Diadenosine pentaphosphate affects electrical activity in guinea pig atrium via activation of potassium acetylcholine-dependent inward rectifier.

PubMed

Abramochkin, Denis V; Karimova, Viktoria M; Filatova, Tatiana S; Kamkin, Andre

2017-07-01

Diadenosine pentaphosphate (Ap5A) belongs to the family of diadenosine polyphosphates, endogenously produced compounds that affect vascular tone and cardiac performance when released from platelets. The previous findings indicate that Ap5A shortens action potentials (APs) in rat myocardium via activation of purine P2 receptors. The present study demonstrates alternative mechanism of Ap5A electrophysiological effects found in guinea pig myocardium. Ap5A (10 -4  M) shortens APs in guinea pig working atrial myocardium and slows down pacemaker activity in the sinoatrial node. P1 receptors antagonist DPCPX (10 -7  M) or selective GIRK channels blocker tertiapin (10 -6  M) completely abolished all Ap5A effects, while P2 blocker PPADS (10 -4  M) was ineffective. Patch-clamp experiments revealed potassium inward rectifier current activated by Ap5A in guinea pig atrial myocytes. The current was abolished by DPCPX or tertiapin and therefore was considered as potassium acetylcholine-dependent inward rectifier (I KACh ). Thus, unlike rat, in guinea pig atrium Ap5A produces activation of P1 receptors and subsequent opening of KACh channels leading to negative effects on cardiac electrical activity.

Potassium channels in articular chondrocytes

PubMed Central

Mobasheri, Ali; Lewis, Rebecca; Ferreira-Mendes, Alexandrina; Rufino, Ana; Dart, Caroline; Barrett-Jolley, Richard

2012-01-01

Chondrocytes are the resident cells of cartilage, which synthesize and maintain the extracellular matrix. The range of known potassium channels expressed by these unique cells is continually increasing. Since chondrocytes are non-excitable, and do not need to be repolarized following action potentials, the function of potassium channels in these cells has, until recently, remained completely unknown. However, recent advances in both traditional physiology and “omic” technologies have enhanced our knowledge and understanding of the chondrocyte channelome. A large number of potassium channels have been identified and a number of putative, but credible, functions have been proposed. Members of each of the potassium channel sub-families (calcium activated, inward rectifier, voltage-gated and tandem pore) have all been identified. Mechanotransduction, cell volume regulation, apoptosis and chondrogenesis all appear to involve potassium channels. Since evidence suggests that potassium channel gene transcription is altered in osteoarthritis, future studies are needed that investigate potassium channels as potential cellular biomarkers and therapeutic targets for treatment of degenerative joint conditions. PMID:23064164

Calcium-Activated Potassium Channels at Nodes of Ranvier Secure Axonal Spike Propagation

PubMed Central

Gründemann, Jan; Clark, Beverley A.

2015-01-01

Summary Functional connectivity between brain regions relies on long-range signaling by myelinated axons. This is secured by saltatory action potential propagation that depends fundamentally on sodium channel availability at nodes of Ranvier. Although various potassium channel types have been anatomically localized to myelinated axons in the brain, direct evidence for their functional recruitment in maintaining node excitability is scarce. Cerebellar Purkinje cells provide continuous input to their targets in the cerebellar nuclei, reliably transmitting axonal spikes over a wide range of rates, requiring a constantly available pool of nodal sodium channels. We show that the recruitment of calcium-activated potassium channels (IK, KCa3.1) by local, activity-dependent calcium (Ca2+) influx at nodes of Ranvier via a T-type voltage-gated Ca2+ current provides a powerful mechanism that likely opposes depolarizing block at the nodes and is thus pivotal to securing continuous axonal spike propagation in spontaneously firing Purkinje cells. PMID:26344775

Studies of potassium-promoted nickel catalysts for methane steam reforming: Effect of surface potassium location

NASA Astrophysics Data System (ADS)

Borowiecki, Tadeusz; Denis, Andrzej; Rawski, Michał; Gołębiowski, Andrzej; Stołecki, Kazimierz; Dmytrzyk, Jaromir; Kotarba, Andrzej

2014-05-01

The effect of potassium addition to the Ni/Al2O3 steam reforming catalyst has been investigated on several model systems, including K/Al2O3 with various amounts of alkali promoters (1-4 wt% of K2O), a model catalyst 90%NiO-10%Al2O3 promoted with potassium and a commercial catalyst. The potassium surface state and stability were investigated by means of the Species Resolved Thermal Alkali Desorption method (SR-TAD). The activity of the catalysts in the steam reforming of methane and their coking-resistance were also evaluated. The results reveal that the beneficial effect of potassium addition is strongly related to its location in the catalysts. The catalyst surface should be promoted with potassium in order to obtain high coking-resistant catalysts. Moreover, the catalyst preparation procedure should ensure a direct interaction of potassium with the Al2O3 support surface. Due to the low stability of potassium on θ-Al2O3 this phase is undesirable during the preparation of a stable steam reforming catalyst.

Potassium

MedlinePlus

... disease with vomiting and diarrhea) and drugs, especially diuretics ('water pills'), remove potassium from the body. Potassium ... captopril (Capoten), enalapril (Vasotec),and lisinopril (Prinivil, Zestril); diuretics ('water pills'); and vitamins. Do not take potassium ...

A neutron activation analysis procedure for the determination of uranium, thorium and potassium in geologic samples

USGS Publications Warehouse

Aruscavage, P. J.; Millard, H.T.

1972-01-01

A neutron activation analysis procedure was developed for the determination of uranium, thorium and potassium in basic and ultrabasic rocks. The three elements are determined in the same 0.5-g sample following a 30-min irradiation in a thermal neutron flux of 2??1012 n??cm-2??sec-1. Following radiochemical separation, the nuclides239U (T=23.5 m),233Th (T=22.2 m) and42K (T=12.36 h) are measured by ??-counting. A computer program is used to resolve the decay curves which are complex owing to contamination and the growth of daughter activities. The method was used to determine uranium, throium and potassium in the U. S. Geological Survey standard rocks DTS-1, PCC-1 and BCR-1. For 0.5-g samples the limits of detection for uranium, throium and potassium are 0.7, 1.0 and 10 ppb, respectively. ?? 1972 Akade??miai Kiado??.

The Trk Potassium Transporter Is Required for RsmB-Mediated Activation of Virulence in the Phytopathogen Pectobacterium wasabiae

PubMed Central

Valente, Rita S.

2015-01-01

ABSTRACT Pectobacterium wasabiae (previously known as Erwinia carotovora) is an important plant pathogen that regulates the production of plant cell wall-degrading enzymes through an N-acyl homoserine lactone-based quorum sensing system and through the GacS/GacA two-component system (also known as ExpS/ExpA). At high cell density, activation of GacS/GacA induces the expression of RsmB, a noncoding RNA that is essential for the activation of virulence in this bacterium. A genetic screen to identify regulators of RsmB revealed that mutants defective in components of a putative Trk potassium transporter (trkH and trkA) had decreased rsmB expression. Further analysis of these mutants showed that changes in potassium concentration influenced rsmB expression and consequent tissue damage in potato tubers and that this regulation required an intact Trk system. Regulation of rsmB expression by potassium via the Trk system occurred even in the absence of the GacS/GacA system, demonstrating that these systems act independently and are both required for full activation of RsmB and for the downstream induction of virulence in potato infection assays. Overall, our results identified potassium as an essential environmental factor regulating the Rsm system, and the consequent induction of virulence, in the plant pathogen P. wasabiae. IMPORTANCE Crop losses from bacterial diseases caused by pectolytic bacteria are a major problem in agriculture. By studying the regulatory pathways involved in controlling the expression of plant cell wall-degrading enzymes in Pectobacterium wasabiae, we showed that the Trk potassium transport system plays an important role in the regulation of these pathways. The data presented further identify potassium as an important environmental factor in the regulation of virulence in this plant pathogen. We showed that a reduction in virulence can be achieved by increasing the extracellular concentration of potassium. Therefore, this work highlights how

Terbinafine is a novel and selective activator of the two-pore domain potassium channel TASK3.

PubMed

Wright, Paul D; Veale, Emma L; McCoull, David; Tickle, David C; Large, Jonathan M; Ococks, Emma; Gothard, Gemma; Kettleborough, Catherine; Mathie, Alistair; Jerman, Jeffrey

2017-11-04

Two-pore domain potassium channels (K2Ps) are characterized by their four transmembrane domain and two-pore topology. They carry background (or leak) potassium current in a variety of cell types. Despite a number of important roles there is currently a lack of pharmacological tools with which to further probe K2P function. We have developed a cell-based thallium flux assay, using baculovirus delivered TASK3 (TWIK-related acid-sensitive K + channel 3, KCNK9, K2P9.1) with the aim of identifying novel, selective TASK3 activators. After screening a library of 1000 compounds, including drug-like and FDA approved molecules, we identified Terbinafine as an activator of TASK3. In a thallium flux assay a pEC50 of 6.2 ( ±0.12) was observed. When Terbinafine was screened against TASK2, TREK2, THIK1, TWIK1 and TRESK no activation was observed in thallium flux assays. Several analogues of Terbinafine were also purchased and structure activity relationships examined. To confirm Terbinafine's activation of TASK3 whole cell patch clamp electrophysiology was carried out and clear potentiation observed in both the wild type channel and the pathophysiological, Birk-Barel syndrome associated, G236R TASK3 mutant. No activity at TASK1 was observed in electrophysiology studies. In conclusion, we have identified the first selective activator of the two-pore domain potassium channel TASK3. Copyright © 2017 Elsevier Inc. All rights reserved.

The Effect of Potassium Impurities Deliberately Introduced into Activated Carbon Cathodes on the Performance of Lithium-Oxygen Batteries

DOE PAGES

Zhai, Dengyun; Lau, Kah Chun; Wang, Hsien-Hau; ...

2015-12-02

Rechargeable lithium-air (Li-O 2) batteries have drawn much interest owing to their high energy density. We report on the effect of deliberately introducing potassium impurities into the cathode material on the electrochemical performance of a Li-O 2 battery. Small amounts of potassium introduced into the activated carbon (AC) cathode material in the synthesis process are found to have a dramatic effect on the performance of the Li-O 2 cell. An increased amount of potassium significantly increases capacity, cycle life, and round-trip efficiency. This improved performance is probably due to a larger amount of LiO 2 in the discharge product, whichmore » is a mixture of LiO 2 and Li 2O 2, resulting from the increase in the amount of potassium present. No substantial correlation with porosity or surface area in an AC cathode is found. Lastly, experimental and computational studies indicate that potassium can act as an oxygen reduction catalyst, which can account for the dependence of performance on the amount of potassium.« less

Extracellular Potassium Homeostasis: Insights from Hypokalemic Periodic Paralysis

PubMed Central

Cheng, Chih-Jen; Kuo, Elizabeth; Huang, Chou-Long

2014-01-01

The extracellular potassium makes up only about 2% of the total body potassium store. The majority of the body potassium is distributed in the intracellular space, and of which about 80% is in skeletal muscle. Movement of potassium in and out of skeletal muscle thus plays a pivotal role in extracellular potassium homeostasis. The exchange of potassium between the extracellular space and skeletal muscle is mediated by specific membrane transporters. These include potassium uptake by Na+, K+-ATPase and release by inward rectifier K+ channels. These processes are regulated by circulating hormones, peptides, ions, and by physical activity of muscle as well as dietary potassium intake. Pharmaceutical agents, poisons and disease conditions also affect the exchange and alter extracellular potassium concentration. Here, we review extracellular potassium homeostasis focusing on factors and conditions that influence the balance of potassium movement in skeletal muscle. Recent findings that mutations of a skeletal muscle-specific inward rectifier K+ channel cause hypokalemic periodic paralysis provide interesting insights into the role of skeletal muscle in extracellular potassium homeostasis. These recent findings will be reviewed. PMID:23953801

Effects of Potassium Permanganate Oxidation on Subsurface Microbial Activity

NASA Technical Reports Server (NTRS)

Rowland, Martin A.; Brubaker, Gaylen R.; Westray, Mark; Morris, Damon; Kohler, Keisha; McCool, Alex (Technical Monitor)

2001-01-01

In situ chemical oxidation has the potential for degrading large quantities of organic contaminants and can be more effective and timely than traditional ex situ treatment methods. However, there is a need to better characterize the potential effects of this treatment on natural processes. This study focuses on potential inhibition to anaerobic dechlorination of trichloroethene (TCE) in soils from a large manufacturing facility as a result of in situ oxidation using potassium permanganate (KMn04)Previous microcosm studies established that natural attenuation occurs on-site and that it is enhanced by the addition of ethanol to the system. A potential remediation scheme for the site involves the use of potassium permanganate to reduce levels of TCE in heavily contaminated areas, then to inject ethanol into the system to "neutralize" excess oxidant and enhance microbial degradation. However, it is currently unknown whether the exposure of indigenous microbial populations to potassium permanganate may adversely affect biological reductive dechlorination by these microorganisms. Consequently, additional microcosm studies were conducted to evaluate this remediation scheme and assess the effect of potassium permanganate addition on biological reductive dechlorination of TCE. Samples of subsurface soil and groundwater were collected from a TCE-impacted area of the site. A portion of the soil was pretreated with nutrients and ethanol to stimulate microbial activity, while the remainder of the soil was left unamended. Soil/groundwater microcosms were prepared in sealed vials using the nutrient-amended and unamended soils, and the effects of potassium permanganate addition were evaluated using two permanganate concentrations (0.8 and 2.4 percent) and two contact times (1 and 3 weeks). TCE was then re-added to each microcosm and TCE and dichloroethene (DCE) concentrations were monitored to determine the degree to which microbial dechlorination occurred following chemical

The Trk Potassium Transporter Is Required for RsmB-Mediated Activation of Virulence in the Phytopathogen Pectobacterium wasabiae.

PubMed

Valente, Rita S; Xavier, Karina B

2016-01-15

Pectobacterium wasabiae (previously known as Erwinia carotovora) is an important plant pathogen that regulates the production of plant cell wall-degrading enzymes through an N-acyl homoserine lactone-based quorum sensing system and through the GacS/GacA two-component system (also known as ExpS/ExpA). At high cell density, activation of GacS/GacA induces the expression of RsmB, a noncoding RNA that is essential for the activation of virulence in this bacterium. A genetic screen to identify regulators of RsmB revealed that mutants defective in components of a putative Trk potassium transporter (trkH and trkA) had decreased rsmB expression. Further analysis of these mutants showed that changes in potassium concentration influenced rsmB expression and consequent tissue damage in potato tubers and that this regulation required an intact Trk system. Regulation of rsmB expression by potassium via the Trk system occurred even in the absence of the GacS/GacA system, demonstrating that these systems act independently and are both required for full activation of RsmB and for the downstream induction of virulence in potato infection assays. Overall, our results identified potassium as an essential environmental factor regulating the Rsm system, and the consequent induction of virulence, in the plant pathogen P. wasabiae. Crop losses from bacterial diseases caused by pectolytic bacteria are a major problem in agriculture. By studying the regulatory pathways involved in controlling the expression of plant cell wall-degrading enzymes in Pectobacterium wasabiae, we showed that the Trk potassium transport system plays an important role in the regulation of these pathways. The data presented further identify potassium as an important environmental factor in the regulation of virulence in this plant pathogen. We showed that a reduction in virulence can be achieved by increasing the extracellular concentration of potassium. Therefore, this work highlights how elucidation of the

Intractable hyperkalemia due to nicorandil induced potassium channel syndrome.

