Membrane permeability. Medical search. Frequent questions

In medicinal chemistry, parallel artificial membrane permeability assay (PAMPA) is a method which determines the permeability of substances from a donor compartment, through a lipid-infused artificial membrane into an acceptor compartment. (wikipedia.org)
AAPS Workshop on Permeability Definitions and Regulatory Standards, Arlington, VA, USA (1998) 17-19 Aug. Kansy M, Senner F, Gubernator K. (1998) Physicochemical high throughput screening: parallel artificial membrane permeability assay in the description of passive absorption processes. (wikipedia.org)
The Parallel Artificial Membrane Permeability Assay (PAMPA) PAMPA was applied to screen compounds for passive diffusion. (thisisbeep.com)
We synthesized cyclic peptomer libraries by split-pool techniques, separately permuting side chain and backbone geometry, and analyzed their membrane permeabilities using the parallel artificial membrane permeability assay. (circlepharma.com)

subsequently, commercial products were introduced which incorporated more sophisticated lipid membranes. (wikipedia.org)
In particular, the impact of α-spinasterol on the structure and organization of lipid membranes was investigated and compared with those of cholesterol. (mdpi.com)

Artursson, P. Application of physicochemical properties of molecules to predict intestinal permeability. (wikipedia.org)
Plasma membranes are bi-layered membranes made up of amphiphillic molecules (having charged polar heads tending to be hydrophillic and uncharged fatty acid tails tending to be hydrophobic) that selectively allow entrance of certain large molecules into the cell's cytosol and through which water and small non-polar molecules may freely diffuse. (ukessays.com)
Some of the factors upon which permeability of the plasma membranes of biological organisms depend are differences in pH on opposite sides of the membrane, temperature, osmolarity, expression of certain membrane receptors and the concentration gradients of various molecules. (ukessays.com)
Diffusing molecules or ions do not combine with the constituents of the membrane. (biologydiscussion.com)
Diffusing molecules move through the membrane with the help of transport protein or carrier proteins. (biologydiscussion.com)
Therefore, molecules generally need to pass through the cell in order to cross the barrier, and must cross the plasma membrane to access the interior of the cell. (thisisbeep.com)
Once we understand the factors that can affect membrane permeability, we are then able to better understand the transport of molecules into and out of the cell. (thisisbeep.com)
Any process that modulates the frequency, rate or extent of the passage or uptake of molecules by the mitochondrial membrane. (planteome.org)
ABSTRACT Assessing the permeation rate of drug-like molecules across a lipid membrane is of paramount importance for pharmaceutical applications. (tristanbereau.com)
We focus on acidic molecules: for weak acids, the permeability largely depends on the main free-energy differences of the problem, which directly link to our molecular descriptors. (tristanbereau.com)
Nonthrombogenic PVA-Chit (4 : 6) membranes were derived by immobilizing bioactive molecules like PGE1 on heparin-modified membranes, via free radical mechanisms, by N2 plasma. (sctimst.ac.in)
This novel membrane demonstrated good permeability properties for small molecules and showed a dramatic reduction in platelet attachement. (sctimst.ac.in)
This activity is controlled by a protein of unknown function, YhdP, and deletion of yhdP damages the OM permeability barrier in a cyclic ECA-dependent manner, allowing harmful molecules such as antibiotics into the cell. (princeton.edu)
The media of mitochondria treated with LL-37 (8 μM) for 2 h contained 50% more AIF and three times more cytochrome C than that of control mitochondria, showing that LL-37 promotes release of both AIF and cytochrome C. Moreover, in vesicles reflecting mitochondrial membrane lipid composition, LL-37 stimulates membrane permeabilization and release of tracer molecules. (lu.se)
Cell membranes are biologic barriers that selectively inhibit passage of drug molecules. (msdmanuals.com)
Sometimes various globular proteins embedded in the matrix function as receptors and help transport molecules across the membrane. (msdmanuals.com)
Small molecules tend to penetrate membranes more rapidly than larger ones. (msdmanuals.com)

