Coexpression of Drosophila TRP and TRP-like proteins in Xenopus oocytes reconstitutes capacitative Ca2+ entry.
AuthorsGillo B, Chorna I, Cohen H, Cook B, Manistersky I, Chorev M, Arnon A, Pollock JA, Selinger Z, Minke B
JournalProc Natl Acad Sci U S A
PubMed ID8943075
'Capacitative Ca2+ entry is a component of the inositol-lipid signaling in which depletion of inositol 1,4,5-trisphosphate (InsP3)-sensitive Ca2+ stores activates Ca2+ influx by a mechanism that is still unknown. This pathway plays a central role in cellular signaling, which is mediated by many hormones, neurotransmitters, and growth factors. Studies of ... More
Use of fluorescent Ca2+ dyes with green fluorescent protein and its variants: problems and solutions.
AuthorsBolsover S, Ibrahim O, O'luanaigh N, Williams H, Cockcroft S
JournalBiochem J
PubMed ID11368760
'We have studied the degree to which fluorescent Ca(2+) indicator dyes, and green fluorescent protein and its variants, can be used together. We find that the most commonly used fluorescent protein, enhanced green fluorescent protein (EGFP), seriously contaminates fura 2 signals. We suggest two alternative combinations for which there is ... More
An optical method for measurement of dioxygen concentration based upon quenching of phosphorescence.
AuthorsVanderkooi JM, Maniara G, Green TJ, Wilson DF
JournalJ Biol Chem
PubMed ID3571219
'An optical method for measuring oxygen concentrations in aqueous solutions is described. This method is based upon the oxygen-dependent quenching of phosphorescence. Phosphorescence excitation and emission spectra and lifetimes of some of the probe molecules suitable for measurement of oxygen in aqueous solutions are given. The probes include fluorescein derivatives, ... More
Light quenching of fluorescence: a new method to control the excited state lifetime and orientation of fluorophores.
AuthorsLakowicz JR, Gryczynski I, Kusba J, Bogdanov V
JournalPhotochem Photobiol
PubMed ID7870760
'Experimental studies have recently demonstrated that fluorescence emission can be quenched by laser light pulses from modern high-repetition rate lasers, a phenomenon we call "light quenching." In this overview article, we describe the possible effects of light quenching on the steady-state and time-resolved intensity and anisotropy of fluorophores. One can ... More
Use of fura red as an intracellular calcium indicator in frog skeletal muscle fibers.
AuthorsKurebayashi N, Harkins AB, Baylor SM
JournalBiophys J
PubMed ID8369415
'Fura red, a fluorescent Ca2+ indicator with absorbance bands at visible wavelengths, was injected into intact single muscle fibers that had been stretched to a long sarcomere length (approximately 3.8 microns) and bathed in a ''high-Ca2+'' Ringer ([Ca2+] = 11.8 mM). From fura red''s slow diffusion coefficient in myoplasm, 0.16 ... More
Submicroscopic calcium signals as fundamental events of excitation--contraction coupling in guinea-pig cardiac myocytes.
AuthorsLipp P, Niggli E
JournalJ Physiol
PubMed ID8730580
'1. Subcellularly localized Ca2+ signals have been proposed to represent elementary events of cardiac Ca2+ signalling (Ca2+ sparks), whereby an individual sarcolemmal L-type Ca2+ channel locally controls opening of a single (or a few) Ca2+ release channels in the sarcoplasmic reticulum (SR). 2. To investigate directly the elementary nature of ... More
A continuous spectrophotometric assay for simultaneous measurement of calcium uptake and ATP hydrolysis in sarcoplasmic reticulum.
AuthorsKaron BS, Nissen ER, Voss J, Thomas DD
JournalAnal Biochem
PubMed ID7573954
'A continuous, spectrophotometric assay to simultaneously measure Ca uptake and ATP hydrolysis has been developed, in order to assess the function of the Ca-ATPase in skeletal and cardiac sarcoplasmic reticulum (SR) vesicles. The absorbance of Fura Red was measured continuously at 490 nm, in EGTA-buffered solutions containing initial free ionized ... More
Distribution of Ca2+ extrusion sites on the mouse pancreatic acinar cell surface.
