Cholesterol distribution in cells of the stria vascularis of the mammalian cochlea and some effects of ototoxic diuretics

1985 ◽  
Vol 79 (1) ◽  
pp. 181-197
Author(s):  
A. Forge
Keyword(s):  
Cell Membranes ◽  
Plasma Membranes ◽  
Early Stage ◽  
Stria Vascularis ◽  
Freeze Fracture ◽  
Ultrastructural Level ◽  
Body Region ◽  
Intermediate Cell ◽  
Marginal Cells ◽  
In Cells

The distribution of cholesterol in cells of the stria vascularis of guinea pigs and gerbils has been investigated at the ultrastructural level by incubation of tissue in filipin, followed by freeze-fracture. Verification of results has been sought by using tomatin. It is shown that in the cell body region of the marginal cells, the apical and lateral membranes reacted intensely with both agents, but the membranes of the basal processes of the marginal cells did not respond significantly to either filipin or tomatin. On basal cell membranes, filipin-cholesterol complexes were present at a high density, even within the strands of the tight-junctional network of these cells and occasionally within the gap-junctional areas also. Complexes were present on intermediate cell membranes at a lower density than on other plasma membranes that showed a positive response. Tissue from animals that had received an ototoxic diuretic, either ethacrynic acid or furosemide, was characterized by the appearance of membrane regions with closely clustered filipin complexes, suggesting some change in cell membrane structure. At an early stage following diuretic administration, such clusters were particularly noticeable on the membranes of intermediate cells. As intercellular spaces enlarged in response to the effects of diuretics, vesicles released into the extracellular spaces appeared to be cholesterol-enriched. The results are discussed in relation to known features of the structure and function of cells in the normal stria vascularis and of the changes that follow from acute diuretic ototoxicity.

scholarly journals Quantitative immunocytochemical localization of Na+,K+-ATPase alpha-subunit in the lateral wall of rat cochlear duct.

1989 ◽  
Vol 37 (3) ◽  
pp. 353-363 ◽  
Author(s):  
T Iwano ◽  
A Yamamoto ◽  
K Omori ◽  
M Akayama ◽  
T Kumazawa ◽  
...  
Keyword(s):  
Plasma Membranes ◽  
Rat Kidney ◽  
Stria Vascularis ◽  
Basolateral Membrane ◽  
Lateral Wall ◽  
Alpha Subunit ◽  
Membrane Domain ◽  
Cochlear Duct ◽  
Gold Particles ◽  
Marginal Cells

Ultrastructural localization of the alpha-subunit of Na+,K+-ATPase on the lateral wall of rat cochlear duct was investigated quantitatively by the protein A-gold method, using affinity-purified antibody against the alpha-subunit of rat kidney Na+,K+-ATPase. In the stria vascularis, gold particles were sparse over the endolymphatic luminal surface of the marginal cells but were numerous over the basolateral membrane. The labeling density of the basolateral membrane was almost equal to that of the same domain of the distal tubule cells of kidney. The intermediate cells were studded with a large number of gold particles on the plasma membrane domain facing the basolateral domain of the marginal cells. On the luminal surfaces of the other epithelial cells, including those of Reissner's membrane, no significant amount of gold particles was found. Many gold particles were localized on all the plasma membranes of the spiral prominence stromal cells and on the intracellular membrane domain of the external sulcus cells.

scholarly journals Cerium-based cytochemical method for detection of ouabain-sensitive, potassium-dependent p-nitrophenylphosphatase activity at physiological pH.

1987 ◽  
Vol 35 (5) ◽  
pp. 601-611 ◽  
Author(s):  
T Kobayashi ◽  
T Okada ◽  
H Seguchi
Keyword(s):  
Plasma Membranes ◽  
Stria Vascularis ◽  
Enzymatic Reaction ◽  
Salt Gland ◽  
Enzyme Concentration ◽  
Secretory Cells ◽  
Cerium Chloride ◽  
Reaction Products ◽  
Cytochemical Method ◽  
Marginal Cells

We have developed a new cytochemical method for detecting the ouabain-sensitive, potassium-dependent p-nitrophenylphosphatase (K-NPPase) activity of the sodium-potassium-activated adenosine triphosphatase (Na-K ATPase) complex. The incubation medium contains p-nitrophenylphosphate (p-NPP) as substrate, cerium chloride as capture agent, Tricine buffer, MgCl2, and KCl. Tricine buffer protected against the medium turbidity caused by non-enzymatic reaction at pH 7.5. Biochemically, the accumulation of p-nitrophenol and phosphate in the reaction precipitate was proportionally related to the enzyme concentration. Ultracytochemically, the reaction products of the K-NPPase activity were localized as fine and uniform electron-dense deposits in the cytoplasmic side of specialized basolateral plasma membranes of cells of kidney distal convoluted tubules, secretory cells of salt gland, and marginal cells of stria vascularis. This method has the advantage of being useful at physiological pH.

scholarly journals Tetrameric assembly of CHIP28 water channels in liposomes and cell membranes: a freeze-fracture study.

