

scholarly journals Chromogranins or chromogranin-like proteins are present in lamellar bodies and pulmonary surfactant of rat alveolar type II cells.

1991 ◽  
Vol 39 (2) ◽  
pp. 213-220 ◽  
Author(s):  
M Kalina ◽  
L Grimelius
Keyword(s):  
Chromogranin A ◽  
Lattice Structure ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Lamellar Bodies ◽  
Electron Microscopic ◽  
Alveolar Type Ii Cells ◽  
Tissue Sections ◽  
Cell Compartments

Rat alveolar Type II cells were immunostained with antibodies directed against chromogranin A (monoclonal, LK2H10) and chromogranins A and B (polyclonal, LKZM1U). The chromogranins or chromogranin-like proteins were identified in cells in lung tissue sections and isolated Type II cells at the light and electron microscopic levels. We used post-embedding immunoelectron microscopy, with immunogold, to detect the proteins' immunoreactivity in osmicated tissues. Gold particles were distributed over the phospholipid lamellae within the lamellar bodies of alveolar Type II cells and over the lattice structure of tubular myelin. Quantitative analysis of gold labeling densities in the various cell compartments indicated that only the latter two structures were specifically labeled. Controls, which included pre-absorption of both anti-chromogranin antibodies with excess chromogranin A or with native surfactant, resulted in a greater than 60% decrease in gold labeling. A possible role of chromogranins or chromogranin-like proteins as Ca2+ binding proteins in alveolar Type II cells is discussed.

Cytoplasmic Invaginations in Trophoblasts and Epithelial Cells of Rat

1971 ◽  
Vol 29 ◽  
pp. 524-525
Author(s):  
Iracema M. Baccarini
Keyword(s):  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Nuclear Inclusions ◽  
Mucous Cells ◽  
Electron Microscopic ◽  
Cervical Epithelium ◽  
Intact Membrane ◽  
Microscopic Studies ◽  
Abnormal Cells ◽  
Nuclear Features

Some morphological nuclear features (invaginations) in normal and abnormal cells have been described in several electron microscopic studies. They have been referred to by others as blebs, loops, pockets, sheets, bodies, nuclear inclusions and cytoplasmic invaginations. Identical appearing structures were found in cells of the uterine cervical epithelium, in trophoblasts of blastocysts and in trophoblasts of rat placenta.Methods. Uterine cervix (normal rats), rat placenta (9-10 days gestation) and blastocyst were placed in 3% glutarahdehyde for 3 hours. The tissue was washed in phosphate buffer for 24 hours, postfixed in 1%. buffered osmium tetroxide for 1-2 hours and embedded in epon araldite. Sections were double stained with uranyl acetate and lead citrate and viewed in E. M. Siemens 200.Observations. Nuclear invaginations were found in basal, parabasal and mucous cells of the cervix epithelium, in trophoblasts of blastocyst and in trophoblasts of placenta. An oval, round or elongated invagination contained heterogenously cytoplasm surrounded by a double intact membrane; usually several invaginations were found in the same nucleus.

Giant Lamellar Bodies in Alveolar Type II Cells of Rats Exposed to a Low Concentration of Ozone

Respiration ◽  
1984 ◽  
Vol 46 (3) ◽  
pp. 303-309 ◽  
Author(s):  
Sanae Shimura ◽  
Shinsaku Maeda ◽  
Tamotsu Takismima
Keyword(s):  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Lamellar Bodies ◽  
Alveolar Type Ii Cells ◽  
Low Concentration

Pulmonary surfactant protein A-mediated uptake of phosphatidylcholine by alveolar type II cells

1993 ◽  
Vol 265 (2) ◽  
pp. L193-L199 ◽  
Author(s):  
A. Tsuzuki ◽  
Y. Kuroki ◽  
T. Akino
Keyword(s):  
Pulmonary Surfactant ◽  
Protein A ◽  
Lamellar Body ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Lamellar Bodies ◽  
Pulmonary Surfactant Protein