Here, we have used two-color multiparameter flow cytometry to study simultaneously its effects on cell membrane permeability, intracellular pH, and cell size/structure of EMT6 mouse mammary tumor cells and HL-60 human promyelocytic leukemia cells in vitro . (aacrjournals.org)
Although latest data claim that the era of intracellular ceramide boosts mitochondrial permeability, the foundation of mitochondrial ceramide continues to be unknown. (nsdfu.org)
Membrane-traversing peptides offer opportunities for targeting intracellular proteins and oral delivery. (bvsalud.org)

Link to all annotated objects annotated to regulation of mitochondrial membrane permeability. (planteome.org)
Link to all direct and indirect annotations to regulation of mitochondrial membrane permeability. (planteome.org)
Introduction An elevated permeability from the mitochondrial external membrane is implicated in the first levels of apoptosis [1]. (nsdfu.org)
Electron microscopic Kaempferide tomography verified that upon the forming of ceramide systems, the invaginated parts of the plasma membrane prolong deep in to the cytoplasm developing direct physical connections with mitochondrial external membranes. (nsdfu.org)
Ceramide may so end up being transferred in the plasma membrane towards the mitochondrial external membrane directly. (nsdfu.org)
Alternatively, a rise in mitochondrial permeability continues to be ascribed to ceramide itself: Deposition of mitochondrial ceramide might Rabbit Polyclonal to CDON promote the forming of membrane stations and the next discharge of proapoptotic protein in the mitochondrial intermembrane space [6]. (nsdfu.org)
Fendiline demonstrated depolarization of mitochondrial membrane potential, with increased reactive oxygen species production in amlodipine and fendiline treated Leishmania , but without plasma membrane disruption. (hindawi.com)
The human antimicrobial peptide LL-37 permeabilizes the plasma membrane of host cells, but LL-37-induced direct effects on mitochondrial membrane permeability and function has not been reported. (lu.se)
Subcellular fractionation and Western blot disclose that stimulation with LL-37 (8 μM) for 2 h triggers release of the mitochondrial protein apoptosis-inducing factor (AIF) to the cytosol, whereas LL-37 causes no release of cytochrome C oxidase subunit IV of the inner mitochondrial membrane, suggesting that LL-37 affects mitochondrial membrane. (lu.se)
We conclude that LL-37 is rapidly internalized by MG63 cells and accumulates in mitochondria, and that the peptide triggers release of pro-apoptotic AIF and directly affects mitochondrial membrane structural properties. (lu.se)

Inhibiting Rho kinase (ROCK) significantly reduces the smoke-induced permeability to both ions and macromolecules, while inhibiting protein tyrosine kinases (PTK) only reduces smoke-induced macromolecular permeability. (nih.gov)
In addition, cell membrane permeability for ions also increased under anesthesia. (frontiersin.org)
Lidocaine decreases permeability to sodium ions in neuronal membranes. (medscape.com)

However, many other parameters govern the solute permeability, like the amount of solutes dissolved in bound water and the status of water in the polymer matrix. (sctimst.ac.in)

abstract = "A novel preparation method for modified chitosan membranes was developed. (elsevierpure.com)
Permeabilities of KCl, sucrose, and urea through these modified chitosan membranes were investigated. (elsevierpure.com)
The PVA-blended chitosan membranes showed improved strength properties and permeability functions for low-molecular-weight compounds. (sctimst.ac.in)

Previously, we identified several genes in Escherichia coli K-12 responsible for an RpoS-dependent decrease in envelope permeability during carbon-limited stationary phase. (princeton.edu)
ECA biosynthesis gene deletions suppressed envelope permeability from yhdP deletion independently of envelope stress responses and interactions with other biosynthesis pathways, demonstrating suppression is caused directly by removing ECA. (princeton.edu)
We determined that the suppression of envelope permeability with yhdP deletion is caused specifically by the loss of cyclic ECA, despite lowered levels of this molecule found with yhdP deletion. (princeton.edu)
This role in maintenance of the envelope permeability barrier is the first time a phenotype has been described for cyclic ECA. (princeton.edu)