1993 ◽  
Vol 123 (3) ◽  
pp. 605-618 ◽  
Author(s):  
J M Verbavatz ◽  
D Brown ◽  
I Sabolić ◽  
G Valenti ◽  
D A Ausiello ◽  
...  
Keyword(s):  
Water Permeability ◽  
Cho Cells ◽  
Cell Membranes ◽  
Plasma Membranes ◽  
Single Channel ◽  
Water Channel ◽  
Freeze Fracture ◽  
Water Channels ◽  
Straight Tubules ◽  
Tetrameric Assembly

Channel forming integral protein of 28 kD (CHIP28) functions as a water channel in erythrocytes, kidney proximal tubule and thin descending limb of Henle. CHIP28 morphology was examined by freeze-fracture EM in proteoliposomes reconstituted with purified CHIP28, CHO cells stably transfected with CHIP28k cDNA, and rat kidney tubules. Liposomes reconstituted with HPLC-purified CHIP28 from human erythrocytes had a high osmotic water permeability (Pf0.04 cm/s) that was inhibited by HgCl2. Freeze-fracture replicas showed a fairly uniform set of intramembrane particles (IMPs); no IMPs were observed in liposomes without incorporated protein. By rotary shadowing, the IMPs had a diameter of 8.5 +/- 1.3 nm (mean +/- SD); many IMPs consisted of a distinct arrangement of four smaller subunits surrounding a central depression. IMPs of similar size and appearance were seen on the P-face of plasma membranes from CHIP28k-transfected (but not mock-transfected) CHO cells, rat thin descending limb (TDL) of Henle, and S3 segment of proximal straight tubules. A distinctive network of complementary IMP imprints was observed on the E-face of CHIP28-containing plasma membranes. The densities of IMPs in the size range of CHIP28 IMPs, determined by non-linear regression, were (in IMPs/microns 2): 2,494 in CHO cells, 5,785 in TDL, and 1,928 in proximal straight tubules; predicted Pf, based on the CHIP28 single channel water permeability of 3.6 x 10(-14) cm3/S (10 degrees C), was in good agreement with measured Pf of 0.027 cm/S, 0.075 cm/S, and 0.031 cm/S, respectively, in these cell types. Assuming that each CHIP28 monomer is a right cylindrical pore of length 5 nm and density 1.3 g/cm3, the monomer diameter would be 3.2 nm; a symmetrical arrangement of four cylinders would have a greatest diameter of 7.2 nm, which after correction for the thickness of platinum deposit, is similar to the measured IMP diameter of approximately 8.5 nm. These results provide a morphological signature for CHIP28 water channels and evidence for a tetrameric assembly of CHIP28 monomers in reconstituted proteoliposomes and cell membranes.

Rectal papillae in Musca domestica: the cuticle and lateral membranes

1979 ◽  
Vol 39 (1) ◽  
pp. 167-186
Author(s):  
N.E. Flower ◽  
G.D. Walker
Keyword(s):  
Cell Membranes ◽  
Plasma Membranes ◽  
Membrane Surface ◽  
Freeze Fracture ◽  
Cell Junctions ◽  
Septate Junctions ◽  
Main Site ◽  
Lanthanum Tracer ◽  
Pass Through ◽  
Permeability Studies

