Tension and electrolyte changes with Na+-K+ pump inhibition in rat papillary muscle

1989 ◽  
Vol 257 (3) ◽  
pp. H942-H953
Author(s):  
D. Parsons ◽  
K. P. Burton ◽  
H. K. Hagler ◽  
J. T. Willerson ◽  
L. M. Buja
Keyword(s):  
Electron Probe ◽  
Cell Injury ◽  
Membrane Integrity ◽  
Bimodal Distribution ◽  
High Energy ◽  
Atp Depletion ◽  
X Ray ◽  
Elemental Concentrations ◽  
Intracellular Ca ◽  
The Mean

Myocardial ischemic injury results in altered membrane integrity, energy depletion, and electrolyte shifts leading to accumulation of intracellular Ca. However, analysis of the direct effects of Ca accumulation is complicated by other concomitant cellular changes produced by ischemia. The purpose of this study was to examine the effects of Ca loading in rat papillary muscles produced by Na+-K+ pump inhibition in oxygenated K+-free buffer. Changes in contractile characteristics, high energy phosphate, and elemental concentrations of subcellular compartments were measured. Electron probe X-ray microanalysis was used to assess elemental concentrations in cryosections. After 3 h of Na+-K+ pump inhibition, resting tension (RT) increased to 164% and developed tension (DT) fell to 16.8% of control values. One hour after return to complete buffer, RT and DT partially recovered but remained significantly different from the 180 to 240-min values for the control muscles. Electron probe X-ray microanalysis showed increases in cytoplasmic and mitochondrial Na and Ca and a decrease in K during Na+-K+ pump inhibition. Mitochondrial Ca was greater than 100-fold greater than Ca in control mitochondria. Morphologically, the majority of cells showed ultrastructural damage. The mean ATP level was 20% of control. After 1 h of recovery, the cells appeared more heterogeneous, and the mean mitochondrial Ca decreased, whereas mean cytoplasmic Ca increased. Further statistical analysis showed a bimodal distribution for Na, Ca, K, Mg, and Cl, which coincided with the morphologically mixed population of cells. This suggests that replacement of extracellular K+ was associated with restored electrolyte gradients in some cells and the persistent or further alteration of electrolytes in others. These results suggest that variable Ca accumulation and associated ATP depletion without the compounding effects of ischemia lead to cell injury similar to reperfusion injury reported in ischemic myocardium.

Localization of calcium and zinc in the sperm storage tubules of chicken, quail and turkey using X-ray microanalysis

Reproduction ◽  
2000 ◽  
pp. 331-336 ◽  
Author(s):  
L Holm ◽  
H Ekwall ◽  
GJ Wishart ◽  
Y Ridderstrale
Keyword(s):  
Calcium Concentration ◽  
Sperm Storage ◽  
X Ray ◽  
Elemental Concentrations ◽  
Low Concentrations ◽  
Intracellular Content ◽  
Wet Weight ◽  
The Mean ◽  
Sperm Storage Tubules ◽  
Scanning Electron

Sperm storage tubules from the utero-vaginal junction of chickens, quails and turkeys were analysed for calcium and zinc using X-ray microanalysis of ultra-rapidly frozen tissue in a scanning electron microscope. This technique enabled the tubular fluid surrounding the stored spermatozoa and the intracellular content of the cells of the sperm storage tubules to be analysed separately and, by using standards with known concentrations, their elemental concentrations were estimated. The mean (+/- SEM) concentration of calcium in the tubular fluid from chickens, quails and turkeys was 17 +/- 3, 19 +/- 3 and 17 +/- 4 mmol kg(-1) wet weight, respectively. The intracellular calcium concentration of the cells of the tubules did not differ significantly from these values and was also similar in the mucosal epithelial cells of the utero-vaginal junction. Zinc was localized in the cells of turkey sperm storage tubules and tubular fluid, but at low concentrations. No zinc could be detected in corresponding structures from chickens and quails. The concentration of calcium in the tubular fluid is within the range known to inhibit the motility of spermatozoa, supporting this function for calcium during storage. Zinc is known to depress turkey sperm metabolism and it may also be involved in inducing quiescence of spermatozoa during storage in this species.

