Expression of the voltage-gated sodium channel NaV1.5 in the macrophage late endosome regulates endosomal acidification.
AuthorsCarrithers MD, Dib-Hajj S, Carrithers LM, Tokmoulina G, Pypaert M, Jonas EA, Waxman SG,
JournalJ Immunol
PubMed ID17548620
'Voltage-gated sodium channels expressed on the plasma membrane activate rapidly in response to changes in membrane potential in cells with excitable membranes such as muscle and neurons. Macrophages also require rapid signaling mechanisms as the first line of defense against invasion by microorganisms. In this study, our goal was to ... More
Interaction of cofilin with triose-phosphate isomerase contributes glycolytic fuel for Na,K-ATPase via Rho-mediated signaling pathway.
AuthorsJung J, Yoon T, Choi EC, Lee K
JournalJ Biol Chem
PubMed ID12359716
'We reported previously that cofilin, an actin-binding protein, interacts with Na,K-ATPase and enhances its activity (Lee, K., Jung, J., Kim, M., and Guidotti, G. (2001) Biochem. J. 353, 377-385). To understand the nature of this interaction and the role of cofilin in the regulation of Na,K-ATPase activity, we searched for ... More
Pleural surface fluorescence measurement of Na+ and Cl- transport across the air space-capillary barrier.
AuthorsJiang J, Song Y, Bai C, Koller BH, Matthay MA, Verkman AS
JournalJ Appl Physiol
PubMed ID12391048
'We developed a pleural surface fluorescence method to measure Na(+) and Cl(-) transport in perfused mouse lungs. The air space was filled with aqueous fluid containing membrane-impermeant fluorescent indicators of Cl(-) (lucigenin) or Na(+) (Sodium Green). After instillation of a Cl(-)-free solution into the air space, an increase in perfusate ... More
Fluorescence measurement of intracellular sodium concentration in single Escherichia coli cells.
AuthorsLo CJ, Leake MC, Berry RM
JournalBiophys J
PubMed ID16227503
'The energy-transducing cytoplasmic membrane of bacteria contains pumps and antiports maintaining the membrane potential and ion gradients. We have developed a method for rapid, single-cell measurement of the internal sodium concentration ([Na(+)](in)) in Escherichia coli using the sodium ion fluorescence indicator, Sodium Green. The bacterial flagellar motor is a molecular ... More
Regional crypt function in rat large intestine in relation to fluid absorption and growth of the pericryptal sheath.
AuthorsNaftalin RJ, Pedley KC
JournalJ Physiol
PubMed ID9831728
'1. Confocal microscopic studies of rat colonic mucosa showed that the pericryptal sheath surrounding distal colonic crypts is an effective barrier both to dextran and NaCl movement, whereas no such structure surrounds the caecal crypts. 2. The distal colonic pericryptal barrier was functionally demonstrated by accumulation of Sodium Green within ... More
Intracellular Na+ measurements using sodium green tetraacetate with flow cytometry.
AuthorsAmorino GP, Fox MH
JournalCytometry
PubMed ID8582247
'Intracellular sodium concentration ([Na+]i) can be measured using SBFI with image analysis or spectrofluorometry. However, SBFI cannot be used with most flow cytometry systems, due to its requirement for dual excitation in the UV range. Recently a new sodium indicator, Sodium Green, was developed which can be used with flow ... More
Use of colorimetric test strips for monitoring the effect of hemodialysis on salivary nitrite and uric acid in patients with end-stage renal disease: a proof of principle.
AuthorsBlicharz TM, Rissin DM, Bowden M, Hayman RB, DiCesare C, Bhatia JS, Grand-Pierre N, Siqueira WL, Helmerhorst EJ, Loscalzo J, Oppenheim FG, Walt DR,
JournalClin Chem
PubMed ID18676588
'BACKGROUND: Initial screening of potential biomarkers for monitoring dialysis was performed with saliva samples collected from patients with end-stage renal disease (ESRD). A more thorough analysis of the most promising markers identified in the initial screening was conducted with saliva samples acquired at hourly intervals throughout dialysis to monitor analyte ... More
Fluorescence imaging of Na+ influx via P2X receptors in cochlear hair cells.
AuthorsHousley GD, Raybould NP, Thorne PR
JournalHear Res
PubMed ID9641314
'The adenosine 5''-triphosphate (ATP)-activated membrane conductance, mediated by P2X receptors, was examined in isolated guinea-pig cochlear inner and outer hair cells. Photo-activated release of caged-ATP elicted a 30-ms latency inwardly rectifying non-selective cation conductance, blocked by the P2X receptor antagonist pyridoxalphosphate-6-azophenyl-2'',4''-disulphonic acid (PPADS; 10-100 microM), consistent with the direct activation ... More
Induction of salt and osmotic stress tolerance by overexpression of an intracellular vesicle trafficking protein AtRab7 (AtRabG3e).
