Simultaneous measurement of intracellular pH and Ca2+ in insulin-secreting cells by spectral imaging microscopy.
AuthorsMartínez-Zaguilán R,Gurulé MW,Lynch RM
JournalThe American journal of physiology
PubMed ID8967445
Molecular cloning and functional expression of a rat Na+/H+ exchanger (NHE5) highly expressed in brain.
AuthorsAttaphitaya S, Park K, Melvin JE
JournalJ Biol Chem
PubMed ID9933642
We report here the cloning, primary structure, heterologous expression, tissue distribution, and localization of a cDNA encoding rat NHE5, a fifth member of the mammalian plasma membrane Na+/H+ exchanger (NHE) gene family. The full-length open reading frame as well as 34 nucleotides of 5'-untranslated and 1443 nucleotides of 3'-untranslated sequences ... More
Measurement of intracellular pH.
AuthorsBoyer MJ, Hedley DW
JournalMethods Cell Biol
PubMed ID7532259
Simultaneous imaging of intracellular [Ca2+] and pH in single MDCK and glomerular epithelial cells.
AuthorsWiegmann TB, Welling LW, Beatty DM, Howard DE, Vamos S, Morris SJ
JournalAm J Physiol
PubMed ID8238309
The interrelationships between changes in intracellular calcium concentration ([Ca2+]i) and intracellular pH in Madin-Darby canine kidney cells and kidney glomerular epithelial cells exposed to various stimuli were analyzed simultaneously using a new design of a fluorescence video microscope. Cells were double labeled with indo 1 and SNARF 1 dyes and ... More
Identification of band 3-like proteins and Cl-/HCO3- exchange in isolated cardiomyocytes.
AuthorsPucéat M, Korichneva I, Cassoly R, Vassort G
JournalJ Biol Chem
PubMed ID7836397
'The identification of the protein that exerts the function of Cl-/HCO3- exchange is still unresolved in cardiac tissue. We have addressed this issue by using a multiple technical approach. Western blotting analysis with an antibody raised against human erythroid whole band 3 protein, the so-called protein that mediates the Cl-/HCO3- ... More
Defective fluid secretion and NaCl absorption in the parotid glands of Na+/H+ exchanger-deficient mice.
AuthorsPark K, Evans RL, Watson GE, Nehrke K, Richardson L, Bell SM, Schultheis PJ, Hand AR, Shull GE, Melvin JE
JournalJ Biol Chem
PubMed ID11358967
'Multiple Na(+)/H(+) exchangers (NHEs) are expressed in salivary gland cells; however, their functions in the secretion of saliva by acinar cells and the subsequent modification of the ionic composition of this fluid by the ducts are unclear. Mice with targeted disruptions of the Nhe1, Nhe2, and Nhe3 genes were used ... More
Temperature-dependent arrest of neutrophil apoptosis. Failure of Bax insertion into mitochondria at 15 degrees C prevents the release of cytochrome c.
AuthorsPryde JG, Walker A, Rossi AG, Hannah S, Haslett C
JournalJ Biol Chem
PubMed ID10896657
'Apoptosis is essential for the resolution of neutrophilic inflammation. To define the mechanisms triggering the execution phase of apoptosis we developed and utilized a model in which culture of human neutrophils at 15 degrees C for 20 h arrested apoptosis and subsequent warming to 37 degrees C triggered a synchronous ... More
The cytosolic entry of diphtheria toxin catalytic domain requires a host cell cytosolic translocation factor complex.
AuthorsRatts R, Zeng H, Berg EA, Blue C, McComb ME, Costello CE, vanderSpek JC, Murphy JR
JournalJ Cell Biol
PubMed ID12668662
'In vitro delivery of the diphtheria toxin catalytic (C) domain from the lumen of purified early endosomes to the external milieu requires the addition of both ATP and a cytosolic translocation factor (CTF) complex. Using the translocation of C-domain ADP-ribosyltransferase activity across the endosomal membrane as an assay, the CTF ... More
Evaluation of cryopreserved stallion semen from Tori and Estonian breeds using CASA and flow cytometry.
AuthorsKavak A, Johannisson A, Lundeheim N, Rodriguez-Martinez H, Aidnik M, Einarsson S
JournalAnim Reprod Sci
PubMed ID12586493
'Methods to evaluate the quality of frozen-thawed stallion semen are still needed, particularly those considering the sperm function. The present study evaluated sperm motility, membrane and acrosome integrity and the capacitation status of frozen-thawed spermatozoa from seven Tori and six Estonian breed stallions by way of computer assisted sperm analysis ... More
Regulation of intracellular pH gradients by identified Na/H exchanger isoforms and a short-chain fatty acid.
AuthorsGonda T, Maouyo D, Rees SE, Montrose MH
JournalAm J Physiol
PubMed ID9887003
'Colonic luminal short-chain fatty acids (SCFA) stimulate electroneutral sodium absorption via activation of apical Na/H exchange. HT29-C1 cells were used previously to demonstrate that transepithelial SCFA gradients selectively activate polarized Na/H exchangers. Fluorometry and confocal microscopy (with BCECF and carboxy SNARF-1, respectively) are used to measure intracellular pH (pHi) in ... More
AuthorsVan Damme P, Callewaert G, Eggermont J, Robberecht W, Van Den Bosch L
JournalJ Neurosci
PubMed ID12832516
'AMPA receptor-mediated excitotoxicity has been implicated in the pathogenesis of stroke, neurotrauma, epilepsy, and many neurodegenerative diseases such as motoneuron disease. We studied the role of Cl- in AMPA receptor-mediated Ca2+-dependent excitotoxicity in cultured rat spinal motoneurons. Using the gramicidin perforated patch-clamp technique, the intracellular Cl- concentration could be calculated ... More
Extracellular pH regulation in microdomains of colonic crypts: effects of short-chain fatty acids.
AuthorsChu S, Montrose MH
JournalProc Natl Acad Sci U S A
PubMed ID7724557
'It has been suggested that transepithelial gradients of short-chain fatty acids (SCFAs; the major anions in the colonic lumen) generate pH gradients across the colonic epithelium. Quantitative confocal microscopy was used to study extracellular pH in mouse distal colon with intact epithelial architecture, by superfusing tissue with carboxy SNARF-1 (a ... More
The intracellular pH-regulatory HCO3-/Cl- exchanger in the mouse oocyte is inactivated during first meiotic metaphase and reactivated after egg activation via the MAP kinase pathway.
AuthorsPhillips KP, Petrunewich MA, Collins JL, Baltz JM
JournalMol Biol Cell
PubMed ID12429825
'The HCO(3)(-)/Cl(-) exchanger is quiescent in the unfertilized mouse egg but is highly active in regulating intracellular pH in the early embryo and required for normal development. We show here that the HCO(3)(-)/Cl(-) exchanger is active in first meiotic prophase (GV) oocyte but inactivated during meiotic metaphase before the MI ... More
Out-of-equilibrium pH transients in the guinea-pig ventricular myocyte.
