Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Potassium Ion Level”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMedDate not supplied

[Role of hypoxia factor in changes of ionic composition of blood and muscle tissue in experimental botulinum poisoning].

Levels of sodium and potassium ions in muscle tissue, blood plasma and red cells were measured, and the index characterizing the capacity of tissue to accumulate cations from the environment and the discrimination coefficient were calculated in experiments on white rats subjected to experimental generalized botulinum poisoning. Late stages of botulism were found to involve a deficit of potassium and sodium ions in red cells. With the progress of intoxication, a deficit of potassium ions develops in muscle tissue and the capacity of this tissue to accumulate potassium ions from the environment declines. All these disorders are more expressed in rapidly contracting skeletal muscles. An antihypoxant gutimin reduces sodium deficit in the blood plasma and red cells and leads to normalization of potassium ion levels in muscle tissue.

Animals↗
PubMed1985

Erythrocyte cationic transport systems in normal male and female volunteers.

The erythrocyte concentrations and the transmembrane fluxes of sodium and potassium were investigated in normal men and also in twenty normal women during the two stages of the menstrual cycle. Half of them were taking the contraceptive pill and the other half were not. In women with a normal menstrual cycle, the erythrocyte sodium concentration (Naic) and the ouabain-insensitive total potassium efflux were lower in the luteal than in the follicular phase. Intracellular potassium concentration (Kic), ouabain-sensitive 86rubidium-uptake and the furosemide-sensitive Na+ and K+ efflux did not differ significantly between the two periods of the cycle. No cycle-related variation in Naic or Kic was observed in women using the contraceptive pill. In these women, however, the ouabain-sensitive 86rubidium-uptake was increased in the second part of the menstrual cycle. Compared to men, the intra-erythrocyte sodium concentration was lower in women during the second stage of the menstrual cycle. These two groups were similar for Na+, K+-ATPase pump activity estimated from the ouabain-sensitive 86rubidium-uptake and for the furosemide-sensitive sodium and potassium efflux. Women in the first stage of the menstrual cycle had intra-erythrocyte sodium concentration similar to men, but their furosemide-sensitive sodium efflux was lower. No significant difference was observed in the intraerythrocyte potassium concentration and transmembrane fluxes of potassium in men and women in either stage of the menstrual cycle. We therefore conclude from this study that one should take into account sex-related variability when studying cationic fluxes and concentrations in red blood cells of men and women.

Adult↗
PubMed1978

Calcium-dependent 3':5'-cyclic nucleotide phosphodiesterase. Inhibition of basal activity at physiological levels of potassium ions.

A calcium-dependent cyclic nucleotide phosphodiesterase from rat cerebrum was, in the absence of activator protein, inhibited by various monovalent cations. The inhibition was rapid, readily reversible, and concentration-dependent, with 100 mM cesium, rubidium, or potassium ion inhibiting essentially all basal enzyme activity, while 100 mM sodium or lithium ions produced only moderate inhibition. The potency of the cations in inhibiting the enzyme was Cs greater than or equal to Rb greater than K greater than Na greater than or equal to Li. Potassium ions increased the apparent Km for cyclic GMP and cyclic AMP by 3- and 5-fold, respectively. At 100 mM, the monovalent cations inhibited enzyme activated by the calcium-dependent activator by only 15 to 30%, while at 55 mM no inhibition pertained. Potassium and sodium ions at 55 mM had no effect on the calcium-independent phosphodiesterase from rat cerebrum. The results indicate that at normal intracellular concentrations of potassium ions the activity of the calcium-dependent phosphodiesterase is virtually completely dependent on the presence of calcium plus activator protein.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1988

The role of the iris-ciliary complex in the control of protein synthesis by the organ cultured rabbit ocular lens.

When freshly isolated rabbit lenses were co-cultured with iris-ciliary body (IC), the protein synthetic activity of these lenses decreased significantly. The inhibitory effect is temporal as longer incubation showed greater inhibition. it was also found that the presence of IC in the culture medium increases the sodium ion levels in the lenses and causes some decrease in the potassium ion levels. Both the protein synthetic activity and cation levels of the lenses cocultured with IC are at least partially reversible. It seems that the IC-derived factor(s) has a molecular weight of more than 1 kDa. It is not clear from these experiments whether the altered cation balance is responsible for the inhibition of the protein synthesis.

Animals↗
PubMedDate not supplied

[Acid-base equilibrium of cerebrospinal fluid in inflammatory diseases of the central nervous system].