PubMed

Chowdhry, Vivek; Mohanty, B B

2015-01-01

Nicorandil is a commonly used antianginal agent, which has both nitrate-like and ATP-sensitive potassium (K ATP ) channel activator properties. Activation of potassium channels by nicorandil causes expulsion of potassium ions into the extracellular space leading to membrane hyperpolarization, closure of voltage-gated calcium channels and finally vasodilatation. However, on the other hand, being an activator of K ATP channel, it can expel K + ions out of the cells and can cause hyperkalemia. Here, we report a case of nicorandil induced hyperkalemia unresponsive to medical treatment in a patient with diabetic nephropathy.

Plasma potassium and diurnal cyclic potassium excretion in the rat.

PubMed

Rabinowitz, L; Berlin, R; Yamauchi, H

1987-12-01

The relation of the plasma potassium concentration to the daily cyclic variation in potassium excretion was examined in undisturbed, unanesthetized male Sprague-Dawley rats maintained on a liquid diet in a 12-h light-dark environment. Potassium excretion increased from a light-phase minimum of 16 mu eq/h to a peak of 256 mu eq/h 3 h after the beginning of the dark phase. Plasma potassium concentration in arterial blood, sampled in rats at 90-min intervals during these changes in potassium excretion, showed no significant change and was in the range 4.50-4.99 meq/liter. In adrenalectomized rats receiving aldosterone and dexamethasone at constant basal rates by implanted pumps, the daily cycle of potassium excretion was the same as in the intact rats, and plasma potassium was not significantly different when measured at the time of minimum and maximum rates of potassium excretion (4.79 +/- 0.42 vs 5.16 +/- 0.47 meq/liter, mean +/- SD). These results indicate that plasma potassium concentration is not the efferent factor controlling diurnal cyclic changes in potassium excretion in adrenal intact rats and may not be the only significant factor in adrenalectomized-steroid replaced rats.

The Sodium-Activated Potassium Channel Slack Is Required for Optimal Cognitive Flexibility in Mice

ERIC Educational Resources Information Center

Bausch, Anne E.; Dieter, Rebekka; Nann, Yvette; Hausmann, Mario; Meyerdierks, Nora; Kaczmarek, Leonard K.; Ruth, Peter; Lukowski, Robert

2015-01-01

"Kcnt1" encoded sodium-activated potassium channels (Slack channels) are highly expressed throughout the brain where they modulate the firing patterns and general excitability of many types of neurons. Increasing evidence suggests that Slack channels may be important for higher brain functions such as cognition and normal intellectual…

Potassium Secondary Batteries.

PubMed

Eftekhari, Ali; Jian, Zelang; Ji, Xiulei

2017-02-08

Potassium may exhibit advantages over lithium or sodium as a charge carrier in rechargeable batteries. Analogues of Prussian blue can provide millions of cyclic voltammetric cycles in aqueous electrolyte. Potassium intercalation chemistry has recently been demonstrated compatible with both graphite and nongraphitic carbons. In addition to potassium-ion batteries, potassium-O 2 (or -air) and potassium-sulfur batteries are emerging. Additionally, aqueous potassium-ion batteries also exhibit high reversibility and long cycling life. Because of potentially low cost, availability of basic materials, and intriguing electrochemical behaviors, this new class of secondary batteries is attracting much attention. This mini-review summarizes the current status, opportunities, and future challenges of potassium secondary batteries.

Potassium in diet

MedlinePlus

... the diet; Hypokalemia - potassium in the diet; Chronic kidney disease - potassium in diet; Kidney failure - potassium in diet ... are also excellent sources of potassium. People with kidney problems, especially those on dialysis, should not eat ...

Potassium Ferrate: A Novel Chemical Warfare Agent Decontaminant

DTIC Science & Technology

2004-11-16

POTASSIUM FERRATE : A NOVEL CHEMICAL WARFARE AGENT DECONTAMINANT Russell Greene greener@battelle.org (Battelle Memorial Institute, West...difficulties, and/or unsatisfactory CWA destruction efficiencies. Potassium ferrate (K2FeO4) addresses all of these issues through its high oxidation...used and proposed, are unstable (with respect to loss of activity) and/or difficult to prepare, store and transport. Potassium ferrate (K2FeO4) has

Physicochemical action of potassium-magnesium citrate in nephrolithiasis

NASA Technical Reports Server (NTRS)

Pak, C. Y.; Koenig, K.; Khan, R.; Haynes, S.; Padalino, P.

1992-01-01

Effect of potassium-magnesium citrate on urinary biochemistry and crystallization of stone-forming salts was compared with that of potassium citrate at same dose of potassium in five normal subjects and five patients with calcium nephrolithiasis. Compared to the placebo phase, urinary pH rose significantly from 6.06 +/- 0.27 to 6.48 +/- 0.36 (mean +/- SD, p less than 0.0167) during treatment with potassium citrate (50 mEq/day for 7 days) and to 6.68 +/- 0.31 during therapy with potassium-magnesium citrate (containing 49 mEq K, 24.5 mEq Mg, and 73.5 mEq citrate per day). Urinary pH was significantly higher during potassium-magnesium citrate than during potassium citrate therapy. Thus, the amount of undissociated uric acid declined from 118 +/- 61 mg/day during the placebo phase to 68 +/- 54 mg/day during potassium citrate treatment and, more prominently, to 41 +/- 46 mg/day during potassium-magnesium citrate therapy. Urinary magnesium rose significantly from 102 +/- 25 to 146 +/- 37 mg/day during potassium-magnesium citrate therapy but not during potassium citrate therapy. Urinary citrate rose more prominently during potassium-magnesium citrate therapy (to 1027 +/- 478 mg/day from 638 +/- 252 mg/day) than during potassium citrate treatment (to 932 +/- 297 mg/day). Consequently, urinary saturation (activity product) of calcium oxalate declined significantly (from 1.49 x 10(-8) to 1.03 x 10(-8) M2) during potassium-magnesium citrate therapy and marginally (to 1.14 x 10(-8) M2) during potassium citrate therapy.(ABSTRACT TRUNCATED AT 250 WORDS).

Low Potassium (Hypokalemia)

MedlinePlus

Symptoms Low potassium (hypokalemia) By Mayo Clinic Staff Low potassium (hypokalemia) refers to a lower than normal potassium level ... 2 millimoles per liter (mmol/L). A very low potassium level (less than 2.5 mmol/L) ...

Potassium channel openers and prostacyclin play a crucial role in mediating the vasorelaxant activity of Gynura procumbens

PubMed Central

2013-01-01

Background Previous studies of Gynura procumbens (G. procumbens) have shown that partially purified fractions of the leaves are capable of lowering the blood pressure of rats by inhibiting angiotensin-converting enzymic activity and causing vasodilatation. The objectives of this study were therefore to further purify the active compounds that exhibited selective effects on blood vessels, determine the mechanism of actions, and to qualitatively analyse the putative compounds present. Methods The butanolic fraction (BU) of the crude ethanolic extract was purified using column chromatography to obtain several sub-fractions of different polarities. The in vitro effects of BU and the sub-fractions on vascular tension were subsequently determined using isolated rat thoracic aortic rings. The most potent sub-fraction (F1) alone was then investigated for its mechanisms of the vasorelaxant activity. In another experiment, thin-layer chromatography was used to qualitatively analyse the active compounds found in F1. Results The BU and the sub-fractions ranging from 10-7 to 10-2 g/ml significantly (p < 0.05) inhibited the sustained tonic contractions induced by phenylephrine and potassium chloride in a concentration-dependent manner with various degree of potency. The most potent sub-fraction (F1) antagonised the calcium-induced vasocontractions (1 x 10-4 – 1 x 10-2 M) in calcium-free with high concentration of potassium as well as in calcium- and potassium-free Krebs-Henseleit solutions. Contractions induced by noradrenaline and caffeine were not affected by F1. The vasorelaxing effect caused by F1 was significantly attenuated with preincubation of potassium channel blockers (glibenclamide and 4-aminopyridine) and prostacyclin inhibitor (indomethacin) while it was not affected by preincubation with tetraethylammonium, l-nitro-arginine methyl esther, propanolol, atropine, oxadiazolo quinoxalin one and methylene blue. The qualitative phytochemical analysis of F1

Overexpression of calcium-activated potassium channels underlies cortical dysfunction in a model of PTEN-associated autism.

PubMed

Garcia-Junco-Clemente, Pablo; Chow, David K; Tring, Elaine; Lazaro, Maria T; Trachtenberg, Joshua T; Golshani, Peyman

2013-11-05

De novo phosphatase and tensin homolog on chromosome ten (PTEN) mutations are a cause of sporadic autism. How single-copy loss of PTEN alters neural function is not understood. Here we report that Pten haploinsufficiency increases the expression of small-conductance calcium-activated potassium channels. The resultant augmentation of this conductance increases the amplitude of the afterspike hyperpolarization, causing a decrease in intrinsic excitability. In vivo, this change in intrinsic excitability reduces evoked firing rates of cortical pyramidal neurons but does not alter receptive field tuning. The decreased in vivo firing rate is not associated with deficits in the dendritic integration of synaptic input or with changes in dendritic complexity. These findings identify calcium-activated potassium channelopathy as a cause of cortical dysfunction in the PTEN model of autism and provide potential molecular therapeutic targets.

23Na and 35/37Cl as NMR probes of growth and shape of sodium taurodeoxycholate micellar aggregates in the presence of NaCl.

PubMed

Asaro, Fioretta; Feruglio, Luigi; Galantini, Luciano; Nardelli, Alessia

2013-02-15

The growth of the aggregates of the dihydroxylated bile salt sodium taurodeoxycholate (NaTDC) upon NaCl addition and the involvement of the counterion were investigated by NMR spectroscopy of monoatomic ionic species. (23)Na T(1) values from 0.015, 0.100, and 0.200 mol kg(-1) NaTDC solutions in D(2)O, at variable NaCl content, proved to be sensitive to the transition from primary to secondary aggregates, which occurs in the former sample, and to intermicellar interaction. Some (79)Br NMR measurements were performed on a 0.100 mol kg(-1) NaTDC sample added by NaBr in place of NaCl for comparison purposes. The (23)Na, (35)Cl, and (37)Cl double quantum filtered (DQF) patterns, from the 0.100 mol kg(-1) NaTDC sample, and (23)Na ones also from the 0.200 mol kg(-1) NaTDC one, in the presence of 0.750 mol kg(-1) NaCl, are a clear manifestation of motional anisotropy. Moreover, the DQF spectra of (23)Na and (37)Cl, which possess close quadrupole moments, display a striking similarity. The DQF lineshapes were simulated exploiting the Scilab environment to obtain an estimate of the residual quadrupole splitting magnitude. These results support the description of NaTDC micelles as cylindrical aggregates, strongly interacting at high ionic strengths, and capable of association with added electrolytes. Copyright © 2012 Elsevier Inc. All rights reserved.

Targeting solid tumours with potassium channel activators. A return to fundamentals?

PubMed

Trechot, Philippe

2014-01-01

From a pharmacological point of view nicotinamide and minoxidil are potassium channel activators. Nicotinamide is used as a radiosensitizer in ARCON (accelerated radiotherapy combined with carbogen breathing and nicotinamide) therapeutic strategy with promising results but not confirmed so far. Minoxidil has never been considered by radiotherapists. Based from recent pathophysiological considerations we suggest a new perspective for the use of these two "old" molecules in order to target solid tumours. © 2014 Société Française de Pharmacologie et de Thérapeutique.

Serum potassium level and dietary potassium intake as risk factors for stroke.

PubMed

Green, D M; Ropper, A H; Kronmal, R A; Psaty, B M; Burke, G L

2002-08-13

Numerous studies have found that low potassium intake and low serum potassium are associated with increased stroke mortality, but data regarding stroke incidence have been limited. Serum potassium levels, dietary potassium intake, and diuretic use in relation to risk for stroke in a prospectively studied cohort were investigated. The study comprised 5,600 men and women older than 65 years who were free of stroke at enrollment. Baseline data included serum potassium level, dietary potassium intake, and diuretic use. Participants were followed for 4 to 8 years, and the incidence and types of strokes were recorded. Low serum potassium was defined as less than 4.1 mEq/L, and low potassium intake as less than 2.4 g/d. Among diuretic users, there was an increased risk for stroke associated with lower serum potassium (relative risk [RR]: 2.5, p < 0.0001). Among individuals not taking diuretics, there was an increased risk for stroke associated with low dietary potassium intake (RR: 1.5, p < 0.005). The small number of diuretic users with lower serum potassium and atrial fibrillation had a 10-fold greater risk for stroke compared with those with higher serum potassium and normal sinus rhythm. A lower serum potassium level in diuretic users, and low potassium intake in those not taking diuretics were associated with increased stroke incidence among older individuals. Lower serum potassium was associated with a particularly high risk for stroke in the small number of diuretic users with atrial fibrillation. Further study is required to determine if modification of these factors would prevent strokes.

The renal TRPV4 channel is essential for adaptation to increased dietary potassium

PubMed Central

Mamenko, Mykola; Boukelmoune, Nabila; Tomilin, Viktor; Zaika, Oleg; Jensen, V. Behrana; O’Neil, Roger G.; Pochynyuk, Oleh

2016-01-01

To maintain potassium homeostasis, kidneys exert flow-dependent potassium secretion to facilitate kaliuresis in response to elevated dietary potassium intake. This process involves stimulation of calcium-activated large conductance maxi-K (BK) channels in the distal nephron, namely the connecting tubule and the collecting duct. Recent evidence suggests that the TRPV4 channel is a critical determinant of flow-dependent intracellular calcium elevations in these segments of the renal tubule. Here, we demonstrate that elevated dietary potassium intake (five percent potassium) increases renal TRPV4 mRNA and protein levels in an aldosterone-dependent manner and causes redistribution of the channel to the apical plasma membrane in native collecting duct cells. This, in turn, leads to augmented TRPV4-mediated flow-dependent calcium ion responses in freshly isolated split-opened collecting ducts from mice fed the high potassium diet. Genetic TRPV4 ablation greatly diminished BK channel activity in collecting duct cells pointing to a reduced capacity to excrete potassium. Consistently, elevated potassium intake induced hyperkalemia in TRPV4 knockout mice due to deficient renal potassium excretion. Thus, regulation of TRPV4 activity in the distal nephron by dietary potassium is an indispensable component of whole body potassium balance. PMID:28187982

The renal TRPV4 channel is essential for adaptation to increased dietary potassium.

