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
Inverse relationship of CA2+ mobilization and cell proliferation in CD8+ memory and virgin T cells.
'Memory T cells can now be defined with various monoclonal antibodies but little is known about the functional properties of these cells as compared to virgin T cells. We have studied Ca2+ mobilization and proliferation of memory and virgin cells in both the CD4 and CD8 subsets in response to ... More
Direct measurement of free Ca in organelles of gastric epithelial cells.
AuthorsHofer AM, Machen TE
JournalAm J Physiol
PubMed ID7943242
'When loaded as the acetoxymethyl ester (AM) derivative, the fluorescent probe mag-fura 2 accumulates in both the cytoplasm and the subcellular compartments. The relatively high dissociation constant of this dye for Ca (53 microM) permits the measurement of changes in the free concentration of this ion in a variety of ... 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
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
Inositol 1,4,5-trisphosphate and ryanodine receptor distributions and patterns of acetylcholine- and caffeine-induced calcium release in cultured mouse hippocampal neurons.
AuthorsSeymour-Laurent KJ, Barish ME
JournalJ Neurosci
PubMed ID7722617
'The distributions of inositol 1,4,5-trisphosphate and ryanodine receptors (InsP3R and RyR) and the patterns of increase in intracellular calcium ion concentration ([Ca2+]i) elicited by their activation were compared in cultured hippocampal neurons. InsP3R and RyR were labeled using specific antibodies and formed small aggregations in the somata and dendrites of ... More
The effects of PMA and TFP and alterations in intracellular pH and calcium concentration on the membrane associations of phospholipid-binding proteins fodrin, protein kinase C and annexin II in cultured MDCK cells.
AuthorsVääräniemi J, Huotari V, Lehto VP, Eskelinen S
JournalBiochim Biophys Acta
PubMed ID8305455
'Annexin II, alpha-fodrin and protein kinase C (PKC) are associated with the cytoplasmic surface of the plasma membranes. When assayed with liposomes, they show affinity for acidic phospholipids and bind calcium ions. They also respond to or participate in cell signal transduction by altered membrane binding properties. In the present ... 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
In situ characterization of nonmitochondrial Ca2+ stores in individual pancreatic beta-cells.
AuthorsTengholm A, Hagman C, Gylfe E, Hellman B
JournalDiabetes
PubMed ID9703321
'Free Ca2+ was measured in intracellular stores of individual mouse pancreatic beta-cells using dual-wavelength microfluorometry and the low-affinity Ca2+ indicator furaptra. Controlled permeabilization of the plasma membrane with 4 micromol/l digitonin revealed that 22% of the furaptra was trapped in intracellular nonnuclear compartments. When 3 mmol/l ATP and 200 nmol/l ... More
Calmodulin levels are dynamically regulated in living vascular smooth muscle cells.
AuthorsHulvershorn J, Gallant C, Wang CA, Dessy C, Morgan KG
JournalAm J Physiol Heart Circ Physiol
PubMed ID11179093
'The total unbound calmodulin (i.e., not bound to target proteins) level in living smooth muscle cells from the ferret portal vein was monitored with a low-affinity, calmodulin-binding peptide tagged with an environmentally sensitive fluorophore. GS17C, a previously characterized peptide, from the calmodulin-binding domain of caldesmon was tagged with iodoacetyl nitrobenz-2-oxa-1,3-diazole ... 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
Ionophore bromo-A23187 reveals cellular calcium stores in single pituitary somatotropes.
AuthorsHoll RW, Thorner MO, Zysk JR, Leong DA
JournalMol Cell Endocrinol
PubMed ID2569428
'Free cytosolic calcium concentration, [Ca2+]i, in single rat pituitary cells can be measured with the fluorescent, calcium-sensitive probe fura-2 and digital image analysis. A reverse hemolytic plaque assay (RHPA) identifies somatotropes in the mixed population of pituitary cells. Previous studies showed that growth hormone releasing factor (GRF) stimulates growth hormone ... 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
Ionophore 4-BrA23187 transports Zn2+ and Mn2+ with high selectivity over Ca2+.
AuthorsErdahl WL, Chapman CJ, Wang E, Taylor RW, Pfeiffer DR
JournalBiochemistry
PubMed ID8901524
'The cation transport selectivities of the Ca2+ ionophores A23187, Ionomycin, and 4-BrA23187 have been determined using a model system comprised of phospholipid vesicles loaded with the chelator/indicator Quin-2. At pH 7.00 and a 100 microM concentration of the cations, A23187 displays the transport selectivity sequence Zn2+ > Mn2+ > Ca2+ ... More
Mitochondrial permeability transition in the central nervous system: induction by calcium cycling-dependent and -independent pathways.
AuthorsKristal BS, Dubinsky JM
JournalJ Neurochem
PubMed ID9231710
'Isolated rat CNS mitochondria and cultured cortical astrocytes were examined for behavior indicative of a mitochondrial permeability transition (mPT). Exposure of isolated CNS mitochondria to elevated calcium or phosphate or both produced loss of absorbance indicative of mitochondrial swelling. The absorbance decreases were prevented by ADP and Mg2+ and reduced ... More
Measurement of intracellular free zinc in living cortical neurons: routes of entry.
'We used the ratioable fluorescent dye mag-fura-5 to measure intracellular free Zn2+ ([Zn2+]i) in cultured neocortical neurons exposed to neurotoxic concentrations of Zn2+ in concert with depolarization or glutamate receptor activation and identified four routes of Zn2+ entry. Neurons exposed to extracellular Zn2+ plus high K+ responded with a peak ... More
Modulation of calcium flux influences interleukin 1 beta effects on insulin release from isolated islets of Langerhans.
'The controlled flux of calcium across the cell membrane is intimately linked to the release of insulin from pancreatic beta-cells, but the uncontrolled influx of calcium is a common final denominator of cell death. Because interleukin 1 has been shown to be cytotoxic to beta-cells in isolated rat islets of ... More
Association of cytoplasmic free Ca2+ gradients with subcellular organelles.
AuthorsWahl M, Sleight RG, Gruenstein E
JournalJ Cell Physiol
PubMed ID1537888
'Previous investigations have identified gradients of intracellular free (Ca2+)i (Ca2+i) in the cytoplasm of human fibroblasts. In this study we have compared the spatial distribution of these gradients with the subcellular distribution of cytoplasmic organelles. Using the Ca(2+)-sensitive dye fura-2 and organelle-specific fluorescent dyes, we have found that the highest ... More
Secretagogue-induced changes in intracellular pH and amylase release in mouse pancreatic acini.