AuthorsLeem CH, Vaughan-Jones RD
JournalJ Physiol
PubMed ID9575296
'1. Following an intracellular alkali load (imposed by acetate prepulsing in CO2/HCO3- buffer), intracellular pH (pHi) of the guinea-pig ventricular myocyte (recorded from intracellular SNARF fluorescence) recovers to control levels. Recovery has two phases. An initial rapid phase (lasting up to 2 min) is followed by a later slow phase ... More
HIV-1 entry into T-cells is not dependent on CD4 and CCR5 localization to sphingolipid-enriched, detergent-resistant, raft membrane domains.
AuthorsPercherancier Y, Lagane B, Planchenault T, Staropoli I, Altmeyer R, Virelizier JL, Arenzana-Seisdedos F, Hoessli DC, Bachelerie F
JournalJ Biol Chem
PubMed ID12431990
'The contribution of raft domains to human immunodeficiency virus (HIV) 1 entry was assessed. In particular, we asked whether the CD4 and CCR5 HIV-1 receptors need to associate with sphingolipid-enriched, detergent-resistant membrane domains (rafts) to allow viral entry into primary and T-cell lines. Based on Triton X-100 solubilization and confocal ... More
Opposite effects of pressurized steady versus pulsatile perfusion on vascular endothelial cell cytosolic pH: role of tyrosine kinase and mitogen-activated protein kinase signaling.
AuthorsWittstein IS, Qiu W, Ziegelstein RC, Hu Q, Kass DA
JournalCirc Res
PubMed ID10864913
'Endothelial cytosolic pH (pH(i)) modulates ion channel function, vascular tone, and cell proliferation. Steady shear induces rapid acidification in bicarbonate buffer. However, in vivo shear is typically pulsatile, potentially altering this response. We tested effects and mechanisms of pH(i) modulation by flow pulsatility, comparing pressurized steady versus pulse-flow responses in ... More
Endosomal accumulation of pH indicator dyes delivered as acetoxymethyl esters.
AuthorsSlayman CL, Moussatos VV, Webb WW
JournalJ Exp Biol
PubMed ID7823037
'Intracellular distributions of the putative cytosolic pH indicator dyes BCECF [2',7'-bis-(2-carboxyethyl)-5(and 6)-carboxyfluorescein], C.SNARF [5(and 6)-carboxy-seminaphthorhodafluor-1], and C.SNARF-calcein have been examined in Neurospora crassa and in murine fibroblasts (NIH-3T3 cells) under conditions in which both kinds of cells produce visible microscopic vacuoles. All three dyes were administered in electroneutral forms, with ... More
Stimulus-dependent modulation of smooth muscle intracellular calcium and force by altered intracellular pH.
AuthorsTaggart MJ, Burdyga T, Heaton R, Wray S
JournalPflugers Arch
PubMed ID8772130
'Measurements of simultaneous force and intracellular Ca2+ concentration ([Ca2+]i) in rat uterine smooth muscle have been made to elucidate the mechanisms involved when force produced spontaneously, by high-K+ depolarization or carbachol is altered by a change of intracellular pH (pHi). Rises in force and [Ca2+]i were closely correlated for all ... More
Comparison of spectrum-shifting intracellular pH probes 5'(and 6')-carboxy-10-dimethylamino-3-hydroxyspiro[7H-benzo[c]xanthene-7, 1'(3'H)-isobenzofuran]-3'-one and 2',7'-biscarboxyethyl-5(and 6)-carboxyfluorescein.
AuthorsOwen CS
JournalAnal Biochem
PubMed ID1514696
'The dyes carboxy-SNARF-1 and BCECF are fluorescent probes of intracellular pH that exhibit changes in spectral shape upon proton binding which allow one to use measurements of fluorescence at two or more wavelengths in order to measure pH without artifacts associated with variability in dye loading, etc. In evaluating these ... More
Adult-derived liver stem cells acquire a cardiomyocyte structural and functional phenotype ex vivo.
AuthorsMuller-Borer BJ, Cascio WE, Anderson PA, Snowwaert JN, Frye JR, Desai N, Esch GL, Brackham JA, Bagnell CR, Coleman WB, Grisham JW, Malouf NN
JournalAm J Pathol
PubMed ID15215169
'We examined the differentiation potential of an adult liver stem cell line (WB F344) in a cardiac microenvironment, ex vivo. WB F344 cells were established from a single cloned nonparenchymal epithelial cell isolated from a normal male adult rat liver. Genetically modified, WB F344 cells that express beta-galactosidase and green ... More
The influence of age of pH regulation in hippocampal slices before, during, and after anoxia.
AuthorsRoberts EL, Chih CP
JournalJ Cereb Blood Flow Metab
PubMed ID9183294
'Changes in intracellular and extracellular pH may influence the vulnerability of brain tissue to anoxic or ischemic damage. In the present study, we investigated whether the increased vulnerability of aged brain tissue to anoxic damage is associated with age-related alterations in pH regulation. We obtained evidence for altered pH regulation ... More
Interactions between benzylamiloride and fura-2: studies in vitro and in cardiac myocytes.
AuthorsHudson CA, Rojas JD, Sarvazyan N, Wesson DE, Martínez-Zaguilán R
JournalArch Biochem Biophys
PubMed ID9681987
'Amiloride derivatives are commonly used inhibitors of Na+/H+- and Na+/Ca2+-exchange. Because they are fluorescent molecules the use of benzylamiloride (BZA), an inhibitor of Na+/Ca2+ exchange, in conjunction with Fura-2, a commonly used fluorescent Ca2+ indicator, might complicate interpretation of fluorescence data obtained. In vitro data show that BZA decreases the ... More
Detection of calcium transients in Drosophila mushroom body neurons with camgaroo reporters.
AuthorsYu D, Baird GS, Tsien RY, Davis RL
JournalJ Neurosci
PubMed ID12514202
'Camgaroos are yellow fluorescent protein derivatives that hold promise as transgenically encoded calcium sensors in behaving animals. We expressed two versions of camgaroo in Drosophila mushroom bodies using the galactosidase-4 (GAL4) system. Potassium depolarization of brains expressing the reporters produces a robust increase in fluorescence that is blocked by removing ... More
An increase in intracellular calcium concentration that is induced by basolateral CO2 in rabbit renal proximal tubule.
AuthorsBouyer P, Zhou Y, Boron WF
JournalAm J Physiol Renal Physiol
PubMed ID12812914
'Working with isolated perfused S2 proximal tubules, we asked whether the basolateral CO2 sensor acts, in part, by raising intracellular Ca2+ concentration ([Ca2+]i), monitored with the dye fura 2 (or fura-PE3). In paired experiments, adding 5% CO2/22 mM HCO3- (constant pH 7.40) to the bath (basolateral) solution caused [Ca2+]i to ... More
Angiotensin II activates the Na+/HCO3- symport through a phosphoinositide-independent mechanism in cardiac cells.
