Thermodynamic energy stability and in vitro potassium exchange capacity of ZS-9, a novel selective cation trap for the treatment of hyperkalemia

2014 ◽  
Vol 8 (4) ◽  
pp. e134
Author(s):  
Alex Yang ◽  
Alejandro Leon ◽  
Mark Nuttall ◽  
John J. Low ◽  
Henrik S. Rasmussen
Keyword(s):  
Exchange Capacity ◽  
Energy Stability ◽  
Potassium Exchange ◽  
Thermodynamic Energy

Effect of ouabain on potassium exchange in hypothermic mammalian heart

1962 ◽  
Vol 203 (5) ◽  
pp. 834-838
Author(s):  
Sidney S. Schreiber ◽  
Murray Oratz ◽  
Marcus A. Rothschild
Keyword(s):  
Ventricular Fibrillation ◽  
Guinea Pig ◽  
Low Temperatures ◽  
Minimal Effect ◽  
Apparent Effect ◽  
Guinea Pig Heart ◽  
Cold Temperatures ◽  
Ouabain Inhibition ◽  
Potassium Exchange

Potassium exchange was studied in the intact working hypothermic guinea pig heart in vitro with K42. As at 37 C, buildup and washout experiments demonstrated two compartments of K exchange, but these behaved differently with reductions in temperature to 20 C. The rate of K exchange of the "fast" compartment decreased with lowered temperatures, whereas the rate of "slow" compartment exchange either remained unaffected or increased slightly. Ouabain had no apparent effect on the fast compartment K exchange. Toxic levels of ouabain, which inhibited entrance of K into the slowly exchanging phase at 37 C, showed a minimal effect on this compartment at 20 C. The decreased ouabain inhibition at 20 C was paralleled by a concomitant decrease in toxicity (contracture and ventricular fibrillation). It was postulated that intracellular cardiac K exchange involved two separate processes which responded differently to low temperatures. Ouabain action was indicated to be specifically on that process which was insensitive to cold temperatures.

scholarly journals An In Vitro Evaluation of the Capacity of Local Tanzanian Crude Clay and Ash-Based Materials in Binding Aflatoxins in Solution

Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 510 ◽  
Author(s):  
Emmanuel Ayo ◽  
Athanasia Matemu ◽  
Germana Laswai ◽  
Martin Kimanya
Keyword(s):  
Cation Exchange ◽  
Adsorption Capacity ◽  
Cation Exchange Capacity ◽  
Volcanic Ash ◽  
Rice Husk Ash ◽  
Binding Capacity ◽  
Exchange Capacity ◽  
In Vitro Technique ◽  
Great Health

Aflatoxins in feeds cause great health hazards to animals, and thus eventually to humans as well. The potential of clays from Arusha (AC), Kilimanjaro (KC), the Coast (CC), and Morogoro (MC), as well as volcanic ash (VA) and rice husk ash (RA), were evaluated for their capacity to adsorb aflatoxins B1 (AFB1), B2 (AFB2), G1 (AFG1), and G2 (AFG2) relative to a commercial binder Mycobind® (R) using in vitro technique. On average, CC, VA, KC, MC, AC, RA, and R adsorbed 39.9%, 51.3%, 61.5%, 62.0%, 72.6%, 84.7%, and 98.1% of the total aflatoxins from solution, respectively. The capacity of AC and RA was statistically (p < 0.05) better in binding aflatoxins next to R. The adsorption capacity seemed to follow the trend of the cation exchange capacity (CEC) of these materials. The CEC (meq/100 g) of CC, MC, KC, VA, AC, RA, and R were 7.0, 15.4, 18.8, 25.4, 27.2, 27.2, and 38.9, respectively. On average 96.3%, 42.7%, 80.8%, and 32.1% of AFB1, AFB2, AFG1, and AFG2 were adsorbed, respectively. The binding capacity of the clays and ashes relative to Mycobind® was about 100% for AC and RA, 50% for KC, MC, and VA, and 33.3% for CC. The AC and RA seem to be promising resources in binding aflatoxins in solution.