Osmosis: Water Permeability. (thisisbeep.com)
The effect of different pore formers on the microstructure, mechanical strength, porosity and pore size distribution, air, and water permeability of porous SiC ceramics were investigated. (csircentral.net)
All membranes showed high oil rejection rate (89%-93%) from feed wastewater with oil concentration of 1557 mg/L. The membrane with porosity similar to 48 vol% and mechanical strength 31.5 MPa showed and highest pure water permeability of 13 298 Lm(-2)h(-1)bar(-1). (csircentral.net)
A promising separation performance with extremely high water permeability has been attained for dehydration of an 85 wt% ethanol aqueous solution at 45°C. The study on the free volume evolution of the TFM membranes may provide useful insights about the microstructure and mass transport behavior of the microporous polymeric materials. (edu.sa)

SPERTA Membrane is known for its high permeability and flux rates. (spertasystems.com)
Incorporating SPERTA Membrane into your MBR system can provide several advantages, including enhanced fouling resistance, high permeability, and tailored solutions. (spertasystems.com)

Furthermore, outer membrane permeability of the host organism(s) will be adjusted in-process using moleculobiological tools. (boku.ac.at)
The goal is to quantify and link outer membrane permeability to different mechanical properties of the cell. (boku.ac.at)
This collection of strains a decrease in bacterial outer-membrane permeability, with also included 46 strains that were fully susceptible to car- overexpression of -lactamases with no carbapenemase ac- bapenems or showed a decreased susceptibility to car- tivity or to expression of carbapenemases ( 2,4,5 ). (cdc.gov)
Gram-negative bacteria have an outer membrane (OM) impermeable to many toxic compounds that can be further strengthened during stress. (princeton.edu)
Here, we have determined that the periplasmic form of ECA, cyclic ECA, plays a role in maintaining the outer membrane permeability barrier. (princeton.edu)
The Gram-negative bacterial outer membrane (OM) is a unique bilayer that forms an efficient permeation barrier to protect the cell from noxious compounds 1 , 2 . (nature.com)
This asymmetry is maintained by the Mla pathway, a six-component system that is widespread in Gram-negative bacteria and is thought to mediate retrograde transport of misplaced phospholipids from the outer leaflet of the OM to the cytoplasmic membrane 4 . (nature.com)
Three systems are known to maintain OM lipid asymmetry: the OM phospholipase A 2 PldA 7 , the lipopolysaccharide (LPS) palmitoyl transferase PagP 8 and the Mla (maintenance of outer membrane lipid asymmetry) system. (nature.com)
In addition, the Mla system was recently shown to regulate outer membrane vesicle formation 16 . (nature.com)

What does the permeability coefficient of a membrane tell us? (thisisbeep.com)
Consequently, the permeability coefficient gives us an idea of the velocity with which a given substance will permeate a given membrane. (thisisbeep.com)
While the Meyer-Overton rule relates the permeability coefficient to a few thermodynamic properties, its accuracy is limited by the homogeneity assumption. (tristanbereau.com)
We connect the permeability coefficient of a compound to two molecular descriptors: partitioning free-energy and acid dissociation constant. (tristanbereau.com)
The permeability is the ratio D/d where d=thickness of barrier and D=diffusion coefficient across the barrier. (harvard.edu)

Sodium permeability of dog red blood cell membranes. (cdc.gov)
Lepke S, Passow H. Effects of fluoride on potassium and sodium permeability of the erythrocyte membrane. (cdc.gov)

However, PAF was more potent than SRI 62-834 in causing membrane permeabilization with both cell lines, whereas PAF was less active than SRI 62-834 in cytotoxicity assays. (aacrjournals.org)

Passive membrane permeability is the diffusion of drug across tissue barriers and cell membranes. (thisisbeep.com)

Although active transport is not modeled by the artificial PAMPA membrane, up to 95% of known drugs are absorbed by passive transport. (wikipedia.org)
1 Passive Membrane Permeability This serves to protect the body or tissue from exposure to potentially toxic substances. (thisisbeep.com)
What is passive membrane permeability? (thisisbeep.com)

