A novel membrane potential-sensitive fluorescent dye improves cell-based assays for ion channels.
AuthorsBaxter DF, Kirk M, Garcia AF, Raimondi A, Holmqvist MH, Flint KK, Bojanic D, Distefano PS, Curtis R, Xie Y
JournalJ Biomol Screen
PubMed ID11897058
The study of ion channel-mediated changes in membrane potential using the conventional bisoxonol fluorescent dye DiBAC(4)(3) has several limitations, including a slow onset of response and multistep preparation, that limit both the fidelity of the results and the throughput of membrane potential assays. Here, we report the characterization of the ... More
Characterization of human urinary bladder KATP channels containing SUR2B splice variants expressed in L-cells.
AuthorsScott VE, Davis-Taber RA, Silvia C, Hoogenboom L, Choi W, Kroeger P, Whiteaker KL, Gopalakrishnan M
JournalEur J Pharmacol
PubMed ID14729107
The molecular properties of the sulfonylurea receptor 2 (SUR2) subunits of K(ATP) channels expressed in urinary bladder were assessed by polymerase chain reaction (PCR). This showed that SUR2B exon 17- mRNA (72%) was predominant over the SUR2B exon 17+ splice variant (28%). The pharmacological properties of both of these isoforms ... More
Overexpression of Na(+)/K (+)-ATPase parallels the increase in sodium transport and potassium recycling in an in vitro model of proximal tubule cellular ageing.
AuthorsSilva E, Gomes P, Soares-da-Silva P,
JournalJ Membr Biol
PubMed ID17334838
'Na(+)/K(+)-ATPase plays a key role in the transport of Na(+) throughout the nephron, but ageing appears to be accompanied by changes in the regulation and localization of the pump. In the present study, we examined the effect of in vitro cell ageing on the transport of Na(+) and K(+) ions ... More
TRPC1 associates with BK(Ca) channel to form a signal complex in vascular smooth muscle cells.
AuthorsKwan HY, Shen B, Ma X, Kwok YC, Huang Y, Man YB, Yu S, Yao X,
JournalCirc Res
PubMed ID19168436
'TRPC1 (transient receptor potential canonical 1) is a Ca(2+)-permeable cation channel involved in diverse physiological function. TRPC1 may associate with other proteins to form a signaling complex, which is crucial for channel function. In the present study, we investigated the interaction between TRPC1 and large conductance Ca(2+)-sensitive K(+) channel (BK(Ca)). ... More
Lipid factor (bVLF) from bovine vitreous body evokes in EGFR-T17 cells a Ca2+-dependent K+ current associated with inositol 1,4,5-trisphosphate-independent Ca2+ mobilization.
'Bovine vitreous lipid factor (bVLF) is a complex phospholipid isolated from bovine vitreous body with strong Ca(2+)-mobilizing activity. In this study, the effects of bVLF on membrane potential were investigated in EGFR-T17 fibroblasts with the whole-cell patch clamp technique on monolayer cells, as well as with the fluorescent dye bis-oxonol ... More
Extracellular K(+) and opening of voltage-gated potassium channels activate T cell integrin function: physical and functional association between Kv1.3 channels and beta1 integrins.
AuthorsLevite M, Cahalon L, Peretz A, Hershkoviz R, Sobko A, Ariel A, Desai R, Attali B, Lider O
JournalJ Exp Med
PubMed ID10748234
'Elevated extracellular K(+) ([K(+)](o)), in the absence of "classical" immunological stimulatory signals, was found to itself be a sufficient stimulus to activate T cell beta1 integrin moieties, and to induce integrin-mediated adhesion and migration. Gating of T cell voltage-gated K(+) channels (Kv1.3) appears to be the crucial "decision-making" step, through ... More
Blockade of the voltage-gated potassium channel Kv1.3 inhibits immune responses in vivo.
AuthorsKoo GC, Blake JT, Talento A, Nguyen M, Lin S, Sirotina A, Shah K, Mulvany K, Hora D, Cunningham P, Wunderler DL, McManus OB, Slaughter R, Bugianesi R, Felix J, Garcia M, Williamson J, Kaczorowski G, Sigal NH, Springer MS, Feeney W
JournalJ Immunol
PubMed ID9164927
'The voltage activated K+ channel (Kv1.3) has recently been identified as the molecule that sets the resting membrane potential of peripheral human T lymphoid cells. In vitro studies indicate that blockage of Kv1.3 inhibits T cell activation, suggesting that Kv1.3 may be a target for immunosuppression. However, despite the in ... More
Pharmacological activation of plasma-membrane KATP channels reduces reoxygenation-induced Ca(2+) overload in cardiac myocytes via modulation of the diastolic membrane potential.
AuthorsBaczkó I, Giles WR, Light PE
JournalBr J Pharmacol
PubMed ID14993099
'1. The opening of cardiac plasma-membrane ATP-sensitive K(+) channels (pmK(ATP)) can protect the heart against ischaemia/reperfusion injury. We recently demonstrated that the resting membrane potential (E(m)) of ventricular myocytes strongly modulates reoxygenation-induced Ca(2+) overload. This led to the hypothesis that activation of pmK(ATP) can influence the extent of chemically induced ... More
Antimicrobial action of rabbit leukocyte CAP18(106-137).
AuthorsMason DJ, Dybowski R, Larrick JW, Gant VA
JournalAntimicrob Agents Chemother
PubMed ID9056004
'CAP18 is a cationic antimicrobial protein originally isolated from rabbit neutrophils, of which a 32-mer sequence from its C-terminal and (CAP18(106-137)) has been found to be the most active. The bactericidal action of this peptide has been characterized by conventional culture techniques and flow cytometry. Cultures of Escherichia coli NCTC10418 ... More
Glucose stimulates Ca2+ influx and insulin secretion in 2-week-old beta-cells lacking ATP-sensitive K+ channels.
AuthorsSzollosi A, Nenquin M, Aguilar-Bryan L, Bryan J, Henquin JC
JournalJ Biol Chem
PubMed ID17138557
'In adult beta-cells glucose-induced insulin secretion involves two mechanisms (a) a K(ATP) channel-dependent Ca(2+) influx and rise of cytosolic [Ca(2+)](c) and (b) a K(ATP) channel-independent amplification of secretion without further increase of [Ca(2+)](c). Mice lacking the high affinity sulfonylurea receptor (Sur1KO), and thus K(ATP) channels, have been developed as a ... More
Hydrogen peroxide attenuates store-operated calcium entry and enhances calcium extrusion in thyroid FRTL-5 cells.
AuthorsTörnquist K, Vainio PJ, Björklund S, Titievsky A, Dugué B, Tuominen RK
JournalBiochem J
PubMed ID10998346
'Redox modulation participates in the regulation of intracellular free calcium concentration ([Ca(2+)](i)) in several cell types. In thyroid cells, including FRTL-5 cells, changes in [Ca(2+)](i) regulate several important functions, including the production of H(2)O(2) (hydrogen peroxide). As H(2)O(2) is of crucial importance for the production of thyroid hormones, we investigated ... More
N-methyl-D-aspartate excitotoxicity: relationships among plasma membrane potential, Na(+)/Ca(2+) exchange, mitochondrial Ca(2+) overload, and cytoplasmic concentrations of Ca(2+), H(+), and K(+).
