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
Arabidopsis abi1-1 and abi2-1 phosphatase mutations reduce abscisic acid-induced cytoplasmic calcium rises in guard cells.
AuthorsAllen GJ,Kuchitsu K,Chu SP,Murata Y,Schroeder JI
JournalThe Plant cell
PubMed ID10488243
Elevations in cytoplasmic calcium ([Ca(2)+](cyt)) are an important component of early abscisic acid (ABA) signal transduction. To determine whether defined mutations in ABA signal transduction affect [Ca(2)+](cyt) signaling, the Ca(2)+-sensitive fluorescent dye fura 2 was loaded into the cytoplasm of Arabidopsis guard cells. Oscillations in [Ca(2)+](cyt) could be induced when ... More
Ca2+ transients in cardiac myocytes measured with high and low affinity Ca2+ indicators.
AuthorsBerlin JR,Konishi M
JournalBiophysical journal
PubMed ID8274651
Intracellular calcium ion ([Ca2+]i) transients were measured in voltage-clamped rat cardiac myocytes with fura-2 or furaptra to quantitate rapid changes in [Ca2+]i. Patch electrode solutions contained the K+ salt of fura-2 (50 microM) or furaptra (300 microM). With identical experimental conditions, peak amplitude of stimulated [Ca2+]i transients in furaptra-loaded myocytes ... More
Evidence for role of cytosolic free calcium in hypoxia-induced proximal tubule injury.
AuthorsKribben A, Wieder ED, Wetzels JF, Yu L, Gengaro PE, Burke TJ, Schrier RW
JournalJ Clin Invest
PubMed ID8182125
The role of cytosolic free Ca2+ ([Ca2+]i) in hypoxic injury was investigated in rat proximal tubules. [Ca2+]i was measured using fura-2 and cell injury was estimated with propidium iodide (PI) in individual tubules using video imaging fluorescence microscopy. [Ca2+]i increased from approximately 170 to approximately 390 nM during 5 min ... More
Hyposmotic activation hyperpolarizes outer hair cells of guinea pig cochlea.
AuthorsHarada N, Ernst A, Zenner HP
JournalBrain Res
PubMed ID8348313
The electrophysiological responses of isolated guinea pig outer hair cells (OHCs) to hyposmotic activation were studied using the whole-cell patch-clamp technique. The cell swelling by hyposmotic activation hyperpolarized OHCs by 6.6 +/- 2.3 mV from the resting membrane potential of -58.5 +/- 5.9 mV (n = 48). This hyperpolarization was ... More
Gap junction-mediated intercellular diffusion of Ca2+ in cultured human corporal smooth muscle cells.
AuthorsChrist GJ, Moreno AP, Melman A, Spray DC
JournalAm J Physiol
PubMed ID1325115
Ratio imaging using the calcium-sensitive probe fura-2 was employed to study intracellular calcium concentrations and intercellular calcium flux through gap junctions in homogeneous vascular smooth muscle cell cultures derived from the human corpora cavernosa. Microinjection techniques demonstrated that fura-2 free acid was freely diffusible through gap junctions between cultured cells. ... More
Polyamines are intracellular messengers in the beta-adrenergic regulation of Ca2+ fluxes, [Ca2+]i and membrane transport in rat heart myocytes.
AuthorsKoenig H, Goldstone AD, Lu CY
JournalBiochem Biophys Res Commun
PubMed ID2839169
The beta-adrenergic agonist 1-isoproterenol (0.1 microM) evokes an acute (less than 5-10 sec) transient increase in the activity of ornithine decarboxylase (ODC), and the levels of polyamines (putrescine, spermidine, spermine) in acutely isolated rat ventricular myocytes. Isoproterenol rapidly (less than 15 sec) increases 45Ca influx and efflux, decreases [Ca2+]i, and ... More
Fluorescent indicators of ion concentrations.
AuthorsTsien RY
JournalMethods Cell Biol
PubMed ID2538708
Patch pipettes used for loading small cells with fluorescent indicator dyes.
AuthorsNeher E, Almers W
JournalAdv Exp Med Biol
PubMed ID3604783
Ca2+ regulation in the near-membrane microenvironment in smooth muscle cells.
AuthorsBazzazi H, Kargacin ME, Kargacin GJ
JournalBiophys J
PubMed ID12944290
'The microenvironment between the plasma membrane and the near-membrane sarcoplasmic reticulum (SR) may play an important role in Ca(2+) regulation in smooth muscle cells. We used a three-dimensional mathematical model of Ca(2+) diffusion and regulation and experimental measurements of SR Ca(2+) uptake and the distribution of the SR in isolated ... More
N-methyl-D-aspartate increases cytosolic Ca2+ via G proteins in cultured hippocampal neurons.
AuthorsHarada K, Yoshimura T, Nakajima K, Ito H, Ebina Y, Shingai R
JournalAm J Physiol
PubMed ID1314490
'The changes of the cytosolic Ca2+ concentrations ([Ca2+]i) induced by N-methyl-D-aspartate (NMDA) in fura-2-loaded cultured hippocampal neurons from rat embryos were investigated by the fast application method, using a fine pipe under extracellular Mg(2+)-free conditions. In the presence of Ca2+, NMDA, at concentrations in excess of 3 microM, induced a ... More
Resolution of structural changes associated with calcium activation of calmodulin using frequency domain fluorescence spectroscopy.
AuthorsYao Y, Schöneich C, Squier TC
JournalBiochemistry
PubMed ID8011644
'Structural changes associated with the calcium-dependent activation of wheat germ calmodulin (CaM) were assessed through measurements of steady-state and time-resolved changes in the fluorescence associated with (1) the unique tyrosine (Tyr139) located in calcium binding loop IV or (2) N-(1-pyrenyl)-maleimide (PM) or 4-(iodoacetamido)salicylic acid (IASA) covalently attached to Cys27 present ... More
Determination of cytoplasmic calcium concentration in Dryopteris spores: a developmentally non-disruptive technique for loading of the calcium indicator fura-2.
AuthorsScheuerlein R, Schmidt K, Poenie M, Roux SJ
JournalPlanta
PubMed ID11538116
'Germination of Dryopteris spores is mediated by the physiologically active, far-red-absorbing form of phytochrome, Pfr, and external Ca2+ is necessary for the transduction of the light signal. Because knowledge about the cytoplasmic calcium ion concentration, [Ca2+]i, is of great importance for understanding the role of calcium during signal transduction, ... More
Differences in Ca2+ buffering properties between excitatory and inhibitory hippocampal neurons from the rat.
AuthorsLee SH, Rosenmund C, Schwaller B, Neher E
JournalJ Physiol
PubMed ID10835043
'Endogenous calcium binding ratios (kappaS) in dendrites of cultured hippocampal neurons were estimated according to the single compartment model for transients in intracellular Ca2+ concentration ([Ca2+]). In addition, the electrophysiological characteristics of neurons were classified by their autaptic currents and intrinsic firing patterns. These data were analysed in order to ... More
Flow-induced changes in Ca2+ signaling of vascular endothelial cells: effect of shear stress and ATP.
