Hierarchy of interactions dictating the thermodynamics of real cell membranes: Following the insulin secretory granules paradigm up to fifteen-components vesicles

2020 ◽  
Vol 186 ◽  
pp. 110715
Author(s):  
Francesca Saitta ◽  
Marco Signorelli ◽  
Dimitrios Fessas
Keyword(s):  
Cell Membranes ◽  
Secretory Granules ◽  
Real Cell

QUALITATIVE AND SEMIQUANTITATIVE CALCIUM CYTOCHEMISTRY IN B CELLS OF MICE TREATED WITH CYPROHEPTADINE AND MANNOHEPTULOSE

1978 ◽  
Vol 87 (4) ◽  
pp. 786-798 ◽  
Author(s):  
Günter Klöppel ◽  
Gerhard Bommer ◽  
Elke Ruttmann ◽  
Hans-Jörg Schäfer
Keyword(s):  
B Cells ◽  
B Cell ◽  
Insulin Release ◽  
Cell Membranes ◽  
Secretory Granules ◽  
Calcium Content ◽  
Calcium Handling ◽  
Cytoplasmic Matrix ◽  
Plasma Insulin Levels ◽  
Calcium Deposits

ABSTRACT The effect of cyproheptadine (CPH) and D-mannoheptulose (MH) on the function and the histo- (GBHA-method) and ultracytochemical (pyroantimonate method) calcium handling by pancreatic B cell were studied in mice. Intraperitoneal injection of CPH (45 mg/kg) or MH (1500 mg/kg) produced a hyperglycaemic syndrome, which was accompanied by decreased plasma insulin levels. CPH and MH also abolished glucose-induced insulin release. CPH led to a decrease of about 30 to 40 % in the histochemical calcium content of islets as revealed by semi-quantitative micro-densitometry, while MH did not change the calcium content of the islets. The ultracytochemical distribution pattern of calcium-rich precipitates were identical in CPH and MH treated B cells. The subcellular calcium deposits were predominantly located in the cytoplasmic matrix, but were rarely seen in granule halos and along the cell membranes. In contrast, glucose stimulation of the B cells resulted in an accumulation of the precipitates along the cell membranes and in the secretory granules. The results suggest that CPH and MH inhibit insulin release by either directly or indirectly interfering with the normal calcium handling by the B cell.

Making Lipid Membranes Rough, Tough, and Ready to Hit the Road

MRS Bulletin ◽  
2006 ◽  
Vol 31 (7) ◽  
pp. 536-540 ◽  
Author(s):  
Susan Daniel ◽  
Fernando Albertorio ◽  
Paul S. Cremer
Keyword(s):  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Cell Membranes ◽  
Supported Membranes ◽  
Air Exposure ◽  
Actual Structure ◽  
The Road ◽  
Sensor Platforms ◽  
Real Cell ◽  
Continuous Use

Solid-supported lipid bilayers hold strong promise as bioanalytical sensor platforms because they readily mimic the same multivalent ligand-receptor interactions that occur in real cells. Such devices might be used to monitor air and water quality under real-world conditions. At present, however, supported membranes are considered too fragile to survive the harsh environments typically required for non-laboratory use. Specifically, they lack the resiliency to withstand air exposure and the thermal and mechanical stresses associated with device transport, storage, and continuous use over long periods of time. Several successful strategies are now emerging to make supported membranes tougher. These strategies incorporate mimics of the cytoskeleton and glycocalyx of real cell membranes. The promise of these more robust lipid bilayer architectures indicates that future materials should be designed to more fully resemble the actual structure of cell membranes.

Role of freeze-fracture technique in tumour pathology

1992 ◽  
Vol 50 (1) ◽  
pp. 616-617
Author(s):  
T. M. Mukherjee ◽  
J. G. Swift
Keyword(s):  
Plasma Membrane ◽  
Cell Membranes ◽  
Secretory Granules ◽  
Freeze Fracture ◽  
Intercellular Junctions ◽  
Structural Components ◽  
Thin Sections ◽  
Human Tumours ◽  
Tumour Pathology

The freeze-fracture technique is unique in its ability to expose extensive face views of the interior of the cell membranes. This feature is particularly useful for studies of events occurring at the plasma membrane, such as exocytosis of secretory granules and of structural components within the membrane such as the intercellular junctions. We have used freeze-fracture preparations in conjunction with conventional thin sections to study the intercellular junctions in a variety of human tumours.

scholarly journals Visualization of perforin/gasdermin/complement-formed pores in real cell membranes using atomic force microscopy

2018 ◽  
Vol 16 (6) ◽  
pp. 611-620 ◽  
Author(s):  
Yuying Liu ◽  
Tianzhen Zhang ◽  
Yabo Zhou ◽  
Jiping Li ◽  
Xiaoyu Liang ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Cell Membranes ◽  
Force Microscopy ◽  
Atomic Force ◽  
Real Cell

Acid Phosphatase Activity in Mammalian Parathyroid Glands

1971 ◽  
Vol 29 ◽  
pp. 516-517
Author(s):  
W. Allen Shannon ◽  
Sanford I. Roth
Keyword(s):  
Enzymatic Activity ◽  
Cell Membranes ◽  
Secretory Granules ◽  
Basement Membranes ◽  
Parathyroid Glands ◽  
Capillary Endothelium ◽  
Golgi Membranes ◽  
Parenchymal Cells ◽  
Relationship Of ◽  
The Relationship