PubMed

Mamenko, Mykola V; Boukelmoune, Nabila; Tomilin, Viktor N; Zaika, Oleg L; Jensen, V Behrana; O'Neil, Roger G; Pochynyuk, Oleh M

2017-06-01

To maintain potassium homeostasis, kidneys exert flow-dependent potassium secretion to facilitate kaliuresis in response to elevated dietary potassium intake. This process involves stimulation of calcium-activated large conductance maxi-K (BK) channels in the distal nephron, namely the connecting tubule and the collecting duct. Recent evidence suggests that the TRPV4 channel is a critical determinant of flow-dependent intracellular calcium elevations in these segments of the renal tubule. Here, we demonstrate that elevated dietary potassium intake (five percent potassium) increases renal TRPV4 mRNA and protein levels in an aldosterone-dependent manner and causes redistribution of the channel to the apical plasma membrane in native collecting duct cells. This, in turn, leads to augmented TRPV4-mediated flow-dependent calcium ion responses in freshly isolated split-opened collecting ducts from mice fed the high potassium diet. Genetic TRPV4 ablation greatly diminished BK channel activity in collecting duct cells pointing to a reduced capacity to excrete potassium. Consistently, elevated potassium intake induced hyperkalemia in TRPV4 knockout mice due to deficient renal potassium excretion. Thus, regulation of TRPV4 activity in the distal nephron by dietary potassium is an indispensable component of whole body potassium balance. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Potassium

MedlinePlus

... Guidelines for Americans and the U.S. Department of Agriculture’s MyPlate . Where can I find out more about ... on food sources of potassium: U.S. Department of Agriculture’s (USDA) National Nutrient Database Nutrient List for potassium ( ...

Potassium Beta-Alumina/Molybdenum/Potassium Electrochemical Cells

NASA Technical Reports Server (NTRS)

Williams, R.; Kisor, A.; Ryan, M.; Nakamura, B.; Kikert, S.; O'Connor, D.

1994-01-01

potassium alkali metal thermal-to-electric converter (K-AMTEC) cells utilizing potassium beta alumina solid electrolyte (K-BASE) are predicted to have improved properties for thermal to electric conversion at somewhat lower temperatures than sodium AMTEC's.

Active potassium transport coupled to active sodium transport in vesicles reconstituted from purified sodium and potassium ion-activated adenosine triphosphatase from the rectal gland of Squalus acanthias.

PubMed

Hilden, S; Hokin, L E

1975-08-25

Vesicles containing a purified shark rectal gland (sodium + potassium)-activated adenosine triphosphatase-(NaK ATPase) were prepared by dialyzing for 2 days egg lecithin, cholate, and the NaK ATPase purified from the rectal gland of Squalus acanthias. These vesicles were capable of both Na+ and K+ transport. Studies of K+ transport were made by measuring the ATP-stimulated transport outward of 42K+ or 86Rb+. Vesicles were preloaded with isotope by equilibration at 4 degrees for 1 to 3 days. Transport of 42K+ or 86Rb+ was initiated by addition of MgATP to the vesicles. The ATP-dependent exit of either isotope was the same. Experiments are presented which show that this loss of isotope was not due to changes in ion binding but rather due to a loss in the amount of ion trapped in the vesicular volume. The transport of K+ was dependent on external Mg2+. CTP was almost as effective as ATP in stimulating K+ transport, while UTP was relatively ineffective. These effects of nucleotides parallel their effects on Na+ accumulation and their effectiveness as substrates for the enzyme. Potassium transport was inhibited by ouabain and required the presence of Na+. The following asymmetries were seen: (a) addition of external Mg2+ supported K+ transport; (b) ouabain inhibited K+ transport only if it was present inside the vesicles; (c) addition of external Na+ to the vesicles stimulated K+ transport. External Li+ was ineffective as a Na+ substitute. The specific requirement of external Na+ for K+ transport indicates that K+ exit is coupled to Na+ entry. Changes in the internal vesicular ion concentrations were studied with vesicles prepared in 20 mM NaCl and 50 mM KCl. After 1 hour of transport at 25 degrees, a typical Na+ concentration in the vesicles in the presence of ATP was 72 mM. A typical K+ concentration in the vesicles was 10 mM as measured with 42K+ or 6 mM as measured with 86Rb+. The following relationships have been calculated for Na+ transport, K+ transport and ATP

Dietary potassium regulates vascular calcification and arterial stiffness.

PubMed

Sun, Yong; Byon, Chang Hyun; Yang, Youfeng; Bradley, Wayne E; Dell'Italia, Louis J; Sanders, Paul W; Agarwal, Anupam; Wu, Hui; Chen, Yabing

2017-10-05

Vascular calcification is a risk factor that predicts adverse cardiovascular complications of several diseases including atherosclerosis. Reduced dietary potassium intake has been linked to cardiovascular diseases such as hypertension and incidental stroke, although the underlying molecular mechanisms remain largely unknown. Using the ApoE-deficient mouse model, we demonstrated for the first time to our knowledge that reduced dietary potassium (0.3%) promoted atherosclerotic vascular calcification and increased aortic stiffness, compared with normal (0.7%) potassium-fed mice. In contrast, increased dietary potassium (2.1%) attenuated vascular calcification and aortic stiffness. Mechanistically, reduction in the potassium concentration to the lower limit of the physiological range increased intracellular calcium, which activated a cAMP response element-binding protein (CREB) signal that subsequently enhanced autophagy and promoted vascular smooth muscle cell (VSMC) calcification. Inhibition of calcium signals and knockdown of either CREB or ATG7, an autophagy regulator, attenuated VSMC calcification induced by low potassium. Consistently, elevated autophagy and CREB signaling were demonstrated in the calcified arteries from low potassium diet-fed mice as well as aortic arteries exposed to low potassium ex vivo. These studies established a potentially novel causative role of dietary potassium intake in regulating atherosclerotic vascular calcification and stiffness, and uncovered mechanisms that offer opportunities to develop therapeutic strategies to control vascular disease.

Potassium Inhibits Dietary Salt-Induced Transforming Growth Factor-β Production

PubMed Central

Ying, Wei-Zhong; Aaron, Kristal; Wang, Pei-Xuan; Sanders, Paul W.

2009-01-01

Human and animal studies demonstrate an untoward effect of excess dietary NaCl (salt) intake on cardiovascular function and life span. The endothelium in particular augments the production of transforming growth factor (TGF)-β, a fibrogenic growth factor, in response to excess dietary salt intake. This study explored the initiating mechanism that regulates salt-induced endothelial cell production of TGF-β. Male Sprague-Dawley rats were given diets containing different amounts of NaCl and potassium for 4 days. A bioassay for TGF-β demonstrated increased (35.2%) amounts of active TGF-β in the medium of aortic ring segments from rats on the high-salt diet compared with rats maintained on a 0.3% NaCl diet. Inhibition of the large-conductance, calcium-activated potassium channel inhibited dietary salt-induced vascular production of TGF-β but did not affect production of TGF-β by ring segments from rats on the low-salt diet. Immunohistochemical and Western analyses demonstrated the α subunit of the calcium-activated potassium channel in endothelial cells. Increasing medium [K+] inhibited production of dietary salt-induced vascular production levels of total and active TGF-β but did not alter TGF-β production by aortic rings from rats on the 0.3% NaCl diet. Increasing dietary potassium content decreased urinary active TGF-β in animals receiving the high-salt diet but did not change urinary active TGF-β in animals receiving the low-salt diet. The findings demonstrated an interesting interaction between the dietary intake of potassium and excess NaCl and further showed the fundamental role of the endothelial calcium-activated potassium channel in the vascular response to excess salt intake. PMID:19738156

Biochemical composition and antioxidant activity affected by spraying potassium sulfate in black grape (Vitis vinifera L. cv. Rasha).

PubMed

Zareei, Elnaz; Javadi, Taimoor; Aryal, Rishi

2018-04-27

The physiological and metabolic processes involved with grapevine growth and production are influenced by key macro and micro-nutrients. Potassium is an essential plant nutrient that affects growth and fruit quality. In this study, the impact of foliar spraying of potassium sulfate (K 2 SO 4 ) on qualitative characteristics of grape berries was evaluated in the cultivar 'Rasha', a commonly cultivated cultivar in Kurdistan province of Iran. Leaves of the fully-grown vines were sprayed with each of the 1.5 g L -1 and 3 g L -1 potassium sulfate solution once (one month after petal senescence) and twice (15 days after first spraying). The control plants were sprayed with distilled water. Various biochemical content and enzyme activities on the ripe berries were analyzed. Significant increase in anthocyanin, total protein content and antioxidant enzyme activities were observed in the berries treated twice with 3 g L -1 K 2 SO 4 . Concentrations of total carbohydrate, phenol and antioxidant activity in berries sprayed with K 2 SO 4 were higher compared to the controls. We observed a strong correlation between antioxidant activity and different phenolic compounds. These findings suggest that K 2 SO 4 treatment influences biosynthesis of phenolic compounds and antioxidant enzymes. Thus treatment by K 2 SO 4 could improve nutritional and qualitative attributes of grape. This article is protected by copyright. All rights reserved.

Possible potassium chlorate nephrotoxicity associated with chronic matchstick ingestion.

PubMed

Thurlow, John S; Little, Dustin J; Baker, Thomas P; Yuan, Christina M

2013-06-01

We present a case of a 48-year-old active duty male soldier with a history of chronic exposure to potassium chlorate, later diagnosed with chronic interstitial nephritis. He reported regular matchstick consumption to prevent chigger (Trombicula autumnalis) bites, amounting to ∼5.8 g of potassium chlorate over 3 years. Potassium chlorate can cause anuric renal failure within days of a toxic dose. Its slow excretion and mechanism of action suggest that renal toxicity may result from lower-dose chronic exposure. This case represents possible sequelae of chronic potassium chlorate ingestion.

Possible potassium chlorate nephrotoxicity associated with chronic matchstick ingestion*

PubMed Central

Thurlow, John S.; Little, Dustin J.; Baker, Thomas P.; Yuan, Christina M.

2013-01-01

We present a case of a 48-year-old active duty male soldier with a history of chronic exposure to potassium chlorate, later diagnosed with chronic interstitial nephritis. He reported regular matchstick consumption to prevent chigger (Trombicula autumnalis) bites, amounting to ∼5.8 g of potassium chlorate over 3 years. Potassium chlorate can cause anuric renal failure within days of a toxic dose. Its slow excretion and mechanism of action suggest that renal toxicity may result from lower-dose chronic exposure. This case represents possible sequelae of chronic potassium chlorate ingestion. PMID:26064493

Slick (Kcnt2) Sodium-Activated Potassium Channels Limit Peptidergic Nociceptor Excitability and Hyperalgesia.

PubMed

Tomasello, Danielle L; Hurley, Edward; Wrabetz, Lawrence; Bhattacharjee, Arin

2017-01-01

The Slick (Kcnt2) sodium-activated potassium (K Na ) channel is a rapidly gating and weakly voltage-dependent and sodium-dependent potassium channel with no clearly defined physiological function. Within the dorsal root ganglia (DRGs), we show Slick channels are exclusively expressed in small-sized and medium-sized calcitonin gene-related peptide (CGRP)-containing DRG neurons, and a pool of channels are localized to large dense-core vesicles (LDCV)-containing CGRP. We stimulated DRG neurons for CGRP release and found Slick channels contained within CGRP-positive LDCV translocated to the neuronal membrane. Behavioral studies in Slick knockout (KO) mice indicated increased basal heat detection and exacerbated thermal hyperalgesia compared with wild-type littermate controls during neuropathic and chronic inflammatory pain. Electrophysiologic recordings of DRG neurons from Slick KO mice revealed that Slick channels contribute to outward current, propensity to fire action potentials (APs), and to AP properties. Our data suggest that Slick channels restrain the excitability of CGRP-containing neurons, diminishing pain behavior after inflammation and injury.

Magnolol and honokiol regulate the calcium-activated potassium channels signaling pathway in Enterotoxigenic Escherichia coli-induced diarrhea mice.

PubMed

Deng, Yanli; Han, Xuefeng; Tang, Shaoxun; Xiao, Wenjun; Tan, Zhiliang; Zhou, Chuanshe; Wang, Min; Kang, Jinghe

2015-05-15

To explore the regulatory mechanisms of magnolol and honokiol on calcium-activated potassium channels signaling pathway in Enterotoxigenic Escherichia coli (ETEC)-induced diarrhea mice, the concentrations of serum chloride ion (Cl(-)), sodium ion (Na(+)), potassium ion (K(+)) and calcium ion (Ca(2+)) were measured. Additionally, the mRNA expressions of calmodulin 1 (CaM), calcium/calmodulin-dependent protein kinase II alpha subunit (CaMKIIα) and beta subunit (CaMKIIβ), ryanodine receptor 1, inositol 1,4,5-trisphosphate receptors (IP3 receptors), protein kinases C (PKC), potassium intermediate/small conductance calcium-activated channels (SK) and potassium large conductance calcium-activated channels(BK)were determined. A diarrhea mouse model was established using ETEC suspensions (3.29×10(9)CFU/ml) at a dosage of 0.02ml/g live body weight (BW). Magnolol or honokiol was intragastrically administered at dosages of 100 (M100 or H100), 300 (M300 or H300) and 500 (M500 or H500) mg/kg BW according to a 3×3 factorial arrangement. Magnolol and honokiol increased the Cl(-) and K(+) concentrations, further, upregulated the CaM, BKα1 and BKβ3 mRNA levels but downregulated the IP3 receptors 1, PKC, SK1, SK2, SK3, SK4 and BKβ4 mRNA expressions. Magnolol and honokiol did not alter the CaMKIIα, CaMKIIβ, ryanodine receptor 1, IP3 receptor 2, IP3 receptor 3, BKβ1 and BKβ2 mRNA expressions. These results clarify that magnolol and honokiol, acting through Ca(2+) channel blockade, inhibit the activation of IP3 receptor 1 to regulate the IP3-Ca(2+) store release, activate CaM to inhibit SK channels, and effectively suppress PKC kinases to promote BKα1 and BKβ3 channels opening and BKβ4 channel closing, which modulates the intestinal ion secretion. Copyright © 2015 Elsevier B.V. All rights reserved.

Primary, Secondary Metabolites, Photosynthetic Capacity and Antioxidant Activity of the Malaysian Herb Kacip Fatimah (Labisia Pumila Benth) Exposed to Potassium Fertilization under Greenhouse Conditions

PubMed Central

Ibrahim, Mohd Hafiz; Jaafar, Hawa Z. E.; Karimi, Ehsan; Ghasemzadeh, Ali

2012-01-01

A randomized complete block design was used to characterize the relationship between production of total phenolics, flavonoids, ascorbic acid, carbohydrate content, leaf gas exchange, phenylalanine ammonia-lyase (PAL), soluble protein, invertase and antioxidant enzyme activities (ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD) in Labisia pumila Benth var. alata under four levels of potassium fertilization experiments (0, 90, 180 and 270 kg K/ha) conducted for 12 weeks. It was found that the production of total phenolics, flavonoids, ascorbic acid and carbohydrate content was affected by the interaction between potassium fertilization and plant parts. As the potassium fertilization levels increased from 0 to 270 kg K/ha, the production of soluble protein and PAL activity increased steadily. At the highest potassium fertilization (270 kg K/ha) L. pumila exhibited significantly higher net photosynthesis (A), stomatal conductance (gs), intercellular CO2 (Ci), apparent quantum yield (ξ) and lower dark respiration rates (Rd), compared to the other treatments. It was found that the production of total phenolics, flavonoids and ascorbic acid are also higher under 270 kg K/ha compared to 180, 90 and 0 kg K/ha. Furthermore, from the present study, the invertase activity was also found to be higher in 270 kg K/ha treatment. The antioxidant enzyme activities (APX, CAT and SOD) were lower under high potassium fertilization (270 kg K/ha) and have a significant negative correlation with total phenolics and flavonoid production. From this study, it was observed that the up-regulation of leaf gas exchange and downregulation of APX, CAT and SOD activities under high supplementation of potassium fertilizer enhanced the carbohydrate content that simultaneously increased the production of L. pumila secondary metabolites, thus increasing the health promoting effects of this plant. PMID:23203128

Adaptation of Bacillus subtilis to Life at Extreme Potassium Limitation.