AuthorsKohout TA, Rogers TB
JournalJ Biol Chem
PubMed ID7657618
'Angiotensin II (AngII) is a hormone that alters contractility as well as myocyte growth in heart. Since many hormones that regulate cardiac contractility have also been found to modulate intracellular pH (pHi) the goal of this study was to determine if AngII altered pHi in cultured neonatal rat ventricular myocytes. ... More
Intracellular pH of the preimplantation mouse embryo: effects of extracellular pH and weak acids.
AuthorsEdwards LJ, Williams DA, Gardner DK
JournalMol Reprod Dev
PubMed ID9669527
'Although intracellular pH (pHi), is a regulator of numerous biological processes, it has received relatively little attention with regard to the physiology of the mammalian preimplantation embryo. Interestingly, there is some controversy as to whether the early embryo can recover from an acid load. The significance of this is that ... More
Identification of Na+/H+ exchange as a new target for toxic polycyclic aromatic hydrocarbons.
AuthorsHuc L, Sparfel L, Rissel M, Dimanche-Boitrel MT, Guillouzo A, Fardel O, Lagadic-Gossmann D
JournalFASEB J
PubMed ID14656999
'The ubiquitous environmental pollutants polycyclic aromatic hydrocarbons are responsible for important carcinogenic and apoptotic effects, whose mechanisms are still poorly understood, owing to the multiplicity of possible cellular targets. Among these mechanisms, alterations of ionic homeostasis have been suggested. In this work, the effects of benzo(a)pyrene [B(a)P] on pHi were ... More
An investigation into the mechanism whereby pH affects tension in guinea-pig ureteric smooth muscle.
AuthorsBurdyga TV, Taggart MJ, Wray S
JournalJ Physiol
PubMed ID8799906
'1. We have altered intracellular (pHi) and extracellular pH (pHo) in the smooth muscle of guinea-pig ureter and determined the effects on evoked phasic contractions. In order to investigate the mechanisms underlying the effects of pH alteration, intracellular Ca2+ ([Ca2+]i), pHi, electrical activity and force were measured. 2. Intracellular acidification, ... More
SNARF-1 as an intracellular pH indicator in laser microspectrofluorometry: a critical assessment.
AuthorsSeksek O, Henry-Toulmé N, Sureau F, Bolard J
JournalAnal Biochem
PubMed ID2042742
'The use of SNARF-1-AM (seminaphtorhodafluor-1-acetoxymethylester) to measure the internal pH of a single living cell by laser microspectrofluorometry has been analyzed with a lymphocyte murine B cell line A20. After incubation of the cells at 37 degrees C in the presence of 10 microM SNARF-1-AM, the internal concentration of SNARF-1 ... More
Characterization of intracellular pH gradients in human multidrug-resistant tumor cells by means of scanning microspectrofluorometry and dual-emission-ratio probes.
AuthorsBelhoussine R, Morjani H, Sharonov S, Ploton D, Manfait M
JournalInt J Cancer
PubMed ID10077157
'Multidrug-resistant cells are believed to contain a plasma-membrane-efflux pump which is hypothesized to expel anticancer drugs from the cytosol to the cell exterior. Many of these drugs are classified as weak bases whose binding to intracellular targets is pH-dependent. Slight alterations in intracellular pH gradients have been shown to affect ... More
A comparison of the effects of intracellular and extracellular pH on contraction in isolated rat portal vein.
AuthorsTaggart M, Austin C, Wray S
JournalJ Physiol
PubMed ID8021835
'1. The effects of changes in extracellular and intracellular pH on spontaneous contractile activity in isolated rat portal vein have been investigated. 2. Small strips of portal vein were loaded with the pH-sensitive fluorophore carboxy-SNARF and intracellular pH (pHi) and contraction were measured simultaneously at 37 degrees C. The tissue ... More
Characterisation of proton fluxes across the cytoplasmic membrane of the yeast Saccharomyces cerevisiae.
AuthorsHaworth RS, Lemire BD, Crandall D, Cragoe EJ, Fliegel L
JournalBiochim Biophys Acta
PubMed ID1661160
'We have tested the efficacy of fluorescent probes for the measurement of intracellular pH in Saccharomyces cerevisiae. Of the compounds tested (fluorescein, carboxyseminaphthorhodafluor-1 (C.SNARF-1) and 2'',7''bis(carboxyethyl)-5(6'')-carboxyfluorescein), C.SNARF-1 was found to be the most useful indicator of internal pH. Fluorescence microscopy showed that in Saccharomyces cerevisiae strain DAUL1, C.SNARF-1 and fluorescein ... More
Direct measurement of acid permeation into rat oesophagus.
AuthorsTanaka S, Chu S, Hirokawa M, Montrose MH, Kaunitz JD
JournalGut
PubMed ID12740330
'BACKGROUND AND AIMS: The early responses of the oesophageal mucosa to acid perfusion may predict subsequent pathology. Mucosal responses to luminal acid may result either from acid permeating through the mucosa or from other unknown transduction mechanisms. In order to better understand the dynamics of acid permeation into the oesophageal ... More
Dopamine D2 receptors regulate in vitro melanotrope L-type Ca2+ channel activity via c-fos.
'Dopamine D2 receptor stimulation of cultured primary melanotropes was found to depress L-type calcium channel activity, whereas D2 receptor antagonist application increased it. When tested on culture days 10, 16, and 20, control cells displayed increasing rises of intracellular Ca2+ in response to K+ depolarization, indicating an increase in channel ... More
Dihydrorhodamine 123: a fluorescent probe for superoxide generation?
AuthorsHenderson LM, Chappell JB
JournalEur J Biochem
PubMed ID8223655
'Imaging techniques, such as confocal microscopy and fluorescent activated cells scan are facilitating the study of responses at the single-cell level. Superoxide is reported to oxidise the non-fluorescent dihydrorhodamine 123 (DHR) to rhodamine 123. The generation of rhodamine 123 by human neutrophils, stimulated by the phorbol ester phorbol 12-myristate 13-acetate ... More
NADH enzyme-dependent fluorescence recovery after photobleaching (ED-FRAP): applications to enzyme and mitochondrial reaction kinetics, in vitro.
AuthorsJoubert F, Fales HM, Wen H, Combs CA, Balaban RS
JournalBiophys J
PubMed ID14695307
'NADH enzyme-dependent fluorescence recovery after photobleaching (ED-FRAP) was evaluated for studying enzyme kinetics in vitro and in isolated mitochondria. Mass, optical, and nuclear magnetic resonance spectroscopy data were consistent with the UV NADH photolysis reaction being NADH --> NAD* + H+ + e-. The overall net reaction was O2 + ... More
Stepwise cytoskeletal polarization as a series of checkpoints in innate but not adaptive cytolytic killing.
AuthorsWulfing C, Purtic B, Klem J, Schatzle JD
JournalProc Natl Acad Sci U S A
PubMed ID12802007
'Cytolytic killing is a major effector mechanism in the elimination of virally infected and tumor cells. The innate cytolytic effectors, natural killer (NK) cells, and the adaptive effectors, cytotoxic T cells (CTL), despite differential immune recognition, both use the same lytic mechanism, cytolytic granule release. Using live cell video fluorescence ... More
Facilitation of intracellular H(+) ion mobility by CO(2)/HCO(3)(-) in rabbit ventricular myocytes is regulated by carbonic anhydrase.