Vasoactive agents and splanchnic oxygen uptake

1982 ◽  
Vol 243 (1) ◽  
pp. G1-G9 ◽  
Author(s):  
P. R. Kvietys ◽  
D. N. Granger
Keyword(s):  
Blood Flow ◽  
Oxygen Uptake ◽  
Oxidative Metabolism ◽  
Flow Distribution ◽  
Capillary Density ◽  
Exchange Capacity ◽  
Vasoactive Agents ◽  
Splanchnic Oxygen

Many vasoactive agents are known to alter oxygen uptake by splanchnic organs. Data from the literature indicate that, in general, vasodilators increase, whereas vasoconstrictors decrease oxygen uptake. We compare and contrast the effects of vasoactive agents on oxygen uptake observed in vivo, under constant-flow and free-flow conditions, to those observed in vitro. The discrepancies between the in vivo and in vitro data are discussed relative to the effects of vasoactive agents on blood flow, intraorgan blood flow distribution, the countercurrent exchange of oxygen, capillary exchange capacity, and oxidative metabolism. Changes in blood flow, oxidative metabolism, and capillary density appear to be the major mechanisms by which vasoactive agents alter splanchnic oxygen uptake in vivo. Experimental designs are proposed that may help minimize inconsistencies in the data in future studies.

scholarly journals RATE OF POTASSIUM EXCHANGE OF THE HUMAN ERYTHROCYTE

1950 ◽  
Vol 33 (6) ◽  
pp. 691-702 ◽  
Author(s):  
John W. Raker ◽  
Isaac M. Taylor ◽  
John M. Weller ◽  
A. Baird Hastings
Keyword(s):  
Exchange Rate ◽  
Temperature Coefficient ◽  
Human Erythrocyte ◽  
Extracellular Fluid ◽  
Plasma Potassium ◽  
Red Cells ◽  
Essentially Normal ◽  
Time Required ◽  
Potassium Exchange

1. The exchange of potassium by the human erythrocyte has been studied in vitro using radioactive potassium. 2. An incubation technique which maintains erythrocytes in an essentially normal state for over 48 hours was employed. 3. Exchange of radioactive potassium between the red cells and the extracellular fluid was regular and progressive, the specific activities of the intra- and extracellular fluids reaching equal values. This indicates that all the erythrocyte potassium is exchangeable and is exchanging at the same rate. 4. From these data, it was calculated that at 37°C., 1.6 per cent of the erythrocyte potassium exchanges per hour, corresponding to an exchange of 1.5 mM of potassium per liter of red cells per hour. The time required for the exchange of 50 per cent of the red cell potassium is calculated to be 43 hours. 5. The temperature coefficient (Q10) of the potassium exchange rate is 2.2. This is the same as the temperature coefficient of the rate of utilization of glucose by the human erythrocyte. 6. Varying the percentage of red cells, plasma potassium concentration, initial glucose level, and pH between 7.0 and 7.7 had no effect on the potassium exchange rate.

scholarly journals An In-Vitro Evaluation of the Capacity of Local Tanzanian Crude Clay and Ash Based Materials in Binding Aflatoxins in Solution

2018 ◽  
Author(s):  
Emmanuel Ayo ◽  
Athanasia Matemu ◽  
Germana Laswai ◽  
Martin Kimanya
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Binding Capacity ◽  
Exchange Capacity ◽  
Health Hazards ◽  
Human Potential ◽  
In Vitro Evaluation ◽  
In Vitro Technique ◽  
Great Health

Aflatoxins in feeds cause great health hazards to animals and in advance, to human. Potential of crude clays designated AC, KC, CC and MC and ashes VA and RA were evaluated for their capacity to adsorb aflatoxins B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) relative to a commercial binder MycobinderR (Evonik Industries AG) using in-vitro technique. On average, CC, VA, KC, MC, AC, RA and MycobindR adsorbed 39.9%, 51.3%, 61.5%, 62.0%, 72.6%, 84.7% and 98.1% of the total aflatoxins in buffered solution, respectively. The capacity of AC and RA was statistically (p&lt;0.05) better in binding aflatoxins next to MycobindR. Capacity of the TBM and MycobindR to bind aflatoxins, seemed to follow the trend of their cation exchange capacity (CEC). The CEC (meq/100g) of CC, MC, KC, VA, AC, RA and MycobindR were 7.0, 15.4, 18.8, 25.4, 27.2, 27.2 and 38.9, respectively. On average 96.3%, 42.7%, 80.8% and 32.1% of AFB1, AFB2, AFG1 and AFG2 were adsorbed, respectively. &nbsp;Binding capacity of the clays and ashes relative to MycobindR was about 100% for AC and RA, 50% for KC, MC and VA and 33.3% for CC.&nbsp; The AC and RA seem to be promising resources in binding aflatoxins in solution.