AuthorsMazel A, Leshem Y, Tiwari BS, Levine A
JournalPlant Physiol
PubMed ID14657401
'Adaptation to stress requires removal of existing molecules from various cellular compartments and replacing them with new ones. The transport of materials to and from the specific compartments involved in the recycling and deposition of macromolecules is carried out by an intracellular vesicle trafficking system. Here, we report the isolation ... More
Intracellular sodium in mammalian muscle fibers after eccentric contractions.
AuthorsYeung EW, Ballard HJ, Bourreau JP, Allen DG
JournalJ Appl Physiol
PubMed ID12588791
'The effect of eccentric contractions on intracellular Na(+) concentration ([Na(+)](i)) and its distribution were examined in isolated rat and mouse muscle fiber bundles. [Na(+)](i) was measured with either Na(+)-binding benzofuran isophthalate or sodium green. Ten isometric contractions had no significant effect on force (measured after 5 min of recovery) and ... More
Actin-ATP hydrolysis is a major energy drain for neurons.
AuthorsBernstein BW, Bamburg JR
JournalJ Neurosci
PubMed ID12514193
In cultured chick ciliary neurons, when ATP synthesis is inhibited, ATP depletion is reduced approximately 50% by slowing actin filament turnover with jasplakinolide or latrunculin A. Jasplakinolide inhibits actin disassembly, and latrunculin A prevents actin assembly by sequestering actin monomers. Cytochalasin D, which allows assembly-disassembly, but only at pointed ends, ... More
Anoxia induces an increase in intracellular sodium in rat central neurons in vitro.
AuthorsFriedman JE, Haddad GG
JournalBrain Res
PubMed ID7874519
Following our previous observations that anoxia induces a drop in extracellular Na+ in the brain slice and that removal of extracellular Na+ prevents the anoxia-induced morphological changes in dissociated hippocampal neurons, we hypothesized that intracellular Na+ increases during anoxia in isolated neurons. Using the fluorophore Sodium Green in freshly dissociated ... 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
Visual imaging of ion distribution in human epidermis.
AuthorsDenda M, Hosoi J, Asida Y
JournalBiochem Biophys Res Commun
PubMed ID10872816
The distribution of calcium, magnesium, potassium, sodium, and hydrogen ions in the human epidermis was visualized by blotting to gel containing chemical indicators and the effects of skin barrier disruption were examined. In normal skin, both calcium and magnesium were localized with high concentration in the upper epidermis. EDTA blocked ... More
Sodium Green as a potential probe for intracellular sodium imaging based on fluorescence lifetime.
AuthorsSzmacinski H, Lakowicz JR
JournalAnal Biochem
PubMed ID9245429
We characterized the use of the fluorescent probe Sodium Green for measurements of intracellular free sodium using frequency-domain, phase-modulation fluorometry. The intensity decays were found to be strongly Na+ dependent, with mean lifetime increasing from 1.13 ns in the absence of Na+ to 2.39 ns in the presence of 140 ... More
Na+/Mg2+ transporter acts as a Mg2+ buffering mechanism in PC12 cells.
AuthorsKubota T, Tokuno K, Nakagawa J, Kitamura Y, Ogawa H, Suzuki Y, Suzuki K, Oka K
JournalBiochem Biophys Res Commun
PubMed ID12646207
Mg(2+) buffering mechanisms in PC12 cells were demonstrated with particular focus on the role of the Na(+)/Mg(2+) transporter by using a newly developed Mg(2+) indicator, KMG-20, and also a Na(+) indicator, Sodium Green. Carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP), a protonophore, induced a transient increase in the intracellular Mg(2+) concentration ([Mg(2+)](i)). ... More
Analysis of nanoliter samples of electrolytes using a flow-through microfluorometer.
AuthorsZhelyaskov VR, Liu S, Broderick MP
JournalKidney Int
PubMed ID10760113
Several techniques have been developed to study the transport properties of nanoliter samples of renal tubule segments, such as continuous flow colorimetry and continuous fluorometry. We have extended the capability of the NANOFLO, a flow-through microfluorometer, designed for measurement of carbon dioxide, urea, ammonia, glucose, lactate, etc., to analyze sodium, ... More
Intracellular ionic concentration by calibration from fluorescence indicator emission spectra, its relationship to the K(d), F(min), F(max) formula, and use with Na-Green for presynaptic sodium.