AuthorsMo M, Eskin SG, Schilling WP
JournalAm J Physiol
PubMed ID2035689
'The effect of hemodynamic flow on apparent cytosolic free Ca2+ concentration ([Ca2+]i) of cultured bovine aortic endothelial cells was examined in the absence and presence of adenine nucleotides using microfluorimetric analysis of fura-2 fluorescence. In the absence of adenine nucleotides, flow-induced shear stress produced little change (less than 10 nM) ... More
Bradykinin-induced cytosolic Ca2+ oscillations and inositol tetrakisphosphate-induced Ca2+ influx in voltage-clamped ras-transformed NIH/3T3 fibroblasts.
AuthorsHashii M, Nozawa Y, Higashida H
JournalJ Biol Chem
PubMed ID8366088
'Microspectrofluorometry (fura-2) was combined with the whole-cell patch-clamp technique to study bradykinin-activated calcium (Ca2+) influx in single control or v-Ki-ras-transformed NIH/3T3 (DT) fibroblasts. Application of bradykinin on DT cells, but not on control NIH/3T3 cells, evoked cytosolic Ca2+ oscillations in the presence of extracellular Ca2+, but not in the absence ... More
Agonist-dependent patterns of cytosolic Ca2+ changes in single bovine adrenal chromaffin cells: relationship to catecholamine release.
AuthorsStauderman KA, Murawsky MM, Pruss RM
JournalCell Regul
PubMed ID2078572
'The patterns of agonist-induced elevations of cytosolic free Ca2+ ([Ca2+]i) were characterized and compared by the use of single adrenal chromaffin cells. Initial histamine- or angiotensin II (AII)-induced elevations of [Ca2+]i were equal in magnitude (peaks 329 +/- 20 [SE] and 338 +/- 46 nM, respectively). These initial increases of ... More
Fura-2 calcium signals in skeletal muscle fibres loaded with high concentrations of EGTA.
AuthorsStruk A, Szücs G, Kemmer H, Melzer W
JournalCell Calcium
PubMed ID9570007
'Fura-2 is one of the most frequently used fluorescent Ca indicator dyes; yet it has limitations in tracking large intracellular Ca transients due to its high affinity for Ca. Since high affinity is of advantage when small Ca changes are to be detected, we tried the application of Fura-2 in ... More
'Gelsolins are actin-binding proteins that cap, nucleate, and sever actin filaments. Microinjection of cytoplasmic or plasma gelsolin into living fibroblasts and macrophages did not affect the shape, actin distribution, deformability, or ruffling activity of the cells. Gelsolin requires calcium for activity, but the NH2-terminal half is active without calcium. Microinjection ... More
Acute electrophysiological responses of bradykinin-stimulated human fibroblasts.
AuthorsEstacion M
JournalJ Physiol
PubMed ID1648132
'1. Acute responses to bradykinin in human dermal fibroblasts were studied at 20-24 degrees C using both the patch-clamp technique to monitor ion currents and Fura-2 fluorescence to monitor [Ca2+]i. 2. During subconfluent culture, human dermal fibroblasts can express a diversity of ion channels as described in the preceding paper. ... More
Single-cell analysis of Ca++ changes in human lung mast cells: graded vs. all-or-nothing elevations after IgE-mediated stimulation.
AuthorsMacGlashan D
JournalJ Cell Biol
PubMed ID2473078
'Human lung mast cells were examined by digital video microscopy for changes in cytosolic free ionized calcium [( Ca++]i) after stimulation with anti-IgE antibody or specific antigens. These studies sought to determine whether the mast cell response resembled a graded or an all-or-nothing process. Preliminary experiments indicated that labeling mast ... More
Receptor-operated Ca2+ channels in gastric parietal cells: gastrin and carbachol induce Ca2+ influx in depleting intracellular Ca2+ stores.
AuthorsRoche S, Bali JP, Magous R
JournalBiochem J
PubMed ID8380979
'The mechanism whereby gastrin-type receptor and muscarinic M3-type receptor regulate free intracellular Ca2+ concentration ([Ca2+]i) was studied in rabbit gastric parietal cells stimulated by either gastrin or carbachol. Both agonists induced a biphasic [Ca2+]i response: a transient [Ca2+]i rise, followed by a sustained steady state depending on extracellular Ca2+. Gastrin ... More
Mechanisms for activation and subsequent removal of cytosolic Ca2+ in bradykinin-stimulated neuronal and glial cell lines.
AuthorsReiser G, Binmöller FJ, Donié F
JournalExp Cell Res
PubMed ID2298236
'Mechanisms for activation and for removal of cytosolic Ca2+ after stimulation with bradykinin were investigated in two neural cell lines by measuring cytosolic Ca2+ activity and 45Ca2+ fluxes. In the neuronal (neuroblastoma x glioma hybrid) and in the glial (rat glioma) cell lines, the transient, bradykinin-induced rise in cytosolic Ca2+ ... More
Transfer and tunneling of Ca2+ from sarcoplasmic reticulum to mitochondria in skeletal muscle.
AuthorsShkryl VM, Shirokova N
JournalJ Biol Chem
PubMed ID16216882
'The role of mitochondrial Ca2+ transport in regulating intracellular Ca2+ signaling and mitochondrial enzymes involved in energy metabolism is widely recognized in many tissues. However, the ability of skeletal muscle mitochondria to sequester Ca2+ released from the sarcoplasmic reticulum (SR) during the muscle contraction-relaxation cycle is still disputed. To assess ... More
Calcium wave fronts that cross gap junctions may signal neuronal death during development.
AuthorsWolszon LR, Rehder V, Kater SB, Macagno ER
JournalJ Neurosci
PubMed ID8207465
'Embryonic anterior pagoda (AP) neurons in the leech interact with their segmental homologs in adjacent ganglia through transient axons that overlap during a critical period of development and then retract. However, when an AP neuron is ablated mechanically or by irradiation during this period, an adjacent homolog responds by reinitiating ... More
The spread of Na+ spikes determines the pattern of dendritic Ca2+ entry into hippocampal neurons.
AuthorsJaffe DB, Johnston D, Lasser-Ross N, Lisman JE, Miyakawa H, Ross WN
JournalNature
PubMed ID1350327
'The dendrites of many types of neurons contain voltage-dependent Na+ and Ca2+ conductances that generate action potentials (see ref. 1 for review). The function of these spikes is not well understood, but the Ca2+ entry stimulated by spikes probably affects Ca(2+)-dependent processes in dendrites. These include synaptic plasticity, cytotoxicity and ... More
Epidermal growth factor-stimulated calcium ion transients in individual A431 cells: initiation kinetics and ligand concentration dependence.