In 51 patients with meningoencephalitis the acid-base equilibrium of the cerebrospinal fluid (CSF) was assessed. In the fluid the following gasometry parameters were determined: pH, pCO2, pO2 and HCO3-, and also the levels of lactic acid, ATP, pyruvic acid, and sodium and potassium ion concentrations. The control group included 13 patients in whom on the basis of CSF examination, inflammatory disease of the central nervous system was ruled out. The results were analysed in groups of patients with purulent and lymphocytic meningitis. The changes were taken into account of the determined parameters in the course of the disease as well as their relationship with clinical condition of the patients. The differences were found in the values of acid-base equilibrium parameters of the CSF between purulent and lymphocytic meningitis. The differences of the values of the determined parameters between the patients in the group of purulent meningoencephalitis depended on their clinical condition and the outcome of the pathological process. In patients with purulent meningoencephalitis metabolic, lactic acidosis of the CSF occurred which was statistically significantly higher than in the group of patients with lymphocytic meningitis. The lowest values of pH and HCO3- concentration and the highest concentrations of lactic and pyruvic acids and potassium ion levels were found in the group of patients with purulent meningoencephalitis. The highest degree of acid-base equilibrium disturbances in the CSF was observed in the subgroup of patients with purulent meningoencephalitis who died.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Imbalance↗
PubMed1976

Cellular metabolic control by chemical modification of cell membrane.

Various reagents used in the chemical modification of amino- and carboxy-groups of proteins, and of carbohydrates of glycoproteins and glycolipids, inhibit respiration in ascites tumor cells concomitant with release of potassium ion from those cells. The respiratory activity of washed ascites tumor cells is increased by exogenous addition of potassium ion. The lowered respiratory control index as well as oxidative phosphorylation of aged mitochondria are restored upon increasing the potassium concentration of the incubation mixture in the presence of respiratory substrates. The data suggest that the potassium ion level of cells is changed by modifying physicochemical properties of membrane components and that cellular energy metabolism is regulated by intracellular potassium ion concentration.

4-Aminobenzoic Acid↗
PubMed1988

The evaluation of therapeutic efficacy of hachimi-jio-gan (traditional Chinese medicine) to mouse hereditary cataract.

This study was of a series of the evaluation of Hachimi-Jio-Gan (Rehmannia Eight Formula, pa-wei-ti-huang-wan or Bawei dihuang wan) to the various cataracts. In this study, the drug was evaluated for its therapeutic efficacy to mouse hereditary cataract from the delay effect of cataract appearance age and the suppression rates of variation of some biochemical parameters. The dose of 200 mg of Hachimi-Jio-Gan/day/100 g of mouse body weight significantly delayed the cataract appearance age by 4 days as compared to that of non-treated group. We estimated that the delay effect of 4 days in mouse may be corresponded to 13.9 years, when it was converted into the case of human. This drug also suppressed variation of sodium and potassium ions level in the lens with cataractogenesis. Furthermore, the drug dramatically reactivated the sodium-potassium ATPase activity damaged with the cataract formation, and also had a slight action of reducing agent. From these facts, we presumed that the drug may have a prophylactic efficacy to the cataract caused by the inhibition of sodium-potassium ATPase activity and also the oxidation of lens protein.

Administration, Oral↗
PubMedDate not supplied

Membrane potential and input resistance in syncytiotrophoblast of human term placenta in vitro.

Direct measurements of electrical potential and input resistance were performed on the syncytial membrane facing maternal blood. The potentials varied according to the external potassium ion levels and, to a lesser extent, with sodium ion concentrations. Ouabain provoked a rapid and consistent depolarization which indicates an electrogenic component. Amiloride slightly hyperpolarized the membrane, confirming the predominant role of potassium ions in the control of the diffusional component of the membrane potential. The electrical potential revealed in this study might play a part in the maternofetal transport of ions.

Antimetabolites↗
PubMed1980

Serum stimulation of potassium fluxes, ouabain binding, and sodium fluxes in quiescent chicken embryo fibroblasts.

Growth-contingent alterations in potassium and sodium fluxes, ouabain binding, and potassium ion content were examined following serum stimulation of quiescent, density-inhibited chicken embryo fibroblasts. Serum stimulation resulted in very rapid 1.5- to 1.8-fold increases in ouabain-sensitive potassium influx and lesser 1.4- to 1.5-fold increases in potassium efflux and sodium influx. Potassium influx stimulation was maximal after addition of 5-20% calf serum and was unaffected by cycloheximide inhibition of protein synthesis. Reflecting the slightly greater stimulation of potassium influx versus potassium efflux, potassium ion levels were 10-15% higher in serum-stimulated compared to unstimulated cells. Specific ouabain binding levels in stimulated and unstimulated control cells were initially similar, however, by four hours after stimulation a 40-50% increase in specific ouabain binding was observed. Incubation with ouabain was found also to inhibit later serum-stimulated hexose uptake and thymidine incorporation; this blockage may be consequence of subnormal potassium levels rather than ouabain inhibition of the serum-stimulated potassium influx.