AuthorsSpitzer KW, Skolnick RL, Peercy BE, Keener JP, Vaughan-Jones RD
JournalJ Physiol
PubMed ID12015427
'Intracellular H(+) mobility was estimated in the rabbit isolated ventricular myocyte by diffusing HCl into the cell from a patch pipette, while imaging pH(i) confocally using intracellular ratiometric SNARF fluorescence. The delay for acid diffusion between two downstream regions approximately 40 microm apart was reduced from approximately 25 s to ... More
Prostaglandin F2 alpha-induced calcium transient in ovine large luteal cells: I. Alterations in cytosolic-free calcium levels and calcium flux.
'The effect of prostaglandin F2 alpha (PGF2 alpha) on cytosolic calcium homeostasis was studied in suspensions of ovine large or small luteal cells from superovulated ewes. In large cells loaded with fura-2 (AM), resting cytosolic-free calcium ([Ca2+]i) was 62 +/- 5 nM (Hanks'' medium, pH 7.15), and PGF2 alpha (0.5 ... More
Occurrence of intracellular pH transients during spontaneous contractions in rat uterine smooth muscle.
AuthorsTaggart MJ, Wray S
JournalJ Physiol
PubMed ID8145141
'1. Intracellular pH (pHi) and contraction have been measured simultaneously in isolated longitudinal rat myometrium. Tissue was loaded with the pH-sensitive fluorophore carboxy-SNARF and superfused with oxygenated, buffered salt solution at 37 degrees C and pH 7.4. 2. Small (0.04 pH unit) transient intracellular acidifications followed each spontaneous uterine contraction. ... More
Formation of triads without the dihydropyridine receptor alpha subunits in cell lines from dysgenic skeletal muscle.
AuthorsPowell JA, Petherbridge L, Flucher BE
JournalJ Cell Biol
PubMed ID8707823
'Muscular dysgenesis (mdg/mdg), a mutation of the skeletal muscle dihydropyridine receptor (DHPR) alpha 1 subunit, has served as a model to study the functions of the DHPR in excitation-contraction coupling and its role in triad formation. We have investigated the question of whether the lack of the DHPR in dysgenic ... More
Hypocrellin A photosensitization involves an intracellular pH decrease in 3T3 cells.
AuthorsChaloupka R, Sureau F, Kocisova E, Petrich JW
JournalPhotochem Photobiol
PubMed ID9679450
'The fluorescent pH probe carboxy-seminaphtorhodafluor-1 (C-Snarf-1) has been used for laser microspectro-fluorometric assays of intracellular pH in 3T3 mouse fibroblasts treated with hypocrellin A. These results are compared to those previously obtained with the structurally related hydroxylated polycyclic quinone, hypericin (Sureau et al., J. Am. Chem. Soc. 118, 9484-9487, 1996). ... More
Regulation of the mitochondrial Na+/Ca2+ antiport by matrix pH.
'The effect of matrix pH (pHi) on the activity of the mitochondrial Na+/Ca2+ antiport has been studied using the fluorescence of SNARF-1 to monitor pHi and Na(+)-dependent efflux of accumulated Ca2+ to follow antiport activity. Heart mitochondria respiring in a KCl medium maintain a large delta pH (interior alkaline) and ... More
Regulation of intracellular pH in rat lactotrophs: involvement of anionic exchangers.
AuthorsGarcia L, Boué-Grabot E, Garret M, Sartor P
JournalEndocrinology
PubMed ID9322929
'Regulation of the intracellular pH (pHi) of normal rat lactotrophs was studied. As this cell type, cultured with 10% FCS, can achieve a relatively alkaline pHi (7.3-7.5), we investigated the presence of a mechanism based on Cl-/HCO3- exchange. Using the pHi-sensitive probe SNARF-1 (seminaphtorodafluor) in its permeant form, SNARF-1/AM, we ... More
Computed tomography-based spectral imaging for fluorescence microscopy.
'The computed tomography imaging spectrometer (CTIS) is a non-scanning instrument capable of simultaneously acquiring full spectral information (450-750 nm) from every position element within its field of view (75 microm x 75 microm). The current spatial and spectral sampling intervals of the spectrometer are 1.0 microm and 10 nm, respectively. ... More
Both subtype 1 and 2 receptors of angiotensin II participate in regulation of intracellular calcium in glomerular epithelial cells.
AuthorsSharma R, Sharma M, Vamos S, Savin VJ, Wiegmann TB
JournalJ Lab Clin Med
PubMed ID11433227
'We have documented that both receptors of angiotensin II (ANG II) (AT1 and AT2) are involved in regulation of intracellular signals in glomerular epithelial cells (GECs). We studied the role of these receptors in regulation of intracellular ionized calcium [Ca2(+)]i in GECs. Cells were loaded with Indo-1 (Ca2(+)) and SNARF-1 ... More
Tyrosine-containing sequence motifs of the human immunoglobulin G receptors FcRIIb1 and FcRIIb2 essential for endocytosis and regulation of calcium flux in B cells.
AuthorsBudde P, Bewarder N, Weinrich V, Schulzeck O, Frey J
JournalJ Biol Chem
PubMed ID7527034
'Human B cells express two closely related immunoglobulin G receptors, FcRIIb1 and FcRIIb2, which differ by a 19 amino acid insertion in the cytoplasmic tail of FcRIIb1. The cytoplasmic tails of both isoforms contain a conserved sequence motif (AENTITYSLL) essential for mediating endocytosis via FcRIIb2. Truncation of this motif abolished ... More
Occurrence and a possible mechanism of penetration of natural killer cells into K562 target cells during the cytotoxic interaction.
AuthorsRadosevic K, van Leeuwen AM, Segers-Nolten IM, Figdor CG, de Grooth BG, Greve J
JournalCytometry
PubMed ID7587714
'The cytotoxic interaction between cloned human Natural Killer (NK) cells and K562 target cells was studied using confocal laser scanning microscopy (CLSM) and conventional fluorescence microscopy. We observed, using fixed as well as living cells, the occurrence of (pseudo) emperipolesis during the interaction. About 30% of conjugated NK cells penetrated, ... More
Effects of NH4Cl and dimethylamine on Cl- fluxes in resting and stimulated rat submandibular acinar cells.
AuthorsSeagrave JC, Barker S, Curry M, Martinez JR
JournalAm J Physiol
PubMed ID1415715
'Transmembrane movements of K+ and Cl- in salivary acinar cells are important in the formation of saliva, and may be affected by changes in intracellular pH (pHi). Exposure to NH4Cl increases pHi transiently, but NH4+ may have effects independent of pHi. To investigate how Cl- transport may be altered under ... More
Cysteine protease activity is required for surfactant protein B processing and lamellar body genesis.