PubMed

Gundlach, Jan; Herzberg, Christina; Hertel, Dietrich; Thürmer, Andrea; Daniel, Rolf; Link, Hannes; Stülke, Jörg

2017-07-05

Potassium is the most abundant metal ion in every living cell. This ion is essential due to its requirement for the activity of the ribosome and many enzymes but also because of its role in buffering the negative charge of nucleic acids. As the external concentrations of potassium are usually low, efficient uptake and intracellular enrichment of the ion is necessary. The Gram-positive bacterium Bacillus subtilis possesses three transporters for potassium, KtrAB, KtrCD, and the recently discovered KimA. In the absence of the high-affinity transporters KtrAB and KimA, the bacteria were unable to grow at low potassium concentrations. However, we observed the appearance of suppressor mutants that were able to overcome the potassium limitation. All these suppressor mutations affected amino acid metabolism, particularly arginine biosynthesis. In the mutants, the intracellular levels of ornithine, citrulline, and arginine were strongly increased, suggesting that these amino acids can partially substitute for potassium. This was confirmed by the observation that the supplementation with positively charged amino acids allows growth of B. subtilis even at the extreme potassium limitation that the bacteria experience if no potassium is added to the medium. In addition, a second class of suppressor mutations allowed growth at extreme potassium limitation. These mutations result in increased expression of KtrAB, the potassium transporter with the highest affinity and therefore allow the acquisition and accumulation of the smallest amounts of potassium ions from the environment. IMPORTANCE Potassium is essential for every living cell as it is required for the activity for many enzymes and for maintaining the intracellular pH by buffering the negative charge of the nucleic acids. We have studied the adaptation of the soil bacterium Bacillus subtilis to life at low potassium concentrations. If the major high-affinity transporters are missing, the bacteria are unable to grow

Potassium modulates electrolyte balance and blood pressure through effects on distal cell voltage and chloride.

PubMed

Terker, Andrew S; Zhang, Chong; McCormick, James A; Lazelle, Rebecca A; Zhang, Chengbiao; Meermeier, Nicholas P; Siler, Dominic A; Park, Hae J; Fu, Yi; Cohen, David M; Weinstein, Alan M; Wang, Wen-Hui; Yang, Chao-Ling; Ellison, David H

2015-01-06

Dietary potassium deficiency, common in modern diets, raises blood pressure and enhances salt sensitivity. Potassium homeostasis requires a molecular switch in the distal convoluted tubule (DCT), which fails in familial hyperkalemic hypertension (pseudohypoaldosteronism type 2), activating the thiazide-sensitive NaCl cotransporter, NCC. Here, we show that dietary potassium deficiency activates NCC, even in the setting of high salt intake, thereby causing sodium retention and a rise in blood pressure. The effect is dependent on plasma potassium, which modulates DCT cell membrane voltage and, in turn, intracellular chloride. Low intracellular chloride stimulates WNK kinases to activate NCC, limiting potassium losses, even at the expense of increased blood pressure. These data show that DCT cells, like adrenal cells, sense potassium via membrane voltage. In the DCT, hyperpolarization activates NCC via WNK kinases, whereas in the adrenal gland, it inhibits aldosterone secretion. These effects work in concert to maintain potassium homeostasis. Copyright © 2015 Elsevier Inc. All rights reserved.

Potassium Modulates Electrolyte Balance and Blood Pressure through Effects on Distal Cell Voltage and Chloride

PubMed Central

Terker, Andrew S.; Zhang, Chong; McCormick, James A.; Lazelle, Rebecca A.; Zhang, Chengbiao; Meermeier, Nicholas P.; Siler, Dominic A.; Park, Hae J.; Fu, Yi; Cohen, David M.; Weinstein, Alan M.; Wang, Wen-Hui; Yang, Chao-Ling; Ellison, David H.

2015-01-01

SUMMARY Dietary potassium deficiency, common in Western diets, raises blood pressure and enhances salt sensitivity. Potassium homeostasis requires a molecular switch in the distal convoluted tubule (DCT), which fails in familial hyperkalemic hypertension (pseudohypoaldosteronism type 2), activating the thiazide-sensitive NaCl cotransporter, NCC. Here, we show that dietary potassium deficiency activates NCC, even in the setting of high salt intake, thereby causing sodium retention and a rise in blood pressure. The effect is dependent on plasma potassium, which modulates DCT cell membrane voltage and, in turn, intracellular chloride. Low intracellular chloride stimulates WNK kinases to activate NCC, limiting potassium losses, even at the expense of increased blood pressure. These data show that DCT cells, like adrenal cells, sense potassium via membrane voltage. In the DCT, hyperpolarization activates NCC via WNK kinases, whereas in the adrenal gland, it inhibits aldosterone secretion. These effects work in concert to maintain potassium homeostasis. PMID:25565204

Potassium toxicity at low serum potassium levels with refeeding syndrome.

PubMed

Vemula, Praveen; Abela, Oliver G; Narisetty, Keerthy; Rhine, David; Abela, George S

2015-01-01

Refeeding syndrome is a life-threatening condition occurring in severely malnourished patients after initiating feeding. Severe hypophosphatemia with reduced adenosine triphosphate production has been implicated, but little data are available regarding electrolyte abnormalities. In this case, we report electrocardiographic changes consistent with hyperkalemia during potassium replacement after a serum level increase from 1.9 to 2.9 mEq/L. This was reversed by lowering serum potassium back to 2.0 mEq/L. In conclusion, the patient with prolonged malnutrition became adapted to low potassium levels and developed potassium toxicity with replacement. Copyright © 2015 Elsevier Inc. All rights reserved.

Dietary potassium regulates vascular calcification and arterial stiffness

PubMed Central

Sun, Yong; Byon, Chang Hyun; Yang, Youfeng; Bradley, Wayne E.; Dell’Italia, Louis J.; Agarwal, Anupam; Wu, Hui

2017-01-01

Vascular calcification is a risk factor that predicts adverse cardiovascular complications of several diseases including atherosclerosis. Reduced dietary potassium intake has been linked to cardiovascular diseases such as hypertension and incidental stroke, although the underlying molecular mechanisms remain largely unknown. Using the ApoE-deficient mouse model, we demonstrated for the first time to our knowledge that reduced dietary potassium (0.3%) promoted atherosclerotic vascular calcification and increased aortic stiffness, compared with normal (0.7%) potassium–fed mice. In contrast, increased dietary potassium (2.1%) attenuated vascular calcification and aortic stiffness. Mechanistically, reduction in the potassium concentration to the lower limit of the physiological range increased intracellular calcium, which activated a cAMP response element–binding protein (CREB) signal that subsequently enhanced autophagy and promoted vascular smooth muscle cell (VSMC) calcification. Inhibition of calcium signals and knockdown of either CREB or ATG7, an autophagy regulator, attenuated VSMC calcification induced by low potassium. Consistently, elevated autophagy and CREB signaling were demonstrated in the calcified arteries from low potassium diet–fed mice as well as aortic arteries exposed to low potassium ex vivo. These studies established a potentially novel causative role of dietary potassium intake in regulating atherosclerotic vascular calcification and stiffness, and uncovered mechanisms that offer opportunities to develop therapeutic strategies to control vascular disease. PMID:28978809

Oxidative Stress and Maxi Calcium-Activated Potassium (BK) Channels

PubMed Central

Hermann, Anton; Sitdikova, Guzel F.; Weiger, Thomas M.

2015-01-01

All cells contain ion channels in their outer (plasma) and inner (organelle) membranes. Ion channels, similar to other proteins, are targets of oxidative impact, which modulates ion fluxes across membranes. Subsequently, these ion currents affect electrical excitability, such as action potential discharge (in neurons, muscle, and receptor cells), alteration of the membrane resting potential, synaptic transmission, hormone secretion, muscle contraction or coordination of the cell cycle. In this chapter we summarize effects of oxidative stress and redox mechanisms on some ion channels, in particular on maxi calcium-activated potassium (BK) channels which play an outstanding role in a plethora of physiological and pathophysiological functions in almost all cells and tissues. We first elaborate on some general features of ion channel structure and function and then summarize effects of oxidative alterations of ion channels and their functional consequences. PMID:26287261

Comparative Analysis between Ecotoxicity of Nitrogen-, Phosphorus-, and Potassium-Based Fertilizers and Their Active Ingredients

PubMed Central

Simplício, Nathan de Castro Soares; Muniz, Daphne Heloísa de Freitas; Rocha, Fernanda Regina Moreira; Martins, Denis Cavalcanti; Dias, Zélia Malena Barreira; Farias, Bruno Pereira da Costa; Oliveira-Filho, Eduardo Cyrino

2016-01-01

This study aimed to analyze the ecotoxicity of nitrogen-, phosphorus-, and potassium-based compounds to organisms of two different trophic levels in order to compare the toxic effect between high-purity substances and these substances as components of fertilizers. Dilutions were made with the fertilizers’ potassium chloride, potassium nitrate, superphosphate, urea, and their equivalent reagents, to conduct assays to establish the acute lethal concentration for half of the population (LC50). Ten individuals of the benthic snail Biomphalaria glabrata and the fish Danio rerio were exposed to each concentration of tested compounds. As a result, the toxicity levels of potassium chloride, potassium nitrate, and urea were obtained for B. glabrata and D. rerio, with the fish being more susceptible to potassium chloride in the fertilizer and the snail to potassium nitrate and urea, in both commercial and reagent forms. Regarding superphosphate, no significant toxicity was found. This study concluded that among the tested substances, KNO3 and KCl were the most toxic substances and urea the least toxic. It was not possible to establish the most sensitive species since, for KCl, the fish were more susceptible to the fertilizer and the snail to the reagent, while for KNO3 the opposite was observed. PMID:29051434

A Nonaqueous Potassium-Based Battery-Supercapacitor Hybrid Device.

PubMed

Fan, Ling; Lin, Kairui; Wang, Jue; Ma, Ruifang; Lu, Bingan

2018-05-01

A low cost nonaqueous potassium-based battery-supercapacitor hybrid device (BSH) is successfully established for the first time with soft carbon as the anode, commercialized activated carbon as the cathode, and potassium bis(fluoro-slufonyl)imide in dimethyl ether as the electrolyte. This BSH reconciles the advantages of potassium ion batteries and supercapacitors, achieving a high energy density of 120 W h kg -1 , a high power density of 599 W kg -1 , a long cycle life of 1500 cycles, and an ultrafast charge/slow discharge performance (energy density and power density are calculated based on the total mass of active materials in the anode and cathode). This work demonstrates a great potential of applying the nonaqueous BSH for low cost electric energy storage systems. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of potassium ion conducting hollow glass fibers. [potassium sulfur battery

NASA Technical Reports Server (NTRS)

Tsang, F. Y.

1974-01-01

Potassium ion conducting glasses, chemically resistant to potassium, potassium sulfide and sulfur, were made and their possible utility as the membrane material for a potassium/sulfur battery was evaluated. At least one satisfactory candidate was found. It possesses an electrical resistance which makes it usable as a membrane in the form of a fine hollow fiber. It's chemical and electrochemical resistances are excellent. The other aspects of the possible potassium sulfur battery utilizing such fine hollow fibers, including the header (or tube sheet) and a cathode current collector were studied. Several cathode materials were found to be satisfactory. None of the tube sheet materials studied possessed all the desired properties. Multi-fiber cells had very limited life-time due to physical failure of fibers at the fiber/tube sheet junctions.

Solid state green synthesis and catalytic activity of CuO nanorods in thermal decomposition of potassium periodate

NASA Astrophysics Data System (ADS)

Patel, Vinay Kumar; Bhattacharya, Shantanu

2017-09-01

The present study reports a facile solid state green synthesis process using the leaf extracts of Hibiscus rosa-sinensis to synthesize CuO nanorods with average diameters of 15-20 nm and lengths up to 100 nm. The as-synthesized CuO nanorods were characterized by x-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and selected area electron diffraction. The formation mechanism of CuO nanorods has been explained by involving the individual role of amide I (amino groups) and carboxylate groups under excess hydroxyl ions released from NaOH. The catalytic activity of CuO nanorods in thermal decomposition of potassium periodate microparticles (µ-KIO4) microparticles was studied by thermo gravimetric analysis measurement. The original size (~100 µm) of commercially procured potassium periodate was reduced to microscale length scale to about one-tenth by PEG200 assisted emulsion process. The CuO nanorods prepared by solid state green route were found to catalyze the thermal decomposition of µ-KIO4 with a reduction of 18 °C in the final thermal decomposition temperature of potassium periodate.

Calcineurin inhibitors block sodium-chloride cotransporter dephosphorylation in response to high potassium intake.

PubMed

Shoda, Wakana; Nomura, Naohiro; Ando, Fumiaki; Mori, Yutaro; Mori, Takayasu; Sohara, Eisei; Rai, Tatemitsu; Uchida, Shinichi

2017-02-01

Dietary potassium intake is inversely related to blood pressure and mortality. Moreover, the sodium-chloride cotransporter (NCC) plays an important role in blood pressure regulation and urinary potassium excretion in response to potassium intake. Previously, it was shown that NCC is activated by the WNK4-SPAK cascade and dephosphorylated by protein phosphatase. However, the mechanism of NCC regulation with acute potassium intake is still unclear. To identify the molecular mechanism of NCC regulation in response to potassium intake, we used adult C57BL/6 mice fed a 1.7% potassium solution by oral gavage. We confirmed that acute potassium load rapidly dephosphorylated NCC, which was not dependent on the accompanying anions. Mice were treated with tacrolimus (calcineurin inhibitor) and W7 (calmodulin inhibitor) before the oral potassium loads. Dephosphorylation of NCC induced by potassium was significantly inhibited by both tacrolimus and W7 treatment. There was no significant difference in WNK4, OSR1, and SPAK expression after high potassium intake, even after tacrolimus and W7 treatment. Another phosphatase, protein phosphatase 1, and its endogenous inhibitor I-1 did not show a significant change after potassium intake. Hyperkaliuria, induced by high potassium intake, was significantly suppressed by tacrolimus treatment. Thus, calcineurin is activated by an acute potassium load, which rapidly dephosphorylates NCC, leading to increased urinary potassium excretion. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Potassium sensing histidine kinase in Bacillus subtilis.