AuthorsBelan P, Gerasimenko O, Petersen OH, Tepikin AV
JournalCell Calcium
PubMed ID9232347
'The localizations of Ca2+ extrusion sites in mouse pancreatic acinar cells during elevation of the intracellular free calcium concentration ([Ca2+]i) have been studied. During an agonist stimulated calcium elevation as well as when intracellular calcium is released from a ''caged compound'', Ca2+ is primarily extruded from the apical secretory pole ... More
Confocal laser scanning microscopy used to monitor intracellular Ca2+ changes in hippocampal CA 1 neurons during energy deprivation.
AuthorsGrøndahl T, Langmoen IA
JournalBrain Res
PubMed ID9526045
'An increase in intracellular calcium during cerebral ischemia has been proposed as a common final pathway underlying the events leading to neuronal death. Intracellular calcium has been measured with ion selective electrodes during energy deprivation (ED) in hippocampal slices and with fluorescent techniques in neuronal cultures. In the present study, ... More
Intracellular ionized calcium.
AuthorsJune CH, Rabinovitch PS
JournalMethods Cell Biol
PubMed ID7861962
Practical aspects of measuring [Ca2+] with fluorescent indicators.
AuthorsKao JP
JournalMethods Cell Biol
PubMed ID8201975
Conformational transitions of detergent-solubilized Na,K-ATPase are conveniently monitored by the fluorescent probe 6-carboxy-eosin.
AuthorsEsmann M
JournalBiochem Biophys Res Commun
PubMed ID1846544
6-carboxy-eosin is introduced as a sensitive, non-covalently bound fluorescent probe for monitoring conformational changes in detergent-solubilized Na,K-ATPase. The dissociation constant for 6-carboxy-eosin is about 0.1 microM in 20 mM NaCl at 6 degrees C (pH 7.0) for Na,K-ATPase solubilized in C12E8. It is shown that the slow conformational change from ... More
Ratiometric calcium concentration estimation using LED excitation during mechanotransduction in single sensory neurons.
AuthorsHöger U, Torkkeli PH, French AS,
JournalJ Neurosci Methods
PubMed ID17572505
In a previous study using Oregon Green BAPTA-1 fluorescence we found that intracellular calcium concentration in spider mechanoreceptor neurons rose during mechanical stimulation. We also showed that calcium elevation required the opening of voltage-dependent calcium channels by action potentials, and could not be produced by the receptor potential alone. While ... More
Specific inhibition of Na-Ca exchange function by antisense oligodeoxynucleotides.
AuthorsLipp P, Schwaller B, Niggli E
JournalFEBS Lett
PubMed ID7750570
The Na-Ca exchanger is essential for the Ca2+ homeostasis in many cell types. This transporter has been difficult to investigate because no specific inhibitor is available. We have synthesized an antisense oligodeoxynucleotide directed against the rat cardiac Na-Ca exchanger mRNA. To estimate the activity of the Na-Ca exchange in single ... More
Triplet-state detection of labeled proteins using fluorescence recovery spectroscopy.
AuthorsCorin AF, Blatt E, Jovin TM
JournalBiochemistry
PubMed ID2441744
The experimental procedures for detecting the triplet states of chromophores in solutions (cuvettes) by fluorescence recovery spectroscopy (FRS) are described in detail, together with applications in studies of protein structure and protein-cell interactions in the microsecond to millisecond time domain. The experimental configuration has been characterized by measuring the emission ... More
Two dye two wavelength excitation calcium imaging: results from bovine adrenal chromaffin cells.
AuthorsOheim M, Naraghi M, Müller TH, Neher E
JournalCell Calcium
PubMed ID9793690
We tested a mixture of Calcium-Green-1 (CG-1) and Brilliantsulfaflavine (BS) for dual excitation ratiometric measurements of the intracellular free calcium concentration ([Ca2+]i) in bovine adrenal chromaffin cells. Dyes were coloaded (without being molecularly linked to each other) in the whole-cell configuration of the patch clamp technique. We compared the loading ... More
Effect of a 14-day hindlimb suspension on cytosolic Ca2+ concentration in rat portal vein myocytes.