Dalnegroite, Tl5–xPb2x(As,Sb)2l–xS34, a new thallium sulphosalt from Lengenbach quarry, Binntal, Switzerland

2009 ◽  
Vol 73 (6) ◽  
pp. 1027-1032 ◽  
Author(s):  
F. Nestola ◽  
A. Guastoni ◽  
L. Bindi ◽  
L. Secco
Keyword(s):  
Polarized Light ◽  
New Mineral ◽  
X Ray Diffraction ◽  
X Ray ◽  
Elemental Concentrations ◽  
Reflected Light ◽  
Mohs Hardness ◽  
The Mean ◽  
The University ◽  
Probable Space

AbstractDalnegroite, ideally Tl4Pb2(As12Sb8)Σ20S34, is a new mineral from Lengenbach, Binntal, Switzerland. It occurs as anhedral to subhedral grains up to 200 μm across, closely associated with realgar, pyrite, Sb-rich seligmanite in a gangue of dolomite. Dalnegroite is opaque with a submetallic lustre and shows a brownish-red streak. It is brittle; the Vickers hardness (VHN25) is 87 kg mm-2(range: 69—101) (Mohs hardness ∼3—3½). In reflected light, dalnegroite is highly bireflectant and weakly pleochroic, from white to a slightly greenish-grey. In cross-polarized light, it is highly anisotropic with bluish to green rotation tints and red internal reflections.According to chemical and X-ray diffraction data, dalnegroite appears to be isotypic with chabournéite, Tl5-xPb2x(Sb,As)21-xS34. It is triclinic, probable space groupP1, witha= 16.217(7) Å,b= 42.544(9) Å,c= 8.557(4) Å, α = 95.72(4)°, β = 90.25(4)°, γ = 96.78(4)°,V= 5832(4) Å3,Z= 4.The nine strongest powder-diffraction lines [d(Å) (I/I0) (hkl)] are: 3.927 (100) (10 0); 3.775 (45) (22); 3.685 (45) (60); 3.620 (50) (440); 3.124 (50) (2); 2.929 (60) (42); 2.850 (70) (42); 2.579 (45) (02); 2.097 (60) (024). The mean of 11 electron microprobe analyses gave elemental concentrations as follows: Pb 10.09(1) wt.%, Tl 20.36(1), Sb 23.95(1), As 21.33(8), S 26.16(8), totalling 101.95 wt.%, corresponding to Tl4.15Pb2.03(As11.86Sb8.20)S34. The new mineral is named for Alberto Dal Negro, Professor in Mineralogy and Crystallography at the University of Padova since 1976.

Electron probe X-ray microanalysis of the effects of Bacillus thuringiensis var kurstaki crystal protein insecticide on ions in an electrogenic K+-transporting epithelium of the larval midgut in the lepidopteran, Manduca sexta, in vitro

1985 ◽  
Vol 74 (1) ◽  
pp. 137-152
Author(s):  
B.L. Gupta ◽  
J.A. Dow ◽  
T.A. Hall ◽  
W.R. Harvey
Keyword(s):  
Bacillus Thuringiensis ◽  
Manduca Sexta ◽  
Goblet Cell ◽  
Electron Probe ◽  
Apical Membrane ◽  
Short Circuit ◽  
Short Circuit Current ◽  
X Ray ◽  
Elemental Concentrations

An alkaline hydrolysate of Bacillus thuringiensis var kurstaki HD1 (Btk) parasporal crystals was administered at 25 micrograms ml-1 (f.c.) to isolated, short-circuited, midguts of tobacco hornworm (Manduca sexta) larvae. The short-circuit current (s.c.c.), a precise measure of K+ active transport, was inhibited by 78% in 10 min in Btk-treated midguts as compared to controls. The elemental concentrations of K, together with Na, Mg, P, S, Cl and Ca, as well as the water content, were determined by electron probe X-ray microanalysis (EPXMA) in the muscle cells, columnar cells and goblet cells, as well as in the extracellular goblet cavity and the bathing media. The average K concentration in the goblet cell cavity was 129 mmol/kg wet wt in control midguts but only 37 mmol/kg wet wt in Btk-treated midguts. The elemental concentrations, including that of K, in other cell compartments were much less affected by Btk, but a rise in total cell calcium is suggested. It has been previously suggested that in vitro Btk acts specifically on limited regions of the apical membrane of the midgut epithelial cells. The simplest interpretation of the EPXMA results would be that initially Btk interacts specifically with the goblet cell apical membrane, which bounds the goblet cavity and contains the K+ pump responsible for the s.c.c. and high transepithelial potential difference (p.d.). Such interaction results in a rapid disruption of K+ transport across the goblet cell apical membrane, leading to dissipation of the K+ gradient and loss of p.d. The histopathological changes previously reported by other workers would then be a consequence of K+ pump inhibition causing changes in the intracellular pH, Ca2+ etc. Some possible molecular bases for these specific interactions between Btk and cell membrane are discussed.