The role of specialized regions of insect rectal papillae in the regulation of water and ion uptake is well documented. Although the apparatus for active uptake of water or ions is located in various cell membranes, the absorbed molecules must first pass through the cuticle which lines the rectal epithelium. Most cuticle (e.g. abdominal) has been shown to be permeable only to molecules soluble in wax, and to be impermeable to water and ions. Obviously if such cuticle lined the rectum, absorption of water and ions would be severely restricted. The present freeze-fracture and lanthanum tracer study was undertaken to investigate in more detail both the morphological features of the rectal papillae cuticle which could be responsible for its anomalous permeability and the various cell membranes involved in this transport. It has been suggested from permeability studies that the anomalous permeability of rectal papillae cuticle could be due to the lack of a complete wax layer over the surface of the rectal cuticle. The present study strongly supports this suggestion. Thus, the freeze-fracture micrographs have shown that a surface layer of the cuticle reacts during fracturing like a lipid bilayer. However, in rectal papilla cuticle this surface bilayer is interrupted at each epicuticular depression by areas of different fracturing behaviour. These discontinuities in the surface bilayer probably allow the rectal contents to contact directly the true cuticular matrix. They could, therefore, explain the case with which water and ions penetrate the rectal cuticle and so gain access to the underlying epithelial cells. Although similar discontinuities are present on some of the rectal cuticle surface external to the rectal papillae, they appear to be filled in by plugs of lipid-like material. The lateral plasma membranes of the rectal papillae cells are generally considered to be the main site of active transport. The present lanthanum tracer and freeze-fracture study has shown that the lateral plasma membranes contain 3 distinct differentiations. Septate junctions are present at the apical and basal surfaces of the epithelial layer; a further membrane differentiation is found adjacent to the septate junctions; and thirdly, an array of short, variable length, non-anastomosing linear structures covers most of the lateral plasma membrane surface. These latter structures, unlike known types of cell junctions do not show equivalent arrays in apposing membranes even when the lateral plasma membranes of adjacent cells are closely apposed. The possible function of these structures is discussed.

scholarly journals Genetic analysis of membrane differentiation in Paramecium. Freeze-fracture study of the trichocyst cycle in wild-type and mutant strains.

1976 ◽  
Vol 69 (1) ◽  
pp. 126-143 ◽  
Author(s):  
J Beisson ◽  
M Lefort-Tran ◽  
M Pouphile ◽  
M Rossignol ◽  
B Satir
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Single Gene ◽  
Freeze Fracture ◽  
Gene Mutations ◽  
Permissive Temperature ◽  
Paramecium Tetraurelia ◽  
Wild Type ◽  
Circular Arrays ◽  
In Cells

Using a series of mutants of Paramecium tetraurelia, we demonstrate, for the first time, changes in the internal structure of the cell membrane, as revealed by freeze-fracture, that correspond to specific single gene mutations. On the plasma membrane of Paramecium circular arrays of particles mark the sites of attachment of the tips of the intracellular secretory organelles-trichocysts. In wild-type paramecia, where attached trichocysts can be expelled by exocytosis under various stimuli, the plasma membrane array is composed of a double outer ring of particles (300 nm in diameter) and inside the ring a central rosette (fusion rosette) of particles (76 nm in diameter). Mutant nd9, characterized by a thermosensitive ability to discharge trichocysts, shows the same organization in cells grown at the permissive temperature (18 degrees C), while in cells grown at the nonpermissive temperature (27 degrees C) the rosette is missing. In mutant tam 8, characterized by normal but unattached trichocysts, and in mutant tl, completely devoid of trichocysts, no rosette is formed and the outer rings always show a modified configuration called "parentheses", also found in wild-type and in nd9 (18 degrees C) cells. From this comparison between wild type and mutants, we conclude: (a) that the formation of parentheses is a primary differentiation of the plasma membrane, independent of the presence of trichocysts, while the secondary transformation of parentheses into circular arrays and the formation of the rosette are triggered by interaction between trichocysts and plasma membranes; and (b) that the formation of the rosette is a prerequisite for trichocyst exocytosis.

Photoreceptor disk membrane substructures by means of the complementary freeze-fracture-replica methods

1978 ◽  
Vol 36 (2) ◽  
pp. 156-157
Author(s):  
A. Tonosaki ◽  
M. Yamasaki ◽  
H. Washioka ◽  
J. Mizoguchi
Keyword(s):  
Cell Membranes ◽  
Freeze Fracture ◽  
Purple Membrane ◽  
Remarkable Case ◽  
Single Face ◽  
Disk Membrane ◽  
Associated Proteins ◽  
Photoreceptor Membranes

A vertebrate disk membrane is composed of 40 % lipids and 60 % proteins. Its fracture faces have been classed into the plasmic (PF) and exoplasmic faces (EF), complementary with each other, like those of most other types of cell membranes. The hypothesis assuming the PF particles as representing membrane-associated proteins has been challenged by serious questions if they in fact emerge from the crystalline formation or decoration effects during freezing and shadowing processes. This problem seems to be yet unanswered, despite the remarkable case of the purple membrane of Halobacterium, partly because most observations have been made on the replicas from a single face of specimen, and partly because, in the case of photoreceptor membranes, the conformation of a rhodopsin and its relatives remains yet uncertain. The former defect seems to be partially fulfilled with complementary replica methods.