PubMed

López, Daniel; Gontang, Erin A; Kolter, Roberto

2010-01-01

The soil-dwelling organism Bacillus subtilis is able to form multicellular aggregates known as biofilms. It was recently reported that the process of biofilm formation is activated in response to the presence of various, structurally diverse small-molecule natural products. All of these small-molecule natural products made pores in the membrane of the bacterium, causing the leakage of potassium cations from the cytoplasm of the cell. The potassium cation leakage was sensed by the membrane histidine kinase KinC, triggering the genetic pathway to the production of the extracellular matrix that holds cells within the biofilm. This chapter presents the methodology used to characterize the leakage of cytoplasmic potassium as the signal that induces biofilm formation in B. subtilis via activation of KinC. Development of novel techniques to monitor activation of gene expression in microbial populations led us to discover the differentiation of a subpopulation of cells specialized to produce the matrix that holds all cells together within the biofilm. This phenomenon of cell differentiation was previously missed by conventional techniques used to monitor transcriptional gene expression. Copyright © 2010 Elsevier Inc. All rights reserved.

Comparative Efficacy of Potassium Levulinate with/without Potassium Diacetate and Potassium Propionate vs Potassium Lactate and Sodium Diacetate for Control of Listeria monocytogenes on commercially prepared uncured t.breast

USDA-ARS?s Scientific Manuscript database

We evaluated the efficacy of potassium levulinate, potassium diacetate, and potassium propionate to inhibit Listeria monocytogenes on commercially-prepared, uncured turkey breast during refrigerated storage. Whole muscle, uncured turkey breast chubs (ca. 5 kg each) were formulated with or without po...

The inhibitory effects of potassium chloride versus potassium silicate application on (137)Cs uptake by rice.

PubMed

Fujimura, Shigeto; Yoshioka, Kunio; Ota, Takeshi; Ishikawa, Tetsuya; Sato, Makoto; Satou, Mutsuto

2016-03-01

After the accident at the Fukushima Dai-ichi Nuclear Power Plant owned by the Tokyo Electric Power Company on 11 March 2011, potassium fertilizer was applied to agricultural fields in the southern Tohoku and northern Kanto regions of Japan to reduce the uptake of radiocesium by crops. In this study, we examined the effects of two types of potassium fertilizers, potassium chloride (a readily available potassium fertilizer) and potassium silicate (a slow-release potassium fertilizer), as well as a split application of potassium, on the accumulation of (137)Cs by rice plants in two pot experiments. The (137)Cs concentrations in the brown rice and in the above-ground plants were significantly lower after potassium chloride application than after potassium silicate application. The potassium ion (K(+)) concentrations in soil solutions sampled 9 and 21 d after transplanting were significantly higher for the potassium chloride application than for the potassium silicate application. The K(+) concentrations in soil solutions observed in the application of potassium silicate were similar to those in the treatment when no potassium was applied. This finding indicates that the application of potassium silicate did not sufficiently increase the available K(+) for rice plants in the soil, which led to a greater uptake of (137)Cs after the potassium silicate application than after the application of potassium chloride. The (137)Cs concentration in brown rice was higher in the split application of potassium fertilizer with the second application at the full heading stage than that without split application and the split application with the second application before heading. Copyright © 2016 Elsevier Ltd. All rights reserved.

Potassium and Health123

PubMed Central

Weaver, Connie M.

2013-01-01

Potassium was identified as a shortfall nutrient by the Dietary Guidelines for Americans 2010 Advisory Committee. The committee concluded that there was a moderate body of evidence of the association between potassium intake and blood pressure reduction in adults, which in turn influences the risk of stroke and coronary heart disease. Evidence is also accumulating of the protective effect of adequate dietary potassium on age-related bone loss and reduction of kidney stones. These benefits depend on organic anions associated with potassium as occurs in foods such as fruits and vegetables, in contrast to similar blood pressure-lowering benefits of potassium chloride. Benefits to blood pressure and bone health may occur at levels below current recommendations for potassium intake, especially from diet, but dose-response trials are needed to confirm this. Nevertheless, intakes considerably above current levels are needed for optimal health, and studies evaluating small increases in fruit and vegetable intake on bone and heart outcomes for short periods have had disappointing results. In modern societies, Western diets have led to a decrease in potassium intake with reduced consumption of fruits and vegetables with a concomitant increase in sodium consumption through increased consumption of processed foods. Consumption of white vegetables is associated with decreased risk of stroke, possibly related to their high potassium content. Potatoes are the highest source of dietary potassium, but the addition of salt should be limited. Low potassium-to-sodium intake ratios are more strongly related to cardiovascular disease risk than either nutrient alone. This relationship deserves further attention for multiple target tissue endpoints. PMID:23674806

Using 15N-Ammonium to Characterise and Map Potassium Binding Sites in Proteins by NMR Spectroscopy

PubMed Central

Werbeck, Nicolas D; Kirkpatrick, John; Reinstein, Jochen; Hansen, D Flemming

2014-01-01

A variety of enzymes are activated by the binding of potassium ions. The potassium binding sites of these enzymes are very specific, but ammonium ions can often replace potassium ions in vitro because of their similar ionic radii. In these cases, ammonium can be used as a proxy for potassium to characterise potassium binding sites in enzymes: the 1H,15N spin-pair of enzyme-bound 15NH4+ can be probed by 15N-edited heteronuclear NMR experiments. Here, we demonstrate the use of NMR spectroscopy to characterise binding of ammonium ions to two different enzymes: human histone deacetylase 8 (HDAC8), which is activated allosterically by potassium, and the bacterial Hsp70 homologue DnaK, for which potassium is an integral part of the active site. Ammonium activates both enzymes in a similar way to potassium, thus supporting this non-invasive approach. Furthermore, we present an approach to map the observed binding site onto the structure of HDAC8. Our method for mapping the binding site is general and does not require chemical shift assignment of the enzyme resonances. PMID:24520048

A Green Approach to High-Performance Supercapacitor Electrodes: The Chemical Activation of Hydrochar with Potassium Bicarbonate.

PubMed

Sevilla, Marta; Fuertes, Antonio B

2016-07-21

Sustainable synthesis schemes for the production of porous carbons with appropriate textural properties for use as supercapacitor electrodes are in high demand. In this work a greener option to the widely used but corrosive KOH is proposed for the production of highly porous carbons. Hydrochar products are used as carbon precursors. It is demonstrated that a mild alkaline potassium salt such as potassium bicarbonate is very effective to generate porosity in hydrochar to lead to materials with large surface areas (> 2000 m(2)  g(-1) ) and a tunable pore size distribution. Furthermore, the use of KHCO3 instead of KOH gives rise to a significant 10 % increase in the yield of activated carbon, and the spherical morphology of hydrochar is retained, which translates into better packing properties and reduced ion diffusion distances. These features lead to a supercapacitor performance that can compete with, and even surpass, that of KOH-activated hydrochar in a variety of electrolytes. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Impact of trehalose on the activity of sodium and potassium chloride in aqueous solutions: Why trehalose is worth its salt.

PubMed

Poplinger, Michal; Shumilin, Ilan; Harries, Daniel

2017-12-15

Trehalose is revered for its multiple unique impacts on solution properties, including the ability to modulate the salty and bitter tastes of sodium and potassium salts. However, the molecular mechanisms underlying trehalose's effect on taste perception are unknown. Here we focus on the physico-chemical effect of trehalose to alter the activity of monovalent salts in aqueous solution. Using a modified isopiestic methodology that relies on contemporary vapor pressure osmometry, we elucidate how trehalose modifies the thermodynamic chemical activity of sodium and potassium chloride, as well as the effect of the salts on the sugar's activity. We find that trehalose has a specific impact on potassium chloride that is unlike that of other sugars or polyols. Remarkably, especially at low salt concentrations, trehalose considerably elevates the activity (or chemical potential) of KCl, raising the salt activity coefficient as high as ∼1.5 its value in the absence of the sugar. Moreover, in contrast to their action on other known carbohydrates, both KCl and NaCl act as salting-out agents towards trehalose, as seen in the elevated activity coefficient compared with its value in pure water (up to ∼1.5 higher at low sugar and salt concentrations). We discuss the possible relevance of our findings to the mechanism of trehalose taste perception modification, and point to necessary future directed sensory experiments needed to resolve the possible link between our findings and the emerging biochemical or physiological mechanisms involved. Copyright © 2017 Elsevier Ltd. All rights reserved.

Interacting influence of potassium and polychlorinated biphenyl on cortisol and aldosterone biosynthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, L.-A.; Lin, Tsu-Chun Emma

Giving human adrenocortical H295R cells 14 mM KCl for 24 h significantly induced not only aldosterone biosynthesis but also cortisol biosynthesis. Pre-treating the cells with polychlorinated biphenyl 126 (PCB126) further increased potassium-induced aldosterone and cortisol productions in a dose-dependent manner, but all examined concentrations of PCB126 had little effect on the yields of precursor steroids progesterone and 17-OH-progesterone. Subsequent examinations revealed that CYP11B1 and CYP11B2 genes, responsible for the respective final steps of the cortisol and aldosterone biosynthetic pathways, exhibited increased responsiveness to PCB126 under high potassium. While 10{sup -5} M PCB126 was needed to induce a significant increase inmore » the basal mRNA abundance of either gene, PCB126 could enhance potassium-induced mRNA expression of CYP11B1 at 10{sup -7} M and CYP11B2 at 10{sup -9} M. Actually, potassium and PCB126 synergistically upregulated mRNA expression of both genes. Potassium raised the transcriptional rates of CYP11B1 and CYP11B2 probably through a conserved Ad5 cis-element, whereas PCB126 appeared to regulate these two genes at the post-transcriptional level. Positive potassium-PCB126 synergism was also detected in CYP11B2 enzyme activity estimated by aldosterone/progesterone ratio. In contrast, potassium and PCB126 increased CYP11B1 enzyme activity or cortisol/17-OH-progesterone ratio additively. Moreover, potassium improved the time effect of PCB126 on gene expression and enzyme activity of CYP11B2, but not the PCB126 time response of CYP11B1. These data demonstrated that potassium differentially enhanced the potency of PCB126 to induce CYP11B1- and CYP11B2-mediated steroidogenesis.« less

Bioavailability of potassium from potatoes and potassium gluconate: a randomized dose response trial.

PubMed

Macdonald-Clarke, Claire J; Martin, Berdine R; McCabe, Linda D; McCabe, George P; Lachcik, Pamela J; Wastney, Meryl; Weaver, Connie M

2016-08-01

The bioavailability of potassium should be considered in setting requirements, but to our knowledge, the bioavailability from individual foods has not been determined. Potatoes provide 19-20% of potassium in the American diet. We compared the bioavailability and dose response of potassium from nonfried white potatoes with skin [targeted at 20, 40, and 60 milliequivalents (mEq) K] and French fries (40 mEq K) with potassium gluconate at the same doses when added to a basal diet that contained ∼60 mEq K. Thirty-five healthy, normotensive men and women with a mean ± SD age of 29.7 ± 11.2 y and body mass index (in kg/m(2)) of 24.3 ± 4.4 were enrolled in a single-blind, crossover, randomized controlled trial. Participants were partially randomly assigned to the order of testing for nine 5-d interventions of additional potassium as follows: 0 (control; repeated at phases 1 and 5), 20, 40, and 60 mEq K/d consumed as a potassium gluconate supplement or as unfried potato or 40 mEq K from French fries completed at phase 9. The bioavailability of potassium was determined from the area under the curve (AUC) of serial blood draws and cumulative urinary excretion during a 24-h period and from a kinetic analysis. The effects of the potassium source and dose on the change in blood pressure and augmentation index (AIx) were determined. The serum potassium AUC increased with the dose (P < 0.0001) and did not differ because of the source (P = 0.53). Cumulative 24-h urinary potassium also increased with the dose (P < 0.0001) and was greater with the potato than with the supplement (P < 0.0001). The kinetic analysis showed the absorption efficiency was high across all interventions (>94% ± 12%). There were no significant differences in the change in blood pressure or AIx with the treatment source or dose. The bioavailability of potassium is as high from potatoes as from potassium gluconate supplements. Future studies that measure the effect of dietary potassium on blood pressure

Oral potassium supplementation in surgical patients.

PubMed

Hainsworth, Alison J; Gatenby, Piers A

2008-08-01

Hospital inpatients are frequently hypokalaemic. Low plasma potassium levels may cause life threatening complications, such as cardiac arrhythmias. Potassium supplementation may be administered parenterally or enterally. Oral potassium supplements have been associated with oesophageal ulceration, strictures and gastritis. An alternative to potassium salt tablets or solution is dietary modification with potassium rich food stuffs, which has been proven to be a safe and effective method for potassium supplementation. The potassium content of one medium banana is equivalent to a 12 mmol potassium salt tablet. Potassium supplementation by dietary modification has been shown to be equally efficacious to oral potassium salt supplementation and is preferred by the majority of patients. Subsequently, it is our practice to replace potassium using dietary modification, particularly in surgical patients having undergone oesophagogastrectomy or in those with peptic ulcer disease.

Loss of Sodium-Activated Potassium Channel Slack and FMRP Differentially Affect Social Behavior in Mice.

PubMed

Bausch, Anne E; Ehinger, Rebekka; Straubinger, Julia; Zerfass, Patrick; Nann, Yvette; Lukowski, Robert

2018-05-31

The sodium-activated potassium channel Slack (Slo2.2) is widely expressed in central and peripheral neurons where it is supposed to shape firing properties important for neuronal excitability. Slack activity is enhanced by interaction with the Fragile-X-Mental-Retardation-Protein (FMRP) and loss of FMRP leads to decreased sodium-activated potassium currents in medial nucleus of the trapezoid body neurons of the Fmr1-knockout (KO) mouse representing a mouse model of the human Fragile-X-Syndrome (FXS) and autism. Autism is a frequent comorbidity of FXS, but it is unclear whether Slack is involved in autistic or related conditions of FXS in vivo. By applying a wide range of behavioral tests, we compared social and autism-related behaviors in Slack- and FMRP-deficient mice. In our hands, as expected, FMRP-deficiency causes autism-related behavioral changes in nesting and in a marble-burying test. In contrast, Slack-deficient males exhibited specific abnormalities in sociability in direct and indirect social interaction tests. Hence, we show for the first time that a proper Slack channel function is mandatory for normal social behavior in mice. Nevertheless, as deficits in social behaviors seem to occur independently from each other in FMRP and Slack null mutants, we conclude that Slack is not involved in the autistic phenotype of FMRP KO mice. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

A new pH-sensitive rectifying potassium channel in mitochondria from the embryonic rat hippocampus.