AuthorsCarter KJ, Rutledge PL, Steer ML, Silen W
JournalAm J Physiol
PubMed ID2446509
'The response of the intracellular pH (pHi) to stimulation of enzyme secretion in pancreatic acini was measured using the fluorescent dye 2''-7''-bis(carboxyethyl)-5(6)-carboxyfluorescein. Acini suspended in pH 7.40 buffer demonstrated cytoplasmic alkalinization of 0.17, 0.14, and 0.15 pH units 2 min after addition of the secretagogues carbachol (10(-5) M), caerulein (10(-10) ... More
Dynamics of intracellular free Mg2+ changes in a vascular smooth muscle cell line.
AuthorsQuamme GA, Dai LJ, Rabkin SW
JournalAm J Physiol
PubMed ID8342644
'Intracellular free Mg2+ concentration ([Mg2+]i) has been implicated in the pathogenesis of hypertension. It has been postulated that Mg2+ through its antagonistic effects on intracellular Ca2+ concentration may affect tension and contractility of vascular smooth muscle cells. An established cell line of rat thoracic aorta cells (A10) was cultured on ... More
Mapping the phospholipid-binding surface and translocation determinants of the C2 domain from cytosolic phospholipase A2.
AuthorsPerisic O, Paterson HF, Mosedale G, Lara-González S, Williams RL
JournalJ Biol Chem
PubMed ID10329700
'Cytosolic phospholipase A2 (cPLA2) plays a key role in the generation of arachidonic acid, a precursor of potent inflammatory mediators. Intact cPLA2 is known to translocate in a calcium-dependent manner from the cytosol to the nuclear envelope and endoplasmic reticulum. We show here that the C2 domain of cPLA2 alone ... More
A quantitative measurement of the dependence of short-term synaptic enhancement on presynaptic residual calcium.
AuthorsDelaney KR, Tank DW
JournalJ Neurosci
PubMed ID7931551
'We simultaneously measured presynaptic free calcium ion concentration ([Ca2+]i) and synaptic strength at the crayfish claw opener neuromuscular junction (nmj) under a variety of experimental conditions. Our experiments were designed both to test the hypothesis that elevated [Ca2+]i is necessary and sufficient for the induction of a form of synaptic ... 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
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
A confocal scanning laser microscope for quantitative ratiometric 3D measurements of [Ca2+] and Ca2+ diffusions in living cells stained with Fura-2.
AuthorsHelm PJ, Franksson O, Carlsson K
JournalPflugers Arch
PubMed ID7792144
'A confocal scanning laser microscope (CSLM) for observation and quantitative ratiometric measurements of the intracellular dynamics of Ca2+ ions in living neurons has been developed. The instrument consists of a UV-enhanced CSLM, an optical arrangement providing simultaneous excitation at two wavelengths, an electronic arrangement for processing the simultaneous fluorescence response, ... More
Investigation of the role of calpain as a stimulus-response mediator in human platelets using new synthetic inhibitors.
AuthorsAnagli J, Hagmann J, Shaw E
JournalBiochem J
PubMed ID2006912
'A series of peptidyl diazomethanes and monofluoromethane with structures specific for calpain have been synthesized and tested for their ability to inhibit calpain activity in vivo, using human platelets as a model system. Calpain activity in vivo was determined by observing proteolysis of actin-binding protein and talin, two known substrates ... More
Characterization of a selective antagonist of neuropeptide Y at the Y2 receptor. Synthesis and pharmacological evaluation of a Y2 antagonist.
AuthorsGrouzmann E, Buclin T, Martire M, Cannizzaro C, Dörner B, Razaname A, Mutter M
JournalJ Biol Chem
PubMed ID9065428
'Neuropeptide Y (NPY) is a potent inhibitor of neurotransmitter release through the Y2 receptor subtype. Specific antagonists for the Y2 receptors have not yet been described. Based on the concept of template-assembled synthetic proteins we have used a cyclic template molecule containing two beta-turn mimetics for covalent attachment of four ... More
Responsiveness of cytosolic free calcium concentration in cultured rat pulmonary arterial smooth muscle cells: confocal microscopic measurement.
AuthorsLi Z, Zhang Q, Zhao S, Wei M, Shenghui Z, Cong H, Ouda H, Odajima K, Takemura H
JournalRes Commun Mol Pathol Pharmacol
PubMed ID9507567
'Rat pulmonary arterial smooth muscle cells were primarily cultured. alpha-actins in pulmonary arterial smooth muscle cells at day 7 of culture were observed by an immunofluorescence staining method using anti-alpha-actin antibody. Microfluorimetry of Ca2+ signals in fluo-3-loaded single smooth cell at day 7 of culture was performed by a laser-scanned ... More
Elevation of intracellular calcium levels contributes to the inhibition of nitric oxide production by atrial natriuretic peptide.
AuthorsKiemer AK, Vollmar AM
JournalImmunol Cell Biol
PubMed ID11168617
'Atrial natriuretic peptide (ANP) attenuates LPS-induced inducible nitric oxide synthase (iNOS) expression in murine macrophages by destabilizing iNOS mRNA. Because elevated intracellular free Ca2+ levels [Ca2+]i reduce iNOS mRNA stability, the aim of the present study was to determine whether inhibition of iNOS by ANP is due to alterations in ... More
Calcium ionophores increase intracellular pH in chicken granulosa cells.
AuthorsAsem EK, Li M, Tsang BK
JournalJ Mol Endocrinol
PubMed ID1325150
'Several hormone agonists exert their physiological actions by triggering an inositol phospholipid-Ca2+ signalling cascade and cytosolic alkalinization. Although calcium ionophores have been used extensively to probe the role of Ca2+ in the regulation of steroidogenesis in granulosa cells, the precise relationship between changes in intracellular Ca2+ (Ca2+i) and pH (pHi) ... More
Depolarization-induced changes in neurite elongation and intracellular Ca2+ in isolated Helisoma neurons.
AuthorsCohan CS
JournalJ Neurobiol
PubMed ID1460468
'This study focuses on the effects of K+ depolarization on neurite elongation of identified Helisoma neurons isolated into culture. Application of K+ to the external medium caused a dose-dependent suppression of neurite elongation. Lower concentrations of K+ were associated with a slowing in the rate of neurite elongation, whereas higher ... More
Mechanism and specificity of lanthanide series cation transport by ionophores A23187, 4-BrA23187, and ionomycin.