'Surfactant protein (SP)-B is essential for lamellar body genesis and for the final steps in proSP-C post-translational processing. The mature SP-B protein is derived from multistep processing of the primary translation product proSP-B; however, the enzymes required for these events are currently unknown. Recent ultrastructural colocalization studies have suggested that ... More
Ambient pCO2 modulates intracellular pH, intracellular oxidant generation, and interleukin-8 secretion in human neutrophils.
'Although neutrophils are a critical component of the inflammatory process, their functional regulation is incompletely understood. Of note, although pCO2 varies physiologically and pathologically in the neutrophilic milieu, its affect on neutrophil biological processes is unresolved. We demonstrate here that neutrophils respond to hypo- and hypercarbia, (0.04% and 10%) by ... More
Simultaneous measurement of intracellular pH and Ca2+ using the fluorescence of SNARF-1 and fura-2.
'Upon cell stimulation with hormones and other mitogens, a variety of biochemical and physiological responses occur within the first few minutes. Changes in both intracellular pH (pHin) and intracellular Ca2+ concentration ([Ca2+]in) are prominent and play a major role in the signal transduction mechanism leading to the physiological response, i.e., ... More
Glucagon-like peptide-1 increases cAMP but fails to augment contraction in adult rat cardiac myocytes.
AuthorsVila Petroff MG, Egan JM, Wang X, Sollott SJ
JournalCirc Res
PubMed ID11532906
'The gut hormone, glucagon-like peptide-1 (GLP-1), which is secreted in nanomolar amounts in response to nutrients in the intestinal lumen, exerts cAMP/protein kinase A-mediated insulinotropic actions in target endocrine tissues, but its actions in heart cells are unknown. GLP-1 (10 nmol/L) increased intracellular cAMP (from 5.7+/-0.5 to 13.1+/-0.12 pmol/mg protein) ... More
Flow cytometric measurement of [Ca2+]i and pHi in conjugated natural killer cells and K562 target cells during the cytotoxic process.
AuthorsVan Graft M, Kraan YM, Segers IM, Radosevic K, De Grooth BG, Greve J
JournalCytometry
PubMed ID8472603
'We describe a flow cytometric assay that enables one to follow conjugate formation between cytotoxic cells and their target cells during the cytotoxic process. In addition, the internal calcium concentration ([Ca2+]i) and internal pH (pHi) of the conjugated cells can be monitored and directly compared to the nonconjugated cells. This ... More
Peptide mimics as substrates for the intestinal peptide transporter.
AuthorsTemple CS, Stewart AK, Meredith D, Lister NA, Morgan KM, Collier ID, Vaughan-Jones RD, Boyd CA, Bailey PD, Bronk JR
JournalJ Biol Chem
PubMed ID9417040
'4-Aminophenylacetic acid (4-APAA), a peptide mimic lacking a peptide bond, has been shown to interact with a proton-coupled oligopeptide transporter using a number of different experimental approaches. In addition to inhibiting transport of labeled peptides, these studies show that 4-APAA is itself translocated. 4-APAA transport across the rat intact intestine ... More
PH-induced changes in calcium: functional consequences and mechanisms of action in guinea pig portal vein.
AuthorsSmith RD, Eisner DA, Wray S
JournalAm J Physiol Heart Circ Physiol
PubMed ID12427597
'The effects of changing extracellular (pH(o)) and intracellular pH (pH(i)) on force and the mechanisms involved in the guinea pig portal vein were investigated to better understand the control of tone in this vessel. When pH(o) was altered, the effects on force and calcium were the same irrespective of whether ... More
Generation of intracellular pH gradients in single cardiac myocytes with a microperfusion system.
'This study describes the use of a microperfusion system to create rapid, large regional changes in intracellular pH (pH(i)) within single ventricular myocytes. The spatial distribution of pH(i) in single myocytes was measured with seminaphthorhodafluor-1 fluorescence using confocal imaging. Changes in pH(i) were induced by local external application of NH(4)Cl, ... More
Detection of apoptosis by flow cytometry of cells simultaneously stained for intracellular pH (carboxy SNARF-1) and membrane permeability (Hoechst 33342).
AuthorsReynolds JE, Li J, Eastman A
JournalCytometry
PubMed ID8946142
'Intracellular acidification appears to be a frequent and possibly universal occurrence during apoptosis. We have used carboxy SNARF-1 to measure intracellular pH by flow cytometry. We report here that the addition of Hoechst 33342 concurrently with carboxy SNARF-1 provides a clearer discrimination of the apoptotic population. Apoptotic cells accumulate Hoechst ... More
In vitro surfactant protein B deficiency inhibits lamellar body formation.
AuthorsFoster CD, Zhang PX, Gonzales LW, Guttentag SH
JournalAm J Respir Cell Mol Biol
PubMed ID12649122
'Surfactant protein (SP) B is essential for normal pulmonary surfactant activity and lamellar body genesis in type 2 cells. However, the role of SP-B in lamellar body genesis is poorly understood. We developed an adenovirus vector expressing antisense SP-B as an alternative in vitro model of SP-B deficiency to begin ... More
Simultaneous measurement of intracellular pH and contraction in uterine smooth muscle.
AuthorsTaggart M, Wray S
JournalPflugers Arch
PubMed ID8351202
'Changes in intracellular pH (pHi) are thought to produce large changes in force production in the uterus. There have however, been no simultaneous measurements of pHi and force in the uterus and therefore no direct information is available about the relation between the two. We have used carboxy-SNARF (a pH-sensitive ... More
Expression and function of bicarbonate/chloride exchangers in the preimplantation mouse embryo.
AuthorsZhao Y, Chauvet PJ, Alper SL, Baltz JM
JournalJ Biol Chem
PubMed ID7592657
'Bicarbonate/chloride (HCO3-/Cl-) exchangers regulate intracellular pH in the alkaline range. Previously, it has been shown that mouse embryos at the two-cell stage exhibit this activity, but that the otherwise ubiquitous mechanisms for regulating intracellular pH in the acid-to-neutral range are undetectable. We have examined mouse embryos during preimplantation development (one-cell ... More
Inadequacy of high K+/nigericin for calibrating BCECF. I. Estimating steady-state intracellular pH.
AuthorsBoyarsky G, Hanssen C, Clyne LA
JournalAm J Physiol
PubMed ID8897819
'Intracellular pH (pHi) was measured in single vascular smooth muscle (VSM) cells, cultured from rabbit abdominal aorta, using 2'',7''-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF) on a microscope-based fluorescence system. Three lines of evidence are presented that using nigericin along with high external K+ to calibrate intracellular BCECF produces systematic errors in pHi. 1) The ... More
NADH fluorescence of isolated ventricular myocytes: effects of pacing, myoglobin, and oxygen supply.