AuthorsCheyette TE, Gross DJ
JournalCell Regul
PubMed ID1801919
'The A431 epidermoid carcinoma cell line responds to epidermal growth factor (EGF) stimulation with a number of rapid changes, including alterations in free cytosolic calcium ion concentration ([Ca2+]i). At the single cell level, these changes in [Ca2+]i are known to proceed after a clear lag phase subsequent to EGF stimulus ... More
Photophysics of the fluorescent Ca2+ indicator Fura-2.
AuthorsVan den Bergh V, Boens N, De Schryver FC, Ameloot M, Steels P, Gallay J, Vincent M, Kowalczyk A
JournalBiophys J
PubMed ID7756530
'The photophysics of the complex forming reaction of Ca2+ and Fura-2 are investigated using steady-state and time-resolved fluorescence measurements. The fluorescence decay traces were analyzed with global compartmental analysis yielding the following values for the rate constants at room temperature in aqueous solution with BAPTA as Ca2+ buffer: k01 = ... More
Apparent cytosolic calcium gradients in T-lymphocytes due to fura-2 accumulation in mitochondria.
AuthorsQuintana A, Hoth M
JournalCell Calcium
PubMed ID15193858
'Fura-2 is the most common dye to measure cytosolic Ca2+ concentrations ([Ca2+]i). To facilitate simultaneous imaging of many cells while preserving their cytosolic environment, fura-2 is often loaded into the cytosol in its membrane-permeant ester form. It has been reported that small amounts of fura-2 accumulate in intracellular compartments, an ... More
Ca2+ movement in smooth muscle cells studied with one- and two-dimensional diffusion models.
AuthorsKargacin G, Fay FS
JournalBiophys J
PubMed ID1662084
'Although many of the processes involved in the regulation of Ca2+ in smooth muscle have been studied separately, it is still not well known how they are integrated into an overall regulatory system. To examine this question and to study the time course and spatial distribution of Ca2+ in cells ... More
Variable conformation and dynamics of calmodulin complexed with peptides derived from the autoinhibitory domains of target proteins.
AuthorsYao Y, Squier TC
JournalBiochemistry
PubMed ID8639633
'Calcium-saturated calmodulin (CaM) can bind and activate many target proteins through the direct association with the respective autoinhibitory domains. The CaM binding sequences within the autoinhibitory domains of these proteins have little sequence homology, and the mechanisms associated with CaM's ability to recognize and productively bind with these variable sequences ... More
Regulatory volume decrease and intracellular Ca2+ in murine neuroblastoma cells studied with fluorescent probes.
'The possible role of Ca2+ as a second messenger mediating regulatory volume decrease (RVD) in osmotically swollen cells was investigated in murine neural cell lines (N1E-115 and NG108-15) by means of novel microspectrofluorimetric techniques that allow simultaneous measurement of changes in cell water volume and [Ca2+]i in single cells loaded ... More
Inositol phosphates and intracellular calcium after bradykinin stimulation in fibroblasts from young, normal aged and Alzheimer donors.
AuthorsHuang HM, Toral-Barza L, Thaler H, Tofel-Grehl B, Gibson GE
JournalNeurobiol Aging
PubMed ID1770982
'Several studies suggest that alterations in the receptor-mediated phosphoinositide cascade and cytosolic free calcium concentration ([Ca2+]i) are involved in the pathophysiology of aging and Alzheimer''s disease. Therefore, the phosphoinositide cascade and [Ca2+]i were determined under resting conditions and after stimulation with bradykinin (100 nM) in cultured human skin fibroblasts from ... More
Membrane potential, resting calcium and calcium transients in isolated muscle fibres from normal and dystrophic mice.
AuthorsHead SI
JournalJ Physiol
PubMed ID8271194
'1. Single skeletal muscle fibres were enzymatically isolated from the flexor digitorum brevis muscles (FDB) of dystrophic mdx and control C57BL/10 mice aged 3-9 weeks. In this age range the majority (> 95%) of the mdx fibres were morphologically normal. 2. There was no significant difference between the resting membrane ... More
Thin-section ratiometric Ca2+ images obtained by optical sectioning of fura-2 loaded mast cells.
AuthorsMonck JR, Oberhauser AF, Keating TJ, Fernandez JM
JournalJ Cell Biol
PubMed ID1730775
'The availability of the ratiometric Ca2+ indicator dyes, fura-2, and indo-1, and advances in digital imaging and computer technology have made it possible to detect Ca2+ changes in single cells with high temporal and spatial resolution. However, the optical properties of the conventional epifluorescence microscope do not produce a perfect ... More
Simultaneous measurement of Ca2+ influx and reversal potentials in recombinant N-methyl-D-aspartate receptor channels.
AuthorsSchneggenburger R
JournalBiophys J
PubMed ID9172740
'The Ca(2+) permeability of N-methyl-D-aspartate receptor (NMDA-R) channels was studied in human embryonic kidney cells transfected with the NR1-NR2A subunit combination. To determine the fractional Ca(2+) current (P(f)), measurements of fura-2-based Ca(2+) influx and whole-cell currents were made in symmetrical monovalent ion concentrations at membrane potentials between -50 mV and ... More
Effect of fura-2 on action potential-stimulated calcium release in cut twitch fibers from frog muscle.
AuthorsPape PC, Jong DS, Chandler WK, Baylor SM
JournalJ Gen Physiol
PubMed ID8228913
'Cut fibers (striation spacing, 3.6-4.2 microns) were mounted in a double Vaseline-gap chamber and studied at 14-15 degrees C. One or both of the Ca indicators fura-2 and purpurate-3,3'' diacetic acid (PDAA) were introduced into the optical recording site by diffusion from the end pools. Sarcoplasmic reticulum (SR) Ca release ... More
Comparison of quantitative calcium flux through NMDA, ATP, and ACh receptor channels.
AuthorsRogers M, Dani JA
JournalBiophys J
PubMed ID7696503
'NMDA receptors, ATP receptors, and nicotinic ACh receptors respond to agonist by undergoing conformational changes that open weakly selective cationic channels that are permeable to calcium. We determined the fraction of the current carried by calcium by simultaneously measuring membrane current using whole-cell patch-clamp techniques and intracellular Ca2+ using the ... More
Responses to Metabotropic Glutamate Receptor Activation in Cerebellar Purkinje Cells: Induction of an Inward Current.
AuthorsStaub C, Vranesic I, Knöpfel T
JournalEur J Neurosci
PubMed ID12106306
'The responses to activation of metabotropic glutamate receptors (mGluRs) of Purkinje cells in rat cerebellar slice cultures were investigated using intracellular recordings in single-electrode voltage-clamp mode combined with microfluorometric measurements of cytosolic free calcium using fura-2. Purkinje cells were perfused with saline containing 0.5 microM tetrodotoxin and 10 microM bicuculline ... More
Adenosine triphosphate depletion induces a rise in cytosolic free calcium in canine renal epithelial cells.