AuthorsWang E, Taylor RW, Pfeiffer DR
JournalBiophys J
PubMed ID9726927
'A23187, 4-BrA23187, and ionomycin transport several lanthanide series trivalent cations at efficiencies similar to Ca2+, when compared at cation concentrations of approximately 10(-5) M, ionophore concentrations of approximately 10(-6) M, and a pH of 7.00. Selectivity sequences and the range of relative rates are as follows: A23187, Nd3+ > La3+ ... More
Calcium mobilization by muscarinic cholinergic stimulation in bovine single airway smooth muscle.
AuthorsKajita J, Yamaguchi H
JournalAm J Physiol
PubMed ID8388648
'Cellular mechanisms for Ca2+ mobilization by muscarinic cholinergic stimulation were investigated in dispersed bovine airway smooth muscle cells by the fura-2 method. Because the dissociation constant (Kd) of the intracellular fura-2 was not known, we first determined the Kd as 386 +/- 6 nM, which ranged from 368 to 394 ... More
Subcellular calcium transients visualized by confocal microscopy in a voltage-clamped vertebrate neuron.
AuthorsHernández-Cruz A, Sala F, Adams PR
JournalScience
PubMed ID2154851
'Confocal laser-scanned microscopy and long-wavelength calcium (Ca2+) indicators were combined to monitor both sustained and rapidly dissipating Ca2+ gradients in voltage-clamped sympathetic neurons isolated from the bullfrog. After a brief activation of voltage-dependent Ca2+ channels, Ca2+ spreads inwardly, and reaches the center of these spherical cells in about 300 milliseconds. ... More
Lack of a central role for calcium in the induction and release of human interleukin-1.
AuthorsNewton RC
JournalBiochem Biophys Res Commun
PubMed ID2444222
'This study examines the potential role of calcium in the activation of human monocytes by bacterial lipopolysaccharide (LPS) to produce interleukin-1 (IL-1). Monocytes cannot be triggered to produce IL-1 through addition of calcium ionophores. Triggering of IL-1 production by LPS cannot be blocked by depletion of extracellular calcium, blockade of ... More
Calcium influx through annexin V ion channels into large unilamellar vesicles measured with fura-2.
AuthorsBerendes R, Burger A, Voges D, Demange P, Huber R
JournalFEBS Lett
PubMed ID7679080
'A new assay for the calcium channel activity of annexin V was developed. The calcium-sensitive fluorescence indicator, fura-2, was incorporated into large unilamellar vesicles (LUV). After establishing a calcium gradient across the liposomal membranes, native or mutated annexin V was added. The resulting calcium influx into the LUV detected through ... More
Depolarization-induced neurite outgrowth in PC12 cells requires permissive, low level NGF receptor stimulation and activation of calcium/calmodulin-dependent protein kinase.
AuthorsSolem M, McMahon T, Messing RO
JournalJ Neurosci
PubMed ID7666181
'Neuronal activity is required for normal neural development. Excessive activity can cause abnormal growth of neural processes and may contribute to formation of epileptic foci. Using PC12 cells, we investigated mechanisms by which depolarization regulates neurite growth. Depolarization with 45 mM KCl induced neurite outgrowth only if NGF receptors were ... More
Cytoplasmic free Ca2+ in Arabidopsis roots changes in response to touch but not gravity.
AuthorsLegué V, Blancaflor E, Wymer C, Perbal G, Fantin D, Gilroy S
JournalPlant Physiol
PubMed ID9232870
'Changes in cytoplasmic Ca2+ concentration ([Ca2+]i) have been proposed to be involved in signal transduction pathways in response to a number of stimuli, including gravity and touch. The current hypothesis proposes that the development of gravitropic bending is correlated with a redistribution of [Ca2+]i in gravistimulated roots. However, no study ... More
Measurement of intracellular free zinc concentrations accompanying zinc-induced neuronal death.
AuthorsCanzoniero LM, Turetsky DM, Choi DW
JournalJ Neurosci
PubMed ID10493776
'Toxic zinc influx may contribute to selective neuronal death after transient global ischemia. We previously used the high-affinity (K(D) = 27 nm) fluorescent dye mag-fura-5 to detect initial increases in neuronal intracellular free Zn(2+) ([Zn(2+)](i)) associated with brief Zn(2+) exposure. Here we used the specific low-affinity Zn(2+) indicator Newport Green ... More
Rapid mobilization of intracellular Mg2+ by bombesin in Swiss 3T3 cells: mobilization through external Ca(2+)- and tyrosine kinase-dependent mechanisms.
AuthorsIshijima S, Tatibana M
JournalJ Biochem (Tokyo)
PubMed ID8089090
'We examined the effects of growth factors on intracellular free Mg2+ concentrations ([Mg2+]i) in single Swiss 3T3 fibroblasts, using microfluorometry of a Mg(2+)-sensitive dye mag-fura-2. We had already noted an increase in [Mg2+]i after exposure to bombesin for 30-60 min [Ishijima, S., Sonoda, T., & Tatibana, M. (1991) Am. J. ... More
A sensory role for neuronal growth cone filopodia.
AuthorsDavenport RW, Dou P, Rehder V, Kater SB
JournalNature
PubMed ID8441465
'The dynamic nature of neuronal growth cone filopodia led to the suggestion that the primary function of filopodia is to sample their immediate environment, responding to and transducing environmental signals that affect growth cone behaviour and shape. Filopodia seem well suited to serve as antenna-like sensors, their broad span allows ... More
The effects of elevation and depletion of intracellular free calcium on progesterone and prostaglandin production by the primate corpus luteum.
AuthorsHoumard BS, Guan Z, Kim-Lee M, Stokes BT, Ottobre JS
JournalBiol Reprod
PubMed ID1661184
'The role of the phosphatidylinositol second messenger system in luteal regulation has not been extensively studied, particularly in the primate. The objectives of this study were (1) to further characterize the response of the primate CL to the calcium ionophore A23187, in terms of intracellular free calcium concentrations ([Ca2+]i) and ... More
Modulation of a Ca2+ signaling pathway by GM1 ganglioside in PC12 cells.
AuthorsHilbush BS, Levine JM
JournalJ Biol Chem
PubMed ID1447216
'The effects of exogenous GM1 ganglioside on depolarization and ligand-induced Ca2+ signaling were investigated in PC12 cells. Cellular responses to K+ depolarization and bradykinin application in control and GM1-treated cells were examined with respect to: 1) changes in the intracellular Ca2+ concentration ([Ca2+]i) measured using fura-2 fluorescence in single cells, ... More
Platelet-derived growth factor blocks the increase in intracellular free Ca2+ caused by calcium ionophores and a volatile anesthetic agent in Swiss 3T3 fibroblasts without altering toxicity.