AuthorsWinslow JL, Cooper RL, Atwood HL
JournalJ Neurosci Methods
PubMed ID12204307
The emission spectra calibration curves for a fluorescence indicator and the F(min), F(max), and K(d) formula were shown to be related. Using the known calibrated fluorescence emitted by Sodium Green (Na-Green) and photo-multiplier-tube quantum efficiency, we calculated the detection signal over a range of sodium concentrations. The calculated calibration curves ... More
Fluorescence lifetime microscopy of the Na+ indicator Sodium Green in HeLa cells.
AuthorsDespa S, Vecer J, Steels P, Ameloot M
JournalAnal Biochem
PubMed ID10870831
This study investigates the usefulness of lifetime measurements of Sodium Green for evaluating intracellular Na+ concentration ([Na+]i) in HeLa cells. Frequency-domain lifetime measurements are performed in HeLa cells and in different buffer solutions (with and without K+ and bovine serum albumin). In all cases, the fluorescence decays of Sodium Green ... More
Differential effects of stretch and compression on membrane currents and [Na+]c in ventricular myocytes.
AuthorsIsenberg G, Kazanski V, Kondratev D, Gallitelli MF, Kiseleva I, Kamkin A
JournalProg Biophys Mol Biol
PubMed ID12732267
Mechano-electrical feedback was studied in the single ventricular myocytes. A small fraction (approximately 10%) of the cell surface could be stretched or compressed by a glass stylus. Stretch depolarised, shortened the action potential and induced extra systoles. Stretch activated non-selective cation currents (I(ns)) showed a linear voltage dependence, a reversal ... More
Clostridium perfringens epsilon toxin induces a rapid change of cell membrane permeability to ions and forms channels in artificial lipid bilayers.
AuthorsPetit L, Maier E, Gibert M, Popoff MR, Benz R
JournalJ Biol Chem
PubMed ID11278669
Epsilon toxin is a potent toxin produced by Clostridium perfringens types B and D, which are responsible for a rapidly fatal enterotoxemia in animals. One of the main properties of epsilon toxin is the production of edema. We have previously found that epsilon toxin causes a rapid swelling of Madin-Darby ... More
Heat-induced changes in intracellular sodium and membrane potential: lack of a role in cell killing and thermotolerance.
AuthorsAmorino GP, Fox MH
JournalRadiat Res
PubMed ID8752306
Hyperthermia induces transient changes in intracellular free sodium levels and membrane potential. The possible role of these changes in cell killing by hyperthermia and thermotolerance has been evaluated using Chinese hamster ovary IS1 and HeLa cells. Intracellular sodium was measured with Sodium Green and SBFI, while membrane potential was measured ... More
Extracellular ATP induces oscillations of intracellular Ca2+ and membrane potential and promotes transcription of IL-6 in macrophages.
AuthorsHanley PJ, Musset B, Renigunta V, Limberg SH, Dalpke AH, Sus R, Heeg KM, Preisig-Müller R, Daut J
JournalProc Natl Acad Sci U S A
PubMed ID15194822
The effects of low concentrations of extracellular ATP on cytosolic Ca(2+), membrane potential, and transcription of IL-6 were studied in monocyte-derived human macrophages. During inflammation or infection many cells secrete ATP. We show here that application of 10 microM ATP or 10 microM UTP induces oscillations in cytosolic Ca(2+) with ... More
The mammalian amiloride-insensitive non-specific salt taste receptor is a vanilloid receptor-1 variant.
AuthorsLyall V, Heck GL, Vinnikova AK, Ghosh S, Phan TH, Alam RI, Russell OF, Malik SA, Bigbee JW, DeSimone JA
JournalJ Physiol
PubMed ID15146042
The amiloride-insensitive salt taste receptor is the predominant transducer of salt taste in some mammalian species, including humans. The physiological, pharmacological and biochemical properties of the amiloride-insensitive salt taste receptor were investigated by RT-PCR, by the measurement of unilateral apical Na+ fluxes in polarized rat fungiform taste receptor cells and ... More
Modulation of rat chorda tympani NaCl responses and intracellular Na+ activity in polarized taste receptor cells by pH.
AuthorsLyall V, Alam RI, Phan TH, Russell OF, Malik SA, Heck GL, DeSimone JA
JournalJ Gen Physiol
PubMed ID12451050
Mixture interactions between sour and salt taste modalities were investigated in rats by direct measurement of intracellular pH (pH(i)) and Na(+) activity ([Na(+)](i)) in polarized fungiform taste receptor cells (TRCs) and by chorda tympani (CT) nerve recordings. Stimulating the lingual surface with NaCl solutions adjusted to pHs ranging between 2.0 ... More
Alterations in colonic barrier function caused by a low sodium diet or ionizing radiation.