AuthorsMcCoy CE, Selvaggio AM, Alexander EA, Schwartz JH
JournalJ Clin Invest
PubMed ID2844853
'An elevation in cytosolic free calcium (Cai) produced by cellular ATP depletion may contribute to the initiation of cytotoxic events in renal ischemia. To evaluate whether ATP depletion results in a rise in Cai we examined the effect of cyanide and 2-deoxy-D-glucose on the Cai of Madin-Darby canine kidney cells. ... More
Voltage-dependent activation and inactivation of calcium channels in PC12 cells. Correlation with neurotransmitter release.
AuthorsDi Virgilio F, Milani D, Leon A, Meldolesi J, Pozzan T
JournalJ Biol Chem
PubMed ID2439506
'The existence and mechanisms of inactivation of voltage-gated Ca2+ channels are important, but still debatable, physiological problems. By using the Ca2+ indicators quin2 and fura-2, we demonstrate that in PC12 cells voltage-gated Ca2+ channels undergo inactivation dependent on both voltage and [Ca2+]i. Inactivation, however, is never complete and a small ... More
A single optical fiber fluorometric device for measurement of intracellular Ca2+ concentration: its application to hippocampal neurons in vitro and in vivo.
AuthorsKudo Y, Akita K, Nakamura T, Ogura A, Makino T, Tamagawa A, Ozaki K, Miyakawa A
JournalNeuroscience
PubMed ID1436506
'We developed a new system to measure the intracellular Ca2+ concentration in the deep region of the central nervous system with a single optical fiber (300 microns in diameter), used for both excitation and detection of the fluorescence of previously loaded fura-2. With this system, a brain region loaded with ... More
Quantitative measurement of calcium flux through muscle and neuronal nicotinic acetylcholine receptors.
AuthorsVernino S, Rogers M, Radcliffe KA, Dani JA
JournalJ Neurosci
PubMed ID8083751
'A new approach was developed to determine quantitatively the fraction of current carried by Ca2+ through an ion channel under physiological conditions. This approach entails the simultaneous measurement of membrane current and intracellular Ca2+ for single cells. Whole-cell patch-clamp techniques were used to measure current, and intracellular Ca2+ was monitored ... More
Thapsigargin activates a calcium influx pathway in the unfertilized mouse egg and suppresses repetitive calcium transients in the fertilized egg.
AuthorsKline D, Kline JT
JournalJ Biol Chem
PubMed ID1387638
'At fertilization, the sperm initiates development of the mouse egg by inducing a large transient increase in the intracellular Ca2+ concentration ([Ca2+]i), which is followed by repetitive transient increases in [Ca2+]i. To determine how the repetitive Ca2+ transients are produced, thapsigargin, an inhibitor of the endoplasmic reticulum Ca-ATPase, was used ... More
Using fura-2 to measure intracellular free calcium in Propionibacterium acnes.
AuthorsFutsaether CM, Johnsson A
JournalCan J Microbiol
PubMed ID8050064
'The fluorescent probe fura-2 was used to measure the intracellular free calcium concentration [Ca2+]i in the Gram-positive skin bacterium Propionbacterium acnes. Three methods for loading the probe into P. acnes were used. Two consisted of using the membrane permeable acetoxymethyl ester of fura-2, fura-2/AM, whereas in the third method, fura-2 ... More
Fura 2 analysis of cytosolic calcium regulation in elutriated rat gastric parietal cells.
AuthorsBlack EW, Cornwell TL, Lincoln TM, Strada SJ, Thompson WJ
JournalJ Cell Physiol
PubMed ID2472414
'The calcium probe, Fura 2, is used to establish and partially characterize histamine-, carbachol-, and forskolin-induced calcium transients in enriched parietal cell populations prepared by centrifugal elutriation of dispersed rat fundic mucosa cell isolates. The magnitude of the maximal carbachol response, which is blocked by atropine but not cimetidine, is ... More
Calcium signalling in non-excitable cells: notes on oscillations and store refilling.
AuthorsRink TJ, Hallam TJ
JournalCell Calcium
PubMed ID2670242
'Technical advances in studying cellular calcium concentrations, and discoveries about many aspects of signal transduction have transformed this field of biology since this Journal was launched a decade ago. At that time monitoring of the key variable, cytoplasmic free Ca2+ concentration [Ca2+]i, was possible with aequorin or arsenazo ill mainly ... More
Calcium in the nerve terminals of chick ciliary ganglia during facilitation, augmentation and potentiation.
AuthorsBrain KL, Bennett MR
JournalJ Physiol
PubMed ID8788930
'1. The calyciform nerve terminals of chick ciliary ganglia were loaded with the calcium indicators calcium green 1 or fura-2. These were used to determine the change in calcium concentration in the terminal, [Ca2+]t, following short (10 impulses) and long (600 impulses) trains of high-frequency (30 Hz) stimulation. 2. Following ... More
Dopamine modulates GABAc receptors mediating inhibition of calcium entry into and transmitter release from bipolar cell terminals in tiger salamander retina.
AuthorsWellis DP, Werblin FS
JournalJ Neurosci
PubMed ID7623108
'Using optical recording techniques, we directly monitored pre- and postsynaptic calcium dynamics at bipolar cell terminals while inhibiting synaptic release with applied GABA and modulating inhibition with dopamine. To monitor pre-synaptic activity, individual bipolar cells in the retinal slice were filled with either fura-2 or fluo-3 through a patch electrode. ... More
Changes of free calcium levels with stages of the cell division cycle.
AuthorsPoenie M, Alderton J, Tsien RY, Steinhardt RA
JournalNature
PubMed ID3838803
'Although the regulation of events in the cell division cycle by calcium or other cations has been the subject of much interest and speculation, experimental studies have been hampered by the difficulty of measuring submicromolar intracellular free calcium concentrations ([Ca2+]i) over an entire cell cycle. We now describe experiments using ... More
Optical monitoring of excitatory synaptic activity between cultured hippocampal neurons by a multi-site Ca2+ fluorometry.
AuthorsOgura A, Iijima T, Amano T, Kudo Y
JournalNeurosci Lett
PubMed ID2441334
'The fluorescence intensities from cultured hippocampal neurons loaded with a Ca2+-indicator (fura-2), showed spontaneous, periodical oscillations, which were synchronized among the cells. Tetrodotoxin or 2-aminophosphonovalerate, a glutamate-receptor antagonist, blocked the oscillation. The rising phase of the fluorescence was accompanied by a burst of inward currents, as monitored by a patch ... More
Myoplasmic binding of fura-2 investigated by steady-state fluorescence and absorbance measurements.
AuthorsKonishi M, Olson A, Hollingworth S, Baylor SM
JournalBiophys J
PubMed ID3266079
'Binding of the fluorescent Ca2+ indicator dye fura-2 by intracellular constituents has been investigated by steady-state optical measurements. Fura-2''s (a) fluorescence intensity, (b) fluorescence emission anisotropy, (c) fluorescence emission spectrum, and (d) absorbance spectra were measured in glass capillary tubes containing solutions of purified myoplasmic proteins; properties b and c ... More
Suppression of TNF-alpha secretion by azelastine in a rat mast (RBL-2H3) cell line: evidence for differential regulation of TNF-alpha release, transcription, and degranulation.