AuthorsKiedrowski L
JournalMol Pharmacol
PubMed ID10462550
'A high cytoplasmic Na(+) concentration may contribute to N-methyl-D-aspartate (NMDA)-induced excitotoxicity by promoting Ca(2+) influx via reverse operation of the Na(+)/Ca(2+) exchanger (NaCaX), but may simultaneously decrease the electrochemical Ca(2+) driving force by depolarizing the plasma membrane (PM). Digital fluorescence microscopy was used to compare the effects of Na(+) versus ... More
Voltage-sensitive oxonol dyes are novel large-conductance Ca2+-activated K+ channel activators selective for beta1 and beta4 but not for beta2 subunits.
'The large-conductance Ca(2+)-activated K(+) (BK) channel is activated by both the increase of intracellular Ca(2+) concentration and membrane depolarization. The BK channel plays crucial roles as a key molecule in the negative feedback mechanism regulating membrane excitability and cellular Ca(2+) in various cell types. Here, we report that a widely ... More
Sodium-dependent effects of melatonin on membrane potential of neonatal rat pituitary cells.
AuthorsVanecek J, Klein DC
JournalEndocrinology
PubMed ID1322288
'Melatonin inhibits GnRH-stimulated release of LH from neonatal rat pituitary cells, probably by inhibiting GnRH-induced elevation of intracellular Ca2+. This effect of melatonin seems to involve inhibition of Ca2+ influx through voltage-sensitive channels. Accordingly, it is possible that melatonin could act by hyperpolarizing pituitary cells, which would close these channels. ... More
Mitochondrial and plasma membrane potential of cultured cerebellar neurons during glutamate-induced necrosis, apoptosis, and tolerance.
'A failure of mitochondrial bioenergetics has been shown to be closely associated with the onset of apoptotic and necrotic neuronal injury. Here, we developed an automated computational model that interprets the single-cell fluorescence for tetramethylrhodamine methyl ester (TMRM) as a consequence of changes in either delta psi(m) or delta psi(p), ... More
Role of YidC in folding of polytopic membrane proteins.
AuthorsNagamori S, Smirnova IN, Kaback HR
JournalJ Cell Biol
PubMed ID15067017
'YidC of Echerichia coli, a member of the conserved Alb3/Oxa1/YidC family, is postulated to be important for biogenesis of membrane proteins. Here, we use as a model the lactose permease (LacY), a membrane transport protein with a known three-dimensional structure, to determine whether YidC plays a role in polytopic membrane ... More
Characterization of a nucleoside/proton symporter in procyclic Trypanosoma brucei brucei.
Authorsde Koning HP, Watson CJ, Jarvis SM
JournalJ Biol Chem
PubMed ID9545276
'Adenosine transport at 22 degrees C in procyclic forms of Trypanosoma brucei brucei was investigated using an oil-inhibitor stop procedure for determining initial rates of adenosine uptake in suspended cells. Adenosine influx was mediated by a single high affinity transporter (Km 0.26 +/- 0.02 microM, Vmax 0.63 +/- 0.18 pmol/10(7) ... More
The small G-protein Rac mediates depolarization-induced superoxide formation in human endothelial cells.
AuthorsSohn HY, Keller M, Gloe T, Morawietz H, Rueckschloss U, Pohl U
JournalJ Biol Chem
PubMed ID10764736
'Superoxide anions impair nitric oxide-mediated responses and are involved in the development of hypertensive vascular hypertrophy. The regulation of their production in the vascular system is, however, poorly understood. We investigated whether changes in membrane potential that occur in hypertensive vessels modulate endothelial superoxide production. In cultured human umbilical vein ... More
Pre-steady-state studies of the adenosine triphosphatase activity of coupled submitochondrial particles. Regulation by ADP.
AuthorsMartins OB, Tuena de Gómez-Puyou M, Gómez-Puyou A
JournalBiochemistry
PubMed ID2974725
'ATPase activities were measured in 10 mM MgCl2, 5 mM ATP, 1 mM ADP, and 1 microM FCCP with submitochondrial particles from bovine heart that had been stimulated by delta mu H+-forming substrates and with particles whose natural inhibitor protein was partially removed by heating. The activities were not ... More
Calcium-activated potassium channels sustain calcium signaling in T lymphocytes. Selective blockers and manipulated channel expression levels.
AuthorsFanger CM, Rauer H, Neben AL, Miller MJ, Rauer H, Wulff H, Rosa JC, Ganellin CR, Chandy KG, Cahalan MD
JournalJ Biol Chem
PubMed ID11278890
'To maintain Ca(2+) entry during T lymphocyte activation, a balancing efflux of cations is necessary. Using three approaches, we demonstrate that this cation efflux is mediated by Ca(2+)-activated K(+) (K(Ca)) channels, hSKCa2 in the human leukemic T cell line Jurkat and hIKCa1 in mitogen-activated human T cells. First, several recently ... More
The antidepressant fluoxetine blocks the human small conductance calcium-activated potassium channels SK1, SK2 and SK3.
AuthorsTerstappen GC, Pellacani A, Aldegheri L, Graziani F, Carignani C, Pula G, Virginio C
JournalNeurosci Lett
PubMed ID12850554
'The effects of fluoxetine (Prozac) on the activity of human small-conductance calcium-activated potassium (SK) channels were investigated utilizing a functional fluorescence assay with bis-(1,3-dibutylbarbituric acid)trimethine oxonol (DiBAC(4)(3)). Fluoxetine blocked SK channels stably expressed in HEK 293 cells in a concentration-dependent manner displaying half-maximal inhibitory concentrations (IC(50)) of 9 microM for ... More
Differential effects of pulsatile versus steady flow on coronary endothelial membrane potential.
AuthorsQiu WP, Hu Q, Paolocci N, Ziegelstein RC, Kass DA
JournalAm J Physiol Heart Circ Physiol
PubMed ID12793981
'Steady shear stress stimulates transient hyperpolarization coupled to calcium-sensitive potassium (KCa) channels and sustained depolarization linked to chloride-selective channels. Physiological flow is pulsatile not static, and whereas in vivo data suggest phasic shear stress may preferentially activate KCa channels, its differential effects on both currents remain largely unknown. To determine ... More
Sublethal injury and resuscitation of Candida albicans after amphotericin B treatment.
AuthorsLiao RS, Rennie RP, Talbot JA
JournalAntimicrob Agents Chemother
PubMed ID12654647
'Amphotericin B treatment was previously shown to inhibit Candida albicans reproduction and reduce the fluorescence of vitality-specific dyes without causing a corresponding increase in the fluorescence of the mortality-specific dyes bis-(1,3-dibutylbarbituric acid)trimethine oxonol and SYBR Green I. In the present study, we have confirmed these results and have shown that ... More
The calcium response to the excitotoxin kainate is amplified by subsequent reduction of extracellular sodium.
