Chronic K-supplementation Decreases Myocardial [Na,K-ATPase] and Net K-uptake Capacity in Rodents

1998 ◽  
Vol 30 (10) ◽  
pp. 2037-2046 ◽  
Author(s):  
Henning Bundgaard ◽  
Micha Thyge Enevoldsen ◽  
Keld Kjeldsen
Keyword(s):  
Uptake Capacity ◽  
K Uptake

Potassium depletion improves myocardial potassium uptake in vivo

2004 ◽  
Vol 287 (1) ◽  
pp. C135-C141 ◽  
Author(s):  
Henning Bundgaard
Keyword(s):  
Uptake Rate ◽  
High Plasma ◽  
Potassium Depletion ◽  
Uptake Capacity ◽  
K Uptake ◽  
Impulse Generation ◽  
Uptake Rates ◽  
Clinical Interest ◽  
A Minor

Potassium depletion (KD) is a very common clinical entity often associated with adverse cardiac effects. KD is generally considered to reduce muscular Na-K-ATPase density and secondarily reduce K uptake capacity. In KD rats we evaluated myocardial Na-K-ATPase density, ion content, and myocardial K reuptake. KD for 2 wk reduced plasma K to 1.8 ± 0.1 vs. 3.5 ± 0.2 mM in controls ( P < 0.01, n = 7), myocardial K to 80 ± 1 vs. 86 ± 1 μmol/g wet wt ( P < 0.05, n = 7), increased Mg, and induced a tendency to increased Na. Myocardial Na-K-ATPase α2-subunit abundance was reduced by ∼30%, whereas increases in α1- and K-dependent pNPPase activity of 24% ( n = 6) and 13% ( n = 6), respectively, were seen. This indicates an overall upregulation of the myocardial Na-K pump pool. KD rats tolerated a higher intravenous KCl dose. KCl infusion until animals died increased myocardial K by 34% in KD rats and 18% in controls ( P < 0.05, n = 6 for both) but did not induce different net K uptake rates between groups. However, clamping plasma K at ∼5.5 mM by KCl infusion caused a higher net K uptake rate in KD rats (0.22 ± 0.04 vs. 0.10 ± 0.03 μmol·g wet wt−1·min−1; P < 0.05, n = 8). In conclusion, a minor KD-induced decrease in myocardial K increased Na-K pump density and in vivo increased K tolerance and net myocardial K uptake rate during K repletion. Thus the heart is protected from major K losses and accumulates considerable amounts of K during exposure to high plasma K. This is of clinical interest, because a therapeutically induced rise in myocardial K may affect contractility and impulse generation-propagation and may attenuate increased myocardial Na, the hallmark of heart failure.

scholarly journals Enhanced Net K+ Uptake Capacity of NaCl-Adapted Cells

1991 ◽  
Vol 95 (4) ◽  
pp. 1265-1269 ◽  
Author(s):  
Abd-Elrahem A. Watad ◽  
Moshe Reuveni ◽  
Ray A. Bressan ◽  
Paul M. Hasegawa
Keyword(s):  
Uptake Capacity ◽  
K Uptake

Solvent-Free Powder Synthesis and MOF-CVD Thin Films of the Mesoporous Metal-Organic Framework MAF-6

2019 ◽  
Author(s):  
Timothée Stassin ◽  
Ivo Stassen ◽  
Joao Marreiros ◽  
Alexander John Cruz ◽  
Rhea Verbeke ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Metal Organic Framework ◽  
Chemical Vapor ◽  
Uptake Capacity ◽  
Powder Synthesis ◽  
Crystalline Films ◽  
Metal Organic ◽  
Mesoporous Metal ◽  
First Time ◽  
Organic Framework

A simple solvent- and catalyst-free method is presented for the synthesis of the mesoporous metal-organic framework (MOF) MAF-6 (RHO-Zn(eIm)2) based on the reaction of ZnO with 2-ethylimidazole vapor at temperatures ≤ 100 °C. By translating this method to a chemical vapor deposition (CVD) protocol, mesoporous crystalline films could be deposited for the first time entirely from the vapor phase. A combination of PALS and Kr physisorption measurements confirmed the porosity of these MOF-CVD films and the size of the MAF-6 supercages (diam. ~2 nm), in close agreement with powder data and calculations. MAF-6 powders and films were further characterized by XRD, TGA, SEM, FTIR, PDF and EXAFS. The exceptional uptake capacity of the mesoporous MAF-6 in comparison to the microporous ZIF-8 is demonstrated by vapor-phase loading of a molecule larger than the ZIF-8 windows.