It has been suggested that the parathyroid secretory granules might represent lysosomes. Since lysosomes are known to contain acid phosphatases (AcPase), this enzymatic activity was investigated with a modified Gomori lead method with β-glycerophosphate as the substrate to determine the relationship of secretory granules to lysosomes in adenomatous and hyperplastic (primary chief cell type) human, and normal bovine, human, and rat parathyroid glands.Intracellular activity was demonstrated in the lipofuchsin granules and in rare, membrane-limited bodies consistent with lysosomes (Figs. 1 and 2). These lysosomal granules were often irregular in shape and 450 to 850 mμ in diameter. Lead precipitate was also observed in association with some Golgi membranes and cisternae and in a few small Golgi vesicles (Fig.3). There was strong AcPase reactivity in the lumenal cell membranes of the capillary endothelium (Fig. 4) though the cell membranes adjacent to the basement membranes and those of the parathyroid parenchymal cells were devoid of enzymatic activity. No activity was present in the numerous small secretory granules or in the granular endoplasmic reticulum (Figs. 1 and 2).

Pituitary Follicular Cells: Their Origin, Possible Function and Fate

1974 ◽  
Vol 32 ◽  
pp. 34-35
Author(s):  
E. Horvath ◽  
K. Kovacs ◽  
G. Penz ◽  
C. Ezrin
Keyword(s):  
Fine Structure ◽  
Secretory Granules ◽  
Follicular Cells ◽  
Human Pituitary ◽  
Rat Pituitary ◽  
Pituitary Glands ◽  
Junctional Complexes

Follicular structures, in the rat pituitary, composed of cells joined by junctional complexes and possessing few organelles and few, if any, secretory granules, were first described by Farquhar in 1957. Cells of the same description have since been observed in several species including man. The importance of these cells, however, remains obscure. While studying human pituitary glands, we have observed wide variations in the fine structure of follicular cells which may lead to a better understanding of their morphogenesis and significance.

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.

Introduction to Cell Membranes at Molecular Resolution

1978 ◽  
Vol 36 (3) ◽  
pp. 497-502
Author(s):  
R.J. Barrnett
Keyword(s):  
Cell Membranes ◽  
International Federation ◽  
Mountain Range ◽  
Cellular Membranes ◽  
Short History ◽  
Biological Organization ◽  
Macromolecular Assemblies ◽  
The Past

This subject, is like observing the panorama of a mountain range, magnificent towering peaks, but it doesn't take much duration of observation to recognize that they are still in the process of formation. The mountains consist of approaches, materials and methods and the rocky substance of information has accumulated to such a degree that I find myself concentrating on the foothills in the foreground in order to keep up with the advance; the edifices behind form a wonderous, substantive background. It's a short history for such an accumulation and much of it has been moved by the members of the societies that make up this International Federation. My panel of speakers are here to provide what we hope is an interesting scientific fare, based on the fact that there is a continuum of biological organization from biochemical molecules through macromolecular assemblies and cellular membranes to the cell itself. Indeed, this fact explains the whole range of towering peaks that have emerged progressively during the past 25 years.

Ultrastructural Aspects of Golgi Complex Function in Parathyroid Cells of Winter Frogs

1973 ◽  
Vol 31 ◽  
pp. 680-681
Author(s):  
William J. Dougherty
Keyword(s):  
Golgi Complex ◽  
Secretory Granules ◽  
Complex Function ◽  
Secretory Activity ◽  
Secretory Proteins ◽  
Perivascular Spaces ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
Ca Ions ◽  
Regulation Of Secretion

The regulation of secretion in exocrine and endocrine cells has long been of interest. Electron microscopic and other studies have demonstrated that secretory proteins synthesized on ribosomes are transported by the rough ER to the Golgi complex where they are concentrated into secretory granules. During active secretion, secretory granules fuse with the cell membrane, liberating and discharging their contents into the perivascular spaces. When secretory activity is suppressed in anterior pituitary cells, undischarged secretory granules may be degraded by lysosomes. In the parathyroid gland, evidence indicates that the level of blood Ca ions regulates both the production and release of parathormone. Thus, when serum Ca is low, synthesis and release of parathormone are both stimulated; when serum Ca is elevated, these processes are inhibited.

Analysis of the Anterior Secretory Cells of Onchidohs Muricata (Nudibranchia)

1981 ◽  
Vol 39 ◽  
pp. 614-615
Author(s):  
Roy Skidmore
Keyword(s):  
Endoplasmic Reticulum ◽  
Secretory Granules ◽  
Golgi Body ◽  
The Body ◽  
Secretory Cells ◽  
Secretory Vesicles ◽  
High Magnification ◽  
Large Numbers ◽  
Membrane Bound ◽  
Sole Of The Foot

The long-necked secretory cells in Onchidoris muricata are distributed in the anterior sole of the foot. These cells are interspersed among ciliated columnar and conical cells as well as short-necked secretory gland cells. The long-necked cells contribute a significant amount of mucoid materials to the slime on which the nudibranch travels. The body of these cells is found in the subepidermal tissues. A long process extends across the basal lamina and in between cells of the epidermis to the surface of the foot. The secretory granules travel along the process and their contents are expelled by exocytosis at the foot surface.The contents of the cell body include the nucleus, some endoplasmic reticulum, and an extensive Golgi body with large numbers of secretory vesicles (Fig. 1). The secretory vesicles are membrane bound and contain a fibrillar matrix. At high magnification the similarity of the contents in the Golgi saccules and the secretory vesicles becomes apparent (Fig. 2).

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