AuthorsOlsen RA, Seewald MJ, Melder DC, Berggren M, Iaizzo PA, Powis G
JournalToxicol Lett
PubMed ID1998194
'Platelet-derived growth factor (PDGF) produced an almost complete block of the increase in intracellular free Ca2+ concentration ([Ca2+]i) in Swiss 3T3 fibroblasts caused by the Ca2(+)-selective ionophores 4-bromo-A23187 and ionomycin, and by the volatile anesthetic agent halothane. The effect of PDGF was similar to the decreased [Ca2+]i response to Ca2(+)-ionophores ... More
Glucose regulation of free Ca(2+) in the endoplasmic reticulum of mouse pancreatic beta cells.
AuthorsTengholm A, Hellman B, Gylfe E
JournalJ Biol Chem
PubMed ID10601240
'Free Ca(2+) was measured in organelles of individual mouse pancreatic beta cells loaded with the low affinity indicator furaptra. After removal of cytoplasmic indicator by controlled digitonin permeabilization the organelle Ca(2+) was located essentially in the endoplasmic reticulum (ER), >90% being sensitive to inhibition of sarco(endo)plasmic reticulum Ca(2+)-ATPases. The Ca(2+) ... More
Cerebral type 2 astroglia are heterogeneous with respect to their ability to respond to neuroligands linked to calcium mobilization.
AuthorsDave V, Gordon GW, McCarthy KD
JournalGlia
PubMed ID1657779
'Very little information is available concerning the pharmacology of type 2 astroglia. During the past decade it has become apparent that two distinct lineages of astroglial cells can be defined in vitro. These two lineages are commonly referred to as type 1 and type 2 and are distinguished from each ... More
Synthesis and characterization of halogenated derivatives of the ionophore A23187: enhanced calcium ion transport specificity by the 4-bromo derivative.
AuthorsDebono M, Molloy RM, Dorman DE, Paschal JW, Babcock DF, Deber CM, Pfeiffer DR
JournalBiochemistry
PubMed ID6797465
Bromo-A23187: a nonfluorescent calcium ionophore for use with fluorescent probes.
AuthorsDeber CM, Tom-Kun J, Mack E, Grinstein S
JournalAnal Biochem
PubMed ID3927770
4-Bromo-A23187, a halogenated analog of the widely studied divalent cation ionophore A23187, is a nonfluorescent Ca2+ ionophore suitable for use in the calibration of cytoplasmic free Ca2+ by fluorescent probes. Br-A23187 is shown to saturate Ca2+ sites in quin-2-loaded rat thymic lymphocytes in a manner essentially identical to ionomycin. ... More
Increased calcium response to ADP in blood platelets from women during ovulation compared with menstruation: cytoplasmic calcium measured with the fura-2 technique.
AuthorsPedersen OS, Reichelt KL
JournalActa Physiol Scand
PubMed ID3227879
Blood platelets from women showed increased sensitivity to adenosine diphosphate (ADP) during ovulation compared with menstruation. The increased sensitivity was registered as an increase in cytoplasmic calcium response measured with the fluorescent indicator fura-2. Agonist dose-response studies revealed an increased maximal response, but the dose that gave half maximal response ... More
Estimation of intramitochondrial pCa and pH by fura-2 and 2,7 biscarboxyethyl-5(6)-carboxyfluorescein (BCECF) fluorescence.
AuthorsDavis MH, Altschuld RA, Jung DW, Brierley GP
JournalBiochem Biophys Res Commun
PubMed ID3689416
Isolated heart mitochondria hydrolyze the acetoxymethyl esters of the Ca2+-sensitive fluorescent probe fura-2 and the fluorescent pH indicator biscarboxyethyl-5(6)-carboxyfluorescein (BCECF). The free acid forms of both probes are retained in the matrix and their fluorescence can be used to monitor the pCa and pH, respectively, of this compartment. When fura-2 ... More
Pancreastatin increases cytosolic Ca2+ in insulin secreting RINm5F cells.
AuthorsSánchez-Margalet V, Lucas M, Goberna R
JournalMol Cell Endocrinol
PubMed ID1334006
We have investigated the effect of pancreastatin on cytosolic Ca2+ concentration in the insulin secreting cell line RINm5F. Changes in [Ca2+]i induced by pancreastatin were detected by Fluo-3 fluorescence using both flow cytometry and batch analysis measurements, and turned out to be from 90 to 315 nM equivalent to 80% ... More
Synaptosomes prepared from brains of rats were incubated in different concentrations of diazepam under conditions designed to reduce the action of a reversed Na+/Ca2+ exchanger. In synaptosomes depolarized in the presence of added Ca2+, doses of diazepam ranging from 0.1 to 100 microM were found to significantly enhance Ca2+ levels ... More
High-resolution measurement and calibration of Ca(2+)-transients using Indo-1 in guinea-pig atrial myocytes under voltage clamp.
AuthorsCallewaert G, Lipp P, Pott L, Carmeliet E
JournalCell Calcium
PubMed ID1855249
Spherical atrial myocytes obtained by enzymatic dispersion of hearts from adult guinea-pigs were loaded with the fluorescent Ca(2+)-indicator Indo-1 via patch-clamp pipettes. The dialysing solution additionally contained citrate (60 mM) as low-affinity ('linear') Ca(2+)-chelating compound in order to slow intracellular Ca(2+)-transients. Changes in Indo-1 fluorescence under voltage-clamp due to Ca(2+)-entry ... More
Measurement of free [Ca2+] changes in agonist-sensitive internal stores using compartmentalized fluorescent indicators.
AuthorsHofer AM,
JournalMethods Mol Biol
PubMed ID16422202
This chapter provides a guide for the use of compartmentalized fluorescentdyes to measure free [Ca2+] in the agonist-sensitive internal store of single cells. The basic steps involve incubating cells with the AM-ester derivative of the appropriate dye (resulting in partitioning of the probe in both the cytoplasm and organelles), and ... More
Very early detection of changes associated with cellular activation using a modified flow cytometer.
AuthorsKelley KA
JournalCytometry
PubMed ID1935460
A sample station modification previously described has been redesigned to provide greater flexibility and enhanced performance. The improved modification provides mixing and temperature regulation in a compact unit that mounts close to the nozzle holder for reduced transit times, allowing for addition of mediators to a sample in place on ... More
Calcium transport by ionophorous peptides in dog and human lymphocytes detected by quin-2 fluorescence.