PubMed

Kajma, Anna; Szewczyk, Adam

2012-10-01

Patch-clamp single-channel studies on mitochondria isolated from embryonic rat hippocampus revealed the presence of two different potassium ion channels: a large-conductance (288±4pS) calcium-activated potassium channel and second potassium channel with outwardly rectifying activity under symmetric conditions (150/150mM KCl). At positive voltages, this channel displayed a conductance of 67.84pS and a strong voltage dependence at holding potentials from -80mV to +80mV. The open probability was higher at positive than at negative voltages. Patch-clamp studies at the mitoplast-attached mode showed that the channel was not sensitive to activators and inhibitors of mitochondrial potassium channels but was regulated by pH. Moreover, we demonstrated that the channel activity was not affected by the application of lidocaine, an inhibitor of two-pore domain potassium channels, or by tertiapin, an inhibitor of inwardly rectifying potassium channels. In summary, based on the single-channel recordings, we characterised for the first time mitochondrial pH-sensitive ion channel that is selective for cations, permeable to potassium ions, displays voltage sensitivity and does not correspond to any previously described potassium ion channels in the inner mitochondrial membrane. This article is part of a Special Issue entitled: 17th European Bioenergetics Conference (EBEC 2012). Copyright © 2012 Elsevier B.V. All rights reserved.

High levels of potassium inside tumors suppress immune activity | Center for Cancer Research

Cancer.gov

Nicholas P. Restifo, a senior investigator in CCR’s Surgery Branch and his team have discovered that an abundance of potassium inside tumors dampens immune responses, helping the tumors evade the body’s defenses. In animal experiments, genetically equipping immune cells rid themselves of potassium made them more effective at fighting cancer. The finding, published September

Physiology and pathophysiology of potassium homeostasis.

PubMed

Palmer, Biff F; Clegg, Deborah J

2016-12-01

Total body potassium content and proper distribution of potassium across the cell membrane is of critical importance for normal cellular function. Potassium homeostasis is maintained by several different methods. In the kidney, total body potassium content is achieved by alterations in renal excretion of potassium in response to variations in intake. Insulin and beta-adrenergic tone play critical roles in maintaining the internal distribution of potassium under normal conditions. Despite homeostatic pathways designed to maintain potassium levels within the normal range, disorders of altered potassium homeostasis are common. The clinical approach to designing effective treatments relies on understanding the pathophysiology and regulatory influences which govern the internal distribution and external balance of potassium. Here we provide an overview of the key regulatory aspects of normal potassium physiology. This review is designed to provide an overview of potassium homeostasis as well as provide references of seminal papers to guide the reader into a more in depth discussion of the importance of potassium balance. This review is designed to be a resource for educators and well-informed clinicians who are teaching trainees about the importance of potassium balance. Copyright © 2016 the American Physiological Society.

Potassium: friend or foe?

PubMed

Rodan, Aylin R

2017-07-01

The kidney plays an essential role in maintaining homeostasis of ion concentrations in the blood. Because the concentration gradient of potassium across the cell membrane is a key determinant of the membrane potential of cells, even small deviations in serum potassium level from the normal setpoint can lead to severe muscle dysfunction, resulting in respiratory failure and cardiac arrest. Less severe hypo- and hyperkalemia are also associated with morbidity and mortality across various patient populations. In addition, deficiencies in potassium intake have been associated with hypertension and adverse cardiovascular and renal outcomes, likely due in part to the interrelated handling of sodium and potassium by the kidney. Here, data on the beneficial effects of potassium on blood pressure and cardiovascular and renal outcomes will be reviewed, along with the physiological basis for these effects. In some patient populations, however, potassium excess is deleterious. Risk factors for the development of hyperkalemia will be reviewed, as well as the risks and benefits of existing and emerging therapies for hyperkalemia.

Chronic potassium depletion increases adrenal progesterone production that is necessary for efficient renal retention of potassium.

PubMed

Elabida, Boutaïna; Edwards, Aurélie; Salhi, Amel; Azroyan, Anie; Fodstad, Heidi; Meneton, Pierre; Doucet, Alain; Bloch-Faure, May; Crambert, Gilles

2011-08-01

Modern dietary habits are characterized by high-sodium and low-potassium intakes, each of which was correlated with a higher risk for hypertension. In this study, we examined whether long-term variations in the intake of sodium and potassium induce lasting changes in the plasma concentration of circulating steroids by developing a mathematical model of steroidogenesis in mice. One finding of this model was that mice increase their plasma progesterone levels specifically in response to potassium depletion. This prediction was confirmed by measurements in both male mice and men. Further investigation showed that progesterone regulates renal potassium handling both in males and females under potassium restriction, independent of its role in reproduction. The increase in progesterone production by male mice was time dependent and correlated with decreased urinary potassium content. The progesterone-dependent ability to efficiently retain potassium was because of an RU486 (a progesterone receptor antagonist)-sensitive stimulation of the colonic hydrogen, potassium-ATPase (known as the non-gastric or hydrogen, potassium-ATPase type 2) in the kidney. Thus, in males, a specific progesterone concentration profile induced by chronic potassium restriction regulates potassium balance.

Time to Consider Use of the Sodium-to-Potassium Ratio for Practical Sodium Reduction and Potassium Increase

PubMed Central

Miura, Katsuyuki; Ueshima, Hirotsugu

2017-01-01

Pathogenetic studies have demonstrated that the interdependency of sodium and potassium affects blood pressure. Emerging evidences on the sodium-to-potassium ratio show benefits for a reduction in sodium and an increase in potassium compared to sodium and potassium separately. As presently there is no known review, this article examined the practical use of the sodium-to-potassium ratio in daily practice. Epidemiological studies suggest that the urinary sodium-to-potassium ratio may be a superior metric as compared to separate sodium and potassium values for determining the relation to blood pressure and cardiovascular disease risks. Higher correlations and better agreements are seen for the casual urine sodium-to-potassium ratio than for casual urine sodium or potassium alone when compared with the 24-h urine values. Repeated measurements of the casual urine provide reliable estimates of the 7-day 24-h urine value with less bias for the sodium-to-potassium ratio as compared to the common formulas used for estimating the single 24-h urine from the casual urine for sodium and potassium separately. Self-monitoring devices for the urinary sodium-to-potassium ratio measurement makes it possible to provide prompt onsite feedback. Although these devices have been evaluated with a view to support an individual approach for sodium reduction and potassium increase, there has yet to be an accepted recommended guideline for the sodium-to-potassium ratio. This review concludes with a look at the practical use of the sodium-to-potassium ratio for assistance in practical sodium reduction and potassium increase. PMID:28678188

Crystal structure transformation in potassium acrylate

NASA Astrophysics Data System (ADS)

Pai Verneker, V. R.; Vasanthakumari, R.

1983-10-01

Potassium acrylate undergoes a reversible phase transformation around 335°K with an activation energy of 133 kcal/mole. Differential scanning calorimetry and high temperature X-ray powder diffraction techniques have been used to probe this phenomenon.

Low potassium level

MedlinePlus

... of low potassium level include: Medicines, such as diuretics (water pills), certain antibiotics Diarrhea or vomiting Using ... potassium through a vein (IV). If you need diuretics, your provider may: Switch you to a form ...

Penicillin V Potassium

MedlinePlus

Penicillin V potassium is used to treat certain infections caused by bacteria such as pneumonia and other ... heart valves and other symptoms) from coming back. Penicillin V potassium is in a class of medications ...

21 CFR 184.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium bicarbonate. 184.1613 Section 184.1613... Listing of Specific Substances Affirmed as GRAS § 184.1613 Potassium bicarbonate. (a) Potassium... potassium hydroxide with carbon dioxide; (2) By treating a solution of potassium carbonate with carbon...

21 CFR 184.1619 - Potassium carbonate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium carbonate. 184.1619 Section 184.1619... Listing of Specific Substances Affirmed as GRAS § 184.1619 Potassium carbonate. (a) Potassium carbonate... of potassium chloride followed by exposing the resultant potassium to carbon dioxide; (2) By treating...

21 CFR 184.1619 - Potassium carbonate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium carbonate. 184.1619 Section 184.1619... Listing of Specific Substances Affirmed as GRAS § 184.1619 Potassium carbonate. (a) Potassium carbonate... of potassium chloride followed by exposing the resultant potassium to carbon dioxide; (2) By treating...

21 CFR 184.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium bicarbonate. 184.1613 Section 184.1613... Listing of Specific Substances Affirmed as GRAS § 184.1613 Potassium bicarbonate. (a) Potassium... potassium hydroxide with carbon dioxide; (2) By treating a solution of potassium carbonate with carbon...

21 CFR 184.1619 - Potassium carbonate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium carbonate. 184.1619 Section 184.1619... Listing of Specific Substances Affirmed as GRAS § 184.1619 Potassium carbonate. (a) Potassium carbonate... of potassium chloride followed by exposing the resultant potassium to carbon dioxide; (2) By treating...

21 CFR 184.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium bicarbonate. 184.1613 Section 184.1613... Listing of Specific Substances Affirmed as GRAS § 184.1613 Potassium bicarbonate. (a) Potassium... potassium hydroxide with carbon dioxide; (2) By treating a solution of potassium carbonate with carbon...

21 CFR 184.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium bicarbonate. 184.1613 Section 184.1613... Listing of Specific Substances Affirmed as GRAS § 184.1613 Potassium bicarbonate. (a) Potassium... potassium hydroxide with carbon dioxide; (2) By treating a solution of potassium carbonate with carbon...

21 CFR 184.1631 - Potassium hydroxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium hydroxide. 184.1631 Section 184.1631... GRAS § 184.1631 Potassium hydroxide. (a) Potassium hydroxide (KOH, CAS Reg. No. 1310-58-3) is also... powders. Potassium hydroxide is obtained commercially from the electrolysis of potassium chloride solution...

21 CFR 172.800 - Acesulfame potassium.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acesulfame potassium. 172.800 Section 172.800 Food... Multipurpose Additives § 172.800 Acesulfame potassium. Acesulfame potassium (CAS Reg. No. 55589-62-3), also... not preclude such use, under the following conditions: (a) Acesulfame potassium is the potassium salt...

21 CFR 172.800 - Acesulfame potassium.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acesulfame potassium. 172.800 Section 172.800 Food... Multipurpose Additives § 172.800 Acesulfame potassium. Acesulfame potassium (CAS Reg. No. 55589-62-3), also... not preclude such use, under the following conditions: (a) Acesulfame potassium is the potassium salt...

21 CFR 172.800 - Acesulfame potassium.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acesulfame potassium. 172.800 Section 172.800 Food... Multipurpose Additives § 172.800 Acesulfame potassium. Acesulfame potassium (CAS Reg. No. 55589-62-3), also... not preclude such use, under the following conditions: (a) Acesulfame potassium is the potassium salt...

21 CFR 172.800 - Acesulfame potassium.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acesulfame potassium. 172.800 Section 172.800 Food... Multipurpose Additives § 172.800 Acesulfame potassium. Acesulfame potassium (CAS Reg. No. 55589-62-3), also... not preclude such use, under the following conditions: (a) Acesulfame potassium is the potassium salt...

Active biodegradable films produced with blends of rice flour and poly(butylene adipate co-terephthalate): effect of potassium sorbate on film characteristics.

PubMed

Sousa, G M; Soares Júnior, M S; Yamashita, F

2013-08-01

The objective of work was to produce and characterize biodegradable films from rice flour, poly(butylene adipate co-terephthalate) (PBAT), glycerol and potassium sorbate, for application as active packaging for fresh lasagna pasta. The films were evaluated with respect to their optical, water vapor barrier, mechanical and microstructural properties. The mechanical properties and microstructure were evaluated after use as packaging material for fresh pasta for 45 days at 7°C. The blends of rice flour, PBAT, glycerol and potassium sorbate showed good processability and allowed for the pilot scale production of films by blow extrusion process. The addition of 1 to 5% potassium sorbate as plasticizer agent of films in place of glycerol did not alter the film mechanical properties and a sorbate concentration greater or equal than 3% reduced the opacity, although increasing the water vapor permeability. The films could be used as active packaging for fresh food pasta, since they remained integral and easy to handle after application. The rice flour was shown to be an excellent material for the formulation of biodegradable films, since it is a low-cost raw material from a renewable source. The addition of potassium sorbate did not affect the extrusion process, and could be used in the production of packaging for use with foods. Copyright © 2013 Elsevier B.V. All rights reserved.

Coupling of activation and inactivation gate in a K+-channel: potassium and ligand sensitivity

PubMed Central

Ader, Christian; Schneider, Robert; Hornig, Sönke; Velisetty, Phanindra; Vardanyan, Vitya; Giller, Karin; Ohmert, Iris; Becker, Stefan; Pongs, Olaf; Baldus, Marc

2009-01-01

Potassium (K+)-channel gating is choreographed by a complex interplay between external stimuli, K+ concentration and lipidic environment. We combined solid-state NMR and electrophysiological experiments on a chimeric KcsA–Kv1.3 channel to delineate K+, pH and blocker effects on channel structure and function in a membrane setting. Our data show that pH-induced activation is correlated with protonation of glutamate residues at or near the activation gate. Moreover, K+ and channel blockers distinctly affect the open probability of both the inactivation gate comprising the selectivity filter of the channel and the activation gate. The results indicate that the two gates are coupled and that effects of the permeant K+ ion on the inactivation gate modulate activation-gate opening. Our data suggest a mechanism for controlling coordinated and sequential opening and closing of activation and inactivation gates in the K+-channel pore. PMID:19661921

Potassium supplements for oral diarrhoea regimens.

PubMed

Clements, M L; Levine, M M; Black, R E; Hughes, T P; Rust, J; Tome, F C

1980-10-18

A study is proposed for supplementing potassium loss from diarrhea in rehydration therapies with fresh fruit and other naturally potassium-rich foods. Bananas contain .1 mol of potassium per gm. Freshly squeezed lemon or orange juices were tested for potassium and sodium content and found to have very low potassium concentration. Therefore, the banana was chosen for an upcoming study that will determine if infants and children suffering from diarrhea can ingest the amounts of the fruit necessary to elevate the potassium level sufficiently. Bananas as the potassium source are thought to be well-accepted in developing areas.

21 CFR 184.1619 - Potassium carbonate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium carbonate. 184.1619 Section 184.1619 Food... Specific Substances Affirmed as GRAS § 184.1619 Potassium carbonate. (a) Potassium carbonate (K2CO3, CAS... potassium chloride followed by exposing the resultant potassium to carbon dioxide; (2) By treating a...

21 CFR 184.1634 - Potassium iodide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium iodide. 184.1634 Section 184.1634 Food... GRAS § 184.1634 Potassium iodide. (a) Potassium iodide (KI, CAS Reg. No. 7681-11-0) is the potassium... reacting hydriodic acid (HI) with potassium bicarbonate (KHCO3). (b) The ingredient meets the...

21 CFR 184.1610 - Potassium alginate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium alginate. 184.1610 Section 184.1610 Food... GRAS § 184.1610 Potassium alginate. (a) Potassium alginate (CAS Reg. No. 9005-36-1) is the potassium salt of alginic acid, a natural polyuronide constituent of certain brown algae. Potassium alginate is...

21 CFR 184.1643 - Potassium sulfate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium sulfate. 184.1643 Section 184.1643 Food... GRAS § 184.1643 Potassium sulfate. (a) Potassium sulfate (K2SO4, CAS Reg. No. 7778-80-5) occurs.... It is prepared by the neutralization of sulfuric acid with potassium hydroxide or potassium carbonate...

Effects of Potassium Sulfate [K2SO4] on The Element Contents, Polyphenol Content, Antioxidant and Antimicrobial Activities of Milk Thistle [Silybum Marianum].