AuthorsHide I, Toriu N, Nuibe T, Inoue A, Hide M, Yamamoto S, Nakata Y
JournalJ Immunol
PubMed ID9300717
'The mast cell plays a pivotal role in initiating allergic inflammation by secreting several cytokines including TNF-alpha, in addition to granule mediators such as histamine. Anti-allergic drugs including azelastine prevent immediate-type hypersensitivity by inhibiting mast cell degranulation, as well as blocking histamine H1 receptors. However, their effects on cytokine release ... More
The effects of metabolic inhibition on intracellular calcium and pH in isolated rat ventricular cells.
AuthorsEisner DA, Nichols CG, O'Neill SC, Smith GL, Valdeolmillos M
JournalJ Physiol
PubMed ID2614727
'1. Intracellular calcium concentration [( Ca2+]i) and pH (pHi) were measured in single, isolated rat ventricular myocytes using, respectively, the fluorescent indicators Fura-2 and BCECF (2',7'-bis(carboxyethyl-5(6)-carboxyfluorescein). Contraction was measured simultaneously. The intracellular calibration of BCECF is demonstrated. In a HEPES-buffered bathing solution of pH 7.4, pHi had a mean value ... More
Sphingosine metabolism induces Ca2+ oscillations in rat pancreatic acinar cells.
AuthorsYule DI, Wu D, Essington TE, Shayman JA, Williams JA
JournalJ Biol Chem
PubMed ID8509375
'The possibility that sphingosine or a related metabolite could mediate inositol-1,4,5-triphosphate (1,4,5-IP3)-independent Ca2+ release in pancreatic acinar cells was investigated. In intact rat pancreatic acini superfused at 37 degrees C, sphingosine (10-100 microM) evoked, after a delay of several minutes, an increase in the cytosolic [Ca2+]i which was oscillatory below ... More
Block of Ca2+ wave and Ca2+ oscillation by antibody to the inositol 1,4,5-trisphosphate receptor in fertilized hamster eggs.
AuthorsMiyazaki S, Yuzaki M, Nakada K, Shirakawa H, Nakanishi S, Nakade S, Mikoshiba K
JournalScience
PubMed ID1321497
'The concentration of cytoplasmic free calcium (Ca2+) increases in various stimulated cells in a wave (Ca2+ wave) and in periodic transients (Ca2+ oscillations). These phenomena are explained by inositol 1,4,5-trisphosphate (IP3)-induced Ca2+ release (IICR) and Ca(2+)-induced Ca2+ release (CICR) from separate intracellular stores, but decisive evidence is lacking. A monoclonal ... More
Intracellular Ca(2+) mobilization and kinase activity during acylated homoserine lactone-dependent quorum sensing in Serratia liquefaciens.
AuthorsWerthén M, Lundgren T
JournalJ Biol Chem
PubMed ID11102448
'Quorum sensing in Gram-negative bacteria involves acylated homoserine lactones (AHLs) and a transcription factor, activated by the AHLs. In this study, a possible involvement of intracellular Ca(2+) as second messenger and/or protein kinase activity during signal transduction is analyzed. When N-hexanoyl-l-homoserine lactone was added to a suspension of Fura-2-loaded Serratia ... More
Inhibition of bradykinin- and thapsigargin-induced Ca2+ entry by tyrosine kinase inhibitors.
AuthorsLee KM, Toscas K, Villereal ML
JournalJ Biol Chem
PubMed ID7683685
'We examined the involvement of tyrosine kinase activity in the bradykinin (BK)-mediated signal transduction process. Immunoblots with anti-phosphotyrosine antibodies following BK stimulation of human fibroblasts showed tyrosine phosphorylation of specific proteins that could be inhibited by the tyrosine kinase inhibitors genistein and tyrphostin. Image analysis data from individual cells stimulated ... More
Calcium homeostasis in the presence of fura-2 in neurons dissociated from rat nucleus basalis: theoretical and experimental analysis of chelating action of fura-2.
AuthorsTatsumi H, Katayama Y
JournalJ Neurosci Methods
PubMed ID7823623
'Intracellular calcium ions (Ca2+) play important roles in cell functions. Measurements of intracellular calcium ion concentration ([Ca2+]i) are often made with the fura-2 fluorescence recording technique in various preparations including neurons. Fura-2 has, however, a Ca(2+)-chelating action which complicates the interpretation of experimental results. In this report the chelating action ... More
Guanine nucleotide- and inositol 1,4,5-trisphosphate-induced calcium release in rabbit main pulmonary artery.
AuthorsKobayashi S, Somlyo AP, Somlyo AV
JournalJ Physiol
PubMed ID3150985
'1. The effects of activation of guanine nucleotide-binding protein (G protein) by guanine nucleotides or sodium fluoride on the release of intracellular Ca2+ and on tension development were determined in chemically skinned strips of rabbit main pulmonary arteries (MPA). Ca2+ movements were monitored with Fura-2, as the change in free ... More
Inactivation kinetics of calcium current of acutely dissociated CA1 pyramidal cells of the mature guinea-pig hippocampus.
AuthorsKay AR
JournalJ Physiol
PubMed ID1653853
'1. The process of inactivation of the Ca2+ current of acutely dissociated pyramidal cells from the CA1 subfield of mature guinea-pig hippocampus was characterized. The decline of the current after rapid activation could be approximated well by the sum of two exponentials (time constants approximately 200 ms and 2 s) ... More
Cytoplasmic calcium levels in protoplasts from the cap and elongation zone of maize roots.
AuthorsKiss HG, Evans ML, Johnson JD
JournalProtoplasma
PubMed ID11537092
'Calcium has been implicated as a key component in the signal transduction process of root gravitropism. We measured cytoplasmic free calcium in protoplasts isolated from the elongation zone and cap of primary roots of light-grown, vertically oriented seedlings of Zea mays L. Protoplasts were loaded with the penta-potassium ... More
Separation between cytosolic calcium and secretion in chromaffin cells superfused with calcium ramps.
AuthorsMichelena P, García-Pérez LE, Artalejo AR, García AG
JournalProc Natl Acad Sci U S A
PubMed ID8475070
'This paper describes experiments in which cytosolic Ca2+ concentrations ([Ca2+]i) and catecholamine release were measured in two populations of chromaffin cells stimulated with a solution enriched in K+ (100 mM). Once depolarized, external Ca2+ or Ba2+ ions were offered to cells either as a single 2.5 mM step or as ... More
Synaptic excitation produces a long-lasting rebound potentiation of inhibitory synaptic signals in cerebellar Purkinje cells.