AuthorsDeber CM, Hsu LC
JournalBiochem Biophys Res Commun
PubMed ID3947349
Synthetic peptides of structure cyclo(Glu(OBz)-Sar-Gly-(N-R)Gly)2 (I), electrogenic Ca2+-selective carriers in phospholipid vesicle membranes, are shown to mediate the uptake of Ca2+ ions into the cytoplasm of dog and human lymphocytes. Ca2+ transport by DECYL-2E (I, R = n-decyl) - monitored by measurements of the fluorescence of an intracellular dye, quin-2 ... More
Phospholipase C-gamma binds directly to the Na+/H+ exchanger 3 and is required for calcium regulation of exchange activity.
AuthorsZachos NC, van Rossum DB, Li X, Caraveo G, Sarker R, Cha B, Mohan S, Desiderio S, Patterson RL, Donowitz M,
JournalJ Biol Chem
PubMed ID19473983
Multiple studies suggest that phospholipase C-gamma (PLC-gamma) contributes to regulation of sodium/hydrogen exchanger 3 (NHE3) in the small intestine, although the mechanism(s) for this regulation remain unknown. We demonstrate here that PLC-gamma binds directly to the C terminus of NHE3 and exists in similar sized multiprotein complexes as NHE3. This ... More
Neuroligand-evoked calcium-dependent release of excitatory amino acids from Schwann cells.
AuthorsParpura V, Liu F, Jeftinija KV, Haydon PG, Jeftinija SD
JournalJ Neurosci
PubMed ID7643223
Bradykinin caused a receptor-mediated increase in release of the excitatory amino acids (EAAs) glutamate and aspartate from Schwann cell cultures obtained from dorsal root ganglia (DRG) together with an increase in the cytoplasmic level of free calcium. Perturbations which inhibited brady-kinin-induced calcium mobilization prevented the release of EAAs from glia. ... More
Intracellular calibration of the fluorescent calcium indicator Fura-2.
AuthorsWilliams DA, Fay FS
JournalCell Calcium
PubMed ID2354505
We present the techniques we have used and the problems we have encountered in our laboratories in the in vivo calibration of the fluorescent Ca2(+)-indicator Fura-2. These techniques include the use of potentiometric methods for the precise control and determination of Ca2+ levels in bathing solutions, in association with methods ... More
Intracellular free magnesium in human lymphocytes and the response to lectins.
AuthorsNg LL, Davies JE, Garrido MC
JournalClin Sci (Lond)
PubMed ID1647916
1. Intracellular free [Mg2+] was measured in human peripheral blood lymphocytes using a fluorimetric method based on the dye furaptra. It was necessary to correct for the extracellular leakage of the dye by using either 10 mmol/l EDTA or 0.05 mmol/l Mn2+. 2. As the proliferative response of lymphocytes to ... More
Hippocampal synaptogenesis in cell culture: developmental time course of synapse formation, calcium influx, and synaptic protein distribution.
AuthorsBasarsky TA, Parpura V, Haydon PG
JournalJ Neurosci
PubMed ID7965045
The formation of chemical synapses between hippocampal neurons in primary cell culture was studied using electrophysiology, calcium imaging, and immunocytochemical approaches. Inhibitory and excitatory synapses formed within 12 d in cell culture (DIC) that were sensitive to the N-type calcium channel blocker omega-conotoxin GVIA (omega-CgTx). At 4 DIC, immature connections ... More
Angiotensin II mediates a sustained rise in nuclear and cytoplasmic calcium via multiple receptor subtypes.
AuthorsMunzenmaier DH, Greene AS
JournalAm J Physiol
PubMed ID7653620
Alterations in nuclear calcium levels in response to angiotensin II (ANG II) may play an important role in the trophic actions of ANG II. This study utilized confocal microscopy and nuclear staining to test the hypothesis that both nuclear and cytoplasmic calcium levels are altered in response to ANG II ... More
Gibberellic acid and abscisic acid coordinately regulate cytoplasmic calcium and secretory activity in barley aleurone protoplasts.
AuthorsGilroy S, Jones RL
JournalProc Natl Acad Sci U S A
PubMed ID1533046
The effects of gibberellic acid (GA3) and abscisic acid (ABA) on the temporal and spatial dynamics of cytosolic calcium concentration ([Ca2+]i) in aleurone protoplasts of barley (Hordeum vulgare L. cv. Himalaya) were measured by using fluorescence ratio analysis and confocal microscopy. After 4-6 h of treatment, GA3 induced a sustained ... More
Expression of CD38 increases intracellular calcium concentration and reduces doubling time in HeLa and 3T3 cells.
AuthorsZocchi E, Daga A, Usai C, Franco L, Guida L, Bruzzone S, Costa A, Marchetti C, De Flora A
JournalJ Biol Chem
PubMed ID9525901
CD38 is a bifunctional ectoenzyme, predominantly expressed on hematopoietic cells during differentiation, that catalyzes the synthesis (cyclase) and the degradation (hydrolase) of cyclic ADP-ribose (cADPR), a powerful calcium mobilizer from intracellular stores. Due to the well established role of calcium levels in the regulation of apoptosis, proliferation, and differentiation, the ... More
Cytosolic free calcium and cell death during metabolic inhibition in a neuronal cell line.
AuthorsJohnson ME, Gores GJ, Uhl CB, Sill JC
JournalJ Neurosci
PubMed ID8027761
Elevated free cytosolic Ca2+ (Ca2+i) has been implicated as a mechanism of hypoxic neuronal death. The calcium hypothesis postulates that the basic metabolic response to hypoxic ATP depletion is a toxic increase in free cytosolic Ca2+i in all cell types. This inherent response then creates the environment in which subsequent ... More
Comparison of epidermal growth factor (EGF) receptor-receptor interactions in intact A431 cells and isolated plasma membranes. Large scale receptor micro-aggregation is not detected during EGF-stimulated early events.
AuthorsCarraway KL, Cerione RA
JournalJ Biol Chem
PubMed ID2026602
We have used resonance energy transfer to monitor epidermal growth factor (EGF) receptor micro-aggregation at the surface of intact human epidermoid carcinoma (A431) cells. EGF molecules labeled with fluorescein isothiocyanate and eosin isothiocyanate were demonstrated to bind tightly to cellsurface receptors, to elicit immediate changes in cytosolic free [Ca2+], and ... More
Determination of intracellular pH of BALB/c-3T3 cells using the fluorescence of pyranine.