Effects of a 14-day hindlimb suspension were examined on increases in cytosolic Ca2+ concentration ([Ca2+]i) evoked by vasoactive compounds and on Ca2+ channels in rat portal vein myocytes. The maximal increases in [Ca2+]i elicited by caffeine, norepinephrine, and angiotensin II were reduced by 30-50% in suspended rats, and complete recovery ... More
Activation of nicotinic receptors triggers exocytosis from bovine chromaffin cells in the absence of membrane depolarization.
AuthorsMollard P, Seward EP, Nowycky MC
JournalProc Natl Acad Sci U S A
PubMed ID7708776
The traditional function of neurotransmitter-gated ion channels is to induce rapid changes in electrical activity. Channels that are Ca(2+)-permeable, such as N-methyl-D-aspartate receptors at depolarized membrane potentials, can have a broader repertoire of consequences, including changes in synaptic efficacy, developmental plasticity, and excitotoxicity. Neuronal nicotinic receptors for acetylcholine (nAChRs) are ... More
A comparison of fluorescent Ca2+ indicator properties and their use in measuring elementary and global Ca2+ signals.
AuthorsThomas D, Tovey SC, Collins TJ, Bootman MD, Berridge MJ, Lipp P
JournalCell Calcium
PubMed ID11032777
Quantifying the magnitude of Ca2+ signals from changes in the emission of fluorescent indicators relies on assumptions about the indicator behaviour in situ. Factors such as osmolarity, pH, ionic strength and protein environment can affect indicator properties making it advantageous to calibrate indicators within the required cellular or subcellular environment. ... More
Microdomain Ca2+ activation during exocytosis in Paramecium cells. Superposition of local subplasmalemmal calcium store activation by local Ca2+ influx.
AuthorsErxleben C, Klauke N, Flötenmeyer M, Blanchard MP, Braun C, Plattner H
JournalJ Cell Biol
PubMed ID9024690
In Paramecium tetraurelia, polyamine-triggered exocytosis is accompanied by the activation of Ca2+-activated currents across the cell membrane (Erxleben. C., and H. Plattner. 1994. J. Cell Biol. 127:935-945). We now show by voltage clamp and extracellular recordings that the product of current x time (As) closely parallels the number of exocytotic ... More
Properties of oligomycin-induced occlusion of Na+ by detergent-solubilized Na,K-ATPase from pig kidney or shark rectal gland.
AuthorsEsmann M
JournalBiochim Biophys Acta
PubMed ID1316160
Oligomycin induces occlusion of Na+ in membrane-bound Na,K-ATPase. Here it is shown that Na,K-ATPase from pig kidney or shark rectal gland solubilized in the nonionic detergent C12E8 is capable of occluding Na+ in the presence of oligomycin. The apparent affinity for Na+ is reduced for both enzymes upon solubilization, and ... More
Monitoring neuronal calcium signalling using a new method for ratiometric confocal calcium imaging.
AuthorsLohr C
JournalCell Calcium
PubMed ID12887977
Ca2+ signalling influences many processes in the adult and developing nervous system like exocytosis, synaptic plasticity, and growth cone motility. Optical techniques in combination with fluorescent Ca2+ indicators are the most frequently used methods to measure Ca2+ signalling in cells. In the present study, a new method for ratiometric confocal ... More
Photolysis of caged compounds characterized by ratiometric confocal microscopy: a new approach to homogeneously control and measure the calcium concentration in cardiac myocytes.
AuthorsLipp P, Lüscher C, Niggli E
JournalCell Calcium
PubMed ID8732265
Here we describe the subcellularly uniform control of the intracellular Ca2+ concentration ([Ca2+]i) by flash photolysis of caged Ca2+ or a caged Ca2+ buffer. A mixture of the two Ca2+ indicators Fluo-3 and Fura-red was used together with a laser-scanning confocal microscope to reveal spatial aspects of intracellular Ca2+ signals. ... More