AuthorsNaftalin R
JournalJ Environ Pathol Toxicol Oncol
PubMed ID15163287
This article reviews how cytokines and radiation-induced apoptosis affect the barrier function of the colonic pericryptal sheath and thereby colonic crypt fluid absorption. A layer of myofibroblasts forming a pericryptal sheath surrounds the colonic crypt epithelial cells. The colonic pericryptal hypertonicity (250--350 mM NaCl) resulting from Na(+) pumping into the ... More
NO decreases thick ascending limb chloride absorption by reducing Na(+)-K(+)-2Cl(-) cotransporter activity.
AuthorsOrtiz PA, Hong NJ, Garvin JL
JournalAm J Physiol Renal Physiol
PubMed ID11592939
We have reported that nitric oxide (NO) inhibits thick ascending limb (THAL) chloride absorption (J(Cl(-))). NaCl transport in the THAL depends on apical Na(+)-K(+)-2Cl(-) cotransporters, apical K(+) channels, and basolateral Na(+)-K(+)-ATPase. However, the transporter inhibited by NO is unknown. We hypothesized that NO decreases THAL J(Cl(-)) by inhibiting the Na(+)-K(+)-2Cl(-) ... More
In the previous sections we demonstrated imaging of intracellular Ca2+ using our approach to FLIM. What other analytes can be imaged using FLIM? We have now characterized the lifetime of a good number of ion indicators. Based on these studies we know that Cl- can be imaged using FLIM with ... More
Production and role of extracellular guanosine cyclic 3', 5' monophosphate in sodium uptake in human proximal tubule cells.
The present study was designed to determine the capability of human renal proximal tubule (RPT) to generate and export guanosine cyclic 3', 5' monophosphate (cGMP) in response to direct stimulation of soluble guanylyl cyclase by nitric oxide (NO) donors. In addition, we investigated whether cGMP extrusion from human RPT cells ... More
Motility initiation in herring sperm is regulated by reverse sodium-calcium exchange.
AuthorsVines CA, Yoshida K, Griffin FJ, Pillai MC, Morisawa M, Yanagimachi R, Cherr GN
JournalProc Natl Acad Sci U S A
PubMed ID11842223
Sperm of the Pacific herring, Clupea pallasi, are unique in that they are immotile upon spawning in the environment. Herring sperm have evolved to remain motionless for up to several days after spawning, yet are still capable of fertilizing eggs. An egg chorion ligand termed "sperm motility initiation factor" (SMIF) ... More
Amphetamine-induced dopamine efflux. A voltage-sensitive and intracellular Na+-dependent mechanism.
AuthorsKhoshbouei H, Wang H, Lechleiter JD, Javitch JA, Galli A
JournalJ Biol Chem
PubMed ID12556446
Amphetamine (AMPH) elicits its behavioral effects by acting on the dopamine (DA) transporter (DAT) to induce DA overflow into the synaptic cleft. Facilitated exchange diffusion is the classical model used to describe AMPH-induced DA efflux. This model hypothesizes that AMPH-induced DA efflux is mediated by DAT and results from the ... More
Bile acids induce a cationic current, depolarizing pancreatic acinar cells and increasing the intracellular Na+ concentration.
AuthorsVoronina SG, Gryshchenko OV, Gerasimenko OV, Green AK, Petersen OH, Tepikin AV
JournalJ Biol Chem
PubMed ID15536077
Biliary disease is a major cause of acute pancreatitis. In this study we investigated the electrophysiological effects of bile acids on pancreatic acinar cells. In perforated patch clamp experiments we found that taurolithocholic acid 3-sulfate depolarized pancreatic acinar cells. At low bile acid concentrations this occurred without rise in the ... More
Regulation of [Na+]i in resting and stimulated submandibular salivary ducts.
AuthorsXu X, Zhao H, Diaz J, Muallem S
JournalJ Biol Chem
PubMed ID7642648
In the preceding manuscript (Zhao, H., Xu, X., Diaz, J., and Muallem, S. (1995) J. Biol. Chem. 270, 19599-19605), we described a Kout(+)-dependent H+/HCO3- and Na+ influx pathway in the luminal membrane of salivary duct cells. In the present studies, we further characterized this pathway to show that the Kout(+)-dependent ... More
Monitoring intracellular nanomolar calcium using fluorescence lifetime imaging.