AuthorsWhite RL, Wittenberg BA
JournalBiophys J
PubMed ID8369428
'Endogenous fluorescence was used to measure the extent of reduction of mitochondrial NAD in individual, isolated rat cardiac myocytes. NAD reduction was determined from emitted fluorescence at 415 and 470 nm during brief epi-illumination at 365 nm. NAD reduction of resting myocytes, superfused with medium equilibrated with 95% O2/5% CO2, ... More
Apoptosis in an interleukin-2-dependent cytotoxic T lymphocyte cell line is associated with intracellular acidification. Role of the Na(+)/H(+)-antiport.
AuthorsLi J, Eastman A
JournalJ Biol Chem
PubMed ID7852405
'Apoptosis is a form of cell death associated with DNA fragmentation and chromatin condensation. We recently established that intracellular acidification occurred during apoptosis following cytotoxic insult. The current studies were designed to determine whether intracellular acidification was more generally associated with apoptosis, specifically in a model of growth factor withdrawal. ... More
Insulin-stimulated cytosol alkalinization facilitates optimal activation of glucose transport in cardiomyocytes.
'Abnormalities in intracellular pH regulation have been proposed to be important in type 2 diabetes and the associated cardiomyopathy and hypertension. We have therefore investigated the dependence of insulin-stimulated glucose transport on cytosolic pH in cardiomyocytes. Insulin treatment of cardiomyocytes resulted in a marked alkalinization of the cytoplasm as measured ... More
Na-independent Cl(-)-HCO3- exchange mediates recovery of pHi from alkalosis in guinea pig ventricular myocytes.
AuthorsXu P, Spitzer KW
JournalAm J Physiol
PubMed ID8048611
'The pH-sensitive fluorescent indicator, carboxy-seminaphthorhodafluor 1 (SNARF 1) was used to assess the contribution of forward Na-independent Cl(-)-HCO3- exchange (1 external Cl- exchanged for 1 internal HCO3-) to intracellular pH (pHi) recovery from alkalosis in adult ventricular myocytes (guinea pig). Intracellular alkalosis was elicited by external application of the weak ... More
A novel role for carbonic anhydrase: cytoplasmic pH gradient dissipation in mouse small intestinal enterocytes.
AuthorsStewart AK, Boyd CA, Vaughan-Jones RD
JournalJ Physiol
PubMed ID10066935
'1. The spatial and temporal distribution of intracellular H+ ions in response to activation of a proton-coupled dipeptide transporter localized at the apical pole of mouse small intestinal isolated enterocytes was investigated using intracellular carboxy-SNARF-1 fluorescence in combination with whole-cell microspectrofluorimetry or confocal microscopy. 2. In Hepes-buffered Tyrode solution, application ... More
Effect of glucose on pHin and [Ca2+]in in NIH-3T3 cells transfected with the yeast P-type H(+)-ATPase.
'NIH-3T3 cells transfected with yeast H(+)-ATPases (RN1a cells) are tumorigenic (Perona and Serrano, 1988, Nature, 334:438). We have previously shown that RN1a cells maintain a chronically high intracellular pH (pHin) under physiological conditions. We have also shown that RN1a cells are serum-independent for growth, maintain a higher intracellular Ca2+ ([Ca2+]in), ... More
Mitochondria buffer physiological calcium loads in cultured rat dorsal root ganglion neurons.
AuthorsWerth JL, Thayer SA
JournalJ Neurosci
PubMed ID8283242
'We sought to determine whether low-affinity, high-capacity mitochondrial Ca2+ uptake contributes to buffering physiological Ca2+ loads in sensory neurons. Intracellular free calcium concentration ([Ca2+]i) and intracellular free hydrogen ion concentration ([H+]i) were measured in single rat dorsal root ganglion (DRG) neurons grown in primary culture using indo-1 and carboxy-SNARF-based dual ... More
A new and simple method to evaluate early membrane changes in frozen-thawed boar spermatozoa.
AuthorsPeña FJ, Saravia F, Johannisson A, Walgren M, Rodríguez-Martínez H
JournalInt J Androl
PubMed ID15811072
'Detection of early changes in the sperm plasma membrane during cryopreservation is of utmost importance when designing freezing protocols and has previously been studied in the pig species using annexin-V detection of phosphatidylserine translocation. In the present study we designed a new assay to detect these changes in boar spermatozoa, ... More
External alkalinization decreases intracellular Ca++ and spontaneous contractions in pregnant rat myometrium.
AuthorsTaggart MJ, Sheader EA, Walker SD, Naderali EK, Moore S, Wray S
JournalAm J Obstet Gynecol
PubMed ID9369852
'OBJECTIVES: As plasma pH rises during pregnancy, the effect of raising external pH on spontaneous contractions in pregnant rat myometrium was investigated to test the hypothesis that elevated external pH depresses contraction. STUDY DESIGN: Strips of longitudinal myometrium were loaded with SNARF (seminaphthorhodafluor) or Indo-1 for simultaneous intracellular pH or ... More
Effects of mitochondrial uncouplers on intracellular calcium, pH and membrane potential in rat carotid body type I cells.
AuthorsBuckler KJ, Vaughan-Jones RD
JournalJ Physiol
PubMed ID9824720
'1. Mitochondrial uncouplers are potent stimulants of the carotid body. We have therefore investigated their effects upon isolated type I cells. Both 2,4-dinitrophenol (DNP) and carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (FCCP) caused an increase in [Ca2+]i which was largely inhibited by removal of extracellular Ca2+ or Na+, or by the addition ... More
The inhibitory potential of Fc receptor homolog 4 on memory B cells.
AuthorsEhrhardt GR, Davis RS, Hsu JT, Leu CM, Ehrhardt A, Cooper MD
JournalProc Natl Acad Sci U S A
PubMed ID14597715
'Fc receptor homolog 4 (FcRH4) is a B cell-specific member of the recently identified family of FcRHs whose intracellular domain contains three potential immunoreceptor tyrosine-based inhibitory motifs (ITIMs). The signaling potential of this receptor, shown here to be preferentially expressed by memory B cells, was compared with the inhibitory receptor ... More
Fluorescent measurement of the intracellular pH during sporulation of Saccharomyces cerevisiae.
AuthorsAon JC, Cortassa S
JournalFEMS Microbiol Lett
PubMed ID9252568
'This work reports the intracellular pH (pHi) dynamics of Saccharomyces cerevisiae cells in sporulation medium. Cells loaded with the pH-sensitive dye carboxy-seminaphthorhodafluor-1 (C.SNARF-1) exhibited an alkalization of the pHi following the extracellular pH during sporulation in the absence of buffer and almost no change in pHi or delta pH when ... More
Simultaneous monitoring of vascular contractility, intracellular pH and intracellular calcium in isolated rat mesenteric arteries; effects of weak bases.
AuthorsOtter D, Austin C
JournalExp Physiol
PubMed ID10825423
'We report the first simultaneous measurements of pHi, [Ca2+]i and tension, upon alteration of pHi, in isolated rat mesenteric arteries loaded with both carboxy SNARF and indo-1. In these vessels (pre-contracted by 30 mM KCl) alterations of pHi, by addition and subsequent washout of weak bases, produced complicated effects on ... More
Fluorophore toxicity in mouse eggs and zygotes.