Ultrastructure of melanocyte-keratinocyte interactions and pigment transfer in vitro

1978 ◽  
Vol 36 (2) ◽  
pp. 650-651
Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo
Keyword(s):  
Direct Injection ◽  
Skin Pigmentation ◽  
Freeze Fracture ◽  
Pigment Granule ◽  
Time Lapse ◽  
Ultrastructural Level ◽  
Lanthanum Tracer ◽  
A Cell

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.

scholarly journals Probing the Intracellular Bio-Nano Interface in Different Cell Lines with Gold Nanostars

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1183
Author(s):  
Cecilia Spedalieri ◽  
Gergo Péter Szekeres ◽  
Stephan Werner ◽  
Peter Guttmann ◽  
Janina Kneipp
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Early Stage ◽  
Protein Corona ◽  
Fibroblast Cell ◽  
Ultrastructural Level ◽  
Epithelial Cell Line ◽  
Animal Cells ◽  
Gold Nanostars

Gold nanostars are a versatile plasmonic nanomaterial with many applications in bioanalysis. Their interactions with animal cells of three different cell lines are studied here at the molecular and ultrastructural level at an early stage of endolysosomal processing. Using the gold nanostars themselves as substrate for surface-enhanced Raman scattering, their protein corona and the molecules in the endolysosomal environment were characterized. Localization, morphology, and size of the nanostar aggregates in the endolysosomal compartment of the cells were probed by cryo soft-X-ray nanotomography. The processing of the nanostars by macrophages of cell line J774 differed greatly from that in the fibroblast cell line 3T3 and in the epithelial cell line HCT-116, and the structure and composition of the biomolecular corona was found to resemble that of spherical gold nanoparticles in the same cells. Data obtained with gold nanostars of varied morphology indicate that the biomolecular interactions at the surface in vivo are influenced by the spike length, with increased interaction with hydrophobic groups of proteins and lipids for longer spike lengths, and independent of the cell line. The results will support optimized nanostar synthesis and delivery for sensing, imaging, and theranostics.

scholarly journals A DISTINCTIVE CELL CONTACT IN THE RAT ADRENAL CORTEX

1972 ◽  
Vol 53 (1) ◽  
pp. 148-163 ◽  
Author(s):  
Daniel S. Friend ◽  
Norton B. Gilula
Keyword(s):  
Cell Membrane ◽  
Adrenal Cortex ◽  
Cell Membranes ◽  
Freeze Fracture ◽  
Typical Feature ◽  
Cell Contact ◽  
Cortical Cells ◽  
Cell Dispersion ◽  
Extensive Cell ◽  
Distinctive Cell

Extensive cell contacts which resemble septate junctions occur between cells in the three major zones of the rat adrenal cortex. Characteristically, they extend between small intercellular canaliculi and the periendothelial space, frequently interrupted by gap junctions and rarely by desmosomes. Zonulae occludentes have not been identified in the adrenal cortex. Along this distinctive cell contact, the cell membranes of apposing cells are separated by 210–300 a bisected by irregularly spaced 100–150-A extracellular particles which are often circular in profile. In lanthanum preparations, these particles appear to form a continuous chain throughout the intercellular space and are visualized as an alveolate structure in sections parallel to the plane of the cell membrane. The cell membrane in the area of septate-like contact does not differ from nonjunctional areas of the cell membrane in freeze-fracture replicas. The cell contact retains its integrity after cell dispersion and after the separation of cell membranes from disrupted cells. The intercellular particles also persist after brief extraction in lipid solvents. Besides adherence, possible functions of this adrenal contact include maintenance of the width of the extracellular space, the provision of channels between intercellular canaliculi and the bloodstream, and utilization as cation depots. Similar structures are also present between adrenal cortical cells of several other species and between interstitial cells of the testis. This type of cell contact may, in fact, be a typical feature of steroid-hormone-secreting tissues in vertebrates.

Fine structure of the band 3 protein in human red cell membranes: Freeze-fracture studies

1978 ◽  
Vol 8 (3) ◽  
pp. 325-335 ◽  
Author(s):  
Ronald S. Weinstein ◽  
Jena K. Khodadad ◽  
Theodore L. Steck
Keyword(s):  
Fine Structure ◽  
Cell Membranes ◽  
Freeze Fracture ◽  
Band 3 ◽  
Red Cell ◽  
Band 3 Protein ◽  
Red Cell Membranes
Sign in / Sign up

Export Citation Format

Share Document