At temperatures below 1223 K, the oxygen permeation (OP) fluxes through dense La(Sr)Ga(Mg,M)O3-delta membranes with the thickness less than 1.5 mm are mainly limited by the exchange rate at membrane/gas boundaries. (ua.pt)
The highest permeation is observed for La0.90Sr0.10Ga0.65Mg0.15Ni0.20O3-delta perovskite membranes, which exhibit level of the oxygen permeability similar to that of La(Sr)Fe(Co)O3-delta and La2NiO4-based solid solutions. (ua.pt)
Permeation theory predicts that filtration rate is proportional to the pressure difference across the filtration membrane and inversely proportional to the thickness of the membrane. (thisisbeep.com)
The Darcian (k(1)) and non-Darcian (k(2)) permeability evaluated from air permeation behavior at room temperature was found to vary from 1.48 x 10(-13) to 4.64 x 10(-13) m(2) and 1.46 x 10(-8) to 6.51 x 10(-8) m, respectively. (csircentral.net)
The permeability of urea was almost the same for both membrane systems, i.e., permeation of urea was not affected by the thiol ⟷ disulfide transition, probably due to the break of hydrogen bonding in the membranes. (elsevierpure.com)

In liver cells, the influx of Na + mediated by nonselective cation (NSC) channels in the plasma membrane contributes importantly to regulation of cell volume. (elsevierpure.com)
These findings indicate that volume-sensitive increases in p60 c-src and/or related tyrosine kinases play a key role in the regulation of membrane Na + permeability, suggesting that increases in the NSC conductance may be mediated in part through rapid recruitment of a distinct pool of channel-containing vesicles. (elsevierpure.com)

Comparing rat in situ, Caco-2, and PAMPA permeability of fluoroquinolones. (wikipedia.org)
2009). P-glycoprotein deficient mouse in situ blood-brain barrier permeability and its prediction using an in combo PAMPA model. (wikipedia.org)
The pristine TFM membrane is in situ fabricated in the course of polymer synthesis via a facile Brønsted-acid-catalyzed cyclotrimerizaiton reaction. (edu.sa)

Energetics of Proteins in Membranes. (thisisbeep.com)
A role for the ubiquitin ligase Nedd4 in membrane sorting of LAPTM4 proteins. (nih.gov)
Massive, calcium-activated endocytosis from the plasma membrane without participation of traditional endocytic proteins is normally a recently defined phenomenon and it is closely from the development of ceramide during mobile stress [17]C[20]. (nsdfu.org)

These benefits contribute to maintaining and improving membrane permeability, ensuring efficient and reliable wastewater treatment in MBR systems. (spertasystems.com)

High TMP can lead to membrane compaction and a reduction in pore size, limiting water flow. (spertasystems.com)
The choice of membrane material and its pore size is another crucial factor. (spertasystems.com)
Selecting the right membrane material and pore size for the specific application is essential for achieving the desired permeability and separation efficiency. (spertasystems.com)

The permeability of urea was quite high and followed by KCl and sucrose in that order. (elsevierpure.com)
The permeabilities of KCl and sucrose through the MSS membrane showed a decrease compared to those through the MSH membrane. (elsevierpure.com)
The thiol ⟷ disulfide transition was responsible for changes in the permeabilities of KCl and sucrose. (elsevierpure.com)

The ionized form has low lipid solubility (but high water solubility-ie, hydrophilic) and high electrical resistance and thus cannot penetrate cell membranes easily. (msdmanuals.com)
We review recent developments in the design and validation of chameleonic cyclic peptides, which can switch between alternative conformations to enable improved permeability through cell membranes, while still maintaining reasonable solubility and exposed polar functional groups for target protein binding. (bvsalud.org)

The tea extracts and components displayed various degrees of antibacterial activity that may involve damage to the bacterial cell membrane and the chelation of iron. (nature.com)

Our data demonstrate cyclic ECA acts to maintain the OM permeability barrier in a manner controlled by YhdP. (princeton.edu)

a quality of cell membranes which permits the passage of solvents and solutes into and out of cells. (thisisbeep.com)
It is also postulated that the total water content of membranes need not be the prime factor governing the permeability of solutes through water-swollen membranes. (sctimst.ac.in)

HE results from defects in the protein scaffolding of the erythrocyte membrane, which decrease the deformability and resilience of the RBCs. (medscape.com)

