scholarly journals ISOLATION OF THE PLASMA MEMBRANE OF THE LUMINAL SURFACE OF RAT BLADDER EPITHELIUM, AND THE OCCURRENCE OF A HEXAGONAL LATTICE OF SUBUNITS BOTH IN NEGATIVELY STAINED WHOLE MOUNTS AND IN SECTIONED MEMBRANES

1970 ◽  
Vol 45 (3) ◽  
pp. 542-553 ◽  
Author(s):  
R. M. Hicks ◽  
B. Ketterer
Keyword(s):  
Plasma Membrane ◽  
Membrane Structure ◽  
Mercuric Acetate ◽  
Hexagonal Lattice ◽  
Negative Contrast ◽  
Luminal Surface ◽  
Hexagonal Array ◽  
Bladder Epithelium ◽  
Luminal Membrane ◽  
Whole Mounts

A method of isolating the thick luminal membrane from homogenates of bladder epithelium is described, which entails pretreatment of the epithelium with fluorescein mercuric acetate and centrifugation of the homogenate on sucrose density gradients. A hexagonal array of hexamers is illustrated by negative contrast staining in whole mounts of the isolated thick membrane. Subunits are also shown in tangential sections of this thick membrane, in fixed, embedded bladder epithelium. The significance of the subunits is discussed in the context of membrane structure and permeability.

Regular structures in membranes: the lumenal plasma membrane of the cow urinary bladder

1976 ◽  
Vol 22 (2) ◽  
pp. 355-370 ◽  
Author(s):  
S. Knutton ◽  
J.D. Robertson
Keyword(s):  
Plasma Membrane ◽  
Urinary Bladder ◽  
Cytoplasmic Membrane ◽  
Membrane Surface ◽  
Hexagonal Lattice ◽  
Freeze Fracture ◽  
Hexagonal Structure ◽  
Unit Cell ◽  
Hexagonal Array ◽  
Thin Sections

The ultrastructure of the lumenal plasma membrane of the cow urianry bladder has been studied in thin sections of glutaraldehyde- and glutaraldehyde-H2O2-fixed specimens, by negative staining and freeze fracture. A regular hexagonal array of particles confined to polygonal plaques 0-1-0-4-mum in diameter and separated by 0-02-mum interplaque areas is revealed by all 3 techniques. Cross-sections through particulate areas fixed with glutarayldehyde-H2O2 display a tetralaminar structure consisting of the usual approximately 8-nm-thick trilamellar unit membrane structure, on the external dense leaflet of which is located an additional approximately 4-nm-thick stratum which is occasionally resolved into a row of regulrly spaced approximately 4-nm-diameter particles. Non-particulate areas feature only the approximately 8-nm-thick trilamellar structure. Tangential sections reveal an hexagonal array of particles with a unit cell of approximately 16 nm. Four membrane faces can be revealed by freeze fracture and etching of membranes of the cow urinary bladder; 2 complementary split inner membrane faces (A and B) revealed by the cleaving process and the lumenal and cytoplasmic membrane surfaces exposed by etching. Face B, which belongs to the external membrane leaflet and faces the cytoplasm, displays plaques of particles arranged in a hexagonal lattice with a unit cell of approximately 16 nm. Face A, which belongs to the cytoplasmic membrane leaflet and faces the lumen, displays a complementary array of hexagonally packed pits. The hexagonally arranged particles also protrude into the lumenal membrane surface where they can occasionally be resolved into 6 approximately 5-nm-diameter subunits; the cytoplasmic surface appears smooth. Six approximately 5-nm-diameter subunits are also revealed in negatively stained preparations. The data are consistent with a model for the membrane in which the particles forming the hexagonal structure protrude above the lumenal membrane surface and also bridge most of the thickness of the membrane.

Cell surface changes during aging of human bladder epithelium examined by lectin probes and SEM

1990 ◽  
Vol 48 (3) ◽  
pp. 966-967
Author(s):  
J. Jacob ◽  
M.F.M. Ismail
Keyword(s):  
The Elderly ◽  
Ultrastructural Changes ◽  
Pokeweed Mitogen ◽  
Asymmetric Structure ◽  
Luminal Surface ◽  
Bladder Epithelium ◽  
Aldehyde Groups ◽  
Cell Surface Changes ◽  
Phosphate Buffered Saline ◽  
Surface Changes

Ultrastructural changes have been shown to occur in the urinary bladder epithelium (urothelium) during the life span of humans. With increasing age, the luminal surface becomes more flexible and develops simple microvilli-like processes. Furthermore, the specialised asymmetric structure of the luminal plasma membrane is relatively more prominent in the young than in the elderly. The nature of the changes at the luminal surface is now explored by lectin-mediated adsorption visualised by scanning electron microscopy (SEM).Samples of young adult (21-31 y old) and elderly (58-82 y old) urothelia were fixed in buffered 2% glutaraldehyde for 10 m and washed with phosphate buffered saline (PBS) containing Ca++ and Mg++ at room temperature. They were incubated overnight at 4°C in 0.1 M ammonium chloride in PBS to block any remaining aldehyde groups. The samples were then allowed to stand in PBS at 37°C for 2 h before incubation at 37°C for 30 m with lectins. The lectins used were concanavalin A (Con A), wheat germ agglutinin (WGA), phytohaemagglutinin (PHA) and pokeweed mitogen (PWM) at a concentration of 500 mg/ml in PBS at pH 7.A.

