Search results for "phosphate"
showing 10 items of 1874 documents
Cytosolic Ca2+ and Phosphoinositide Hydrolysis Linked to Constitutively Active α1d-Adrenoceptors in Vascular Smooth Muscle
2003
In the present study, we analyzed changes in intracellular Ca2+ levels and inositol phosphate accumulation related to a population of alpha 1d-adrenoceptors in rat aorta resembling constitutively active receptors. Following intracellular Ca2+ store depletion by noradrenaline in Ca2+-free medium and removal of the agonist, restoration of extracellular Ca2+ induced four signals: a biphasic (transient and sustained) increase in [Ca2+]i, inositol phosphate accumulation, and a contractile response in the aorta. The transient increase in Ca2+, the inositol phosphate accumulation, and the contractile response were not observed in aortae incubated with prazosin or BMY 7378 [8-[2-[4-(2-methoxyphenyl…
Co-transmitter mediated facilitation by sympathetic nerve stimulation of evoked acetylcholine release from the rabbit perfused atria preparation.
1995
Rabbit atria were isolated with the extrinsic right sympathetic and vagus nerves attached and perfused with Tyrode solution. Acetylcholine overflow was determined after labelling of the transmitter stores with [14C]choline and fractionation of the radioactivity on cation exchange columns. Sympathetic nerve stimulation (SNS, 2 Hz, 3 min) carried out together with vagus nerve stimulation (VNS, 2 Hz, 3 min), but each SNS pulse preceding a vagal one by 19 ms, caused a facilitation of acetylcholine overflow of about 60% versus independent controls in the absence of SNS. Antagonists of putative neurotransmitters were tested to find out the prejunctional mediator involved in the facilitation. The …
Closer to nature: an ATP-driven bioinspired catalytic oxidation process
2013
The capability of DNA to acquire enzyme-like properties has led to the emergence of the so-called DNAzyme field; herein, we take a further leap along this nature-inspired road, demonstrating that a template assembled synthetic G-quartet (TASQ) can act as a pre-catalyst for catalytic peroxidase-mimicking oxidation reactions, whatever its nature (guanine or guanosine-based G-quartets), in an ATP-dependent manner, thereby bringing this bioinspired TASQzyme process even closer to nature.
Extracellular cyclic GMP and its derivatives GMP and guanosine protect from oxidative glutamate toxicity.
2013
Cell death in response to oxidative stress plays a role in a variety of neurodegenerative diseases and can be studied in detail in the neuronal cell line HT22, where extracellular glutamate causes glutathione depletion by inhibition of the glutamate/cystine antiporter system xc(-), elevation of reactive oxygen species and eventually programmed cell death caused by cytotoxic calcium influx. Using this paradigm, we screened 54 putative extracellular peptide or small molecule ligands for effects on cell death and identified extracellular cyclic guanosine monophosphate (cGMP) as a protective substance. Extracellular cGMP was protective, whereas the cell-permeable cGMP analog 8-pCPT-cGMP or the …
�ber das Vorkommen der Glucose-6-Phosphat-Dehydrogenase im Blutserum von Psoriasis vulgaris-Kranken
1963
ImBlutserum von 48Psoriasis vulgaris-Kranken konnte, weitgehend in Abhangigkeit von der Ausdehnung und Akuitat der Hauterscheinungen, eineErhohung derGlucose-6-Phosphat-Dehydrogenase nachgewiesen werden. Dieser Befund wird vergleichend mit den Ergebnissen bei Gesunden und anderen Hautkranken diskutiert und als psoriasistypisches, nicht aber psoriasisspezifisches Phanomen gewertet, fur dessen Zustandekommen auf Grund der bisherigen Untersuchungen eine Erklarung nicht gegeben werden kann, wenngleich im Hinblick auf das Vorkommen von Pentosen in pathologisch veranderter Psoriasis-Haut zu diesem, den Pentose-Cyclus einleitenden Enzym eine hypothetische Verbindung gegeben scheint.