PubMed

Yaldiz, Gulsum

2017-01-01

Silybum marianum L. (Milk thistle) is native to the Mediterranean basin and is now widespread throughout the world. It's sprout is used as a herbal medicine for the treatment of liver disease for centuries. The seeds of milk thistle contain silymarin, an isomeric mixture of flavonolignans [silybin, silychristin, and silydianin]. Silymarin acts as a strong anti-hepatotoxic. The objective of this study was to evaluate the influences of potassium sulfate [K 2 SO 4 ] fertilizer doses on polyphenol content, some nutrient elements, antioxidant and antimicrobial activities of milk thistle at experimental fields of Ordu University in Turkey. The antimicrobial activities of seed ethanol extracts and seed oil were tested in vitro against Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli, (E. coli) Staphylococcus aureus (S. aureus), Aspergillus niger (A. niger) and Candida albicans (C. albicans) using the disc diffusion method. Free radical scavenging activity of the ethanolic extracts of milk thistle was determined spectrophotometrically by monitoring the disappearance of 2, 2-diphenyl-1-picrylhydrazil (DPPH•) at 517 nm according to the method described by Brand-Williams et al .[17] The phenolic contents in the ethanolic extracts of milk thistle were determined according to the procedure described by Slinkard and Singleton[19] with a slight modification of using a Folin-Ciocalteu phenolic reagent. The amount of total flavonoid in the ethanolic extracts was measured by aluminum chloride [AlCl 3 ] colorimetric assay. The ions in aerosol samples were determined by using Dionex ICS 1100 Series ion chromatography. Seed and seed oils obtained from obvious doses of potassium sulfate [0, 30, 60, 90 and 120 kg ha -1 fertilizer applications showed antimicrobial activities against E. coli , A. niger and P. aeruginosa . The application of 90 kg ha -1 of K 2 SO 4 on seed oil resulted in the highest antimicrobial activities. At 100 µg mL -1 and 200 µg mL -1 , except the highest

Effects of Potassium Sulfate [K2SO4] on The Element Contents, Polyphenol Content, Antioxidant and Antimicrobial Activities of Milk Thistle [Silybum Marianum

PubMed Central

Yaldiz, Gulsum

2017-01-01

Background: Silybum marianum L. (Milk thistle) is native to the Mediterranean basin and is now widespread throughout the world. It's sprout is used as a herbal medicine for the treatment of liver disease for centuries. The seeds of milk thistle contain silymarin, an isomeric mixture of flavonolignans [silybin, silychristin, and silydianin]. Silymarin acts as a strong anti-hepatotoxic. Objectives: The objective of this study was to evaluate the influences of potassium sulfate [K2SO4] fertilizer doses on polyphenol content, some nutrient elements, antioxidant and antimicrobial activities of milk thistle at experimental fields of Ordu University in Turkey. Methods: The antimicrobial activities of seed ethanol extracts and seed oil were tested in vitro against Pseudomonas aeruginosa (P. aeruginosa), Escherichia coli, (E. coli) Staphylococcus aureus (S. aureus), Aspergillus niger (A. niger) and Candida albicans (C. albicans) using the disc diffusion method. Free radical scavenging activity of the ethanolic extracts of milk thistle was determined spectrophotometrically by monitoring the disappearance of 2, 2-diphenyl-1-picrylhydrazil (DPPH•) at 517 nm according to the method described by Brand-Williams et al.[17] The phenolic contents in the ethanolic extracts of milk thistle were determined according to the procedure described by Slinkard and Singleton[19] with a slight modification of using a Folin-Ciocalteu phenolic reagent. The amount of total flavonoid in the ethanolic extracts was measured by aluminum chloride [AlCl3] colorimetric assay. The ions in aerosol samples were determined by using Dionex ICS 1100 Series ion chromatography. Results: Seed and seed oils obtained from obvious doses of potassium sulfate [0, 30, 60, 90 and 120 kg ha -1 fertilizer applications showed antimicrobial activities against E. coli, A. niger and P. aeruginosa. The application of 90 kg ha -1 of K2SO4 on seed oil resulted in the highest antimicrobial activities. At 100 µg mL-1 and 200

Hyperkalemia (High Potassium)

MedlinePlus

Symptoms High potassium (hyperkalemia) By Mayo Clinic Staff Hyperkalemia is the medical term that describes a potassium level in your blood that's higher ... medications or dialysis. If you have symptoms of hyperkalemia, particularly if you have kidney disease or are ...

21 CFR 172.800 - Acesulfame potassium.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acesulfame potassium. 172.800 Section 172.800 Food... Acesulfame potassium. Acesulfame potassium (CAS Reg. No. 55589-62-3), also known as acesulfame K, may be... following conditions: (a) Acesulfame potassium is the potassium salt of 6-methyl-1,2,3-oxathiazine-4(3H)-one...

Potassium channels and prostacyclin contribute to vasorelaxant activities of Tridax procumbens crude aqueous leaf extract in rat superior mesenteric arteries.

PubMed

Salahdeen, H M; Adebari, A O; Murtala, B A; Alada, A R A

2015-03-01

Previous studies have shown that aqueous extract of the leaf of Tridax procuinbens is capable of lowering blood pressure through its vasodilatory effects. In the present study attempt was made to examine the biological active components of T procuinbens leaf using GC-MS methods. We further investigated the role of K+ channels in the vasorelaxation effects of Tridax procumbens using rat isolated mesenteric artery. The superior mesenteric artery isolated from healthy, young adult Wistar rats (250-300 g) were precontracted with phenylephrine (PE) (10(-7) M) and potassium chloride (KCl) (60 mM) and were treated with Various concentrations of aqueous extract ofT procumbens (0.9.0 mg/ml). The changes in arterial tension were recorded using a force-displacement transducer (Model 7004; Ugo Basil Varese, Italy) coupled to data capsule acquisition system. The results of GG-MS revealed the presence of linoleic acid. The T. procumbens extract (TPE) ranging from 0.5-9.0 mg/mI significantly (p<0.05) reduced the, contraction induced by (PE) and (KCl) in a concentration-dependent manner. The extract also antagonised the calcium-induced vasoconstriction (1(-9) - 10(-5)) in calcium-free with high concentration of potassium as well as. in calcium- and potassium free physiological solutions. The vasorelaxing effect caused by TPE was significantly (p<0.05) attenuated with preincubation of potassium channels blockers (Barium chloride and apamin), NO synthaseinhibitor (L-NAME), prostacyclin inhibitor (indomethacin), atropine; propranolol, and methylene blue while it was not affected by preincubation with glibenclamide and tetra ethyl ammonium, 4-aminopyridine (4-AP) and oxadiazolo quinoxalin (ODQ). The results of this study demonstrate that T procumbens extract causes vasodilatory effects by blocking calcium channels and the vasodilatory effect of the extract may also be due to stimulation of prostacyclin production and opening of small-conductance Ga2+ activated potassium channels. The

High levels of potassium inside tumors suppress immune activity | Center for Cancer Research

Cancer.gov

Nicholas P. Restifo, a senior investigator in CCR’s Surgery Branch and his team have discovered that an abundance of potassium inside tumors dampens immune responses, helping the tumors evade the body’s defenses. In animal experiments, genetically equipping immune cells rid themselves of potassium made them more effective at fighting cancer. The finding, published September 14, 2016, in the journal Nature, suggests a tactic for improving the effectiveness of cancer immunotherapies.  Learn more...

Effect of polacrilin potassium as disintegrant on bioavailability of diclofenac potassium in tablets : a technical note.

PubMed

Bele, Mrudula H; Derle, Diliprao V

2012-09-01

Polacrilin potassium is an ion exchange resin used in oral pharmaceutical formulations as a tablet disintegrant. It is a weakly acidic cation exchange resin. Chemically, it is a partial potassium salt of a copolymer of methacrylic acid with divinyl benzene. It ionizes to an anionic polymer chain and potassium cations. It was hypothesized that polacrilin potassium may be able to improve the permeability of anionic drugs according to the Donnan membrane phenomenon. The effect of polacrilin potassium on the permeability of diclofenac potassium, used as a model anionic drug, was tested in vitro using diffusion cells and in vivo by monitoring serum levels in rats. The amount of drug permeated across a dialysis membrane in vitro was significantly more in the presence of polacrilin potassium. Significant improvement was found in the extent of drug absorption in vivo. It could be concluded that polacrilin potassium may be used as a high-functionality excipient for improving the bioavailability of anionic drugs having poor gastrointestinal permeability.

21 CFR 184.1625 - Potassium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium citrate. 184.1625 Section 184.1625 Food... GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing citric acid with potassium...

Oxidation kinetics of crystal violet by potassium permanganate in acidic medium

NASA Astrophysics Data System (ADS)

Khan, Sameera Razi; Ashfaq, Maria; Mubashir; Masood, Summyia

2016-05-01

The oxidation kinetics of crystal violet (a triphenylmethane dye) by potassium permanganate was focused in an acidic medium by the spectrophotometric method at 584 nm. The oxidation reaction of crystal violet by potassium permanganate is carried out in an acidic medium at different temperatures ranging within 298-318 K. The kinetic study was carried out to investigate the effect of the concentration, ionic strength and temperature. The reaction followed first order kinetics with respect to potassium permanganate and crystal violet and the overall rate of the reaction was found to be second order. Thermodynamic activation parameters like the activation energy ( E a), enthalpy change (Δ H*), free energy change (Δ G*), and entropy change (Δ S*) have also been evaluated.

Molecular mechanism underlying ethanol activation of G-protein–gated inwardly rectifying potassium channels

PubMed Central

Bodhinathan, Karthik; Slesinger, Paul A.

2013-01-01

Alcohol (ethanol) produces a wide range of pharmacological effects on the nervous system through its actions on ion channels. The molecular mechanism underlying ethanol modulation of ion channels is poorly understood. Here we used a unique method of alcohol-tagging to demonstrate that alcohol activation of a G-protein–gated inwardly rectifying potassium (GIRK or Kir3) channel is mediated by a defined alcohol pocket through changes in affinity for the membrane phospholipid signaling molecule phosphatidylinositol 4,5-bisphosphate. Surprisingly, hydrophobicity and size, but not the canonical hydroxyl, were important determinants of alcohol-dependent activation. Altering levels of G protein Gβγ subunits, conversely, did not affect alcohol-dependent activation, suggesting a fundamental distinction between receptor and alcohol gating of GIRK channels. The chemical properties of the alcohol pocket revealed here might extend to other alcohol-sensitive proteins, revealing a unique protein microdomain for targeting alcohol-selective therapeutics in the treatment of alcoholism and addiction. PMID:24145411

Potassium and zinc increase tolerance to salt stress in wheat (Triticum aestivum L.).

PubMed

Jan, Amin Ullah; Hadi, Fazal; Midrarullah; Nawaz, Muhammad Asif; Rahman, Khaista

2017-07-01

Potassium and zinc are essential elements in plant growth and metabolism and plays a vital role in salt stress tolerance. To investigate the physiological mechanism of salt stress tolerance, a pot experiment was conducted. Potassium and zinc significantly minimize the oxidative stress and increase root, shoot and spike length in wheat varieties. Fresh and dry biomass were significantly increased by potassium followed by zinc as compared to control C. The photosynthetic pigment and osmolyte regulator (proline, total phenolic, and total carbohydrate) were significantly enhanced by potassium and zinc. Salt stress increases MDA content in wheat varieties while potassium and zinc counteract the adverse effect of salinity and significantly increased membrane stability index. Salt stress decreases the activities of antioxidant enzymes (superoxide dismutase, catalase and ascorbate peroxidase) while the exogenous application of potassium and zinc significantly enhanced the activities of these enzymes. A significant positive correlation was found of spike length with proline (R 2  = 0.966 ∗∗∗ ), phenolic (R 2  = 0.741 ∗ ) and chlorophyll (R 2  = 0.853 ∗∗ ). The MDA content showed significant negative correlation (R 2  = 0.983 ∗∗∗ ) with MSI. It is concluded that potassium and zinc reduced toxic effect of salinity while its combine application showed synergetic effect and significantly enhanced salt tolerance. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

21 CFR 184.1631 - Potassium hydroxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium hydroxide. 184.1631 Section 184.1631... Listing of Specific Substances Affirmed as GRAS § 184.1631 Potassium hydroxide. (a) Potassium hydroxide..., including pellets, flakes, sticks, lumps, and powders. Potassium hydroxide is obtained commercially from the...

21 CFR 184.1631 - Potassium hydroxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium hydroxide. 184.1631 Section 184.1631... Listing of Specific Substances Affirmed as GRAS § 184.1631 Potassium hydroxide. (a) Potassium hydroxide..., including pellets, flakes, sticks, lumps, and powders. Potassium hydroxide is obtained commercially from the...

Kinetic studies of potassium permanganate adsorption by activated carbon and its ability as ethylene oxidation material

NASA Astrophysics Data System (ADS)

Aprilliani, F.; Warsiki, E.; Iskandar, A.

2018-03-01

Generally, ethylene production in many horticultural products has been seen to be detrimental to the quality during storage and distribution process. For this reason, removing ethylene from storage or distribution atmosphere is needed to maintain the quality. One of the technologies that can be applied is the use of potassium permanganate (KMnO4). KMnO4 is an active compound that can be used as an oxidizing agent on ethylene removal process. KMnO4 is not recommended for direct used application. As the result, additional material is required to impregnate the potassium permanganate. The inert materials used are commercial activated carbon. Activated carbon is chosen because it has high surface area. The purpose of this research is to determine kinetics adsorption and oxidation model of ethylene removal material. The kinetics adsorption was determined using the pseudo-first and second-order kinetic models. The data on adsorption process show that the second-order equation is more suitable to express the adsorption process on this research. The analyzing of the ethylene oxidation capacity increased with time until it reaches an optimal value. The ethylene oxidation rate is able to be estimated by the formula r = 0.1967 [C2H4]0.99 [KMnO4]0.01; MSE = 0.44 %. The actual and estimation data of ethylene oxidation show that the model is fitted to describe the actual ethylene oxidation under same experimental conditions.

21 CFR 184.1622 - Potassium chloride.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium chloride. 184.1622 Section 184.1622 Food... Specific Substances Affirmed as GRAS § 184.1622 Potassium chloride. (a) Potassium chloride (KCl, CAS Reg... levels not to exceed current good manufacturing practice. Potassium chloride may be used in infant...

21 CFR 184.1622 - Potassium chloride.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium chloride. 184.1622 Section 184.1622 Food... Specific Substances Affirmed as GRAS § 184.1622 Potassium chloride. (a) Potassium chloride (KCl, CAS Reg... levels not to exceed current good manufacturing practice. Potassium chloride may be used in infant...

Synthesis, characterization, thermal and explosive properties of potassium salts of trinitrophloroglucinol.