AuthorsGiuliano KA, Gillies RJ
JournalAnal Biochem
PubMed ID2831755
In terms of accuracy and sensitivity, intracellularly trapped, pH-dependent fluorescent probes are appropriate to accurately measure intracellular pH. These probes are commonly introduced into living cells in esterified form, wherein the free acid is produced through enzymatic hydrolysis. The fluorescence characteristics of the ester and the free acid can differ ... More
Calcium chelators induce apoptosis--evidence that raised intracellular ionised calcium is not essential for apoptosis.
AuthorsKluck RM, McDougall CA, Harmon BV, Halliday JW
JournalBiochim Biophys Acta
PubMed ID8086495
A moderate sustained rise in intracellular ionised calcium has been observed to be associated with apoptosis occurring in many experimental systems. The application of extracellular and intracellular chelators of calcium has been reported to produce a decrease in apoptosis, while the addition of calcium ionophores often increases apoptosis. These findings, ... More
Spatial gradients of cytosolic calcium concentration in neurones during paradoxical activation by calcium.
AuthorsBolsover SR, Kater SB, Guthrie PB
JournalCell Calcium
PubMed ID8939357
4-Br-A23187 caused a calcium influx into chick sensory neurones and raised cytosolic calcium from a rest level of 97 +/- 7 nM to a peak of 296 +/- 30 nM. Despite the continued presence of ionophore, however, cytosolic calcium concentrations then fell. After 30 min in ionophore, cytosolic calcium concentration ... More
Ethanol and excitotoxicity in cultured cortical neurons: differential sensitivity of N-methyl-D-aspartate and sodium nitroprusside toxicity.
AuthorsLustig HS, von Brauchitsch KL, Chan J, Greenberg DA
JournalJ Neurochem
PubMed ID1431900
Neural injury due to ischemia and related insults is thought to involve the action of excitatory amino acids at N-methyl-D-aspartate receptors, which results in the influx of extracellular Ca2+ and the generation of nitric oxide. Because ethanol inhibits physiologic responses to excitatory amino acids, we examined its effect on toxicity ... More
Basal intracellular free Mg2+ concentration in smooth muscle cells of guinea pig tenia cecum: intracellular calibration of the fluorescent indicator furaptra.
AuthorsTashiro M, Konishi M
JournalBiophys J
PubMed ID9414246
Longitudinal muscle strips dissected from tenia cecum of guinea pig were loaded with the Mg2+ indicator, furaptra, and the relation between the fluorescent ratio signal (R) and cytoplasmic free Mg2+ concentration ([Mg2+]i) was studied in smooth muscle cells at 25 degrees C. After the application of ionophores (4-bromo-A23187, monensin, and ... More
Spatial organization of Ca(2+) entry and exocytosis in mouse pancreatic beta-cells.
AuthorsQian WJ, Kennedy RT
JournalBiochem Biophys Res Commun
PubMed ID11500039
Secretion from single pancreatic beta-cells was imaged using a novel technique in which Zn(2+), costored in secretory granules with insulin, was detected by confocal fluorescence microscopy as it was released from the cells. Using this technique, it was observed that secretion from beta-cells was limited to an active region that ... More
The action of oxidized low density lipoprotein on calcium transients in isolated rabbit cardiomyocytes.
AuthorsLiu K, Massaeli H, Pierce GN
JournalJ Biol Chem
PubMed ID8440703
The effect of oxidized low density lipoprotein (oxLDL) on the Ca2+ transients of isolated rabbit cardiomyocytes was assessed. LDL was oxidized by a free radical generating system in vitro. The systolic Ca2+ concentration in transients was significantly increased after treatment with 100 micrograms of oxLDL cholesterol/ml for 16 min without ... More
The role of cytosolic free calcium in the regulation of pyruvate dehydrogenase in synaptosomes.
AuthorsHuang HM, Toral-Barza L, Sheu KF, Gibson GE
JournalNeurochem Res
PubMed ID8139769
Calcium homeostasis and mitochondrial oxidative metabolism interact closely in brain and both processes are impaired during hypoxia. Since the regulation of the pyruvate dehydrogenase complex (PDHC) may link these two processes, the relation of cytosolic free calcium ([Ca2+]i) to the activation state of PDHC (PDHa) was assessed in isolated nerve ... More
Characterization of a rabbit kidney prostaglandin F(2{alpha}) receptor exhibiting G(i)-restricted signaling that inhibits water absorption in the collecting duct.
AuthorsHébert RL, Carmosino M, Saito O, Yang G, Jackson CA, Qi Z, Breyer RM, Natarajan C, Hata AN, Zhang Y, Guan Y, Breyer MD
JournalJ Biol Chem
PubMed ID16096282
PGF(2alpha) is the most abundant prostaglandin detected in urine; however, its renal effects are poorly characterized. The present study cloned a PGF-prostanoid receptor (FP) from the rabbit kidney and determined the functional consequences of its activation. Nuclease protection assay showed that FP mRNA expression predominates in rabbit ovary and kidney. ... More
Mini-dystrophin restores L-type calcium currents in skeletal muscle of transgenic mdx mice.
AuthorsFriedrich O, Both M, Gillis JM, Chamberlain JS, Fink RH
JournalJ Physiol
PubMed ID14594987
L-type calcium currents (iCa) were recorded using the two-microelectrode voltage-clamp technique in single short toe muscle fibres of three different mouse strains: (i) C57/SV129 wild-type mice (wt); (ii) mdx mice (an animal model for Duchenne muscular dystrophy; and (iii) transgenically engineered mini-dystrophin (MinD)-expressing mdx mice. The activation and inactivation properties ... More
Microdomains of high calcium are not required for exocytosis in RBL-2H3 mucosal mast cells.
AuthorsMahmoud SF, Fewtrell C
JournalJ Cell Biol
PubMed ID11309415
We have previously shown that store-associated microdomains of high Ca(2+) are not essential for exocytosis in RBL-2H3 mucosal mast cells. We have now examined whether Ca(2+) microdomains near the plasma membrane are required, by comparing the secretory responses seen when Ca(2+) influx was elicited by two very different mechanisms. In ... More
Rapid screening of possible cytotoxic effects of particulate air pollutants by measurement of changes in cytoplasmic free calcium, cytosolic pH, and plasma membrane potential in alveolar macrophages by flow cytometry.