AuthorsKano M, Rexhausen U, Dreessen J, Konnerth A
JournalNature
PubMed ID1313949
'Persistent changes in synaptic efficacy are thought to underlie the formation of learning and memory in the brain. High-frequency activation of an afferent excitatory fibre system can induce long-term potentiation, and conjunctive activation of two distinct excitatory synaptic inputs to the cerebellar Purkinje cells can lead to long-term depression of ... More
Cumulative effects of glutamate microstimulation on Ca(2+) responses of CA1 hippocampal pyramidal neurons in slice.
AuthorsConnor JA, Cormier RJ
JournalJ Neurophysiol
PubMed ID10634856
'Glutamate stimulation of hippocampal CA1 neurons in slice was delivered via iontophoresis from a microelectrode. Five pulses (approximately 5 muA, 10 s duration, repeated at 1 min intervals) were applied with the electrode tip positioned in the stratum radiatum near the dendrites of a neuron filled with the Ca(2+) indicator ... More
The sperm-induced Ca2+ wave following fertilization of the Xenopus egg requires the production of Ins(1, 4, 5)P3.
AuthorsNuccitelli R, Yim DL, Smart T
JournalDev Biol
PubMed ID7687224
'We used fluorescence ratio imaging of fura-2 in the egg of Xenopus laevis to study the initiation and propagation of the wave of increased free Ca2+ that is normally triggered at fertilization. Naturally matured, jellied eggs were injected with fura-2 and ratio-imaged with fluorescence excitation at 350 and 385 nm ... More
Activity-dependent [Ca2+]i changes in guinea pig vagal motoneurons: relationship to the slow afterhyperpolarization.
AuthorsLasser-Ross N, Ross WN, Yarom Y
JournalJ Neurophysiol
PubMed ID9307116
'Vagal motoneurons in slices from the guinea-pig brain stem were injected with the fluorescent [Ca2+]i indicators fura-2, furaptra, or Calcium Green-1. Spike-induced fluorescence changes were measured in the soma and dendrites and simultaneously the long-lasting afterhyperpolarization was recorded with a sharp microelectrode in the soma. Na+ spikes or Ca2+ spikes ... More
Cytosolic free calcium concentration and glucose transport in isolated cardiac myocytes.
AuthorsCheung JY, Constantine JM, Bonventre JV
JournalAm J Physiol
PubMed ID3103463
'The role of cytosolic free Ca2+ concentration, [Cai], in mediating insulin''s stimulatory effect on glucose transport was investigated in isolated Ca2+-tolerant rat ventricular cells. Approximately 98% of glucose transport in isolated myocytes was inhibited by phloretin. Insulin-accelerated glucose transport by 50-115% over basal transport rate. Removal of extracellular Ca2+ had ... More
Interactions between inositol phosphates and cytosolic free calcium following bradykinin stimulation in cultured human skin fibroblasts.
AuthorsHuang HM, Toral-Barza L, Gibson GE
JournalBiochim Biophys Acta
PubMed ID2001422
'The inositol triphosphate (IP3) that results from hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) is generally accepted to be responsible for the mobilization of intracellular calcium. However, some studies suggest that low concentrations of agonists elevate cytosolic free calcium concentration ([Ca2+]i) without IP3 formation. Thus, in the present studies, a comparison of ... More
Control of intracellular calcium redistribution by guanine nucleotides and inositol 1,4,5-trisphosphate in permeabilized GH4C1 cells.
AuthorsKoshiyama H, Tashjian AH
JournalEndocrinology
PubMed ID1903695
'In GH4C1 rat pituitary cells, a GTP-binding protein appears to be involved in signal transduction between the TRH receptor and phospholipase C. In certain other cell types, another role for GTP has been reported, namely regulation of Ca2+ translocation from one intracellular pool to another. Using digitonin-permeabilized GH4C1 cells, we ... More
Determining zinc with commonly used calcium and zinc fluorescent indicators, a question on calcium signals.
AuthorsMartin JL, Stork CJ, Li YV
JournalCell Calcium
PubMed ID16764924
'Investigations into the roles of Ca(2+) and Zn(2+) in cell biology have been facilitated by the development of sensitive fluorometric probes that have enabled the measurement of Ca(2+) or Zn(2+) in both extracellular and intracellular environments. It is critical to be aware of the specificity and relative selectivity of a ... More
Dual effects of chlorobutanol on secretory response and intracellular Ca2+ dynamics in isolated pancreatic acini of the rat.
AuthorsHabara Y, Kanno T
JournalBr J Pharmacol
PubMed ID7689400
'1. The effects of chlorobutanol, a widely used drug preservative, on exocrine response and intracellular Ca2+ dynamics were examined in isolated pancreatic acini of the rat. 2. Chlorobutanol (1 mg ml-1) markedly inhibited the secretory response to cholecystokinin octapeptide (CCK-8), carbamylcholine chloride (carbachol), or sodium fluoride, a direct G-protein activator. ... More
Secretory responses of rat peritoneal mast cells to high intracellular calcium.
AuthorsPenner R, Neher E
JournalFEBS Lett
PubMed ID3123272
'The patch-clamp technique was used to investigate the secretory responses of rat peritoneal mast cells at various intracellular calcium concentrations ([Ca2+]i). When Calcium was introduced into the cell with pipette-loaded dibromo-BAPTA, elevation of [Ca2+]i into the range 1-10 microM induced membrane capacitance increases indicative of exocytosis in a concentration-dependent manner. ... More
Intracellular pH regulates basolateral K+ and Cl- conductances in colonic epithelial cells by modulating Ca2+ activation.
AuthorsChang D, Kushman NL, Dawson DC
JournalJ Gen Physiol
PubMed ID1719125
'The role of intracellular pH as a modulator of basolateral K+ and Cl- conductances in epithelial cells was studied using digitonin-permeabilized colonic cell layers so that cytosolic pH could be clamped at specific values, while basolateral K+ and Cl- conductances were activated by stepwise increases in intracellular free Ca2+. Increasing ... More
Cholinergic stimulation produces oscillations of cytosolic Ca2+ in a secretory epithelial cell line, T84.
AuthorsDevor DC, Ahmed Z, Duffey ME
JournalAm J Physiol
PubMed ID2003581
'The effects of carbamylcholine (carbachol) on intracellular Ca2+ concentration ([Ca2+]c) of T84 cells were examined using the fluorescent Ca2+ indicator fura-2 and microfluorometric techniques. In single isolated cells, carbachol (100 microM) caused a rapid increase in [Ca2+]c of 184 +/- 15 nM (SE, n = 44) from a resting value ... More
Ultraviolet light activates blocking actions of dantrolene on intracellular Ca2+ release in bullfrog sympathetic neurones.