AuthorsCourtney MJ, Enkvist MO, Akerman KE
JournalNeuroscience
PubMed ID8544981
'The relation between intracellular and extracellular [Na+] and [Ca2+] and membrane potential during stimulation of non-N-methyl-D-aspartate glutamate receptors has been studied in cerebellar granule cells using the fluorescent indicators SBFI, fura-2 and the bisoxonol membrane potential probe DiBaC4(3). Kainate increased both [Ca2+]i (intracellular [Ca2+]) and [Na+]i (intracellular [Na+]) and depolarized ... More
The membrane potential of the intraerythrocytic malaria parasite Plasmodium falciparum.
AuthorsAllen RJ, Kirk K
JournalJ Biol Chem
PubMed ID14630911
'The membrane potential (Deltapsi) of the mature asexual form of the human malaria parasite, Plasmodium falciparum, isolated from its host erythrocyte using a saponin permeabilization technique, was investigated using both the radiolabeled Deltapsi indicator tetraphenylphosphonium ([(3)H]TPP(+)) and the fluorescent Deltapsi indicator DiBAC(4)(3) (bis-oxonol). For isolated parasites suspended in a high ... More
Depolarization of human neuroblastoma cells as a result of muscarinic receptor-induced rise in cytosolic Ca2+.
AuthorsAkerman KE
JournalFEBS Lett
PubMed ID2914616
'The role of intracellular free Ca2+ in muscarinic-receptor linked depolarization of SH-SY5Y neuroblastoma cells has been determined by using the bisoxonol membrane potential probe DiBaC4-(3) and intracellular Ca2+ indicator fura-2 respectively. Carbachol and the Ca2+ ionophore, ionomycin, at concentrations which caused similar rises in intracellular Ca2+ increased the bisoxonol fluorescence ... More
Role of chloride in constriction of descending vasa recta by angiotensin II.
'We investigated the dependence of ANG II (10(-8) M)-induced constriction of outer medullary descending vasa recta (OMDVR) on membrane potential (Psim) and chloride ion. ANG II depolarized OMDVR, as measured by fully loading them with the voltage-sensitive dye bis[1,3-dibutylbarbituric acid-(5)] trimethineoxonol [DiBAC(4)(3)] or selectively loading their pericytes. ANG II was ... More
Bending the primary cilium opens Ca2+-sensitive intermediate-conductance K+ channels in MDCK cells.
AuthorsPraetorius HA, Frokiaer J, Nielsen S, Spring KR
JournalJ Membr Biol
PubMed ID12571753
'Increasing tubular fluid flow rate has previously been shown to induce K+ secretion in mammalian cortical collecting duct. The mechanism responsible was examined in the present study using MDCK cells as a model. The change in membrane potential difference (EM) of MDCK cells was measured with a fluorescent voltage-sensitive dye, ... More
Antibacterial action of ciprofloxacin.
AuthorsMason DJ, Power EG, Talsania H, Phillips I, Gant VA
JournalAntimicrob Agents Chemother
PubMed ID8593014
'The mechanisms by which quinolones rapidly kill are ill defined. We have investigated the action of ciprofloxacin on Escherichia coli KL16 with a combination of traditional and flow cytometric methods and have analyzed cells for changes in membrane potential, membrane integrity, oxidative metabolism, morphology, and viability. Log-phase cultures were exposed ... More
The effect of transmembrane potential on the dynamic behavior of cell membranes.
AuthorsLakos Z, Somogyi B, Balázs M, Matkó J, Damjanovich S
JournalBiochim Biophys Acta
PubMed ID2317496
'The relationship between transmembrane potential and lipid dynamics in the cytoplasmic membrane of mouse thymus cells has been investigated. Changes of transmembrane potential was followed by measuring the fluorescence emission of the anionic dye, bis-(1,3-dibutylbarbiturate)trimethine oxonol (diBa-C4-(3)). Assessment of lipid fluidity was carried out applying three fluorescent lipid probes, 1-[4-(trimethylammonium)phenyl]-6-phenyl-1,3,5-hexatriene ... More
Major histocompatibility complex class I protein conformation altered by transmembrane potential changes.
AuthorsBene L, Szöllósi J, Balázs M, Mátyus L, Gáspár R, Ameloot M, Dale RE, Damjanovich S
JournalCytometry
PubMed ID9098627
'The nature of charge distributions in membrane-bound macromolecular structures renders them susceptible to interaction with transmembrane potential fields. As a result, conformational changes in such species may be expected to occur when this potential is altered. We have detected reversible conformational change in the major histocompatibility complex (MHC) class I ... More
Methodological aspects of measuring absolute values of membrane potential in human cells by flow cytometry.
AuthorsKlapperstück T, Glanz D, Klapperstück M, Wohlrab J,
JournalCytometry A
PubMed ID19504578
'The bis-barbituric acid oxonol, DiBAC(4)(3) is used as a standard potentiometric probe in human cells. However, its fluorescence depends not only on membrane potential but also varies with nonpotential related changes in the amount of intracellular free and bound dye. This study demonstrates the influence of different experimental conditions on ... More
Assessment of the effects of gramicidin, formaldehyde, and surfactants on Escherichia coli by flow cytometry using nucleic acid and membrane potential dyes.
AuthorsComas J, Vives-Rego J
JournalCytometry
PubMed ID9298812
'Two membrane potential sensitive dyes (Rhodamine 123 and bis-oxonol) and three nucleic acid dyes (propidium iodide, SYTO-13, and SYTO-17) were used to assess the effect of surfactants on Escherichia coli. The ability of E. coli to be stained by these probes was validated at different physiological states. Propidium iodide was ... More
The irradiation of hepatocytes with He-Ne laser causes an increase of cytosolic free calcium concentration and an increase of cell membrane potential, correlated with it, both increases taking place in an oscillatory manner.
AuthorsVacca RA, Moro L, Petragallo VA, Greco M, Fontana F, Passarella S
JournalBiochem Mol Biol Int
PubMed ID9415809
'Isolated hepatocytes were irradiated with Helium-Neon laser (fluence: 0.24 Joules x cm-2, fluence rate: 12 mW x cm-2) and changes of both cytosolic free Ca2+ concentration and cell membrane potential were checked by measuring fura-2 and bis-oxonol fluorescence respectively. Irradiation resulted in an enhancement in cytosolic free Ca2+ concentration that ... More
Unique signaling properties of B cell antigen receptor in mature and immature B cells: implications for tolerance and activation.
AuthorsBenschop RJ, Brandl E, Chan AC, Cambier JC
JournalJ Immunol
PubMed ID11591737
'Immature B cells display increased sensitivity to tolerance induction compared with their mature counterparts. The molecular mechanisms underlying these differences are poorly defined. In this study, we demonstrate unique maturation stage-dependent differences in B cell Ag receptor (BCR) signaling, including BCR-mediated calcium mobilization responses. Immature B cells display greater increases ... More
Rapid assessment of antibiotic effects on Escherichia coli by bis-(1,3-dibutylbarbituric acid) trimethine oxonol and flow cytometry.