Protective effects of adenosine in the perfused rat heart: changes in metabolism and intracellular ion homeostasis

1993 ◽  
Vol 264 (4) ◽  
pp. C986-C994 ◽  
Author(s):  
T. A. Fralix ◽  
E. Murphy ◽  
R. E. London ◽  
C. Steenbergen
Keyword(s):  
Cell Injury ◽  
Recovery Of Function ◽  
Ion Homeostasis ◽  
High Energy ◽  
Left Ventricular ◽  
Protective Effects ◽  
Intracellular Ca ◽  
Developed Pressure ◽  
High Energy Phosphate Metabolism ◽  
Glycolytic Rate

Increased concentrations of intracellular H+, Na+, and Ca2+ have been observed during ischemia, and these ionic alterations have been correlated with several indexes of cell injury in a number of studies. Recently, adenosine was proposed to play a role in ischemic preconditioning, since adenosine antagonists block the protective effects of these brief intermittent periods of ischemia and reflow. In this study we evaluated the protective effects of adenosine (20 microM) on high-energy phosphate metabolism, H+ and Ca2+ accumulation, and glycolytic rate during 30 min of no-flow ischemia. Adenosine was observed to slow the onset of contracture (7.0 +/- 0.9 min) and to improve left ventricular developed pressure (62 +/- 7% of initial) during reperfusion compared with untreated hearts (5.0 +/- 0.6 min and 18 +/- 5%, respectively). Intracellular Ca accumulation at the end of 30 min of ischemia was higher in the untreated (2,835 +/- 465 nM) than in the adenosine-treated (2,064 +/- 533 nM) hearts, while intracellular pH fell more in the untreated (5.85 +/- 0.17) than in the adenosine-treated hearts (6.27 +/- 0.16). Glycolytic rate and the rate of ATP decline were significantly attenuated in the adenosine-treated hearts during ischemia. Thus adenosine treatment slowed the rate of metabolism and delayed the accumulation of H+ and Ca2+ during ischemia, resulting in better recovery of function upon reflow.

scholarly journals Structural and magnetic properties of mechanochemically synthesized nanosized yttrium titanate

2012 ◽  
Vol 66 (3) ◽  
pp. 309-315 ◽  
Author(s):  
Tanja Barudzija ◽  
Alexey Gusev ◽  
Dragana Jugovic ◽  
Milena Marinovic-Cincovic ◽  
Miroslav Dramicanin ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Single Phase ◽  
High Energy ◽  
Argon Atmosphere ◽  
Molar Ratio ◽  
Superconducting Quantum Interference Device ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Mean ◽  
First Time

Nanosized perovskite YTiO3 with the mean crystallite size of 18 nm was synthesized for the first time by mechanochemical treatment. The mechanochemical solid state reaction between commercial Y2O3 powder and mechanochemically synthesized TiO powder in molar ratio 0.5:1 was completed for 3 h in a high-energy planetary ball mill in argon atmosphere. The heating in vacuum at 1150 ?C for 12 h transforms nanosized YTiO3 to a well-crystallized single-phase perovskite YTiO3. Both samples were characterized by X-ray diffraction (XRD) and thermogravimetric (TGA/DTA) analyses, as well as superconducting quantum interference device magnetometer (SQUID) measurements.

Quantification of Large Scale Micro-X-Ray Fluorescence Elemental Images

2001 ◽  
Vol 55 (11) ◽  
pp. 1448-1454 ◽  
Author(s):  
Christopher G. Worley ◽  
George J. Havrilla ◽  
Paul S. Dunn
Keyword(s):  
Concentration Distribution ◽  
Large Scale ◽  
Surface Oxidation ◽  
Sample Surface ◽  
High Energy ◽  
Depleted Uranium ◽  
Established Method ◽  
X Ray ◽  
Elemental Concentrations ◽  
Relative Differences

Niobium is commonly alloyed with uranium to prevent surface oxidation, and determining how the niobium concentration is distributed throughout a sample is useful in explaining observed material properties. The niobium concentration distribution was determined across the surface of depleted uranium samples using micro-X-ray fluorescence (MXRF). To date, MXRF has been employed primarily as a qualitative tool for determining relative differences in elemental concentrations across a sample surface. Here, a process was developed to convert qualitative MXRF niobium distribution images from depleted uranium samples into images displaying concentration values. Thus, MXRF was utilized to determine elemental concentrations across a surface in a manner similar to that of the established method of electron microprobe X-ray analysis (EMPA). However, MXRF can provide such information from relatively large sample areas many cm2 in size that are too large to examine by the higher spatial resolution technique of EMPA. Although the sample surfaces were polished to the same degree as the standards, little or no sample preparation should be necessary for sample systems where a high energy analyte XRF line can be used for imaging.

