The solubility of potassium from soil illites. IV. Rates of reaction and exchange constants

Soil Research ◽  
1967 ◽  
Vol 5 (2) ◽  
pp. 191 ◽  
Author(s):  
BM Tucker
Keyword(s):  
Response Time ◽  
Clay Minerals ◽  
Calcium Ions ◽  
Potassium Ions ◽  
Sodium Ions ◽  
Continuous Change ◽  
Exchangeable Potassium ◽  
Electrode Response ◽  
Soil Clays ◽  
Exchange Constants

Potassium-sensitive cationic electrodes have been used to study the rates of release of potassium from five illitic soil clays. This release was complete within a few minutes for clay-size particles and was probably controlled by diffusion. The electrode response time of 15 sec to 0.001 pK unit was too slow to permit accurate measurement of the rate of release, as the process was more than 90% complete in this time. As expected, the chemical reaction was too fast to be measured independently of diffusion. The electrodes were also used to calculate stepwise changes in Gapon constants as potassium (or sodium) was adsorbed by the clay in competition with calcium ions. The Gapon constants for potassium decreased greatly as potassium was adsorbed, but did not reach the low values expected for external exchange sites until comparatively large amounts of potassium were taken up. Potassium ions were held much more tightly thm sodium ions until the external sites began to be filled. The continuous change of Gapon constant with potassium content precluded a sharp distinction between interlayer and external exchangeable potassium. Values of the constants corresponding to the equilibrium solubilities measured in earlier work showed that the clays had a strong preference for potassium over calcium at the potassium contents in these clay preparations, and this showed that the solubility equilibria refer to potassium in the interlayer regions of the clay minerals.

scholarly journals Biochemical and Molecular Studies on the Role of Rosemary (Rosmarinus officinalis) Extract in Reducing Liver and Kidney Toxicity Due to Etoposide in Male Rats

2019 ◽  
pp. 1-11
Author(s):  
Majd Almakhatreh ◽  
Ezar Hafez ◽  
Ehab Tousson ◽  
Ahmed Masoud
Keyword(s):  
Dna Damage ◽  
Calcium Ions ◽  
Chloride Ions ◽  
Male Rats ◽  
Control Group ◽  
Potassium Ions ◽  
Sodium Ions ◽  
Total Proteins ◽  
Kidney Toxicity ◽  
Liver And Kidney

Aims: Etoposide (Vepesid) is chemotherapeutic drugs that inhibit topoisomerase II activity and long been used for treatment of human malignancies, where it is a semi-synthetic compound derived from the plant Podophyllum peltatum. The current study was designed to investigate the possible protective effect of rosemary extract against Etoposide -induced changes in liver and kidney functions, and DNA damage in rats. Materials and Methods: A total of 50 male Wistar albino rats were divided randomly into four groups (1st group was control; 2nd group was treated with rosemary, 3rd group was received etoposide, and 4th & 5th groups was co- and post treated groups respectively). Results: The administration of Etoposide revealed a significant increase in serum ALT, AST, ALP, creatinine, urea, potassium ions, chloride ions, and DNA damage. In contrast; a significant decrease in albumen, total proteins, sodium ions, and calcium ions were when compared with control group. This increased in ALT, AST, ALP, creatinine, urea, potassium ions, chloride ions, and DNA damage was reduced after administration of rosemary when co-treated with etoposide (G4), or post-treated after etoposide  (G5) for four weeks with lowest damage in G4. Also, this decreased in albumen, total proteins, sodium ions, and calcium ions was increased after administration of rosemary when co-treated with etoposide (G4), or post-treated after etoposide (G5) for four weeks with lowest damage in G4. Conclusion: It could be concluded that rosemary has a promising role and it worth to be considered as a natural substance for protective the liver and kidney toxicity induced by etoposide (Vepesid) chemotherapy.

Effects of acetylcholine on potassium-induced changes of water and sodium uptakes in cerebral cortex slices from the rat

1977 ◽  
Vol 55 (3) ◽  
pp. 339-346 ◽  
Author(s):  
A. M. Benjamin ◽  
J. H. Quastel
Keyword(s):  
Calcium Ions ◽  
Incubation Medium ◽  
Physiological Saline ◽  
Brain Cell ◽  
Potassium Ions ◽  
Sodium Ions ◽  
High Concentration ◽  
High Concentrations ◽  
Cortex Slices ◽  
A Site

The increases in uptakes of water and of sodium ions that occur in rat brain cortex slices when they are incubated in a physiological saline – glucose medium in presence of a high concentration of potassium ions (105 μequiv./ml) are abolished by acetylcholine in presence of eserine but not by choline. Acetylcholine is effective at 20 μM but its optimal effect occurs at about 0.7 mM. Its action is suppressed by atropine and not by d-tubocurarine. The potassium-induced change of permeability of brain cell membranes to sodium ions occurs at a site different from the tetrodotoxin-sensitive channel of sodium entry, because the suppressive effects of acetylcholine and tetrodotoxin are apparently independent of each other. The acetylcholine effect does not occur in the absence of calcium ions from the incubation medium. It is suggested that the increase of cell calcium ions, brought about by high concentrations of potassium ions in the incubation medium, induces an increase of glial permeability to sodium ions, with a resultant change in the sodium gradient, and that this increase is suppressed by acetylcholine.