AuthorsJepras RI, Paul FE, Pearson SC, Wilkinson MJ
JournalAntimicrob Agents Chemother
PubMed ID9303401
'The effects of selected antibiotics on Escherichia coli were studied by flow cytometry with the fluorescent anionic membrane potential probe bis-(1,3-dibutylbarbituric acid) trimethine oxonol [DiBAC4(3)]. The actions of azithromycin, cefuroxime, and ciprofloxacin at five times the MIC on E. coli were compared by the traditional CFU assay and flow cytometry. ... More
Flow cytometric analysis of chlorhexidine action.
AuthorsSheppard FC, Mason DJ, Bloomfield SF, Gant VA
JournalFEMS Microbiol Lett
PubMed ID9311126
'The mechanism by which chlorhexidine kills bacteria is still ill defined. We have investigated the action of chlorhexidine on Escherichia coli JM101/psb311 using a combination of flow cytometry and traditional methods. Chlorhexidine-induced uptake by E. coli cells of bis-(1,3-dibutylbarturic acid) trimethine oxonol and propidium iodide, which monitor membrane potential and ... More
Diverse voltage-sensitive dyes modulate GABAA receptor function.
AuthorsMennerick S, Chisari M, Shu HJ, Taylor A, Vasek M, Eisenman LN, Zorumski CF,
JournalJ Neurosci
PubMed ID20181584
'Voltage-sensitive dyes are important tools for assessing network and single-cell excitability, but an untested premise in most cases is that the dyes do not interfere with the parameters (membrane potential, excitability) that they are designed to measure. We found that popular members of several different families of voltage-sensitive dyes modulate ... More
Assessment of Escherichia coli B with enhanced permeability to fluorochromes for flow cytometric assays of bacterial cell function.
AuthorsHerrera G, Martinez A, Blanco M, O'Connor JE
JournalCytometry
PubMed ID12357461
'BACKGROUND: Flow cytometry has become a choice methodology for microbiological research. However, functional cytometric assays in live bacteria are still limited. This is due, in part, to the cell wall impairing penetration of vital dyes in bacteria, thus imposing permeabilization procedures. These manipulations may affect cell physiology, provoke cell aggregation ... More
Development and evaluation of high throughput functional assay methods for HERG potassium channel.
AuthorsTang W, Kang J, Wu X, Rampe D, Wang L, Shen H, Li Z, Dunnington D, Garyantes T
JournalJ Biomol Screen
PubMed ID11689132
'Three functional hERG channel assay methods have been developed and evaluated. The methods were tested against five known hERG channel inhibitors: dofetilide, terfenadine (Seldane), sertindole (Serdolect), astemizole (Hismanal), and cisapride (Propulsid). The DiBAC4(3)-based assays were found to be the most economical but had high false-hit rates as a result of ... More
Pentamidine is active in vitro against Fusarium species.
AuthorsLionakis MS, Lewis RE, Samonis G, Kontoyiannis DP
JournalAntimicrob Agents Chemother
PubMed ID14506038
'Fusariosis is an emerging opportunistic mycosis against which currently used antifungals have limited activity. Here, we investigated the in vitro activities of pentamidine (PNT) against 10 clinical isolates of Fusarium species (five Fusarium solani isolates and five non-F. solani isolates) by using the National Committee for Clinical Laboratory Standards microdilution ... More
Flow cytometric assessment of the postantibiotic effect of methicillin on Staphylococcus aureus.
AuthorsSuller MT, Lloyd D
JournalAntimicrob Agents Chemother
PubMed ID9593149
'The postantibiotic effect (PAE) following a 2-h exposure of Staphylococcus aureus NCTC 6571 to methicillin (5x the MIC) was investigated with fluorescent probes, 5-cyano-2,3-di-4-tolyl tetrazolium chloride (CTC), an indicator of respiratory activity, and the membrane potential-sensitive compound bis-(1,3-dibutylbarbituric acid) trimethine oxonol [DiBAC4(3)]. Counts of the numbers of CFU on solid ... More
A flow cytometric study of antibiotic-induced damage and evaluation as a rapid antibiotic susceptibility test for methicillin-resistant Staphylococcus aureus.
AuthorsSuller MT, Stark JM, Lloyd D
JournalJ Antimicrob Chemother
PubMed ID9249207
'Flow cytometry using the anionic membrane potential-sensitive fluorescent probe, bis-(1,3-dibutylbarbituric acid) trimethine oxonol (DiBAC4(3)), enabled assessment of antibiotic-induced membrane perturbation in five clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and two antibiotic-sensitive reference strains, NCTC 6571 and 8325-4, after establishment of steady-state growth in liquid cultures inoculated from single colonies. ... More
Flow cytometric analysis of membrane potential in embryonic rat spinal cord cells.
AuthorsMandler RN, Schaffner AE, Novotny EA, Lange GD, Barker JL
JournalJ Neurosci Methods
PubMed ID3361946
'Flow cytometric analysis of membrane potential in suspensions of embryonic rat spinal cord cells was carried out in a fluorescence-activated cell sorter (FACS) using anionic voltage-sensitive, fluorescent dyes (oxonols). The FACS or flow cytometer is an analytical instrument that measures optical properties of large cell populations at a single cell ... More
Calcitonin gene-related peptide elevates calcium and polarizes membrane potential in MG-63 cells by both cAMP-independent and -dependent mechanisms.
AuthorsBurns DM, Stehno-Bittel L, Kawase T
JournalAm J Physiol Cell Physiol
PubMed ID15238361
'Published data suggest that the neuropeptide calcitonin gene-related peptide (CGRP) can stimulate osteoblastic bone formation; however, interest has focused on activation of cAMP-dependent signaling pathways in osteogenic cells without full consideration of the importance of cAMP-independent signaling. We have now examined the effects of CGRP on intracellular Ca(2+) concentration ([Ca(2+)](int)) ... More
Effect of u.v. light irradiation, starvation and heat on Escherichia coli beta-D-galactosidase activity and other potential viability parameters.
AuthorsFiksdal L, Tryland I
JournalJ Appl Microbiol
PubMed ID10432588
'The effect of u.v. light irradiation and two other types of stress (heat and starvation) on cellular functions of Escherichia coli have been studied. The severe reduction of the culturable cell number (cfu) and the direct viable count (DVC) after exposure to moderate u.v. light doses (48 mWs cm-2), was ... More
Intracellular ramification of endothelin signal.
AuthorsIijima K, Lin L, Nasjletti A, Goligorsky MS
JournalAm J Physiol
PubMed ID2035621
'Effects of porcine 1-21 endothelin (ET-1) on [Ca2+]i, [Na+]i, and [Cl-]i and on membrane potential were studied in individual mesangial (MC) and vascular smooth muscle (VSMC) cells using microspectrofluorimetry of fura-2, SBFI, SPQ, and bis-oxonol, respectively. ET-1 increased [Ca2+]i by fivefold, showing an immediate and a sustained phase of response. ... More
Accurate flow cytometric membrane potential measurement in bacteria using diethyloxacarbocyanine and a ratiometric technique.