Pulmonary surfactant protein A (SP-A)-mediated uptake of phosphatidylcholine (PC) by alveolar type II cells was investigated. SP-A enhanced the uptake of liposomes containing dipalmitoylphosphatidylcholine (DPPC), 1-palmitoyl-2-linoleoyl phosphatidylcholine (PLPC), or 1,2-dihexadecyl-sn-glycero-3-phosphocholine (DPPC-ether), a diether analogue of DPPC, but about twice as much DPPC was taken up by type II cells as PLPC or DPPC-ether. When subcellular distribution was analyzed, 51.3 +/- 2.9% (mean +/- SD, n = 3) of cell-associated radiolabeled DPPC was recovered in the lamellar body-rich fraction in the presence of SP-A, whereas only 19.3 +/- 1.9% (mean +/- SD, n = 3) was found to this fraction in the absence of SP-A. When type II cells were incubated either with DPPC at 0 degree C or with DPPC-ether at 37 degrees C, or no cells were included, low proportions of the cell-associated lipids were present in the fractions corresponding to lamellar bodies even in the presence of SP-A. Anti-SP-A antibody significantly reduced the radioactivity incorporated into the lamellar body fraction. Phosphatidylcholine that had been incorporated into lamellar bodies remained largely intact when SP-A was present. Subcellular fractionations of type II cells with radiolabeled SP-A and DPPC revealed that the sedimentation characteristics of cell-associated SP-A are different from those of DPPC, although a small broad peak of radiolabeled SP-A was found in the lamellar body fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Alveolar type II cell growth on a pulmonary endothelial extracellular matrix

1996 ◽  
Vol 270 (6) ◽  
pp. L1017-L1022 ◽  
Author(s):  
I. Y. Adamson ◽  
L. Young
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Cell Growth ◽  
Alveolar Type ◽  
Thymidine Uptake ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Lamellar Bodies ◽  
Type Ii Cell

Most of the alveolar epithelium overlies a fused basement membrane produced by epithelial and endothelial cells. To determine how this type of matrix influences type II cell growth and function, we studied the effects of culturing isolated rat alveolar type II cells on an extracellular matrix (ECM) freshly produced by pulmonary vascular endothelial cells grown 5 days in culture. Type II cells from the same rats were cultured on plastic or Matrigel for comparison. A large increase in mitotic activity was seen in type II cells grown on the endothelial ECM at 2 days only; thereafter cells spread rapidly to confluence and lost their lamellar bodies. Cells grown on Matrigel remained cuboidal with lamellar bodies but grew more slowly, as judged by [3H]thymidine uptake and cell numbers. Incorporation of labeled choline into disaturated phosphatidylcholine (DSPC) was used as a marker of surfactant synthesis. After the rapid, brief burst of proliferation, type II cells on endothelial ECM showed a sudden decline in DSPC-DNA by day 4 compared with cells grown on matrigel. Binding of the lectin Bauhinia purpurea (BPA) indicated that after a phase of division, cells on endothelial ECM developed as type I epithelium by 4 days of culture, when > 70% of cells stained positively for BPA binding, whereas few cuboidal cells on Matrigel were stained. The results indicate that type II cells respond briefly to growth factors in pulmonary endothelial ECM; then this type of matrix promotes cell spreading with loss of type II function as cells subsequently resemble type I epithelium.

An En Bloc Staining Protocol Improves The Preservation of Lamellar Bodies in Alveolar Type II Epithelial Cells for Transgenic Mice Expressing Modified Pulmonary Surfactant Protein B

1998 ◽  
Vol 4 (S2) ◽  
pp. 852-853
Author(s):  
C.-L. Na ◽  
D. C. Beck ◽  
J. S. Breslin ◽  
S. E. Wert ◽  
T. E. Weaver
Keyword(s):  
Pulmonary Surfactant ◽  
Surfactant Protein ◽  
Alveolar Type ◽  
Type Ii ◽  
Lamellar Bodies ◽  
En Bloc ◽  
Surfactant Protein B ◽  
Staining Protocol ◽  
Pulmonary Surfactant Protein B ◽  
Pulmonary Surfactant Protein

The extraction of lipids and phospholipids during dehydration and plastic embedding steps results in poor preservation of the phospholipid rich lamellar bodies (LB) in alveolar type II epithelial cells. To achieve better retention of phospholipids, we combined inflation fixation and an en bloc staining protocol using 4% aqueous uranyl acetate (UA), thereby improving the preservation of the LBs for both the wild type and transgenic mice expressing modified pulmonary surfactant protein B (SP-B; Akinbi et al., 1997).Lungs of 6-8 week-old mice were inflation fixed (Bunkingham and Weyder, 1981) with ice cold 2% paraformaldehye and 2% glutaraldehyde in 0.1 M sodium cacodylate buffer (SCB), pH 7.3, postfixed in fresh fixative at 4 °C overnight, incubated with 1% osmium tetroxide in 0.1 M SCB at room temperature for 2 hours, and stained en bloc with 4% aqueous UA overnight.