The solubility of potassium from soil illites. II. Mechanisms of potassium release

Soil Research ◽  
1964 ◽  
Vol 2 (1) ◽  
pp. 67 ◽  
Author(s):  
BM Tucker
Keyword(s):  
Clay Minerals ◽  
Silicic Acid ◽  
Calcium Ions ◽  
Hydrogen Ion ◽  
Displacement Reaction ◽  
Potassium Release ◽  
Ph Values ◽  
Soil Clays ◽  
Mineral Structure

The release of potassium from four soil clays containing illites of different degrees of degradation was found to be independent of the solution of silicic acid or aluminium from the clay minerals. The lattice potassium is released into solution by a displacement reaction. The displacement of potassium by calcium ions is dependent on the prior release of one lattice potassium by one hydrogen ion, presumably because the entry of the hydrogen ion makes the potassium at neighbouring sites in the lattice accessible to other cations. The reaction may be written as 7Ks+ + H+ + 3Ca2+ 7K+ + 3CaS2+, where the subscript S refers to the solid (clay) phase. At pH values above pH 11, potassium is released by breakdown of the mineral structure by the action of hydroxyl ions.

scholarly journals Absorption of lactulose from mammalian gastrointestinal tract

1979 ◽  
Vol 41 (1) ◽  
pp. 47-51 ◽  
Author(s):  
D. F. Evered ◽  
F. Sadoogh-Abasian
Keyword(s):  
Small Intestine ◽  
Calcium Ions ◽  
Clinical Evidence ◽  
Buccal Cavity ◽  
Rat Small Intestine ◽  
Sodium Ions ◽  
Mode Of Transport ◽  
Poor Absorption

1. The disaccharide lactulose (galactosyl-β-1,4-fructose) was poorly absorbed from rat small intestine in vitro and human mouth in vivo.2. These results confirm indirect clinical evidence of poor absorption from the intestine.3. The presence of calcium ions, or absence of sodium ions, had no effect on lactulose absorption from the buccal cavity.4. The presence of ouabain, or absence of Na+, did not decrease the absorption of lactulose from small intestine.5. It is thought that the mode of transport, in both instances, is by passive diffusion with the concentration gradient.

Sodium and Potassium Fluxes in the Abdominal Nerve Cord of the Cockroach, Periplaneta Americana L

1961 ◽  
Vol 38 (2) ◽  
pp. 315-322
Author(s):  
J. E. TREHERNE
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Nerve Cord ◽  
Periplaneta Americana ◽  
Unit Area ◽  
Potassium Ions ◽  
Sodium Ions ◽  
Nerve Sheath ◽  
The Central Nervous System ◽  
Sodium And Potassium

1. The influx of sodium and potassium ions into the central nervous system of Periplaneta americana has been studied by measuring the increase in radioactivity within the abdominal nerve cord following the injection of 24NA and 42K. into the haemolymph. 2. The calculated influx of sodium ions was approximately 320 mM./l. of nerve cord water/hr. and of potassium ions was 312 mM./l. of nerve cord water/hr. These values are very approximately equivalent to an influx per unit area of nerve cord surface of 13.9 x 10-2 M cm. -2 sec.-1 for sodium and 13.5 x 10-12 M cm. -2 sec.-1 for potassium ions. 3. The relatively rapid influxes of these ions are discussed in relation to the postulated function of the nerve sheath as a diffusion barrier. It is suggested that a dynamic steady state rather than a static impermeability must exist across the sheath surrounding the central nervous system in this insect.

Acetylcholine activates nonselective cation channels in guinea pig ileum through a G protein

1990 ◽  
Vol 258 (6) ◽  
pp. C1173-C1178 ◽  
Author(s):  
R. Inoue ◽  
G. Isenberg
Keyword(s):  
G Protein ◽  
Calcium Ions ◽  
Voltage Dependence ◽  
Sodium Ions ◽  
Nonselective Cation Channel ◽  
Guinea Pig Ileum ◽  
Channel Activation ◽  
Present Evidence ◽  
Nonselective Cation Channels ◽  
Gamma S

Acetylcholine (ACh) depolarizes the membrane of mammalian intestinal myocytes by activating a nonselective cation channel (G. D. Benham, T. B. Bolton, and R. J. Lang. Nature Lond. 316: 345-347, 1985; R. Inoue, K. Kitamura, and H. Kuriyama. Pfluegers Arch. 410: 69-74, 1987). Here, we present evidence that occupation of the muscarinic receptor by ACh couples to channel activation via a G protein; the coupling can be blocked by pertussis toxin or by intracellular guanosine 5'-O-(2-thio-diphosphate) (GDP beta S), whereas intracellular guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) activates the channel in the absence of ACh. The currents, activated by either ACh or GTP gamma S, are nonadditive, conduct sodium ions, and are similar in their voltage dependence and facilitation by submicromolar calcium ions in the cytosol.