AuthorsNovo D, Perlmutter NG, Hunt RH, Shapiro HM
JournalCytometry
PubMed ID10554181
'BACKGROUND: Membrane potential (MP) plays a critical role in bacterial physiology. Existing methods for MP estimation by flow cytometry are neither accurate nor precise, due in part to the heterogeneity of size of the particles analyzed. The ratio of a size- and MP-sensitive measurement, and an MP-independent, size-sensitive measurement, should ... More
Rapid estimation of bacterial antibiotic susceptibility with flow cytometry.
AuthorsMason DJ, Allman R, Stark JM, Lloyd D
JournalJ Microsc
PubMed ID7799429
'Bacterial antibiotic susceptibility was rapidly estimated for Escherichia coli and Staphylococcus spp. by flow cytometry. This was achieved by measuring the uptake of a negatively charged membrane potential sensitive dye bis-(1,3-dibutyl-barbituric acid) trimethine oxonol and observing changes in low-angle light scatter (excitation light scattered by up to 15 degrees). Estimations ... More
The ability of membrane potential dyes and calcafluor white to distinguish between viable and non-viable bacteria.
AuthorsMason DJ, Lopéz-Amorós R, Allman R, Stark JM, Lloyd D
JournalJ Appl Bacteriol
PubMed ID7537262
'Various dyes were assessed for their ability to discriminate between viable and non-viable bacteria. Two methods of killing were employed: by heat treatment or by gramicidin treatment. Staining was carried out in two ways; by staining directly in the medium or by washing cells prior to staining in buffer. Carbocyanine ... More
Characterization of Zn(2+) transport in Madin-Darby canine kidney cells.
AuthorsDucoudret O, Barbier O, Tauc M, Fuchs M, Poujeol P
JournalBiochim Biophys Acta
PubMed ID12659958
'The aim of this study was to characterize the mechanism implicated in Zn(2+) transport in MDCK cells. Trace elements such as Zn(2+), Cd(2+) or Cu(2+) induced MDCK cell depolarization at the micromolar level as demonstrated by bis-oxonol fluorescence and whole-cell patch experiments. This depolarization was inhibited by La(3+) and Gd(3+) ... More
In situ study of the membrane potential in microvascular endothelial cells using a fluorescent probe.
AuthorsMiao K, Joyner WL
JournalMicrovasc Res
PubMed ID7990720
Flow cytometric monitoring of bacterial susceptibility to antibiotics.
AuthorsWalberg M, Steen HB
JournalMethods Cell Biol
PubMed ID11070855
Flow cytometric detection of fluorescent redistributional dyes for measurement of cell transmembrane potential.
AuthorsTanner MK, Wellhausen SR
JournalMethods Mol Biol
PubMed ID9664484
Optical measurement of membrane potential in cells, organelles, and vesicles.
AuthorsFreedman JC, Novak TS
JournalMethods Enzymol
PubMed ID2747524
Resting plasma membrane potential of rat peritoneal mast cells is set predominantly by the sodium pump.
AuthorsBronner C, Mousli M, Eleno N, Landry Y
JournalFEBS Lett
PubMed ID2477283
Changes in the plasma membrane potential of two histamine-releasing cells, rat peritoneal mast cells and basophilic leukemia cells 2H3 (RBL 2H3), were recorded with the potential-sensitive dye bis-oxonol. For mast cells, the presence of ouabain or the absence of K+ increased the fluorescence intensity of bis-oxonol; gramicidin had no effect. ... More
Evaluation of the suitability of bis-(1,3-dibutylbarbituric acid) trimethine oxonol, (diBA-C4(3)-), for the flow cytometric assessment of bacterial viability.
AuthorsDeere D, Porter J, Edwards C, Pickup R
JournalFEMS Microbiol Lett
PubMed ID7649437
The usefulness of oxonol (bis-(1,3-dibutylbarbituric acid)trimethine oxonol) as a generally applicable indicator of bacterial viability was investigated using untreated and killed cultures of a variety of bacterial genera. Killing methods involved either heat or bactericidal antibiotics. For all strains tested, the fluorescent dye showed significantly more intense staining of killed ... More
Intracellular pH regulation in rat round spermatids.
AuthorsOsses N, Pancetti F, Benos DJ, Reyes JG
JournalBiol Cell
PubMed ID9447702
Intracellular pH has been shown to be an important physiological parameter in cell cycle control and differentiation, aspects that are central to the spermatogenic process. However, the pH regulatory mechanisms in spermatogenic cells have not been systematically explored. In this work, measuring intracellular pH (pHi) with a fluorescent probe (BCECF), ... More
Effects of bacteriocins on methicillin-resistant Staphylococcus aureus biofilm.
AuthorsOkuda K, Zendo T, Sugimoto S, Iwase T, Tajima A, Yamada S, Sonomoto K, Mizunoe Y,
Journal
PubMed ID23979748
Control of biofilms formed by microbial pathogens is an important subject for medical researchers, since the development of biofilms on foreign-body surfaces often causes biofilm-associated infections in patients with indwelling medical devices. The present study examined the effects of different kinds of bacteriocins, which are ribosomally synthesized antimicrobial peptides produced ... More
Animal cells connected by nanotubes can be electrically coupled through interposed gap-junction channels.
AuthorsWang X, Veruki ML, Bukoreshtliev NV, Hartveit E, Gerdes HH,
JournalProc Natl Acad Sci U S A
PubMed ID20855598
Tunneling nanotubes (TNTs) are recently discovered conduits for a previously unrecognized form of cell-to-cell communication. These nanoscale, F-actin-containing membrane tubes connect cells over long distances and facilitate the intercellular exchange of small molecules and organelles. Using optical membrane-potential measurements combined with mechanical stimulation and whole-cell patch-clamp recording, we demonstrate that ... More
Transmembrane voltage regulates binding of annexin V and lactadherin to cells with exposed phosphatidylserine.
AuthorsSmith C, Gibson DF, Tait JF,
JournalBMC Biochem
PubMed ID19222854
BACKGROUND: Cells expose phosphatidylserine during apoptosis. The voltage across the plasma membrane also decreases or disappears during apoptosis, but the physiological significance of this is unknown. RESULTS: Here we show that transmembrane potential regulates membrane binding of two unrelated proteins that recognize exposed phosphatidylserine on apoptotic cells. In Jurkat T ... More
Validation of FLIPR membrane potential dye for high throughput screening of potassium channel modulators.
AuthorsWhiteaker KL, Gopalakrishnan SM, Groebe D, Shieh CC, Warrior U, Burns DJ, Coghlan MJ, Scott VE, Gopalakrishnan M
JournalJ Biomol Screen
PubMed ID11689130
A fluorescence-based assay using the FLIPR Membrane Potential Assay Kit (FMP) was evaluated for functional characterization and high throughput screening (HTS) of potassium channel (ATP-sensitive K+ channel; K(ATP)) modulators. The FMP dye permits a more sensitive evaluation of changes in membrane potential with a more rapid response time relative to ... More
Glutamate receptor agonists increase intracellular Ca2+ independently of voltage-gated Ca2+ channels in rat cerebellar granule cells.