A modified liquid-mosaic model of plasma membrane structure

1998 ◽  
Vol 30 (4-5) ◽  
pp. 328-329 ◽  
Author(s):  
V. K. Rybal'chenko
Keyword(s):  
Plasma Membrane ◽  
Membrane Structure ◽  
Mosaic Model

Interpretation of yeast plasma membrane structure

Micron (1969) ◽  
1980 ◽  
Vol 11 (3-4) ◽  
pp. 359-364 ◽  
Author(s):  
S. Bullivant
Keyword(s):  
Plasma Membrane ◽  
Membrane Structure ◽  
Yeast Plasma Membrane

Duchenne dystrophy: alteration in muscle plasma membrane structure

Science ◽  
1977 ◽  
Vol 196 (4293) ◽  
pp. 1005-1007 ◽  
Author(s):  
D. Schotland ◽  
E Bonilla ◽  
M Van Meter
Keyword(s):  
Plasma Membrane ◽  
Membrane Structure ◽  
Duchenne Dystrophy ◽  
Muscle Plasma Membrane

An unusual cell surface modification: a double plasma membrane

1979 ◽  
Vol 39 (1) ◽  
pp. 355-372
Author(s):  
N.J. Lane ◽  
J.B. Harrison
Keyword(s):  
Plasma Membrane ◽  
Membrane Structure ◽  
Cell Layer ◽  
Peritrophic Membrane ◽  
Thin Sections ◽  
Double Membrane ◽  
Freeze Fracturing ◽  
Blood Sucking ◽  
Great Pressure ◽  
Insertion Sites

The occurrence of an unusual double plasma membrane structure is reported; it has been studied in conventional thin sections, after lanthanum-impregnation and with freeze-fracturing. This modification of the plasmalemma is found where the luminal cell membrane (I membrane) of gut microvilli in the haematophagous insect, Rhodnius prolixus, is surrounded by a second, outer membrane (O membrane), the 2 separated from one another by a highly regular I-O space of about 10 nm. Lanthanum impregnation reveals the presence of columns inclined at an angle, within this I-O space; as in the continuous junctions which link the lateral borders of these cells, these columns may maintain the very precise I-O distance. From the outer microvillar membranes radiate short spoke-like fibrils or sheets which encounter another more extensive system of myelin-like sheets. Freeze-fracturing reveals that the spoke-like sheets and the other ones which lie like a tube, around and parallel to the microvilli, contain linear ridges composed of particles, lying at random within layers of the myelin-like material which also extends into the lumen of the gut. The microvillar membanes, both O and I, fracture into faces containing rows of either PF particles or EF pits arranged as spiral ridges or grooves around the sides and across the tip of each microbillus. These could be the insertion sites of one or both of the I-O columns and spoke-like sheets while the sheets could represent a variant of peritrophic membrane. The double membrane may be a cellular device to increase the strength of the microvillar layer in these blood-sucking animals, since the cell layer must withstand great pressure owing to a sudden massive extension of the gut during a blood meal.

Synaptic Plasma Membrane Structure and Polarity of Long-Sleep and Short-Sleep Mice

1994 ◽  
Vol 309 (2) ◽  
pp. 369-376 ◽  
Author(s):  
F. Schroeder ◽  
S.M. Colles ◽  
G.P. Kreishman ◽  
C.E. Heyliger ◽  
W.G. Wood
Keyword(s):  
Plasma Membrane ◽  
Membrane Structure ◽  
Synaptic Plasma Membrane ◽  
Short Sleep ◽  
Long Sleep

scholarly journals Paracrystalline arrays of membrane-to-membrane cross bridges associated with the inner surface of plasma membrane

1978 ◽  
Vol 77 (2) ◽  
pp. 323-328 ◽  
Author(s):  
WW Franke ◽  
C Grund ◽  
E Schmid ◽  
E Mandelkow
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Cultured Cells ◽  
Membrane Surface ◽  
Hexagonal Lattice ◽  
Interparticle Distance ◽  
Macromolecular Complexes ◽  
Inner Surface ◽  
Cross Bridges ◽  
Plasma Membrane Surface

In cultured cells of the rat kangaroo PtK2 line, veils of the cell surface were observed which consisted of only plasma membrane and paracrystalline arrays of membrane-associated particles sandwiched in between. These membrane-to-membrane cross-bridging 9-to 11-nm wide particles were somewhat coumellar-shaped and were arranged on a hexagonal lattice with an interparticle distance of 16nm. At higher magnification, they revealed an unstained core, thus suggesting a ringlike substructure. Similar arrays of paracrystal-containing veils, which were rather variable in size and frequency, were also observed in other cultured cells. It is hypothesized that these paracrystals represent protein macromolecular complexes associated with the inner plasma membrane surface which crystallize when plasma membranes come into close intracellular contact and other components of the subsurface network are removed.

scholarly journals Changes in plasma membrane structure and electromotile properties in prestin deficient outer hair cells

Cytoskeleton ◽  
2009 ◽  
pp. n/a-n/a ◽  
Author(s):  
David Z.Z. He ◽  
Shuping Jia ◽  
Takashi Sato ◽  
Jian Zuo ◽  
Leonardo R. Andrade ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Hair Cells ◽  
Membrane Structure ◽  
Outer Hair Cells
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