THE ROLE OF THE CELL MEMBRANE IN MUSCULAR ACTIVITY

1956 ◽  
Vol 12 (3) ◽  
pp. 210-213 ◽  
Author(s):  
B. KATZ
Keyword(s):  
Cell Membrane ◽  
Muscular Activity

The role of (bio)surfactant sorption in promoting the bioavailability of nutrients localized at the solid-water interface

1999 ◽  
Vol 39 (7) ◽  
pp. 91-98 ◽  
Author(s):  
Ryan N. Jordan ◽  
Eric P. Nichols ◽  
Alfred B. Cunningham
Keyword(s):  
Mass Transfer ◽  
Cell Membrane ◽  
Substrate Concentration ◽  
Water Interface ◽  
Industrial Systems ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Surfactant Sorption

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.

Pancreatic beta-cell electrical activity: the role of anions and the control of pH

1983 ◽  
Vol 244 (3) ◽  
pp. C188-C197 ◽  
Author(s):  
G. T. Eddlestone ◽  
P. M. Beigelman
Keyword(s):  
Membrane Potential ◽  
Cell Membrane ◽  
Beta Cell ◽  
Pancreatic Beta Cell ◽  
Proton Exchange ◽  
Disulfonic Acid ◽  
Control Mechanisms ◽  
Exchange System ◽  
Sodium Proton Exchange

The influence of chloride on the mouse pancreatic beta-cell membrane potential and the cell membrane mechanisms controlling intracellular pH (pHi) have been investigated using glass microelectrodes to monitor the membrane potential. It has been shown that chloride is distributed passively across the beta-cell membrane such that chloride potential is equal to the membrane potential. Withdrawal of perifusate chloride or bicarbonate and the application of the drugs 4-acetamido-4'-isethiocyanostilbene-2,2'-disulfonic acid (SITS) and probenecid, both blockers of transmembrane anion movement, have been used to establish that a chloride-bicarbonate exchange system is operative in the cell membrane and that it is one of the control mechanisms of pHi. Amiloride, a specific blocker of the transmembrane sodium proton exchange, has been used to demonstrate that this mechanism is also operative in the beta-cell membrane in the control of pHi. The hypothesis that the calcium-activated potassium permeability is proton sensitive at an intracellular site, a fall in pHi causing a fall in permeability and an increase in pHi causing an increase in permeability, has been used to explain many of the effects observed in this study.

scholarly journals Role of combined cell membrane and wall mechanical properties regulated by polarity signals in cell budding

2020 ◽  
Vol 17 (6) ◽  
pp. 065011
Author(s):  
Kevin Tsai ◽  
Samuel Britton ◽  
Ali Nematbakhsh ◽  
Roya Zandi ◽  
Weitao Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Membrane

scholarly journals The Relationships between Cholesterol and Suicide: An Update

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Domenico De Berardis ◽  
Stefano Marini ◽  
Monica Piersanti ◽  
Marilde Cavuto ◽  
Giampaolo Perna ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cell Membrane ◽  
The Other ◽  
Core Component ◽  
Cell Membrane Stability ◽  
Cholesterol Levels ◽  
The Central Nervous System ◽  
Larger Sample

Cholesterol is a core component of the central nervous system, essential for the cell membrane stability and the correct functioning of neurotransmission. It has been observed that cholesterol may be somewhat associated with suicidal behaviours. Therefore, the aim of this paper was to elucidate current facts and views about the role of cholesterol levels in mood disorders. The majority of the studies reviewed in the present paper suggest an interesting relationship between cholesterol (especially lower levels) and suicidality. On the other hand, particularly during the last years, relationships between serum cholesterol and suicidality were doubted on the basis of some recent studies that have not found any correlation. However, the debate on relationships between cholesterol and suicide is open and longitudinal studies on a larger sample of patients are needed to further clarify this important issue.