AuthorsHolopainen I, Enkvist MO, Akerman KE
JournalNeurosci Lett
PubMed ID2565564
Changes in membrane potential and cytosolic free Ca2+ concentrations, [Ca2+]i, in response to L-glutamate and glutamate receptor agonists were measured in rat cerebellar granule cells grown on coverslips. The membrane was depolarized by the application of L-glutamate and kainate, and by elevating the extracellular K+ concentration, as determined by using ... More
Physiological damages of Listeria monocytogenes treated by high hydrostatic pressure.
AuthorsRitz M, Tholozan JL, Federighi M, Pilet MF
JournalInt J Food Microbiol
PubMed ID12382684
High hydrostatic pressure is a new food preservation technology known for its capacity to inactivate spoilage and pathogenic microorganisms. This study investigated the damages inflicted on Listeria monocytogenes cells treated by high pressure for 10 min at 400 MPa in pH 5.6 citrate buffer. Under these conditions, no cell growth ... More
Involvement of sodium in early phosphatidylserine exposure and phospholipid scrambling induced by P2X7 purinoceptor activation in thymocytes.
AuthorsCourageot MP, Lépine S, Hours M, Giraud F, Sulpice JC
JournalJ Biol Chem
PubMed ID14996828
Extracellular ATP (ATP(ec)), a possible effector in thymocyte selection, induces thymocyte death via purinoceptor activation. We show that ATP(ec) induced cell death by apoptosis, rather than lysis, and early phosphatidylserine (PS) exposure and phospholipid scrambling in a limited thymocyte population (35-40%). PS externalization resulted from the activation of the cationic ... More
Assessment of E. coli and Salmonella viability and starvation by confocal laser microscopy and flow cytometry using rhodamine 123, DiBAC4(3), propidium iodide, and CTC.
AuthorsLópez-Amorós R, Castel S, Comas-Riu J, Vives-Rego J
JournalCytometry
PubMed ID9415412
Assessment of cell viability using methods which do not require cell culture is essential in the field of aquatic microbiology, since many bacteria known to be present in aquatic environments cannot be grown in culture. The study of bacterial biofilms, which previously needed an epifluorescent microscope, has recently been enhanced ... More
Flow cytometric determination of absolute membrane potential of cells.
AuthorsKrasznai Z, Márián T, Balkay L, Emri M, Trón L
JournalJ Photochem Photobiol B
PubMed ID7791010
Membrane potential measurements using fluorescent membrane potential indicator dyes report on relative changes but usually do not result in an absolute value of the measured parameter. The method developed in this paper is based on the assumption that the negatively charged bis-oxonol distributes across the cytoplasmic membrane according to the ... More
Human natural killer cells express Na+ channels. A pharmacologic flow cytometric study.
AuthorsMandler RN, Seamer LC, Whitlinger D, Lennon M, Rosenberg E, Bankhurst AD
JournalJ Immunol
PubMed ID2155964
Voltage-gated excitability of purified human NK cells was studied by using flow cytometry and the voltage-sensitive dye, oxonol. Highly purified human NK cells (CD16 = 95 +/- 1%) from normal volunteers were prepared by using a negative panning technique. The Na(+)-channel agonists batrachotoxin (BTX) (1 to 4 microM) and veratridine ... More
A microfluidic device for measuring cellular membrane potential.
AuthorsFarinas J, Chow AW, Wada HG
JournalAnal Biochem
PubMed ID11488614
Recent developments in microfluidics have enabled the design of a lab-on-a-chip system capable of measuring cellular membrane potential. The chip accesses liquid samples sequentially by sipping from a microplate through a capillary, mixes the samples with cells flowing through a microchannel, contacts the cells with potential-sensitive dyes, and reads out ... More
A flow cytometric study of the membrane potential of natural killer and K562 cells during the cytotoxic process.
AuthorsRadosevic K, Schut TC, van Graft M, de Grooth BG, Greve J
JournalJ Immunol Methods
PubMed ID8486923
This study demonstrates that it is possible to investigate the membrane potential of interacting cells during the cytotoxic process using flow cytometry. Changes in the membrane potential of NK and K562 cells, involved in a cell-mediated cytotoxic process, were studied by standard and slit-scan flow cytometry, using the membrane potential ... More
Nitrosative stress induced cytotoxicity in Giardia intestinalis.
AIMS: To investigate the antigiardial properties of the nitrosating agents: sodium nitrite, sodium nitroprusside and Roussin's black salt. METHODS AND RESULTS: Use of confocal laser scanning microscopy and flow cytometry indicated permeabilization of the plasma membrane to the anionic fluorophore, DiBAC4(3) [bis(1,3-dibutylbarbituric acid) trimethine oxonol]. Loss of plasma membrane electrochemical ... More
[Macrophage activation by synthetic peptides. III. Changes in the membrane potential, Ca2+ content and the regulatory decrease of macrophage volume under the action of tuftsin and its antagonist]
AuthorsGamalei IA, Kaulin AB, Kirpichnikova KM
JournalTsitologiia
PubMed ID1823673
With the use of oxonol voltage-sensitive fluorescent dye it has been shown that the stimulation of macrophages (MP) with tuftsin results in a two-phase change in membrane potential: depolarization followed by hyperpolarization of plasma membrane. The pattern of changes in membrane potential depends on Na+ concentration in the medium and ... More
Rapid antimicrobial susceptibility testing of urinary tract isolates and samples by flow cytometry.
AuthorsGauthier C, St-Pierre Y, Villemur R
JournalJ Med Microbiol
PubMed ID11871613
A multiparametric flow cytometry antimicrobial susceptibility test was developed and its performance was evaluated on clinical urine isolates and samples in comparison with standard methods. Alterations in cytoplasmic membrane integrity were monitored by propidium iodide, and the anionic probe bis-(1,3-dibutylbarbituric acid) trimethine oxonol (DiBAC4(3)) was used to measure changes in ... More
Selective role of intracellular chloride in the regulation of the intrinsic but not extrinsic pathway of apoptosis in Jurkat T-cells.
AuthorsHeimlich G, Cidlowski JA
JournalJ Biol Chem
PubMed ID16299378
Apoptosis is a genetic program for the removal of unwanted cells from an organism, which is distinct from necrosis by its characteristic volume loss or apoptotic volume decrease. This cell shrinkage is the result of ion redistribution that is crucial for both the activation and execution of apoptosis. Here we ... More
Antifungal susceptibility testing of Candida species by flow cytometry.
AuthorsLee W, Kwak Y
JournalJ Korean Med Sci
PubMed ID10102519
The feasibility of flow cytometric antifungal susceptibility testing has been studied using the fluorescent anionic membrane potential probe, bis-(1,3-dibutylbarbituric acid) trimethine oxonol [DiBAC4(3)]. The in vitro antifungal susceptibility testing of amphotericin B was performed on 8 Candida isolates from clinical specimens and 2 ATCC strains by flow cytometry with the ... More
Comparative measurements of membrane potentials with microelectrodes and voltage-sensitive dyes.