Membrane permeability allows for the possibility of concentration gradients across membranes, which in turn have potential energy associated with the concentration dif- ferential across the membrane. (thisisbeep.com)

This experiment is very limited in scope and seeks to answer only the question of what is the time dependence for permeability of glycerol through the cell membrane. (ukessays.com)
Overall, biologically active peptides should be produced extracellularly in soluble form by adjusting the membrane permeability of growing and producing cell. (boku.ac.at)
Cell membrane permeability. (thisisbeep.com)
How is a cell membrane permeated? (thisisbeep.com)
Why is membrane permeability important to the cell? (thisisbeep.com)
The results of this experiment helps us to better understand the function and structure of cell membranes. (thisisbeep.com)
Unless given IV, a drug must cross several semipermeable cell membranes before it reaches the systemic circulation. (msdmanuals.com)
Drugs diffuse across a cell membrane from a region of high concentration (eg, gastrointestinal fluids) to one of low concentration (eg, blood). (msdmanuals.com)
Because the cell membrane is lipoid, lipid-soluble drugs diffuse most rapidly. (msdmanuals.com)
The un-ionized form is usually lipid soluble (lipophilic) and diffuses readily across cell membranes. (msdmanuals.com)
Testing at baseline and 1 hour after overhaul included forced vital capacity (FVC), forced expiratory volume in one second (FEV1), serum Clara cell protein (CC16), and serum surfactant-associated protein A (SP-A). Overhaul increased CC16 in both groups, indicating increased alveolarcapillary membrane permeability. (cdc.gov)
Despite progress in understanding the mechanisms underlying membrane traversal in natural cell-permeable peptides, there are still several challenges to designing membrane-traversing peptides with diverse shapes and sizes. (bvsalud.org)

The hydrogen permeability for SrCe0.7Zr0.25Tm0.05O3−δ and SrCe0.7Zr0.25Yb0.05O3−δ is similar under our measurement window and shows the same hydrogen partial pressure dependency. (sintef.no)
Under short circuit condition, the hydrogen permeability increased significantly by more than one order of magnitude indicating that the hydrogen transport is limited by electronic conduction under open circuit conditions. (sintef.no)
The surface adsorption effect of CO on the hydrogen permeability of a 12.5 micron-thick Pd77Ag23 membrane has been evaluated quantitatively under experimental conditions close to the operating conditions of the highly-efficient membrane reformer (MRF) system developed by Tokyo Gas. (sintef.no)
High feed flow rates and a microchannel module configuration were applied in the flux measurements to ensure that the results are obtained with limited influence of concentration polarization adjacent to the membrane surface and hydrogen depletion along the microchannel length. (sintef.no)
This study quantitatively revealed that the CO inhibition effect on hydrogen flux is extremely small when the membrane is operated at temperatures equal to or higher than 500 °C, even for state-of-the-art thin membranes. (sintef.no)
Some backbone geometries enhanced permeability due to their ability to form more stable intramolecular hydrogen bond networks compared with other scaffolds. (circlepharma.com)

This experiment seeks to understand limited aspects of the permeability of the plasma membrane using the Elodea leaf membrane as model organism. (ukessays.com)
Part two of this experiment will be to determine the period of time it takes for glycerol to diffuse across the plasma membrane. (ukessays.com)
and plasma membrane. (nih.gov)
During apoptosis, ceramide is normally created inside the plasma membrane. (nsdfu.org)
Using tagged annexin A1 fluorescently, we present that, upon its era inside the plasma membrane, ceramide self-associates into systems that invaginate and fuse with mitochondria subsequently. (nsdfu.org)
MlaC probably accepts a phospholipid from MlaA and shuttles it to the ABC transporter for ATP-dependent plasma membrane insertion 5 . (nature.com)
All these data indicate that diethyl ether anesthesia may partially mimic heat stress in plants through the effect on plasma membrane. (frontiersin.org)

HL-60 cells were more sensitive to SRI 62-834 than were EMT6 cells in terms of both cytotoxicity and membrane permeability. (aacrjournals.org)
Furthermore, removing cyclic ECA from wild-type cells also caused changes to OM permeability. (princeton.edu)