H89 enhances the sensitivity of cancer cells to glyceryl trinitrate through a purinergic receptor-dependent pathway
2014
// Marion Cortier 1, 2, 3 , Rahamata Boina-Ali 1, 2, 3 , Cindy Racoeur 1, 2, 3 , Catherine Paul 1, 2, 3 , Eric Solary 2, 4, 5 , Jean-Francois Jeannin 1, 2, 3 , Ali Bettaieb 1, 2, 3 1 EPHE, Tumor Immunology and Immunotherapy Laboratory, Dijon, F-21000, France 2 Inserm U866, Dijon, F-21000, France 3 EA7269, University of Burgundy, Dijon, F-21000, France 4 Inserm UMR1009, Gustave Roussy Institute, Villejuif F-94805, France 5 University Paris-Sud, Faculty of Medicine, Le Kremlin-Bicetre, F-94800, France Correspondence to: Ali Bettaieb, e-mail: ali.bettaieb@u-bourgogne.fr Keywords: H89, GTN, cancer, purinergic receptors, cGMP Received: October 08, 2014 Accepted: January 09, 2015 Publis…
Structure and physical properties of [mu-tris(1,4-bis(tetrazol-1-yl)butane-N4,N4 ')iron(II)] bis(hexafluorophosphate), a new Fe(II) spin-crossover co…
2004
[mu-Tris(1,4-bis(tetrazol-1-yl)butane-N4,N4')iron(II)] bis(hexafluorophosphate), [Fe(btzb)(3)](PF6)(2), crystallizes in a three-dimensional 3-fold interlocked structure featuring a sharp two-step spin-crossover behavior. The spin conversion takes place between 164 and 182 K showing a discontinuity at about T-1/2 = 174 K and a hysteresis of about 4 K between T-1/2 and the low-spin state. The spin transition has been independently followed by magnetic susceptibility measurements, Fe-57-Mossbauer spectroscopy, and variable temperature far and midrange FIR spectroscopy. The title compound crystallizes in the trigonal space group P (3) over bar (No. 147) with a unit cell content of one formula u…
Inorganic Polyphosphate in Human Osteoblast-like Cells
1998
Significant amounts of inorganic polyphosphates and of polyphosphate-degrading exopolyphosphatase activity were detected in human mandibular-derived osteoblast-like cells. The amount of both soluble and insoluble long-chain polyphosphate in unstimulated osteoblast-like cells was higher than in human gingival cells, erythrocytes, peripheral blood mononuclear cells, and human blood plasma. The cellular content of polyphosphate in osteoblast-like cells strongly decreased after a combined treatment of the cells with the stimulators of osteoblast proliferation and differentiation, dexamethasone, beta-glycerophosphate, epidermal growth factor, and ascorbic acid. The amount of soluble long-chain p…
Probing a Polar Cluster in the Retinal Binding Pocket of Bacteriorhodopsin by a Chemical Design Approach
2012
Bacteriorhodopsin has a polar cluster of amino acids surrounding the retinal molecule, which is responsible for light harvesting to fuel proton pumping. From our previous studies, we have shown that threonine 90 is the pivotal amino acid in this polar cluster, both functionally and structurally. In an attempt to perform a phenotype rescue, we have chemically designed a retinal analogue molecule to compensate the drastic effects of the T90A mutation in bacteriorhodopsin. This analogue substitutes the methyl group at position C(13) of the retinal hydrocarbon chain by and ethyl group (20-methyl retinal). We have analyzed the effect of reconstituting the wild-type and the T90A mutant apoprotein…
Mammalian BiP controls posttranslational ER translocation of the hepatitis B virus large envelope protein.
2008
AbstractThe hepatitis B virus L protein forms a dual topology in the endoplasmic reticulum (ER) via a process involving cotranslational membrane integration and subsequent posttranslational translocation of its preS subdomain. Here, we show that preS posttranslocation depends on the action of the ER chaperone BiP. To modulate the in vivo BiP activity, we designed an approach based on overexpressing its positive and negative regulators, ER-localized DnaJ-domain containing protein 4 (ERdj4) and BiP-associated protein (BAP), respectively. The feasibility of this approach was confirmed by demonstrating that BAP, but not ERdj4, destabilizes the L/BiP complex. Overexpressing BAP or ERdj4 inhibits…