AuthorsBräuner T, Hülser DF, Strasser RJ
JournalBiochim Biophys Acta
PubMed ID6704395
The usefulness of a new voltage-sensitive fluorescent dye, the membrane permeant negatively charged oxonol dye diBA-C4-(3)-, was evaluated by measuring the membrane potentials of BICR/M1R-k and L cells with glass microelectrodes and simultaneously recording the fluorescence of the stained cells. The membrane potential of BICR/M1R-k cells was varied between -25 ... More
Xanthine affects [Ca2+]i and contractile responses of ventricular cardiocytes to electrical stimulation.
AuthorsRohn TT, Sauvadet A, Pavoine C, Pecker F
JournalAm J Physiol
PubMed ID9316412
Xanthine, a major purine by-product of ATP, accumulates during myocardial ischemia. In the present study, we show that xanthine (0.5-1 mM) impaired the occurrence of cytosolic Ca2+ concentration ([Ca2+]i) transients, visualized in fura 2-loaded cells, and twitches of contraction in ventricular cardiocytes in response to electrical stimulation. This effect of ... More
Rapid assessment of the physiological status of the polychlorinated biphenyl degrader Comamonas testosteroni TK102 by flow cytometry.
AuthorsHiraoka Y, Kimbara K
JournalAppl Environ Microbiol
PubMed ID11916727
The viability of the polychlorinated biphenyl-degrading bacterium Comamonas testosteroni TK102 was assessed by flow cytometry (FCM) with the fluorogenic ester Calcein-AM (CAM) and the nucleic acid dye propidium iodide (PI). CAM stained live cells, whereas PI stained dead cells. When double staining with CAM and PI was performed, three physiological ... More
Regulation of eosinophil membrane depolarization during NADPH oxidase activation.
AuthorsBankers-Fulbright JL, Gleich GJ, Kephart GM, Kita H, O'Grady SM
JournalJ Cell Sci
PubMed ID12829741
Protein kinase C (PKC) activation in human eosinophils increases NADPH oxidase activity, which is associated with plasma membrane depolarization. In this study, membrane potential measurements of eosinophils stimulated with phorbol ester (phorbol 12-myristate 13-acetate; PMA) were made using a cell-permeable oxonol membrane potential indicator, diBAC4(3). Within 10 minutes after PMA ... More
Peroxynitrite leads to arteriolar smooth muscle cell membrane hyperpolarization and low vasoreactivity in severe shock.
AuthorsZhao KS, Liu J, Yang GY, Jin C, Huang Q, Huang X
JournalClin Hemorheol Microcirc
PubMed ID11321449
This paper aimed to study the mechanism of vascular hyporeactivity during severe hemorrhagic shock. Rats were divided into control and shock group. Membrane potential of arteriolar strips was measured with intracellular recording method and membrane potential changes in arteriolar smooth muscle cells (ASMC) were recorded with membrane potential sensitive fluorescent ... More
Oxidant generation with K(+)-induced depolarization in the isolated perfused lung.
Authorsal-Mehdi AB, Shuman H, Fisher AB
JournalFree Radic Biol Med
PubMed ID9165296
This study evaluated whether cell membrane depolarization can induce oxidant generation in the isolated perfused rat lung as has been demonstrated with bovine pulmonary artery endothelial cells. Depolarization was produced by perfusing the lungs with high [K+] or with glyburide and was evaluated with bis-oxonol lung surface fluorometry. Lung surface ... More
Differential inhibition of AE1 and AE2 anion exchangers by oxonol dyes and by novel polyaminosterol analogs of the shark antibiotic squalamine.
AuthorsAlper SL, Chernova MN, Williams J, Zasloff M, Law FY, Knauf PA
JournalBiochem Cell Biol
PubMed ID10353714
Oxonol and polyaminosterol drugs were examined as inhibitors of recombinant mouse AE1 and AE2 anion exchangers expressed in Xenopus laevis oocytes and were compared as inhibitors of AE1-mediated anion flux in red cells and in HL-60 cells that express AE2. The oxonols WW-781, diBA(5)C4, and diBA(3)C4 inhibited HL-60 cell Cl-/Cl- ... More
Assessment of bacterial endospore viability with fluorescent dyes.
AuthorsLaflamme C, Lavigne S, Ho J, Duchaine C
JournalJ Appl Microbiol
PubMed ID15012806
AIM: To validate three fluorescence viability assays designed primarily for vegetative cells on pure Bacillus endospores. METHODS AND RESULTS: Purified fresh and gamma-irradiated Bacillus endospores (Bacillus cereus, B. coagulans and two strains of B. subtilis) were used. The viability assays were: 5-cyano-2,3-diotolyl tetrazolium chloride (CTC) to test respiratory activity and ... More
Assessment of the effect of amphotericin B on the vitality of Candida albicans.
AuthorsLiao RS, Rennie RP, Talbot JA
JournalAntimicrob Agents Chemother
PubMed ID10223911
The processes involved in cell death are complex, and individual techniques measure specific fractions of the total population. The interaction of Candida albicans with amphotericin B was measured with fluorescent probes with different cellular affinities. These were used to provide qualitative and quantitative information of physiological parameters which contribute to ... More
Membrane permeability changes induce hyperpolarization in transformed lymphoid cells under high-density culture conditions.
AuthorsMárián T, Balkay L, Krasznai Z, Trón L
JournalCytometry
PubMed ID11042615
BACKGROUND: Membrane potential changes in cells from the human lymphoid B cell line, JY, evoked by increasing cell density in culture were investigated, as data published on other cell types are controversial. An attempt was also made to clear the underlying mechanism. METHODS: Nonadherent JY cells were isolated from high-density ... More
Online monitoring of Escherichia coli ghost production.
AuthorsHaidinger W, Szostak MP, Jechlinger W, Lubitz W
JournalAppl Environ Microbiol
PubMed ID12514029
Controlled expression of cloned phi X174 gene E in gram-negative bacteria results in lysis of the bacteria by the formation of a transmembrane tunnel structure built through the cell envelope complex. Production of bacterial ghosts is routinely monitored by classical microbiological procedures. These include determination of the turbidity of the ... More
The plasma membrane of microaerophilic protists: oxidative and nitrosative stress.
The trans-plasma-membrane electrochemical potential of microaerophilic protists was monitored by the use of voltage-sensitive charged lipophilic fluorophores; of the many available probes, the anionic oxonol dye bis(1,3-dibarbituric acid)-trimethine oxonol [DiBAC(4)(3)] is an example of one which has been successfully employed using fluorescence microscopy, confocal laser-scanning microscopy and flow cytometry. Several ... More
Detection of sodium channel activators by a rapid fluorimetric microplate assay.
Marine toxins such as brevetoxins and ciguatoxins are produced by dinoflagellates and can accumulate in seafood. These toxins affect humans through seafood consumption. Intoxication is mainly characterized by gastrointestinal and neurological disorders and, in most severe cases, by cardiovascular problems. To prevent the consumption of food contaminated with these toxins, ... More
Partition of the organochlorine insecticide lindane into the human sperm surface induces membrane depolarization and Ca2+ influx.