Phytotoxicity of clove oil and its primary constituent eugenol and the role of leaf epicuticular wax in the susceptibility to these essential oils

Weed Science ◽  
2006 ◽  
Vol 54 (5) ◽  
pp. 833-837 ◽  
Author(s):  
Luke D. Bainard ◽  
Murray B. Isman ◽  
Mahesh K. Upadhyaya
Keyword(s):  
Cell Membrane ◽  
Essential Oils ◽  
Seedling Growth ◽  
Electrolyte Leakage ◽  
Membrane Integrity ◽  
Clove Oil ◽  
Common Lambsquarters ◽  
Redroot Pigweed ◽  
Leaf Epicuticular Wax

Herbicidal activities of clove oil and its primary constituent eugenol on broccoli, common lambsquarters, and redroot pigweed and the role of crystalline leaf epicuticular wax (LEW) in susceptibility and retention of these essential oils were studied. Clove oil (2.5%) and eugenol (1.5%) were applied to leaves of greenhouse-grown broccoli, common lambsquarters, and redroot pigweed seedlings and effects on seedling growth and leaf cell membrane integrity were studied. Compared with eugenol, clove oil caused greater inhibition of seedling growth in all species. Both eugenol and clove oil caused greater loss of membrane integrity and inhibition of seedling growth in redroot pigweed, which has no crystalline LEW, compared with common lambsquarters, which has a thick layer of crystalline LEW. In broccoli seedlings with LEW, clove oil caused greater inhibition of growth than eugenol. Both clove oil and eugenol caused greater electrolyte leakage from broccoli leaves without LEW than in the leaves with LEW. Removal of LEW increased electrolyte leakage, an indicator of cell membrane damage, by 97% in eugenol-treated and 26% in clove oil–treated broccoli leaves. Susceptibility of broccoli seedlings and possibly some weed species may, therefore, be affected by factors (e.g., genetic, environmental) that influence the amount of LEW. Although the presence of LEW greatly reduced the retention of the essential oil solutions, there was no significant difference between the retention of clove oil and eugenol solutions, indicating that differences in their phytotoxicity to broccoli leaves was not due to differential foliar retention.

Bioavailability of Flavonoids: The Role of Cell Membrane Transporters

2018 ◽  
pp. 295-320 ◽  
Author(s):  
Jovana Čvorović ◽  
Lovro Ziberna ◽  
Stefano Fornasaro ◽  
Federica Tramer ◽  
Sabina Passamonti
Keyword(s):  
Cell Membrane ◽  
Membrane Transporters

A scale associated protein of Apedinella radians (Pedinellophyceae) and its possible role in the adhesion of surface components

1993 ◽  
Vol 104 (2) ◽  
pp. 391-398
Author(s):  
A. Koutoulis ◽  
M. Ludwig ◽  
R. Wetherbee
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Cell Membrane ◽  
Cell Surface ◽  
Immunofluorescence Microscopy ◽  
Endomembrane System ◽  
Thin Sections ◽  
Specific Location ◽  
Whole Cells

Monoclonal antibodies have been generated against cell surface components of the unicellular phytoflagellate Apedinella radians (Pedinellophyceae). One monoclonal antibody, designated Arg 1E5/1B1, labels a scale associated protein (SAP) of 145 kDa. Immunofluorescence microscopy of whole cells as well as immunoelectron microscopy of whole cell mounts and thin sections using Arg 1E5/1B1 have shown that the SAP is located on the proximal surface of body scales and spine-scales. Its specific location suggests that the SAP may play a role in the adhesion of these surface components to the cell membrane and/or to one another. The potential of monoclonal antibody Arg 1E5/1B1 as a tool to study cell surface morphogenesis and the role of the endomembrane system in A. radians is discussed.

Cytological and cytochemical studies of centrifuged eggs of the slug Avion ater rufus L.

Development ◽  
1972 ◽  
Vol 27 (1) ◽  
pp. 1-13
Author(s):  
A. H. Sathananthan
Keyword(s):  
Electron Microscope ◽  
Cell Membrane ◽  
Sea Urchin ◽  
Cell Organelles ◽  
Chemical Substances ◽  
Important Chemical ◽  
Equatorial Band ◽  
Hyaline Zone ◽  
Egg Cortex

The stratification of various cell organelles and of important chemical substances have been studied in the eggs of the slug, after moderate centrifugation. As in other molluscs the egg contents stratify typically into three well-defined zones - lipid, L hyaline and yolky zones - but a distinct equatorial band of inclusions consisting mainly of F phagosomes and associated lysosomes was detected in the most centrifugal region of the hyaline zone. The sub-stratification of various cell inclusions in their respective zones was determined in some detail. The role of the cell membrane and egg cortex in the redistribution of these inclusions and the nature of the ergastoplasm are discussed in the light of electron-microscope studies of eggs of this slug and of the sea urchin.

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