scholarly journals Effect of local anaesthetics on mitochondrial membrane potential in living cells

1990 ◽  
Vol 271 (1) ◽  
pp. 269-272 ◽  
Author(s):  
M Grouselle ◽  
O Tueux ◽  
P Dabadie ◽  
D Georgescaud ◽  
J P Mazat
Keyword(s):  
Cell Culture ◽  
Membrane Potential ◽  
Local Anaesthetic ◽  
Mitochondrial Membrane ◽  
Transmembrane Potential ◽  
Local Anaesthetics ◽  
Living Cells ◽  
Lipid Solubility ◽  
Laser Dye ◽  
Lipophilic Anion

Using the laser dye rhodamine 123, we demonstrated that local anaesthetics can reach mitochondria in cell culture and reversibly decrease, or even collapse, their transmembrane potential. This effect is highly dependent on the lipid-solubility of the local anaesthetic and can be facilitated by the presence of a lipophilic anion.

scholarly journals Shedding light on the mitochondrial matrix through a functional membrane transporter

2020 ◽  
Vol 11 (4) ◽  
pp. 1052-1065 ◽  
Author(s):  
Alberto Blázquez-Moraleja ◽  
Ines Sáenz-de-Santa María ◽  
María D. Chiara ◽  
Delia Álvarez-Fernández ◽  
Inmaculada García-Moreno ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane ◽  
Living Cells ◽  
Membrane Transporter ◽  
Mitochondrial Matrix ◽  
Functional Membrane

A BODIPY derivative of carnitine enters mitochondria regardless of their membrane potential and in an enantioselective way through a specific mitochondrial membrane transporter in living cells.

scholarly journals Development of a High Throughput Screening Assay for Mitochondrial Membrane Potential in Living Cells

2002 ◽  
Vol 7 (4) ◽  
pp. 383-389 ◽  
Author(s):  
Shu-Gui Huang
Keyword(s):  
Membrane Potential ◽  
Mitochondrial Membrane Potential ◽  
High Throughput ◽  
High Throughput Screening ◽  
Mitochondrial Membrane ◽  
Living Cells ◽  
Screening Assay ◽  
Mitochondrial Inner Membrane ◽  
Obesity And Diabetes ◽  
High Throughput Screening Assay

The mitochondrion plays a pivotal role in energy metabolism in eukaryotic cells. The electrochemical potential across the mitochondrial inner membrane is regulated to cope with cellular energy needs and thus reflects the bioenergetic state of the cell. Traditional assays for mitochondrial membrane potential are not amenable to high-throughput drug screening. In this paper, I describe a high-throughput assay that measures the mitochondrial membrane potential of living cells in 96- or 384-well plates. Cells were first treated with test compounds and then with a fluorescent potentiometric probe, the cationic-lipophilic dye tetramethylrhodamine methyl ester (TMRM). The cells were then washed to remove free compounds and probe. The amount of TMRM retained in the mitochondria, which is proportional to the mitochondrial membrane potential, was measured on an LJL Analyst fluorescence reader. Under optimal conditions, the assay measured only the mitochondrial membrane potential. The chemical uncouplers carbonylcyanide m-chlorophenyl hydrazone and dinitrophenol decreased fluorescence intensity, with IC50 values (concentration at 50% inhibition) similar to those reported in the literature. A Z' factor of greater than 0.5 suggests that this cell-based assay can be adapted for high-throughput screening of chemical libraries. This assay may be used in screens for drugs to treat metabolic disorders such as obesity and diabetes, as well as cancer and neurodegenerative diseases.

scholarly journals A membrane-activatable near-infrared fluorescent probe with ultra-photostability for mitochondrial membrane potentials

The Analyst ◽  
2016 ◽  
Vol 141 (12) ◽  
pp. 3679-3685 ◽  
Author(s):  
Wei Ren ◽  
Ao Ji ◽  
Omran Karmach ◽  
David G. Carter ◽  
Manuela M. Martins-Green ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Fluorescent Probe ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Near Infrared ◽  
Living Cells ◽  
Membrane Potentials ◽  
Fluorescence Quencher

Dark for light: A fluorescence quencher was turned into a near-infrared probe for mitochondrial membrane potential in living cells and mice.

scholarly journals Monitoring of relative mitochondrial membrane potential in living cells by fluorescence microscopy.

1981 ◽  
Vol 88 (3) ◽  
pp. 526-535 ◽  
Author(s):  
L V Johnson ◽  
M L Walsh ◽  
B J Bockus ◽  
L B Chen
Keyword(s):  
Membrane Potential ◽  
Fluorescence Microscopy ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Specific Interaction ◽  
Living Cells ◽  
Cellular Level ◽  
Energy Requirements ◽  
Active Movement ◽  
Biological Functions

Permeant cationic fluorescent probes are shown to be selectively accumulated by the mitochondria of living cells. Mitochondria-specific interaction of such molecules is apparently dependent on the high trans-membrane potential (inside negative) maintained by functional mitochondria. Dissipation of the mitochondrial trans-membrane and potential by ionophores or inhibitors of electron transport eliminates the selective mitochondrial association of these compounds. The application of such potential-dependent probes in conjunction with fluorescence microscopy allows the monitoring of mitochondrial membrane potential in individual living cells. Marked elevations in mitochondria-associated probe fluorescence have been observed in cells engaged in active movement. This approach to the analysis of mitochondrial membrane potential should be of value in future investigations of the control of energy metabolism and energy requirements of specific biological functions at the cellular level.