AuthorsTárnok A, Dörger M, Berg I, Gercken G, Schlüter T
JournalCytometry
PubMed ID11170108
BACKGROUND: Inhalable particulate dusts are involved in the genesis of several lung diseases. Besides the well-known toxic dusts, i.e., asbestos and quartz, heavy metal-containing pollutants are considered as possible harmful substances. In the present study, we compared the effect of silica chemically coated with certain metal oxides and dusts from ... More
Calcium response of single adrenal glomerulosa cells to external potassium.
AuthorsQuinn SJ, Williams GH, Tillotson DL
JournalAm J Physiol
PubMed ID3177635
The cytosolic calcium (Cai2+) response to external potassium (K+) was examined in single rat zona glomerulosa (ZG) cells by monitoring fura-2-fluorescence with microspectrofluorometry and digital imaging microscopy. The majority (68%) of morphologically identified ZG cells demonstrated an increase in Cai2+ during K+ stimulation. Cai2+ rose monotonically from a mean basal ... More
Intracellular Ca2+ measurement with Indo-1 in substrate-attached cells: advantages and special considerations.
AuthorsWahl M, Lucherini MJ, Gruenstein E
JournalCell Calcium
PubMed ID2272082
The dual emission, Ca2+ sensitive fluorescent dye, Indo-1, offers several potential advantages over its dual excitation analogue, Fura-2. Most notable among these advantages are increased speed of measurement using dual wavelength photometry and the absence of a requirement for special quartz optics. Despite these potential advantages, only a tiny fraction ... More
Flow cytometric measurement of cytoplasmic free calcium in human peripheral blood T lymphocytes with fluo-3, a new fluorescent calcium indicator.
AuthorsVandenberghe PA, Ceuppens JL
JournalJ Immunol Methods
PubMed ID2107260
Cytoplasmic free calcium [( Ca2+]i) is a key intracellular messenger in many cell types. We have used fluo-3, a recently developed calcium probe, to study [Ca2+]i in resting and stimulated human peripheral blood T lymphocytes. The spectral properties of fluo-3 permit analysis of [Ca2+]i in flow cytometers with a 488 ... More
Hormonal regulation of Cl transport in polar airway epithelia measured by a fluorescent indicator.
AuthorsVerkman AS, Chao AC, Hartmann T
JournalAm J Physiol
PubMed ID1310213
Cl transport mechanisms in polarized cultures of canine tracheal epithelium were examined using an Ussing-type chamber with independent mucosal and serosal perfusion. Cl activity was monitored continuously from fluorescence of entrapped 6-methoxy-N-(3-sulfopropyl)quinolinium (SPQ). When added to the serosal (but not mucosal) solution, isoproterenol increased Cl fluxes across the apical membrane ... More
The intraacrosomal calcium pool plays a direct role in acrosomal exocytosis.
AuthorsDe Blas G, Michaut M, Treviño CL, Tomes CN, Yunes R, Darszon A, Mayorga LS
JournalJ Biol Chem
PubMed ID12379648
The acrosome reaction is a unique type of regulated exocytosis. The single secretory granule of the sperm fuses at multiple points with the overlying plasma membrane. In the past few years we have characterized several aspects of this process using streptolysin O-permeabilized human spermatozoa. Here we show that Rab3A triggers ... More
Transient increases in intracellular calcium result in prolonged site-selective increases in Tau phosphorylation through a glycogen synthase kinase 3beta-dependent pathway.
AuthorsHartigan JA, Johnson GV
JournalJ Biol Chem
PubMed ID10409701
Calcium is a universal intracellular signaling molecule. Through variations in both the amplitude and frequency of intracellular calcium increases, the same calcium ion can elicit different responses. In this report, we investigated the effect of a calcium transient, lasting 2-5 min, on alterations in the phosphorylation state of the cytoskeletal ... More
The annexin A3-membrane interaction is modulated by an N-terminal tryptophan.
AuthorsHofmann A, Raguénès-Nicol C, Favier-Perron B, Mesonero J, Huber R, Russo-Marie F, Lewit-Bentley A
JournalBiochemistry
PubMed ID10869176
The crystal structure of annexin A3 (human annexin III) solved recently revealed a well-ordered folding of its N-terminus with the side chain of tryptophan 5 interacting with residues at the extremity of the central pore. Since the pore of annexins has been suggested as the ion pathway involved in membrane ... More
The effects of alpha-adrenoceptor agonists on intracellular Ca2+ levels in freshly dispersed single smooth muscle cells from rat tail artery.
AuthorsLi XF, Kargacin ME, Triggle CR
JournalBr J Pharmacol
PubMed ID8104649
1. The presence of functional alpha-adrenoceptors in freshly dispersed single smooth muscle cells from rat tail arteries was investigated by use of selective alpha-adrenoceptor agonists and antagonists. 2. Cirazoline, a selective alpha 1-adrenoceptor agonist, caused a prazosin-sensitive, rapid but transient increase in intracellular Ca2+, which was partially inhibited by the ... More
Cytosolic Ca2+ deregulation and blebbing after HgCl2 injury to cultured rabbit proximal tubule cells as determined by digital imaging microscopy.
AuthorsSmith MW, Phelps PC, Trump BF
JournalProc Natl Acad Sci U S A
PubMed ID2052574
Acute injury to renal proximal tubule cells has previously been shown to result in elevated cytosolic Ca2+ ([Ca2+]i), blebbing, and eventual cell death. In this study, digital imaging fluorescence microscopy was used to evaluate these changes in response to HgCl2 treatment of cultured rabbit proximal tubular cells. Monolayer cells loaded ... More
Characteristics of intracellular calcium changes required for augmentation of phorbol ester-stimulated pancreatic enzyme secretion.
AuthorsPandol SJ, Rodriguez G, Muallem S, Mendius KE
JournalCell Calcium
PubMed ID2476234
Previous studies demonstrated that Ca2+ ionophores augment the pancreatic enzyme secretion caused by phorbol esters. The present study was performed to determine the nature of the cellular Ca2+ effects responsible for the augmentation. Relatively low concentrations (0.3-1.0 microM) of the nonfluorescent Ca2+ ionophore, 4-bromo-A23187 (Br-A23187), did not measurably increase free ... More
Changes in intracellular calcium concentration and pH of target cells during the cytotoxic process: a quantitative study at the single cell level.