AuthorsPhillips KP, Zhou WL, Baltz JM
JournalZygote
PubMed ID9770776
'Ion-sensitive fluorophores are commonly used for quantitative measurements of intracellular ion concentrations. However, both the method of intracellular loading--which for many fluorophores involves endogenous esterase-mediated removal of hydrophobic groups such as acetoxymethyl esters (AM)--and fluorescence excitation of fluorophores in the cell, can produce toxic metabolites and reactive species. Techniques used ... More
Fibroblastic reticular cells guide T lymphocyte entry into and migration within the splenic T cell zone.
AuthorsBajénoff M, Glaichenhaus N, Germain RN,
JournalJ Immunol
PubMed ID18768849
'Although a great deal is known about T cell entry into lymph nodes, much less is understood about how T lymphocytes access the splenic white pulp (WP). We show in this study that, as recently described for lymph nodes, fibroblastic reticular cells (FRCs) form a network in the T cell ... More
Novel method for measuring junctional proton permeation in isolated ventricular myocyte cell pairs.
AuthorsSwietach P, Vaughan-Jones RD
JournalAm J Physiol Heart Circ Physiol
PubMed ID15242838
'Partial exposure of single ventricular myocytes to membrane-permeant weak acids or bases, using a dual-microperfusion technique, generates large and stable intracellular pH (pHi) gradients. In this study, we have investigated the feasibility of using the technique to estimate junctional proton permeability. This was done by recording the pHi gradient developed ... More
Intracellular pH and the control of multidrug resistance.
AuthorsSimon S, Roy D, Schindler M
JournalProc Natl Acad Sci U S A
PubMed ID8302842
'Many anticancer drugs are classified as either weak bases or molecules whose binding to cellular structures is pH dependent. Accumulation of these drugs within tumor cells should be affected by transmembrane pH gradients. Indeed, development of multidrug resistance (MDR) in tumor cells has been correlated with an alkaline shift of ... More
Low external pH and osmotic shock increase the expression of human MDR protein.
AuthorsWei LY, Roepe PD
JournalBiochemistry
PubMed ID7911681
'We have studied the effects of extracellular pH (pHo) and osmotic strength on the expression of the human multidrug resistance (MDR) protein. Both lowered pHo and hypertonic shock increase the level of hu MDR protein 5-10-fold in membranes isolated from the human colon carcinoma cell lines SW620 and HCT15 and ... More
Induction of apoptosis in human T-cells by methyl mercury: temporal relationship between mitochondrial dysfunction and loss of reductive reserve.
AuthorsShenker BJ, Guo TL, O I, Shapiro IM
JournalToxicol Appl Pharmacol
PubMed ID10329504
'The objective of our study was to define the mechanism by which MeHgCl induces human T-cell apoptosis. We asked the question: does mercury disrupt the Deltapsim and induce a mitochondrial permeability transition state? Using two fluorescent reagents, JC-1 and DiOC6(3), we demonstrated that MeHgCl exposure resulted in a decrease in ... More
Sarcolemmal mechanisms for pHi recovery from alkalosis in the guinea-pig ventricular myocyte.
AuthorsLeem CH, Vaughan-Jones RD
JournalJ Physiol
PubMed ID9575297
'1. The mechanism of pHi recovery from an intracellular alkali load (induced by acetate prepulse or by reduction/removal of ambient PCO2) was investigated using intracellular SNARF fluorescence in the guinea-pig ventricular myocyte. 2. In Hepes buffer (pHo 7.40), pHi recovery was inhibited by removal of extracellular Cl-, but not by ... More
A simple optical fiber device for quantitative fluorescence microscopy of single living cells.
Authorsvan Graft M, Oosterhuis B, van der Werf KO, de Grooth BG, Greve J
JournalJ Immunol Methods
PubMed ID8445247
'A simple and relatively inexpensive system is described for obtaining quantitative fluorescence measurements on single living cells loaded with a fluorescent probe to study cell physiological processes. The light emitted from the fluorescent cells is captured by and transported through an optical fiber. After passage through appropriate filters the light ... More
Spectral and photophysical studies of benzo[c]xanthene dyes: dual emission pH sensors.
AuthorsWhitaker JE, Haugland RP, Prendergast FG
JournalAnal Biochem
PubMed ID1862936
'A series of fluorescent, long-wavelength, benzo[c]-xanthene dyes has been characterized for pH measurement in both excitation and emission ratio applications. The two general classes of these indicators are seminaphthofluoresceins (SNAFLs) and seminaphthorhodafluors (SNARFs) which are substituted at the 10-position with oxygen or nitrogen, respectively. These probes show separate emissions from ... More
Selection of fluorescent ion indicators for simultaneous measurements of pH and Ca2+.
AuthorsMartínez-Zaguilán R, Parnami G, Lynch RM
JournalCell Calcium
PubMed ID8983854
'The advent of fluorescent ion sensitive indicators has improved our understanding of the mechanisms involved in regulating pHi and [Ca2+]i homeostasis in living cells. However, changes in [Ca2+]i can alter pHi regulatory mechanisms and vice versa, making assignment of either ion to a particular physiological response complex. A further complication ... More
Monitoring clathrin-mediated endocytosis during synaptic activity.
AuthorsMueller VJ, Wienisch M, Nehring RB, Klingauf J
JournalJ Neurosci
PubMed ID14985443
'To visualize clathrin redistribution during endocytosis in hippocampal boutons, we used a fusion protein of clathrin light chain with enhanced green fluorescent protein. Both high potassium and electric field stimulation lead after a stimulus-dependent delay to a transient increase of fluorescence in synapses, but a slight and transient decrease in ... More
Extracellular ATP-induced acidification leads to cytosolic calcium transient rise in single rat cardiac myocytes.
AuthorsPucéat M, Clément O, Scamps F, Vassort G
JournalBiochem J
PubMed ID2001251
'The origin of the increase in cytosolic free Ca2+ concentration ([Ca2+]i) induced by extracellular ATP was investigated in single isolated cardiac myocytes loaded with indo-1. The nucleotide added at a concentration of 10 microM triggers a few Ca2+ spikes, followed by a cluster of Ca2+ oscillations, increasing [Ca2+]i to around ... More
Mitochondrial Ca(2+) uptake depends on the spatial and temporal profile of cytosolic Ca(2+) signals.
AuthorsCollins TJ, Lipp P, Berridge MJ, Bootman MD
JournalJ Biol Chem
PubMed ID11333261
'Using confocal imaging of Rhod-2-loaded HeLa cells, we examined the ability of mitochondria to sequester Ca(2+) signals arising from different sources. Mitochondrial Ca(2+) (Ca(2+)mit) uptake was stimulated by inositol 1,4,5-trisphosphate (InsP(3))-evoked Ca(2+) release, capacitative Ca(2+) entry, and Ca(2+) leaking from the endoplasmic reticulum. For each Ca(2+) source, the relationship between ... More
pH profiles in human skin: influence of two in vitro test systems for drug delivery testing.