Animals↗
PubMed1990

Hereditary cataract of the Nakano mouse.

The Nakano mouse is a hereditary cataract model whose most characteristic change is a deficiency in lens Na+,K(+)-ATPase. Consequently, there is a change in lenticular sodium and potassium ion levels just before cataract formation. The amounts of calcium ion also change suddenly in the lens, with accumulated levels higher than any other type of cataract. Other biochemical changes coincide with the development of lens opacity, including decreases in the levels of reduced glutathione, ATP, biosynthetic activity of proteoglycans in epithelial cells, and the permeability of gap junction channels in fiber cells. The decrease in the activity of Na+,K(+)-ATPase results in changes in a number of key metabolic parameters, resulting in the eventual opacification of the Nakano mouse lens at approximately 30 days of age.

Animals↗
PubMed1989

[Mechanisms of the inhibition of the functional activity of the stomach in acute radiation sickness].

The functional state of the gastric mucosa in dogs after 12.7 Gy abdominal X-ray irradiation was examined. During the first 7 days after irradiation, hypochylia, decrease of proteolytic activity and the H+ (hydrogen-ion) production in the gastric juice was observed. The gastric mucosal cells of rats were examined after the irradiation with 12 Gy to find out the reason for hypochylia. Possibly the reduction of the number of the gastric mucosal cells and their protein content one day after the irradiation, as well as functional disorders of the outer membrane--expressed by the decrease of the intracellular K+ (potassium-ion) level and the ATPase and 5'-nucleotidase activity--may be the reasons for the hypochylia after irradiation.

Acute Disease↗
PubMed1995

Validation of a capillary electrophoresis method for the determination of potassium counter-ion levels in an acidic drug salt.

This paper describes the first report of the validation of a capillary electrophoresis method for the quantitative determination of potassium levels in the potassium salt of an acidic drug. Validation criteria include precision, linearity, robustness and repeatability. The use of an internal standard enabled precision values of < 1% RSD to be obtained for peak area ratios. Careful control of capillary conditioning and temperature enabled migration time precisions of < 0.5% RSD. Results obtained by this method were in agreement with those generated by ion exchange chromatography and the theoretical potassium content of samples tested. Features of the method, compared to alternative analytical techniques, include simplicity, speed and accuracy. The method is now in routine use within our laboratories.

Calibration↗
PubMed1995

Accumulation of glutamate by osmotically stressed Escherichia coli is dependent on pH.

In the present study, we measured the accumulation of glutamate after hyperosmotic shock in Escherichia coli growing in synthetic medium. The accumulation was high in the medium containing sucrose at a pH above 8 and decreased with decreases in the medium pH. The same results were obtained when the hyperosmotic shock was carried out with sodium chloride. The internal level of potassium ions in cells growing at a high pH was higher than that in cells growing in a neutral medium. A mutant deficient in transport systems for potassium ions accumulated glutamate upon hyperosmotic stress at a high pH without a significant increase in the internal level of potassium ions. When the medium osmolarity was moderate at a pH below 8, E. coli accumulated gamma-aminobutyrate and the accumulation of glutamate was low. These data suggest that E. coli uses different osmolytes for hyperosmotic adaptation at different environmental pHs.

Adaptation, Biological↗
PubMedDate not supplied

[Effect of verapamil and anesthetics on the level of sodium and potassium ions in frog muscles. Role of hydrophobic interactions].

Verapamil, general and local anesthetics influences on ionic contents of frog sartorius and cardiac muscles in respect with these drugs hydrophobicity were studied to clarify the role of verapamil hydrophobic interactions in its physiological activity. It was found that concentration thresholds of the agents toxicities were linearly linked with their hydrophobicity (in logarithmic scale). This relationship provides support for our conclusion that verapamil, general and some local anesthetics are the members of a single drug family. It is a reason to believe that a hydrophobic mechanism of general anesthetic action on cellular structure is the same as a mechanism of verapamil activity in muscles. It is possible that verapamil is accepted as medical drug exactly due to optimum combination of high verapamil hydrophobicity with its structural complementarity to receptor site responsible for use-dependent channel blocking.

Anesthetics↗