AuthorsNohmi M, Kuba K, Hua SY
JournalJ Biol Chem
PubMed ID1939247
'Effects of dantrolene, a blocker of intracellular Ca2+ release, on the oscillation of the intracellular Ca2+ ([Ca2+]i) induced by caffeine were studied in bullfrog sympathetic ganglion cells, using a Fura-2 fluorescence technique. Dantrolene blocked the Ca2+ oscillation only in the cell illuminated by ultraviolet light (335-385 nm). Likewise, the blocking ... More
A new generation of Ca2+ indicators with greatly improved fluorescence properties.
AuthorsGrynkiewicz G, Poenie M, Tsien RY
JournalJ Biol Chem
PubMed ID3838314
'A new family of highly fluorescent indicators has been synthesized for biochemical studies of the physiological role of cytosolic free Ca2+. The compounds combine an 8-coordinate tetracarboxylate chelating site with stilbene chromophores. Incorporation of the ethylenic linkage of the stilbene into a heterocyclic ring enhances the quantum efficiency and photochemical ... More
Thapsigargin-induced increase in cytoplasmic Ca2+ concentration and aldosterone production in rat adrenal glomerulosa cells: interaction with potassium and angiotensin-II.
'Thapsigargin (Tg), a microsomal Ca2+ pump inhibitor, dose-dependently increases the cytoplasmic Ca2+ concentration and aldosterone production without having any striking effect on the formation of inositol phosphates in isolated rat adrenal glomerulosa cells. The interaction of Tg with the major Ca2(+)-mediated stimuli of glomerulosa cells on aldosterone production was also ... More
cGMP mobilizes intracellular Ca2+ in sea urchin eggs by stimulating cyclic ADP-ribose synthesis.
AuthorsGalione A, White A, Willmott N, Turner M, Potter BV, Watson SP
JournalNature
PubMed ID7692303
'Many hormones or neurotransmitters act at cell surface receptors to increase the intracellular free calcium concentration, triggering a wide range of cellular responses. As the source of this Ca2+ is often internal stores, additional messengers are required to convey the hormonal message from the plasma membrane. Cyclic ADP-ribose (cADPR) has ... More
Mechanism involved in the mobilization of neutrophil calcium by 5-hydroxyeicosatetraenoate.
AuthorsO'Flaherty JT, Jacobson D, Redman J
JournalJ Immunol
PubMed ID2836511
'5-Hydroxyeicosatetraenoate (5-HETE), like leukotriene B4 and platelet-activating factor, stimulated human polymorphonuclear neutrophils to mobilize intracellular calcium. The three compounds acted through mechanisms that were inhibited by pertussis toxin, cholera toxin, and PMA. Each agonist, furthermore, desensitized (or down-regulated) the neutrophil''s calcium mobilization response to a second challenge with the same ... More
Fluorescence signals from the Mg2+/Ca2+ indicator furaptra in frog skeletal muscle fibers.
AuthorsKonishi M, Suda N, Kurihara S
JournalBiophys J
PubMed ID8431543
'The fluorescent Mg2+/Ca2+ indicator, furaptra, was injected into single frog skeletal muscle fibers, and the indicator''s fluorescence signals were measured and analyzed with particular interest in the free Mg2+ concentration ([Mg2+]) in resting muscle. Based on the fluorescence excitation spectrum of furaptra, the calibrated myoplasmic [Mg2+] level averaged 0.54 mM, ... More
Intracellular chloride and calcium transients evoked by gamma-aminobutyric acid and glycine in neurons of the rat inferior colliculus.
AuthorsFrech MJ, Deitmer JW, Backus KH
JournalJ Neurobiol
PubMed ID10440738
'Microfluorometric recordings showed that the inhibitory neurotransmitters gamma-aminobutyric acid (GABA) and glycine activated transient increases in the intracellular Cl- concentration in neurons of the inferior colliculus (IC) from acutely isolated slices of the rat auditory midbrain. Current recordings in gramicidin-perforated patch mode disclosed that GABA and glycine mainly evoked inward ... More
Pituitary adenylate cyclase activating polypeptide (PACAP) increases cytosolic-free calcium concentration in folliculo-stellate cells and somatotropes of rat pituitary.
AuthorsYada T, Vigh S, Arimura A
JournalPeptides
PubMed ID8483802
'Pituitary adenylate cyclase activating polypeptide (PACAP) is a new member of the secretin/VIP peptide family. In order to identify pituitary target cells for PACAP, we examined the effect of PACAP on the cytosolic-free Ca2+ concentrations, [Ca2+]i, in cells using Fura-2 and a digital imaging system. In a concentration-dependent manner, PACAP ... More
Distribution of sarcomere length and intracellular calcium in mouse skeletal muscle following stretch-induced injury.
AuthorsBalnave CD, Davey DF, Allen DG
JournalJ Physiol
PubMed ID9279815
'1. The effect on sarcomere organization of stretching intact single skeletal muscle fibres by 50% of their optimum length (Lo) during ten consecutive short tetani was investigated. Stretch reduced tetanic force to 36 +/- 4% of the pre-stretch condition. Sarcomere organization was analysed using both electron and confocal microscopy. For ... More
Redistribution of plasma membrane proteins by electroosmosis elicits cytosolic calcium response in tumor mast cells.
AuthorsFeder TJ, Webb WW
JournalJ Cell Physiol
PubMed ID7962106
'Activation of mast cells and basophils by binding of ligands that crosslink and micro-aggregate cell surface receptors leads to a series of responses including a phosphoinositide cascade, elevation of intracellular free calcium ([Ca2+]i), morphological changes in the cell plasma membrane, and ultimately, exocytosis of granules containing histamine and other mediators ... More
Calcium regulates the association between mitochondria and a smooth subdomain of the endoplasmic reticulum.
AuthorsWang HJ, Guay G, Pogan L, Sauvé R, Nabi IR
JournalJ Cell Biol
PubMed ID10995452
'Association between the ER and mitochondria has long been observed, and the formation of close contacts between ER and mitochondria is necessary for the ER-mediated sequestration of cytosolic calcium by mitochondria. Autocrine motility factor receptor (AMF-R) is a marker for a smooth subdomain of the ER, shown here by confocal ... More
Intracellular calcium during chemotaxis of Dictyostelium discoideum: a new fura-2 derivative avoids sequestration of the indicator and allows long-term calcium measurements.
AuthorsSchlatterer C, Knoll G, Malchow D
JournalEur J Cell Biol
PubMed ID1322818
'During stimulation of Dictyostelium discoideum amoebae with the chemoattractant cAMP, extracellular calcium is taken up by the cells. The aim of this study was to determine the cytosolic free calcium concentration ([Ca++]i) during chemotaxis of Dictyostelium cells. In contrast to most vertebrate cells, three major drawbacks were encountered: 1) the ... More
The mechanism of facilitated cell membrane resealing.
AuthorsTogo T, Alderton JM, Bi GQ, Steinhardt RA
JournalJ Cell Sci
PubMed ID9973606
'Disruption of the plasma membrane evokes an exocytotic response that is required for rapid membrane resealing. We show here in Swiss 3T3 fibroblasts that a second disruption at the same site reseals more rapidly than the initial wound. This facilitated response of resealing was inhibited by both low external Ca2+ ... More
Regulation of neuronal growth cone filopodia by intracellular calcium.