AuthorsWagner H, Kostka KH, Lehr CM, Schaefer UF
JournalEur J Pharm Biopharm
PubMed ID12551704
'Investigations to determine pH profiles across human stratum corneum (SC), in vivo as well as in vitro, were carried out using the tape stripping technique and a flat surface pH electrode. This method was extended to the deeper skin layers (=viable epidermis+dermis; DSL) in vitro. Statistically significant changes in the ... More
Effects of the nitric oxide donor sodium nitroprusside on intracellular pH and contraction in hypertrophied myocytes.
AuthorsIto N, Bartunek J, Spitzer KW, Lorell BH
JournalCirculation
PubMed ID9142009
'BACKGROUND: We compared the effects of the nitric oxide donor sodium nitroprusside (SNP) on intracellular pH (pHi), intracellular calcium concentration ([Ca2+]i) transients, and cell contraction in hypertrophied adult ventricular myocytes from aortic-banded rats and age-matched controls. METHODS AND RESULTS: pHi was measured in individual myocytes with SNARF-1, and [Ca2+]i transients ... More
Low pH inhibits compensatory endocytosis at a step between depolarization and calcium influx.
AuthorsSmith RM, Baibakov B, Lambert NA, Vogel SS
JournalTraffic
PubMed ID12010458
'Cell function can be modulated by the insertion and removal of ion channels from the cell surface. The mechanism used to keep channels quiescent prior to delivery to the cell surface is not known. In eggs, cortical vesicle exocytosis inserts voltage-gated calcium channels into the cell surface. Calcium influx through ... More
Effect of vacuolar proton ATPase on pHi, Ca2+, and apoptosis in neonatal cardiomyocytes during metabolic inhibition/recovery.
AuthorsKarwatowska-Prokopczuk E, Nordberg JA, Li HL, Engler RL, Gottlieb RA
JournalCirc Res
PubMed ID9633914
'Recently, we found that vacuolar proton ATPase (VPATPase) operates in cardiomyocytes as a complementary proton-extruding mechanism. Its activity was increased by preconditioning with resultant attenuation of intracellular acidification during ischemia. In this study, we examined whether VPATPase-mediated proton efflux during metabolic inhibition/recovery may spare Na+ overload via Na+-H+ exchange, attenuate ... More
The involvement of protein phosphatases in the activation of ICE/CED-3 protease, intracellular acidification, DNA digestion, and apoptosis.
AuthorsMorana SJ, Wolf CM, Li J, Reynolds JE, Brown MK, Eastman A
JournalJ Biol Chem
PubMed ID8663484
'Many events in apoptosis have been identified but their temporal relationships remain obscure. Apoptosis in human ML-1 cells induced by etoposide is characterized by intracellular acidification, enhanced Hoechst 33342 fluorescence, DNA digestion, chromatin condensation, and proteolysis of poly(ADP-ribose) polymerase. This proteolysis is a marker for the action of ICE/CED-3 proteases, ... More
Simultaneous imaging of multiple fluorescent probes in bio-cells.
AuthorsMatsuoka H, Kosai Y, Saito M, Takeyama N, Suto H
JournalAnal Sci
PubMed ID12502082
'In order to obtain the full spectrum from 400 to 800 nm of each pixel of a microscopic image, a unique spectro-imaging system was developed using an image slicer. The image slicer is composed of 100 photo fibers which are arranged in a matrix of 10 x 10 at the ... More
Src family tyrosine kinase regulates intracellular pH in cardiomyocytes.
AuthorsPucéat M, Roche S, Vassort G
JournalJ Cell Biol
PubMed ID9647655
'The Anion Cl-/HCO3- Exchangers AE1, AE2, and AE3 are membrane pH regulatory ion transporters ubiquitously expressed in vertebrate tissues. Besides relieving intracellular alkaline and CO2 loads, the AEs have an important function during development and cell death and play a central role in such cellular properties as cell shape, metabolism, ... More
Kappa-opioid peptide receptor stimulation increases cytosolic pH and myofilament responsiveness to Ca2+ in cardiac myocytes.
AuthorsVentura C, Capogrossi MC, Spurgeon HA, Lakatta EG
JournalAm J Physiol
PubMed ID1659231
'Although kappa- and delta-opioid receptors on mammalian cardiac myocytes have been discovered recently, the intracellular effects that result from stimulation of these receptors remain unknown. We examine the effects of a rapid and brief exposure to a kappa-opioid receptor agonist on intracellular Ca2+, pH, and cell length in individual isolated ... More
Intracellular pH regulation of CA1 neurons in Na(+)/H(+) isoform 1 mutant mice.
AuthorsYao H, Ma E, Gu XQ, Haddad GG
JournalJ Clin Invest
PubMed ID10487778
'To understand the role of Na(+)/H(+) exchanger 1 (NHE1) in intracellular pH (pH(i)) regulation and neuronal function, we took advantage of natural knockout mice lacking NHE1, the most ubiquitously and densely expressed NHE isoform in the central nervous system (CNS). CA1 neurons from both wild-type (WT) and NHE1 mutant mice ... More
Ischemia alters the electrical activity of pacemaker cells isolated from the rabbit sinoatrial node.
AuthorsGryshchenko O, Qu J, Nathan RD
JournalAm J Physiol Heart Circ Physiol
PubMed ID12003839
'The purpose of this study was to investigate the mechanisms responsible for ischemia-induced changes in spontaneous electrical activity. An ischemic-like Tyrode solution (pH 6.6) reversibly depolarized the maximum diastolic potential (MDP) and reduced the action potential (AP) overshoot (OS). We used SNARF-1, which is an indicator of intracellular pH (pH(i)), ... More
Evidence for an electrogenic Na+-HCO3- symport in rat cardiac myocytes.
AuthorsAiello EA, Petroff MG, Mattiazzi AR, Cingolani HE
JournalJ Physiol
PubMed ID9729624
'1. The perforated whole-cell configuration of patch clamp and the pH fluorescent indicator SNARF were used to determine the electrogenicity of the Na+-HCO3- cotransport in isolated rat ventricular myocytes. 2. Switching from Hepes buffer to HCO3- buffer at constant extracellular pH (pHo) hyperpolarized the resting membrane potential (RMP) by 2.9 ... More
Expression of IGF receptors on alveolar macrophages: IGF-induced changes in InsPi formation, [Ca2+]i, and pHi.
AuthorsGeertz R, Kiess W, Kessler U, Hoeflich A, Tarnok A, Gercken G
JournalMol Cell Biochem
PubMed ID9450643
'Expression of insulin-like growth factor-I (IGF-I) receptors and insulin-like growth factor-II/mannose-6-phosphate (IGF-II/Man6P) receptors in cultured bovine alveolar macrophages (BAM) was demonstrated by competitive binding studies and crosslinking experiments. Western blotting of protein extracts from cultured BAM using an anti bovine IGF-II/Man6P receptor antiserum (#66416) confirmed the presence of IGF-II/Man6P receptors ... More