AuthorsSilvestroni L, Fiorini R, Palleschi S
JournalBiochem J
PubMed ID9032455
The effects of the insecticide lindane (the gamma-isomer of 1,2,3,4,5,6-hexachlorocyclohexane) on membrane potential, cytosolic free Ca2+ concentration ([Ca2+]i) and surface biophysical properties were studied in human spermatozoa. The insecticide induces rapid, transient and reproducible membrane depolarization and opening of voltage-dependent Ca2+ channels leading to an increase in [Ca2+]i. In contrast ... More
Acute reductions in PO2 depolarize pulmonary artery endothelial cells and decrease [Ca2+]i.
Whereas pulmonary artery endothelial cells (PAECs) are sensitive to oxygen, neither the effect of an acute reduction in PO2 on PAEC membrane potential nor its effect on intracellular free Ca2+ ([Ca2+]i) is known. We hypothesized that in confluent primary cultures of PAECs, an acute decrease in PO2 would depolarize the ... More
Peroxynitrite affects Ca2+ influx through voltage-dependent calcium channels.
AuthorsOhkuma S, Katsura M, Higo A, Shirotani K, Hara A, Tarumi C, Ohgi T
JournalJ Neurochem
PubMed ID11208897
The effect of peroxynitrite (OONO-) on voltage-dependent Ca2+ channels (VDCCs) was examined by measuring [45Ca2+] influx into mouse cerebral cortical neurones. OONO- time- and dose-dependently increased [45Ca2+] influx and this increase was abolished by manganese (III) tetrakis (4-benzoic acid) porphyrin, a scavenger for OONO-. Inhibition of cyclic GMP (cGMP) formation ... More
Evidence for the interaction of mast cell-degranulating peptide with pertussis toxin-sensitive G proteins in mast cells.
AuthorsMousli M, Bronner C, Bueb JL, Landry Y
JournalEur J Pharmacol
PubMed ID1716580
K(+)-channel blocker properties have been reported for mast cell-degranulating peptide (MCD) in the central nervous system, but its action mechanism in mast cells remains unknown. We studied the effect of MCD on the membrane potential of rat peritoneal mast cells using the fluorescent probe bis-oxonol. Unexpectedly, MCD induced a decrease ... More
Rapid screening of possible cytotoxic effects of particulate air pollutants by measurement of changes in cytoplasmic free calcium, cytosolic pH, and plasma membrane potential in alveolar macrophages by flow cytometry.
AuthorsTárnok A, Dörger M, Berg I, Gercken G, Schlüter T
JournalCytometry
PubMed ID11170108
BACKGROUND: Inhalable particulate dusts are involved in the genesis of several lung diseases. Besides the well-known toxic dusts, i.e., asbestos and quartz, heavy metal-containing pollutants are considered as possible harmful substances. In the present study, we compared the effect of silica chemically coated with certain metal oxides and dusts from ... More
Extracellular HIV-1 virus protein R causes a large inward current and cell death in cultured hippocampal neurons: implications for AIDS pathology.
AuthorsPiller SC, Jans P, Gage PW, Jans DA
JournalProc Natl Acad Sci U S A
PubMed ID9539783
The small HIV-1 accessory protein Vpr (virus protein R) is a multifunctional protein that is present in the serum and cerebrospinal fluid of AIDS patients. We previously showed that Vpr can form cation-selective ion channels across planar lipid bilayers, introducing the possibility that, if incorporated into the membranes of living ... More
The calcimimetic R-467 potentiates insulin secretion in pancreatic beta cells by activation of a nonspecific cation channel.
AuthorsStraub SG, Kornreich B, Oswald RE, Nemeth EF, Sharp GW
JournalJ Biol Chem
PubMed ID10751384
The extracellular, G protein-linked Ca(2+)-sensing receptor (CaSR), first identified in the parathyroid gland, is expressed in several tissues and cells and can be activated by Ca(2+) and some other inorganic cations and organic polycations. Calcimimetics such as NPS (R)-N-(3-phenylpropyl)-alpha-methyl-3-methoxybenzylamine hydrochloride (R-467), a phenylalkylamine, are thought to activate CaSR by allosterically ... More
Lymphocyte membrane potential and Ca2+-sensitive potassium channels described by oxonol dye fluorescence measurements.
AuthorsWilson HA, Chused TM
JournalJ Cell Physiol
PubMed ID2413058
A method is described for quantitative measurement of lymphocyte transmembrane electrical potential difference (psi) by flow cytometric recording of the oxonol dye fluorescence of single cells. Both the simultaneous collection and analysis of multiple optical parameters and the use of a negatively charged oxonol probe allowed more accurate measurement of ... More
Usefulness and limitation of DiBAC4(3), a voltage-sensitive fluorescent dye, for the measurement of membrane potentials regulated by recombinant large conductance Ca2+-activated K+ channels in HEK293 cells.
AuthorsYamada A, Gaja N, Ohya S, Muraki K, Narita H, Ohwada T, Imaizumi Y
JournalJpn J Pharmacol
PubMed ID11488436
The usefulness of bis-(1,3-dibutylbarbituric acid)-trimethine oxonol (DiBAC4(3)), a voltage-sensitive fluorescent dye, for the measurement of membrane potentials (MPs) was evaluated in HEK293 cells, where alpha or alpha plus beta1 subunits of large conductance Ca2+-activated K+ (BK) channels were expressed (HEKBK alpha and HEKBK alphabeta). The fluorescent intensity of DiBAC4(3) was ... More
Membrane depolarization was required to induce DNA synthesis in murine macrophage cell line PU5-1.8.
AuthorsKong SK, Suen YK, Choy YM, Fung KP, Lee CY
JournalImmunopharmacol Immunotoxicol
PubMed ID1940052
The role of membrane potential (Em) on the initiation of DNA synthesis in murine macrophage cell line PU5-1.8 was investigated with fluorescent probes bis-oxonol and diS-C3-(5). Incubation of PU5-1.8 cells in high K(+)-HEPES buffer or with gramicidin at 37 degrees C for 1h that depolarized the membrane induced [3H]-thymidine incorporation ... More
Use of flow cytometry to monitor cell damage and predict fermentation activity of dried yeasts.
AuthorsAttfield PV, Kletsas S, Veal DA, van Rooijen R, Bell PJ
JournalJ Appl Microbiol
PubMed ID10971752
Viable dried yeast is used as an inoculum for many fermentations in the baking and wine industries. The fermentative activity of yeast in bread dough or grape must is a critical parameter of process efficiency. Here, it is shown that fluorescent stains and flow cytometry can be used in concert ... More
Hyperpolarization of isolated capillaries from guinea-pig heart induced by K+ channel openers and glucose deprivation.
AuthorsLangheinrich U, Daut J
JournalJ Physiol
PubMed ID9263919
1. The present study was designed to test if microvascular coronary endothelial cells express ATP-sensitive K+ channels (KATP channels). We performed microfluorometric measurements of the membrane potential of freshly isolated guinea-pig coronary capillaries equilibrated with the voltage-sensitive dye bis-oxonol (bis-[1,3-dibutylbarbituric acid] trimethineoxonol, [DiBAC4(3)]). 2. The resting membrane potential of capillaries ... More