Sewage Treatment in Helophyte Beds–First Experiences with a New Treatment Procedure

1987 ◽  
Vol 19 (10) ◽  
pp. 1-10 ◽  
Author(s):  
K. Bucksteeg
Keyword(s):  
Waste Water ◽  
Rural Areas ◽  
Root Zone ◽  
Waste Water Treatment ◽  
Sewage Treatment ◽  
Uptake Capacity ◽  
Humid Climate ◽  
Climate Conditions ◽  
Trickling Filters ◽  
Operation Conditions

Waste water treatment in helophyte beds under humid climate conditions has been favoured by some German ecologists for some years. The idea is to cause waste water to flow horizontally through the root zone of helophytes to achieve satisfactory effluent properties. There exist many highly different proposals regarding the choice of soil and helophytes to be applied, bed area, design of inlets and outlets and operation conditions. A few plants have been operated in practice for some years. It appears that clogging is one of the main problems occurring in these plants. The hydraulic uptake capacity of soil is discussed in Darcy's law. Comparisons with observations of plants in operation are drawn. The interactions between soil properties, its uptake capacity, BOD5-, COD-, N- and P-reduction are evaluated. The effluent results of helophyte beds are compared with those of low-loaded trickling filters and of ponds used for sewage treatment in small villages in rural areas of Germany. It has been proved that the total construction costs of sewage treatment plants with helophyte beds used as the biological stage are higher when compared with those of conventional plants in general.

scholarly journals Synthesis of novel adsorbent based on tetrasulfide-functionalized fibrous silica KCC-1 for removal of Hg(II) cations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Azam Marjani ◽  
Reza Khan Mohammadi
Keyword(s):  
Effective Interaction ◽  
Sol Gel ◽  
Aqueous Media ◽  
Synthesis Method ◽  
Mercury Ions ◽  
Toxic Heavy Metals ◽  
Uptake Capacity ◽  
Hydrothermal Preparation ◽  
Ultrasonic Assisted ◽  
First Time

AbstractHg(II) has been identified to be one of the extremely toxic heavy metals because of its hazardous effects and this fact that it is even more hazardous to animals than other pollutants such as Ag, Au, Cd, Ni, Pb, Co, Cu, and Zn. Accordingly, for the first time, tetrasulfide-functionalized fibrous silica KCC-1 (TS-KCC-1) spheres were synthesized by a facile, conventional ultrasonic-assisted, sol–gel-hydrothermal preparation approach to adsorb Hg(II) from aqueous solution. Tetrasulfide groups (–S–S–S–S–) were chosen as binding sites due to the strong and effective interaction of mercury ions (Hg(II)) with sulfur atoms. Hg(II) uptake onto TS-KCC-1 in a batch system has been carried out. Isotherm and kinetic results showed a very agreed agreement with Langmuir and pseudo-first-order models, respectively, with a Langmuir maximum uptake capacity of 132.55 mg g–1 (volume of the solution = 20.0 mL; adsorbent dose = 5.0 mg; pH = 5.0; temperature: 198 K; contact time = 40 min; shaking speed = 180 rpm). TS-KCC-1was shown to be a promising functional nanoporous material for the uptake of Hg(II) cations from aqueous media. To the best of our knowledge, there has been no report on the uptake of toxic Hg(II) cations by tetrasulfide-functionalized KCC-1 prepared by a conventional ultrasonic-assisted sol–gel-hydrothermal synthesis method.

scholarly journals Simultaneously measuring carbon uptake capacity and chlorophyll a fluorescence dynamics in algae

2021 ◽  
Vol 58 ◽  
pp. 102399
Author(s):  
Jason Hupp ◽  
Johnathan I.E. McCoy ◽  
Allen J. Millgan ◽  
Graham Peers
Keyword(s):  
Chlorophyll A ◽  
Chlorophyll A Fluorescence ◽  
Carbon Uptake ◽  
Uptake Capacity
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