Effect of vibration on a canine cutaneous artery

1986 ◽  
Vol 250 (3) ◽  
pp. H519-H523 ◽  
Author(s):  
L. E. Lindblad ◽  
R. R. Lorenz ◽  
J. T. Shepherd ◽  
P. M. Vanhoutte
Keyword(s):  
Electrical Stimulation ◽  
Calcium Ions ◽  
Adrenergic Nerve ◽  
Potassium Ions ◽  
Calcium Entry Blocker ◽  
Plateau Phase ◽  
Sympathetic Nerve Stimulation ◽  
Peak Response ◽  
Prostaglandin F2 Alpha ◽  
Adrenergic Nerve Endings

Vibration of rings of isolated canine saphenous arteries depressed contractions induced by potassium chloride, prostaglandin F2 alpha, and activation of the adrenergic nerve endings by electrical stimulation. Peak contractions to exogenous norepinephrine were not significantly affected by vibration, being augmented, unchanged, or depressed, whereas contractions during the stable plateau phase were depressed. The calcium entry blocker diltiazem reduced the peak response but not the stable plateau phase of the contraction to norepinephrine; in the presence of diltiazem, vibration still depressed the latter. When vibration was applied during the steady state of contractions evoked by electrical stimulation, the depression was immediate, and its extent increased with both the amplitude (0.025-0.10 mm) and the frequency (30-150 Hz) of vibration. In arteries labeled with [3H]norepinephrine, vibration (120 Hz, 0.1 mm amplitude) during electrical stimulation induced a slight but significant increase in the release of labeled transmitter. It is suggested that the depression of contractions to potassium ions, prostaglandin F2 alpha, sympathetic nerve stimulation, and the plateau phase of the response to exogenous norepinephrine are caused by vibration depressing the force-generating process in vascular smooth muscle. Failure of vibration to significantly depress the peak contraction to norepinephrine may be explained by the facilitation by vibration of the influx of extracellular calcium ions.

Intracellular distribution of cations and protein in regenerating rat liver

1963 ◽  
Vol 204 (2) ◽  
pp. 257-261 ◽  
Author(s):  
Edwin M. Uyeki
Keyword(s):  
Liver Regeneration ◽  
Temporal Pattern ◽  
Initial Phase ◽  
Intracellular Distribution ◽  
Potassium Ions ◽  
Sodium Ions ◽  
Protein Distribution ◽  
Intracellular Compartments ◽  
Two Phases ◽  
Early Phases

The intracellular distribution of several cell constituents was studied at different periods after partial hepatectomy in the rat. The temporal pattern of cation and protein distribution can be divided into two phases: there is an initial phase in the first 24 hr posthepatectomy in which sodium and water increased in tissues concomitant with a decrease in potassium and protein. The levels of these several constituents subsequently approached values that were higher than in the control at 1 and 2 days posthepatectomy and were generally maintained at these values throughout the assay period. The reasons for the accumulation of higher than normal levels of both potassium and sodium are as yet uninterpreted; the higher than control potassium-to-sodium ratios generally observed in the intracellular compartments are due to the relative greater accumulation of potassium ions over sodium ions during this period. Comparing the intracellular compartments, the greatest alterations of constituents in the early phases of liver regeneration were observed in the soluble portion.

scholarly journals Sexual maturity in rabbits defined by the physical and chemical characteristics of the semen

1978 ◽  
Vol 12 (1) ◽  
pp. 37-39 ◽  
Author(s):  
M. Macari ◽  
C. R. Machado
Keyword(s):  
New Zealand ◽  
Sexual Maturity ◽  
Chemical Characteristics ◽  
Potassium Ions ◽  
Sodium Ions ◽  
Mean Values ◽  
New Zealand White Rabbits ◽  
The Mean ◽  
Physical And Chemical ◽  
Artificial Vagina

Semen was collected weekly from New Zealand white rabbits from the 1st positive mounting test to 43 weeks of age by means of an artificial vagina. The mean values of the results obtained in the 1st and 20th collection weeks were respectively: volume (ml) 0·61 ± 0·30 and 0·70 ± 0·19; pH 7·22 ± 0·50 and 7·19 ± 0±15; concentration (sperm/mm3 x 103) 750 ± 207 and 381 ± 90; fructose (mg/l00 ml) 117 ± 58 and 203 ± 121; citric acid (mg/l00 ml) 256 ± 90 and 200 ± 97; sodium ions (mEq/l) 133 ± 31 and 163 ± 46; potassium ions (mEq/l) 40 ± 21 and 29 ± 14. On the basis of these results, New Zealand white rabbits reach sexual maturity by 6 months of age.

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