Effects of chloride channel inhibitors on H2O2-induced renal epithelial cell injury

2000 ◽  
Vol 278 (1) ◽  
pp. F83-F90 ◽  
Author(s):  
Xianmin Meng ◽  
W. Brian Reeves
Keyword(s):  
Lipid Peroxidation ◽  
Dna Damage ◽  
Cell Death ◽  
Epithelial Cell ◽  
Small Molecules ◽  
Cell Injury ◽  
Membrane Integrity ◽  
Atp Depletion ◽  
Renal Epithelial Cell ◽  
Epithelial Cell Injury

Oxidative stress contributes to renal epithelial cell injury in certain settings. Chloride influx has also been proposed as an important component of acute renal epithelial cell injury. The present studies examined the role of Cl− in H2O2-induced injury to LLC-PK1 renal epithelial cells. Exposure of LLC-PK1 cells to 1 mM H2O2 resulted in the following: depletion of intracellular ATP content; DNA damage; lipid peroxidation; and a loss of membrane integrity to both small molecules, e.g., trypan blue, and macromolecules, e.g., lactate dehydrogenase (LDH), and cell death. Substitution of Cl− by isethionate or the inclusion of certain Cl− channel blockers, e.g., diphenylamine-2-carboxylate (DPC), 5-nitro-2-(3-phenylpropylamino)· benzoate (NPPB), and niflumic acid, prevented the H2O2-induced loss of membrane integrity to LDH. In addition, the H2O2-induced loss of membrane integrity was prevented by raising the osmolality of the extracellular solutions, by depletion of cell ATP, and by inhibitors of volume-sensitive Cl− channels. However, these maneuvers did not prevent the H2O2-induced permeability to small molecules or H2O2-induced ATP depletion, DNA damage, lipid peroxidation, or cell death. These results support the view that volume-sensitive Cl− channels play a role in the progressive loss of cell membrane integrity during injury.

Extended x-ray emission fine structure and high-energy satellite lines state measured by electron probe microanalysis

2001 ◽  
Vol 31 (2) ◽  
pp. 118-125 ◽  
Author(s):  
Hideyuki Takahashi ◽  
Ian Harrowfield ◽  
Colin MacRae ◽  
Nick Wilson ◽  
Kenichi Tsutsumi
Keyword(s):  
Fine Structure ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
High Energy ◽  
X Ray

scholarly journals Quantitative electron probe x-ray microanalysis and densitometric mass determination of individual rat blood platelets.

1985 ◽  
Vol 33 (3) ◽  
pp. 185-190 ◽  
Author(s):  
P W Linders ◽  
R A Van de Vorstenbosch ◽  
A M Stadhouders
Keyword(s):  
Electron Probe ◽  
Blood Platelets ◽  
Dry Mass ◽  
Elemental Content ◽  
Distribution Data ◽  
Rat Blood ◽  
X Ray ◽  
Mass Fractions ◽  
Calcium Magnesium ◽  
The Mean

An improved method for quantitative electron probe X-ray microanalysis of thin biological specimens, introduced recently, has been applied to the elemental analysis of rat blood platelets. The method uses the X-ray signal to quantify the elemental content of an object and electron scattering to determine the total dry mass of the object. Along with the dry mass distribution, data were obtained on the content and mass fraction of calcium, magnesium, and sulfur in 31 individual platelets. The mean platelet dry mass was found to be 985 fg. The mean Ca, Mg, and S contents were 1.80, 3.41, and 18.3 fg, with mean dry mass fractions of 0.195, 0.396, and 1.96%, respectively. Furthermore, these elements appear to be unevenly distributed among the platelet population.

scholarly journals Cytoprotection by glycine against ATP-depletion-induced injury is mediated by glycine receptor in renal cells1

2005 ◽  
Vol 390 (2) ◽  
pp. 447-453 ◽  
Author(s):  
Chao Pan ◽  
Xiaoming Bai ◽  
Leming Fan ◽  
Yong Ji ◽  
Xiaoyu Li ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Cell Injury ◽  
Glycine Receptor ◽  
Membrane Integrity ◽  
Cellular Membrane ◽  
Atp Depletion ◽  
Hek 293 ◽  
293 Cells ◽  
Marker Compounds

It is known that glycine protects mammalian cells against ischaemic cell injury by preventing cellular membrane leakage. However, the molecular mechanisms have not yet been clearly elucidated. The purpose of the present study was to clarify whether GlyR (glycine receptor) acts as a key mediator in cytoprotection of glycine. cDNA encoding human GlyRα1 (α1-subunit of glycine receptor) was transfected into HEK-293 cells. The membrane integrity of the cells with or without GlyRα1 was examined by the uptake of marker compounds, the release of LDH (lactate dehydrogenase) and the exclusion of Trypan Blue. Glycine prevented the permeability of 70 kDa dextrans and 140 kDa LDH in the cells in which GlyR was expressed under conditions of ATP depletion. The inhibition of endogenous GlyR expression by RNA interference attenuated the cytoprotection by glycine. Furthermore, the mutation of Tyr202 to phenylalanine in GlyRα1 blocked the glycine-mediated cytoprotection, while the mutation of Tyr202 to leucine abolished the cytoprotection by strychnine. Our results suggested that the cytoprotection of glycine against ATP-depletion-induced injury might be mediated by GlyR.

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