AuthorsRadosevic K, de Grooth BG, Greve J
JournalCytometry
PubMed ID7587715
This study reports on the changes in intracellular calcium concentration ([Ca2+]in) and intracellular pH ([pH]in) that occur in K562 target cells during interaction with human Natural Killer (NK) cells. The data were obtained using a quantitative fluorescence microscope and fluorescent ratio probes specific for [Ca2+]in (Fura-2-AM) and [pH]in (BCECF-AM). Results ... More
Transient elevations of cytosolic free calcium retard subsequent apoptosis in neutrophils in vitro.
AuthorsWhyte MK, Hardwick SJ, Meagher LC, Savill JS, Haslett C
JournalJ Clin Invest
PubMed ID8392090
Elevation of cytosolic calcium ([Ca2+]i) has been reported to induce apoptosis in a number of cell types. However, in the neutrophil, which undergoes apoptosis constitutively during aging in vitro, activation by inflammatory mediators elevates [Ca2+]i and prolongs lifespan via inhibition of apoptosis. To examine this paradox, we investigated the effects ... More
Calcium-induced activation of the mitochondrial permeability transition in hippocampal neurons.
AuthorsDubinsky JM, Levi Y
JournalJ Neurosci Res
PubMed ID9753200
The mitochondrial permeability transition (mPT) has been implicated in both excitotoxic and apoptotic neuronal cell death, despite the fact that it has not been previously identified in neurons. To study the mPT in hippocampal neurons, cultures were loaded with the mitochondrial dye JC-1 and observed with confocal and conventional microscopy. ... More
Localization of L-type Ca2+ channels at perisynaptic glial cells of the frog neuromuscular junction.
AuthorsRobitaille R, Bourque MJ, Vandaele S
JournalJ Neurosci
PubMed ID8613781
The presence of L-type Ca2+ channels at the frog neuromuscular junction (nmj) was studied by monitoring changes in intracellular Ca2+ evoked in presynaptic terminals and perisynaptic Schwann cells (PSCs) and by studying the distribution of Ca2+ channels using a monoclonal antibody directed against the alpha 2/delta subunit of L channels. ... More
Dynamic recruitment of human CD2 into lipid rafts. Linkage to T cell signal transduction.
AuthorsYang H, Reinherz EL
JournalJ Biol Chem
PubMed ID11376005
CD2 mediates T cell adhesion via its ectodomain and signal transduction utilizing its 117-amino acid cytoplasmic tail. Here we show that a significant fraction of human CD2 molecules is inducibly recruited into lipid rafts upon CD2 cross-linking by a specific pair of mitogenic anti-CD2 monoclonal antibodies (anti-T11(2) + anti-T11(3)) or ... More
Involvement of intracellular calcium ions in the release of the fluorescent dye calcein by cholinergic and alpha-adrenergic agonists from rat parotid acinar cells.
AuthorsSugita M, Shiba Y, Furuya K, Yamagishi S, Kanno Y
JournalPflugers Arch
PubMed ID7617446
Effects of cholinergic and adrenergic agonists on the secretion of the fluorescent dye calcein were examined to clarify the involvement of calcium ions in the secretion of calcein from acinar cells dispersed from the rat parotid gland. Addition of carbachol (CCh) and noradrenalin (NA), but not isoproterenol (IPR), enhanced the ... More
Dual effects of a phorbol ester on calcium-dependent chloride secretion by T84 epithelial cells.
AuthorsKachintorn U, Vongkovit P, Vajanaphanich M, Dinh S, Barrett KE, Dharmsathaphorn K
JournalAm J Physiol
PubMed ID1733229
Ca(2+)-dependent secretagogues (e.g., carbachol, histamine, ionomycin, and 4-bromo-A23187) have relatively transient effects on chloride secretion, even if there is a sustained increase in cytosolic calcium ([Ca2+]i) (as for the ionophores). Because these agents increase both [Ca2+]i and protein kinase C (PKC) activity, chloride secretion might be stimulated by [Ca2+]i and ... More
Evidence that binding of Indo-1 to cardiac myocyte protein does not markedly change Kd for Ca2+.
AuthorsIkenouchi H, Peeters GA, Barry WH
JournalCell Calcium
PubMed ID1884395
Quantitative measurement of [Ca2+]i with the fluorescent Ca(2+)-indicators Indo-1 and Fura-2 is complicated by the possibility that the value of the dissociation constant (Kd) may be influenced by binding to intracellular proteins. We investigated this question in cultured chick ventricular myocytes by use of two different Indo-1 calibration methods. First, ... More
The initial stages of neural regeneration are dependent upon intracellular calcium levels.
AuthorsRehder V, Jensen JR, Kater SB
JournalNeuroscience
PubMed ID1488115
The earliest events of neuronal regeneration require resealing of the neurite's membrane after injury and the subsequent formation of a new growth cone. We have investigated these activities in vitro employing the large identified neurons of the snail Helisoma. Regeneration was elicited by transection of neurite processes and assessed by ... More
Ortho-substituted polychlorinated biphenyls alter microsomal calcium transport by direct interaction with ryanodine receptors of mammalian brain.
AuthorsWong PW, Brackney WR, Pessah IN
JournalJ Biol Chem
PubMed ID9182535
A stringent structure-activity relationship among polychlorinated biphenyls (PCBs) possessing two or more ortho-chlorine substituents is observed for activation of ryanodine receptors in mammalian brain, revealing an arylhydrocarbon receptor-independent mechanism through which non-coplanar PCBs disrupt neuronal Ca2+ signaling. Of the congeners assayed, non-coplanar PCB 95 exhibits the highest potency (EC50 = ... More
Quantification of intraluminal free [Ca] in the agonist-sensitive internal calcium store using compartmentalized fluorescent indicators: some considerations.
AuthorsHofer AM, Schulz I
JournalCell Calcium
PubMed ID8894270
Many fluorescent Ca indicators, particularly those loaded as acetoxymethyl (AM)-ester derivatives, are known to become compartmentalized into organelles. This property can be exploited to measure changes in free [Ca] in subcellular compartments, including the inositol (1,4,5)-trisphosphate-sensitive store. However, quantitative measurement of free [Ca] within a particular compartment is complicated by ... More
Noninvolvement of the heat-induced increase in the concentration of intracellular free Ca2+ in killing by heat and induction of thermotolerance.
AuthorsVidair CA, Wang ZH, Dewey WC
JournalRadiat Res
PubMed ID2247596
Mouse C3H 10T1/2 cells exhibited a two- to threefold increase in the concentration of free Ca2+ during heating at 45 degrees C. The increase was maximal for a heat dose which was still in the shoulder region of the survival curve. The increase was fully reversible in heat-sterilized cells. By ... More