Adsorption-desorption of sotalol hydrochloride by Na-montmorillonite

Clay Minerals ◽  
1987 ◽  
Vol 22 (2) ◽  
pp. 121-128 ◽  
Author(s):  
M. Sánchez-Camazano ◽  
M. J. Sánchez-Martín ◽  
M. T. Vicente ◽  
A. Dominguez-Gil
Keyword(s):  
Ir Spectroscopy ◽  
Salt Concentration ◽  
Interlayer Space ◽  
Elimination Rate ◽  
Exchange Capacity ◽  
Maximum Amount ◽  
Organic Cations ◽  
Dipole Interactions ◽  
Adsorption Desorption

AbstractThe interaction of montmorillonite with sotalol hydrochloride (4-(1-hydroxy-N-isopropylaminoethyl) methane sulfanilide) was studied by means of adsorption isotherms, XRD and IR spectroscopy. The amount of sotalol adsorbed depended on pH, the maximum amount adsorbed (0·56 mEq g−1) being considerably less than the exchange capacity of the mineral (0·80 mEq g−1). XRD and IR data revealed that the sotalol is adsorbed into the interlayer space, forming a monolayer complex with a d001 spacing of 17·7 Å, and that the mechanisms involved are cation exchange and ion-dipole interactions. Experiments on the in vitro desorption of the drug from the sotalol-montmorillonite complex indicated that desorption is affected by pH, by the salt concentration of the electrolyte, and by the elimination rate of the desorbed organic cations.

Effect of ouabain on potassium exchange in the mammalian heart

1961 ◽  
Vol 200 (5) ◽  
pp. 1055-1062 ◽  
Author(s):  
Sidney S. Schreiber ◽  
Murray Oratz ◽  
Marcus A. Rothschild
Keyword(s):  
Guinea Pig ◽  
Guinea Pig Heart ◽  
Intracellular Potassium ◽  
Ringer’S Solution ◽  
Mammalian Heart ◽  
Digitalis Glycoside ◽  
Ouabain Inhibition ◽  
Potassium Exchange

The effect of the digitalis glycoside, ouabain, on potassium exchange in the guinea pig heart in vitro was studied with the aid of K42. With modified Ringer's solution as a perfusate at 38 C, K was found to exchange at two rates in both washout and buildup studies. In vivo equilibration studies also suggested more than one rate of exchange. Ouabain, in vitro, effected inhibition of entrance of K into the slowly exchanging compartment, but did not affect influx into the fast compartment or efflux from the fast or slow compartments. The ouabain inhibition was seen at Ringer's K concentrations of 3.8–4.3 mEq/liter was equivocal at K concentrations of 5.0–5.5 mEq/ liter and absent at K concentrations of 7.0–7.5 mEq/liter. It was postulated that ouabain inhibition was directed toward the slowly exchanging fraction of intracellular potassium.

Potassium and Sodium Exchange in the Working Frog Heart Effects of Overwork, External Concentrations of Potassium and Ouabain

1956 ◽  
Vol 185 (2) ◽  
pp. 337-347 ◽  
Author(s):  
Sidney S. Schreiber
Keyword(s):  
Scintillation Counter ◽  
Test Tube ◽  
Radioactive Isotopes ◽  
Frog Heart ◽  
Contractile Mechanism ◽  
Digitalis Glycoside ◽  
Two Phases ◽  
Potassium Exchange ◽  
Sodium Exchange

Potassium and sodium exchange was studied in vitro in the working frog heart with the use of the radioactive isotopes K42 and Na24. Measurement of loss or gain of radioactivity, and hence the outflux or influx of the cations, is accomplished by placing a test tube containing the continuously perfused preparation into the well of a scintillation counter. Intracellular potassium in the working ventricle exists in two phases or components which exchange at different rates. The slowly exchanging phase is sensitive to the amount of work performed, external concentrations of K and failure of the contractile mechanism. The digitalis glycoside, ouabain, causes an inhibition of entrance of potassium into the slowly exchanging phase, while the fast component exchanges freely. It is suggested that the two phases of potassium exchange exist in parallel within the cell, and that potassium exchanges freely across a nonlimiting membrane.

The Effect of External Potassium Concentration on Leucocyte Cation Transport in Vitro

1975 ◽  
Vol 49 (5) ◽  
pp. 385-390
Author(s):  
P. J. Hilton ◽  
R. P. S. Edmondson ◽  
R. D. Thomas ◽  
J. Patrick
Keyword(s):  
Potassium Concentration ◽  
Potassium Transport ◽  
Potassium Efflux ◽  
Sodium Efflux ◽  
Maximum Value ◽  
External Potassium ◽  
Potassium Influx ◽  
Potassium Exchange ◽  
Sodium And Potassium

1. Sodium and potassium transport rates in human leucocytes were measured in vitro at different external potassium concentrations. 2. At nominally zero external potassium concentrations, the ouabain-sensitive sodium efflux was reduced to less than 20% of its maximum value. There was evidence that under these conditions a ouabain-sensitive sodium-sodium exchange occurs. 3. Both total and ouabain-insensitive potassium influx increased with increasing external potassium concentration. The ouabain-sensitive potassium influx showed saturation. 4. Ouabain-insensitive potassium efflux was also stimulated by increasing the external potassium concentration, suggesting significant potassium-potassium exchange at physiological external potassium concentrations.

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