AuthorsRehder V, Kater SB
JournalJ Neurosci
PubMed ID1494951
'Filopodia have been regarded as the sensory extensions of neuronal growth cones. As such, filopodia assay distant environments and are important for directing growth cones toward their targets. Since the territory encountered by a growth cone depends on the area spanned by the filopodia, changes in filopodial length or number ... More
Intracellular calcium responses of circadian pacemaker neurons measured with fura-2.
AuthorsGeusz ME, Michel S, Block GD
JournalBrain Res
PubMed ID8199851
'The circadian pacemaker in the eye of the mollusk Bulla gouldiana is located within basal retinal neurons (BRNs) that express a circadian rhythm in cell culture. Light and other depolarizing stimuli shift the phase of the pacemaker in the eye through a process that requires extracellular calcium and is blocked ... More
Identification of a novel neuromedin U receptor subtype expressed in the central nervous system.
AuthorsShan L, Qiao X, Crona JH, Behan J, Wang S, Laz T, Bayne M, Gustafson EL, Monsma FJ, Hedrick JA
JournalJ Biol Chem
PubMed ID11010960
'Neuromedin U is a neuropeptide prominently expressed in the upper gastrointestinal tract and central nervous system. Recently, GPR66/FM-3 (NmU-R1) was identified as a specific receptor for neuromedin U. A BLAST search of the GenBank(TM) genomic database using the NmU-R1 cDNA sequence revealed a human genomic fragment encoding a G protein-coupled ... More
Ca(2+)-dependent kinase and phosphatase control inositol 1,4,5-trisphosphate-mediated Ca2+ release. Modification by agonist stimulation.
AuthorsZhang BX, Zhao H, Muallem S
JournalJ Biol Chem
PubMed ID8388379
'A permeable cell system in which Ca2+ release can be evoked by inositol 1,4,5-trisphosphate (IP3) or agonist stimulation was used to study the regulation of Ca2+ release by Ca2+ itself. At low concentrations, Ca2+ activated IP3-mediated Ca2+ release (IMCR) with half-maximal effect at about 15 nM. At high concentrations, Ca2+ ... More
Segmentally distinct effects of depolarization on intracellular [Ca2+] in renal arterioles.
AuthorsCarmines PK, Fowler BC, Bell PD
JournalAm J Physiol
PubMed ID8238547
'Experiments were performed to determine the influence of depolarization on intracellular Ca2+ concentration ([Ca2+]i) in renal arterioles and the possible role of voltage-gated Ca2+ channels in these responses. Glomeruli with attached arterioles and thick ascending limb were dissected from rabbit kidney and loaded with fura 2. [Ca2+]i of nonperfused arterioles ... More
Myofilament properties comprise the rate-limiting step for cardiac relaxation at body temperature in the rat.
AuthorsJanssen PM, Stull LB, Marbán E
JournalAm J Physiol Heart Circ Physiol
PubMed ID11788397
'The majority of studies aimed at characterizing basic contractile mechanisms have been conducted at room temperature. To elucidate the mechanism of cardiac relaxation under more physiological conditions, we investigated contractile function and calcium handling in ultrathin rat cardiac trabeculae. Active developed tension was unaltered between 22.5 and 30.0 degrees C ... More
Continuous monitoring of Ca2+ uptake in membrane vesicles with fura-2.
AuthorsKargacin ME, Scheid CR, Honeyman TW
JournalAm J Physiol
PubMed ID3189534
'The Ca2+-selective, fluorescent dye, fura-2, was used to monitor ATP-dependent Ca2+ uptake by membrane vesicles isolated from rabbit skeletal muscle. Micromolar fura-2 concentrations, added outside the vesicles, served as a high-affinity, low-capacity Ca2+ buffer. Changes in fura-2 fluorescence resulted from the decline in free Ca2+ concentration [( Ca2+]free) owing to ... More
Multifunctional Ca2+/calmodulin-dependent protein kinase is necessary for nuclear envelope breakdown.
AuthorsBaitinger C, Alderton J, Poenie M, Schulman H, Steinhardt RA
JournalJ Cell Biol
PubMed ID2229172
'The role of multifunctional Ca2+/calmodulin-dependent protein kinase (CaM kinase) in nuclear envelope breakdown (NEB) was investigated in sea urchin eggs. The eggs contain a 56-kD polypeptide which appears to be a homologue of neuronal CaM kinase. For example, it undergoes Ca2+/calmodulin-dependent autophosphorylation that converts it to a Ca2(+)-independent species, a ... More
Multiple effects of ryanodine on intracellular free Ca2+ in smooth muscle cells from bovine and porcine coronary artery: modulation of sarcoplasmic reticulum function.
AuthorsWagner-Mann C, Hu Q, Sturek M
JournalBr J Pharmacol
PubMed ID1504718
'1. The effects of ryanodine and caffeine on intracellular free Ca2+ concentration ([Ca2+]i) were studied by use of fura-2 microfluorometry in single smooth muscle cells freshly dispersed from bovine and porcine coronary artery. 2. Bovine and porcine cells demonstrated similar sensitivities to 10 min of exposure to ryanodine in physiological ... More
Mobilization of intracellular Ca2+ and suppression of inward currents in a neuronal hybrid cell line triggered by bradykinin.
AuthorsShimahara T, Icard-Liepkalins C, Ohmori H, Shigemoto T
JournalBrain Res
PubMed ID1963337
'Bradykinin triggered intracellular Ca mobilizations and ionic conductance changes were studied in the neuroblastoma x glioma hybrid cell line NG108-15 using Ca-sensitive fluorescent indicator fura-2 under patch pipette whole cell voltage clamp condition. The time course of outward current induced by bradykinin was closely related to the time-course of [Ca2+]i ... More
Optical measurement of presynaptic calcium currents.
AuthorsSabatini BL, Regehr WG
JournalBiophys J
PubMed ID9512051
'Measurements of presynaptic calcium currents are vital to understanding the control of transmitter release. However, most presynaptic boutons in the vertebrate central nervous system are too small to allow electrical recordings of presynaptic calcium currents (I(Ca)pre). We therefore tested the possibility of measuring I(Ca)pre optically in boutons loaded with calcium-sensitive ... More
The relationship between intracellular free iron and cell injury in cultured neurons, astrocytes, and oligodendrocytes.
AuthorsKress GJ, Dineley KE, Reynolds IJ
JournalJ Neurosci
PubMed ID12122047
'Iron is an essential element for cells but may also be an important cytotoxin. However, very little is known about iron transport, redox status, or toxicity specifically inside cells. In this study, we exploited the sensitivity of fura-2 to quenching by ferrous iron (Fe(2+)) to detect intracellular free iron ([Fe(2+)](i)) ... More