Properties of Mouse Leukemia Viruses X V . Electron Microscopic Studies on the Organization of Friend Leukemia Virus and Other Mammalian C-Type Viruses

1978 ◽  
Vol 33 (1-2) ◽  
pp. 124-138 ◽  
Author(s):  
Hermann Frank ◽  
Heinz Schwarz ◽  
Thomas Graf ◽  
Werner Schäfer
Keyword(s):  
Leukemia Virus ◽  
Microscopic Analysis ◽  
Uranyl Acetate ◽  
Viral Envelope ◽  
Preparation Technique ◽  
Electron Microscopic ◽  
Friend Leukemia ◽  
Microscopic Studies ◽  
Detergent Treatment ◽  
Leukemia Viruses

Abstract Further investigations on the structure of Friend murine leukemia virus (FLV) revealed that the transition from the “immature” (now termed “native”) to the structurally less organized “mature” (now termed “collapsed”) form occurs mainly as a result of the preparation for the electron microscope. A short pretreatment of virus with the detergent NP40 prior to negative staining with uranyl acetate is able to preserve the “native” structure of a high percentage of virus particles from standard preparations. Treatment with conventional fixatives was found to be in ­ effective.Using this preparation technique, a more detailed electron microscopic analysis of the viral internal organization became possible. A thin layer designated “inner coat” was newly detected in close apposition to the viral membrane between the viral envelope and core. Removal of the unit membrane by more intensive detergent treatment suggests the existence of material extending be­ tween the viral surface knobs and the viral interior. The icosahedral core shell has an opening at one side and this opening matches with the hole in the apparently beehive-like arranged ribo-nucleoprotein (RNP) strand which represents the innermost structure.A comparative study of a series of representative mammalian C-type viruses with the same technique indicated a close similarity to Friend virus in fine structure, although differences in stability were observed.Based on these and earlier findings a model of the structure of mammalian C-type viruses is presented.

Secretory granule calcium loss after isolation of rat alveolar type II cells

1991 ◽  
Vol 260 (2) ◽  
pp. L129-L135 ◽  
Author(s):  
R. G. Eckenhoff ◽  
S. R. Rannels ◽  
A. B. Fisher
Keyword(s):  
Primary Culture ◽  
Sulfur Content ◽  
Lamellar Body ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Lamellar Bodies ◽  
Isolated Cells ◽  
Alveolar Type Ii Cells ◽  
Type Ii Cell

Morphological change and lamellar body loss suggests that alveolar type II cells rapidly de- or redifferentiate after several days of primary culture. To determine whether type II cells or lamellar body compositional changes precede these obvious morphological changes, we examined the in situ elemental composition of lamellar bodies and type II cells from intact lung and at different times after isolation using electron probe microanalysis (EPMA). Isolated cells were prepared by standard methods and plated on either tissue culture plastic or kept in suspension with stirrer flasks. Cell pellets obtained at 0, 3, 24, and 48 h after isolation were rapidly frozen, and thin freeze-dried cryosections were prepared and examined cold in a transmission electron microscope equipped for EPMA. Eight to ten type II cells from each of three to four different preparations for each time period were analyzed. A rapid, progressive, and sustained fall in lamellar body calcium and sulfur content occurred by 48 h of primary culture, suggesting rapid alteration in calcium and protein metabolism by type II cells and/or lamellar bodies after isolation. Also, marked changes in type II cell cytoplasmic Na and K occurred in freshly isolated cells, with incomplete normalization by 48 h. Culture on laminin-enriched Matrigel for 1 wk increased both lamellar body calcium or sulfur content, but 100 nM dexamethasone had no effect. Lamellar body calcium accumulation appears to be a very sensitive index of differentiated type II cell function.

Binding and uptake of surfactant protein D by freshly isolated rat alveolar type II cells

2000 ◽  
Vol 278 (4) ◽  
pp. L830-L839 ◽  
Author(s):  
Joel F. Herbein ◽  
Jordan Savov ◽  
Jo Rae Wright
Keyword(s):  
Surfactant Protein ◽  
Surfactant Protein D ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Dependent Manner ◽  
Type Ii ◽  
Lipid Uptake ◽  
Lamellar Bodies ◽  
Alveolar Type Ii Cells ◽  
Type Ii Cell

Alveolar type II cells secrete, internalize, and recycle pulmonary surfactant, a lipid and protein complex that increases alveolar compliance and participates in pulmonary host defense. Surfactant protein (SP) D, a collagenous C-type lectin, has recently been described as a modulator of surfactant homeostasis. Mice lacking SP-D accumulate surfactant in their alveoli and type II cell lamellar bodies, organelles adapted for recycling and secretion of surfactant. The goal of current study was to characterize the interaction of SP-D with rat type II cells. Type II cells bound SP-D in a concentration-, time-, temperature-, and calcium-dependent manner. However, SP-D binding did not alter type II cell surfactant lipid uptake. Type II cells internalized SP-D into lamellar bodies and degraded a fraction of the SP-D pool. Our results also indicated that SP-D binding sites on type II cells may differ from those on alveolar macrophages. We conclude that, in vitro, type II cells bind and recycle SP-D to lamellar bodies, but SP-D may not directly modulate surfactant uptake by type II cells.

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