Oxymetazoline is applied directly to mucous membranes, where it stimulates alpha-adrenergic receptors and causes vasoconstriction. (medscape.com)

Calcium channel blockers (CCBs) are a class of drugs that act by selective inhibition of calcium influx through cellular membranes. (hindawi.com)

Sterols play a unique role for the structural and dynamical organization of membranes. (mdpi.com)
Fifty-one firefighters in two groups, 25 without respiratory protection and 26 wearing cartridge respirators, were monitored for exposure to products of combustion and changes in spirometric measurements and lung permeability following overhaul of a structural fire. (cdc.gov)

We discuss how - and when - combining together these profiles for a large variety of compounds can result in a smooth dependence of the permeability on the molecular descriptors. (tristanbereau.com)

Additionally, our results indicate that activation of PTK and ROCK and inactivation of MLCK contribute to the increased airway permeability caused by mainstream cigarette smoke. (nih.gov)
Additionally, the permeability of pig skin was located to become related to that of human skin, even though becoming diverse from that of other animals, especially dog or rodents, as referred in [25,27]. (5htreceptor.com)

In contrast to PAMPA or PVPA barriers, this model will not comprise a filter assistance, however it consists of two cellulose membranes enclosing a layer of dry phospholipids involving them. (5htreceptor.com)

Synthetic and natural cyclic peptides provide a testing ground for studying membrane permeability in nontraditional drug scaffolds. (circlepharma.com)

Fouling occurs when particles, microorganisms, or other substances accumulate on the membrane surface or within its pores. (spertasystems.com)

While several factors can influence MBR membrane permeability, the choice of membrane supplier can also significantly impact. (spertasystems.com)

The goal of these studies was to identify the signal transduction pathways that regulate smoke-induced permeability. (nih.gov)

Different membrane materials have varying permeability characteristics. (spertasystems.com)
In conclusion, several factors can affect MBR membrane permeability, including membrane fouling, transmembrane pressure, and membrane material characteristics. (spertasystems.com)
The membranes are composed primarily of a bimolecular lipid matrix, which determines membrane permeability characteristics. (msdmanuals.com)

abstract = "The microstructural evolution of a series of triazine framework-based microporous (TFM) membranes under different conditions has been explored in this work. (edu.sa)

The RBC membrane is composed of a fragile lipid bilayer stretched over a flexible protein cytoskeleton. (medscape.com)

The autoantibodies bind to their reactive epitopes in the basement membranes and activate the complement cascade, resulting in tissue injury. (medscape.com)

Firefighter exposures during overhaul have the potential to cause changes in spirometric measurements and lung permeability, and self-contained breathing apparatus should be worn during overhaul to prevent lung injury. (cdc.gov)

SPERTA Membrane is engineered with advanced fouling-resistant properties. (spertasystems.com)
The current study reports data on the membrane properties of the phytosterol (3β,5α,22 E )-stigmasta-7,22-dien-3-β-ol (α-spinasterol), which represents an important component of argan oil and have not been investigated so far in molecular detail. (mdpi.com)

Anatomy46

Organisms15

Diseases2

Chemicals and Drugs107

Analytical, Diagnostic and Therapeutic Techniques and Equipment25

Phenomena and Processes59

Disciplines and Occupations2

Technology, Industry, Agriculture6

Information Science3

Health Care1

Parallel artificial membrane permeability4

Lipid membranes2

Molecules17

Intracellular3

Mitochondrial10

Ions3

Solute permeability1

Chitosan membranes3

Envelope permeability4

Water Permeability4

High permeability2

Outer9

Coefficient5

Sodium2

Permeabilization1

Diffusion1

Passive3

Permeation5

Regulation2

Situ3

Proteins3

Wastewater treatment1

Pore size3

Sucrose3

Solubility2

Bacterial cell1

Barrier1

Solutes2

Decrease1

Concentration gradients1

Cell12

Hydrogen6

Plasma7

Cells2

Receptors1

Inhibition1

Structural2

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Additionally2

Barriers1

Cyclic1

Particles1

Significantly1

Regulate1

Characteristics3

Abstract1

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Reactive1

Lung1

Properties2