scholarly journals Ubiquitin and regulation of apoptosis in Jurkat cells

2018 ◽  
Vol 17 (3) ◽  
pp. 96-104
Author(s):  
O. L. Nosareva ◽  
E. A. Stepovaya ◽  
N. V. Ryazantseva ◽  
E. V. Shakhristova ◽  
D. S. Orlov ◽  
...  
Keyword(s):  
Cell Culture ◽  
Membrane Potential ◽  
Tumor Cell ◽  
Mitochondrial Membrane ◽  
Molecular Mechanisms ◽  
Caspase 3 ◽  
Annexin V ◽  
Jurkat Cells ◽  
Tnf Receptor ◽  
Apoptosis Inducer

Introduction.One of the crucial tasks in medicine is studying the molecular mechanisms of selective management of tumor cell apoptosis following conformational changes in protein molecules (ubiquitination).The purpose of the study. The aim of the project is to establish the role of ubiquitin and ubiquitinligase in dexamethasone-induced apoptosis in Jurkat cells.Materials and methods.The study was carried out on the Jurkat tumor cell line (intact cells and cells cultured in the presence of an apoptosis inducer dexamethasone in the final concentration of 10 µmol. In intact and dexamethasone-affected Jurkat cells, implementation of apoptosis and the amount of FAS-, TNF Receptor 1 and cells with reduced mitochondrial membrane potential were assessed by flow cytometry using FITC-conjugated Annexin V and Propidium Iodide. The levels of NF-κB, Apaf-1, ubiquitin and ubiquitin ligase were determined by Western blot analysis. The activity of caspase-3 was measured by spectrofluorometry.Results.When adding the apoptosis inducer dexamethasone to the Jurkat cell culture, we registered a fall in the concentration of ubiquitin and a rise in the level of ubiquitinligase against the backdrop of activated receptor(an increase in the amount of Annexin V positive cells, FASand TNF Receptor 1) and mitochondrialmediated (an increase in the number of cells with reduced mitochondrial membrane potential and elevation of Apaf-1 level) pathways of apoptosis, as opposed to the intact cell culture. We estimated the completion of apoptosis by determining the activity of caspase-3 in the investigated tumor cells.Conclusion.The obtained findings allow the conclusion that ubiquitination of regulatory and effector proteins in programmed cell death is one of the molecular mechanisms that regulates and selectively controls apoptosis in Jurkat cells.

Local anaesthetic agents

2017 ◽  
Author(s):  
Malachy O. Columb
Keyword(s):  
Local Anaesthetic ◽  
Neuronal Damage ◽  
Scientific Evidence ◽  
Local Anaesthetics ◽  
Systemic Toxicity ◽  
Lipid Solubility ◽  
Blood Concentrations ◽  
Anaesthetic Agents ◽  
Weak Bases ◽  
Initiation And Propagation

Local anaesthetic agents cause a pharmacologically induced reversible neuropathy characterized by axonal conduction blockade. They act by blocking the sodium ionophore and exhibit membrane stabilizing activity by inhibiting initiation and propagation of action potentials. They are weak bases consisting of three components: a lipophilic aromatic ring, a link, and a hydrophilic amine. The chemical link classifies them as esters or amides. Local anaesthetics diffuse through the axolemma as unionized free-base and block the ionophore in the quaternary ammonium ionized form. The speed of onset of block is therefore dependent on the pKa of the agent and the ambient tissue pH. Esters undergo hydrolysis by plasma esterases and amides are metabolized by hepatic microsomal mixed-function oxidases. Local anaesthetics are bound in the blood to α‎1-acid glycoproteins. Pharmacological potency is dependent on the lipid solubility of the drug as is the potential for systemic toxicity. The blood concentrations required to cause cardiovascular system (CVS) collapse and early central nervous system (CNS) toxicity are used to quantify the CVS:CNS toxicity ratio. Local anaesthetics also have the potential to induce direct neuronal damage. Intravenous lipid emulsion is used for the treatment of systemic toxicity but the scientific evidence is inconsistent. With regard to the pipecoloxylidine local anaesthetics, early evidence indicated that the S- was less toxic than the R-enantiomer. However, clinical research using minimum local analgesic concentration designs suggests that reduced systemic toxicity and motor block sparing is mainly explained by potency rather than enantiomerism.

Fabrication of a fluorescent probe for reversibly monitoring mitochondrial membrane potential in living cells

2021 ◽  
Vol 13 (14) ◽  
pp. 1715-1719
Author(s):  
Dingyi Guo ◽  
Jie Sun ◽  
Minggang Tian ◽  
Weiying Lin
Keyword(s):  
Reactive Oxygen Species ◽  
Membrane Potential ◽  
Fluorescent Probe ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Cell Damage ◽  
Reactive Oxygen ◽  
Living Cells ◽  
Oxygen Species

A fluorescent probe for reversibly monitoring mitochondrial membrane potential in living cells has been constructed successfully, which could be employed to visualize cell damage by reactive oxygen species.

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