PubMed

Wang, Liqiong; Chen, Hongyan; Zhang, Tonglai; Zhang, Jianguo; Yang, Li

2007-08-17

Three different substituted potassium salts of trinitrophloroglucinol (H(3)TNPG) were prepared and characterized. The salts are all hydrates, and thermogravimetric analysis (TG) and elemental analysis confirmed that these salts contain crystal H2O and that the amount crystal H2O in potassium salts of H3TNPG is 1.0 hydrate for mono-substituted potassium salts of H3TNPG [K(H2TNPG)] and di-substituted potassium salt of H3TNPG [K2(HTNPG)], and 2.0 hydrate for tri-substituted potassium salt of H3TNPG [K3(TNPG)]. Their thermal decomposition mechanisms and kinetic parameters from 50 to 500 degrees C were studied under a linear heating rate by differential scanning calorimetry (DSC). Their thermal decomposition mechanisms undergo dehydration stage and intensive exothermic decomposition stage. FT-IR and TG studies verify that their final residua of decomposition are potassium cyanide or potassium carbonate. According to the onset temperature of the first exothermic decomposition process of dehydrated salts, the order of the thermal stability from low to high is from K(H2TNPG) and K2(HTNPG) to K3(TNPG), which is conform to the results of apparent activation energy calculated by Kissinger's and Ozawa-Doyle's method. Sensitivity test results showed that potassium salts of H3TNPG demonstrated higher sensitivity properties and had greater explosive probabilities.

21 CFR 184.1610 - Potassium alginate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium alginate. 184.1610 Section 184.1610 Food... Specific Substances Affirmed as GRAS § 184.1610 Potassium alginate. (a) Potassium alginate (CAS Reg. No. 9005-36-1) is the potassium salt of alginic acid, a natural polyuronide constituent of certain brown...

21 CFR 172.375 - Potassium iodide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium iodide. 172.375 Section 172.375 Food and... Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be safely used in accordance with the following prescribed conditions: (a) Potassium iodide may be safely...

21 CFR 184.1610 - Potassium alginate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium alginate. 184.1610 Section 184.1610 Food... Specific Substances Affirmed as GRAS § 184.1610 Potassium alginate. (a) Potassium alginate (CAS Reg. No. 9005-36-1) is the potassium salt of alginic acid, a natural polyuronide constituent of certain brown...

Dendritic small conductance calcium-activated potassium channels activated by action potentials suppress EPSPs and gate spike-timing dependent synaptic plasticity.

PubMed

Jones, Scott L; To, Minh-Son; Stuart, Greg J

2017-10-23

Small conductance calcium-activated potassium channels (SK channels) are present in spines and can be activated by backpropagating action potentials (APs). This suggests they may play a critical role in spike-timing dependent synaptic plasticity (STDP). Consistent with this idea, EPSPs in both cortical and hippocampal pyramidal neurons were suppressed by preceding APs in an SK-dependent manner. In cortical pyramidal neurons EPSP suppression by preceding APs depended on their precise timing as well as the distance of activated synapses from the soma, was dendritic in origin, and involved SK-dependent suppression of NMDA receptor activation. As a result SK channel activation by backpropagating APs gated STDP induction during low-frequency AP-EPSP pairing, with both LTP and LTD absent under control conditions but present after SK channel block. These findings indicate that activation of SK channels in spines by backpropagating APs plays a key role in regulating both EPSP amplitude and STDP induction.

Dietary Potassium: a Key Mediator of the Cardiovascular Response to Dietary Sodium Chloride

PubMed Central

Kanbay, Mehmet; Bayram, Yeter; Solak, Yalcin; Sanders, Paul W.

2014-01-01

Potassium and sodium share a yin/yang relationship in the regulation of blood pressure (BP). BP is directly associated with the total body sodium and negatively correlated with the total body potassium. Epidemiologic, experimental, and clinical studies have demonstrated that potassium is a significant regulator of BP and further improves cardiovascular outcomes. Hypertensive cardiovascular damage, stroke and stroke-related death are accelerated by salt intake but could be prevented by increased dietary potassium intake. The antihypertensive effect of potassium supplementation appears to occur through several mechanisms that include regulation of vascular sensitivity to catecholamines, promotion of natriuresis, limiting plasma renin activity, and improving endothelial function. In the absence of chronic kidney disease, the combined evidence supports a diet high in potassium content serves a vasculoprotective function, especially in the setting of salt-sensitive hypertension and prehypertension. PMID:23735420

21 CFR 184.1643 - Potassium sulfate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium sulfate. 184.1643 Section 184.1643 Food... Specific Substances Affirmed as GRAS § 184.1643 Potassium sulfate. (a) Potassium sulfate (K2SO4, CAS Reg... having a bitter, saline taste. It is prepared by the neutralization of sulfuric acid with potassium...

21 CFR 184.1619 - Potassium carbonate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium carbonate. 184.1619 Section 184.1619... GRAS § 184.1619 Potassium carbonate. (a) Potassium carbonate (K2CO3, CAS Reg. No. 584-08-7) is produced by the following methods of manufacture: (1) By electrolysis of potassium chloride followed by...

21 CFR 184.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium bicarbonate. 184.1613 Section 184.1613... GRAS § 184.1613 Potassium bicarbonate. (a) Potassium bicarbonate (KHCO3, CAS Reg. No. 298-14-6) is made by the following processes: (1) By treating a solution of potassium hydroxide with carbon dioxide; (2...

21 CFR 184.1643 - Potassium sulfate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium sulfate. 184.1643 Section 184.1643 Food... Specific Substances Affirmed as GRAS § 184.1643 Potassium sulfate. (a) Potassium sulfate (K2SO4, CAS Reg... having a bitter, saline taste. It is prepared by the neutralization of sulfuric acid with potassium...

21 CFR 184.1643 - Potassium sulfate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium sulfate. 184.1643 Section 184.1643 Food... Specific Substances Affirmed as GRAS § 184.1643 Potassium sulfate. (a) Potassium sulfate (K2SO4, CAS Reg... having a bitter, saline taste. It is prepared by the neutralization of sulfuric acid with potassium...

21 CFR 184.1643 - Potassium sulfate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium sulfate. 184.1643 Section 184.1643 Food... Specific Substances Affirmed as GRAS § 184.1643 Potassium sulfate. (a) Potassium sulfate (K2SO4, CAS Reg... having a bitter, saline taste. It is prepared by the neutralization of sulfuric acid with potassium...

Modification of activity-dependent increases in cerebellar blood flow by extracellular potassium in anaesthetized rats

PubMed Central

Caesar, Kirsten; Akgören, Nuran; Mathiesen, Claus; Lauritzen, Martin

1999-01-01

The hypothesis that potassium ions mediate activity-dependent increases of cerebral blood flow was examined in rat cerebellar cortex using ion-selective microelectrodes and laser-Doppler flowmetry. Increases of cerebellar blood flow (CeBF) and extracellular potassium concentration ([K+]o) were evoked by stimulation of parallel fibres and climbing fibres, and by microinjection of KCl into the cortex. For parallel fibre stimulation, there was a maximal increase in [K+]o to 6.3 ± 0.5 mm and in CeBF of 122 ± 11%. Climbing fibre stimulation gave a maximal increase in [K+]o to 4.4 ± 0.2 mm and in CeBF of 157 ± 20%. This indicates different maxima for [K+]o and CeBF, dependent on the afferent system activated. [K+]o and CeBF responses evoked by parallel or climbing fibre stimulation increased rapidly at the onset of stimulation, but exhibited different time courses during the remainder of the stimulation period and during return to baseline. Microinjections of KCl into the cortex increased [K+]o to levels comparable to those evoked by parallel fibre stimulation. The corresponding CeBF increases were the same as, or smaller than, for parallel fibre stimulation, and much smaller than for climbing fibre stimulation. This suggests that mediators other than [K+]o are important for activity-dependent cerebral blood flow increases. The present study showed that increased [K+]o is involved in CeBF regulation in the parallel fibre system, but is of limited importance for CeBF regulation in the climbing fibre system. The hypothesis that K+ is a major mediator of activity-dependent blood flow increases is probably not generally applicable to all brain regions and all types of neuronal stimulation. PMID:10517819

21 CFR 184.1634 - Potassium iodide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium iodide. 184.1634 Section 184.1634 Food... Specific Substances Affirmed as GRAS § 184.1634 Potassium iodide. (a) Potassium iodide (KI, CAS Reg. No. 7681-11-0) is the potassium salt of hydriodic acid. It occurs naturally in sea water and in salt...

21 CFR 184.1634 - Potassium iodide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium iodide. 184.1634 Section 184.1634 Food... Specific Substances Affirmed as GRAS § 184.1634 Potassium iodide. (a) Potassium iodide (KI, CAS Reg. No. 7681-11-0) is the potassium salt of hydriodic acid. It occurs naturally in sea water and in salt...

21 CFR 184.1635 - Potassium iodate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium iodate. 184.1635 Section 184.1635 Food... Specific Substances Affirmed as GRAS § 184.1635 Potassium iodate. (a) Potassium iodate (KIO3, CAS Reg. No. 7758-05-6) does not occur naturally but can be prepared by reacting iodine with potassium hydroxide. (b...

21 CFR 184.1635 - Potassium iodate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium iodate. 184.1635 Section 184.1635 Food... Specific Substances Affirmed as GRAS § 184.1635 Potassium iodate. (a) Potassium iodate (KIO3, CAS Reg. No. 7758-05-6) does not occur naturally but can be prepared by reacting iodine with potassium hydroxide. (b...

21 CFR 184.1635 - Potassium iodate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium iodate. 184.1635 Section 184.1635 Food... Specific Substances Affirmed as GRAS § 184.1635 Potassium iodate. (a) Potassium iodate (KIO3, CAS Reg. No. 7758-05-6) does not occur naturally but can be prepared by reacting iodine with potassium hydroxide. (b...

21 CFR 184.1634 - Potassium iodide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium iodide. 184.1634 Section 184.1634 Food... Specific Substances Affirmed as GRAS § 184.1634 Potassium iodide. (a) Potassium iodide (KI, CAS Reg. No. 7681-11-0) is the potassium salt of hydriodic acid. It occurs naturally in sea water and in salt...

21 CFR 184.1634 - Potassium iodide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium iodide. 184.1634 Section 184.1634 Food... Specific Substances Affirmed as GRAS § 184.1634 Potassium iodide. (a) Potassium iodide (KI, CAS Reg. No. 7681-11-0) is the potassium salt of hydriodic acid. It occurs naturally in sea water and in salt...

21 CFR 184.1635 - Potassium iodate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium iodate. 184.1635 Section 184.1635 Food... Specific Substances Affirmed as GRAS § 184.1635 Potassium iodate. (a) Potassium iodate (KIO3, CAS Reg. No. 7758-05-6) does not occur naturally but can be prepared by reacting iodine with potassium hydroxide. (b...

21 CFR 184.1622 - Potassium chloride.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium chloride. 184.1622 Section 184.1622 Food... GRAS § 184.1622 Potassium chloride. (a) Potassium chloride (KCl, CAS Reg. No. 7447-40-7) is a white... manufacturing practice. Potassium chloride may be used in infant formula in accordance with section 412(g) of...

21 CFR 184.1635 - Potassium iodate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium iodate. 184.1635 Section 184.1635 Food... GRAS § 184.1635 Potassium iodate. (a) Potassium iodate (KIO3, CAS Reg. No. 7758-05-6) does not occur naturally but can be prepared by reacting iodine with potassium hydroxide. (b) The ingredient meets the...

Why Your Mother Was Right: How Potassium Intake Reduces Blood Pressure.

PubMed

Ellison, David H; Terker, Andrew S

2015-01-01

Low potassium intake, common in western diets, increases blood pressure and enhances salt-sensitivity. Most humans in "Westernized" countries also consume excess salt. In studies using mice, we found that a high-salt, low-potassium diet activates the thiazide-sensitive Na-Cl cotransporter in the kidney. This effect led to sodium retention and increased blood pressure, and was dependent on plasma potassium. We postulated that this effect was mediated by changes in intracellular chloride caused by changes in membrane voltage. We developed a model in cultured cells permitting us to confirm this hypothesis. We then confirmed, using urinary exosomes, that dietary changes in normal humans, affect the thiazide-sensitive Na-Cl cotransporter in the same way. These data show that dietary potassium deficiency increases blood pressure largely by stimulating salt reabsorption along the distal nephron. They suggest that global efforts should focus on increasing potassium intake, which will attenuate the effects of high-salt diets.

Potassium channels in brain mitochondria.

PubMed

Bednarczyk, Piotr

2009-01-01

Potassium channels are the most widely distributed class of ion channels. These channels are transmembrane proteins known to play important roles in both normal and pathophysiological functions in all cell types. Various potassium channels are recognised as potential therapeutic targets in the treatment of Parkinson's disease, Alzheimer's disease, brain/spinal cord ischaemia and sepsis. In addition to their importance as therapeutic targets, certain potassium channels are known for their beneficial roles in anaesthesia, cardioprotection and neuroprotection. Some types of potassium channels present in the plasma membrane of various cells have been found in the inner mitochondrial membrane as well. Potassium channels have been proposed to regulate mitochondrial membrane potential, respiration, matrix volume and Ca(+) ion homeostasis. It has been proposed that mitochondrial potassium channels mediate ischaemic preconditioning in various tissues. However, the specificity of a pharmacological agents and the mechanisms underlying their effects on ischaemic preconditioning remain controversial. The following potassium channels from various tissues have been identified in the inner mitochondrial membrane: ATP-regulated (mitoK(ATP)) channel, large conductance Ca(2+)-regulated (mitoBK(Ca)) channel, intermediate conductance Ca(2+)-regulated (mitoIK(Ca)) channel, voltage-gated (mitoKv1.3 type) channel, and twin-pore domain (mitoTASK-3) channel. It has been shown that increased potassium flux into brain mitochondria induced by either the mitoK(ATP) channel or mitoBK(Ca) channel affects the beneficial effects on neuronal cell survival under pathological conditions. Recently, differential distribution of mitoBK(Ca) channels has been observed in neuronal mitochondria. These findings may suggest a neuroprotective role for the mitoBK(Ca) channel in specific brain structures. This minireview summarises current data on brain mitochondrial potassium channels and the efforts to identify

Unique chloride-sensing properties of WNK4 permit the distal nephron to modulate potassium homeostasis.

PubMed

Terker, Andrew S; Zhang, Chong; Erspamer, Kayla J; Gamba, Gerardo; Yang, Chao-Ling; Ellison, David H

2016-01-01

Dietary potassium deficiency activates thiazide-sensitive sodium chloride cotransport along the distal nephron. This may explain, in part, the hypertension and cardiovascular mortality observed in individuals who consume a low-potassium diet. Recent data suggest that plasma potassium affects the distal nephron directly by influencing intracellular chloride, an inhibitor of the with-no-lysine kinase (WNK)-Ste20p-related proline- and alanine-rich kinase (SPAK) pathway. As previous studies used extreme dietary manipulations, we sought to determine whether the relationship between potassium and NaCl cotransporter (NCC) is physiologically relevant and clarify the mechanisms involved. We report that modest changes in both dietary and plasma potassium affect NCC in vivo. Kinase assay studies showed that chloride inhibits WNK4 kinase activity at lower concentrations than it inhibits activity of WNK1 or WNK3. Also, chloride inhibited WNK4 within the range of distal cell chloride concentration. Mutation of a previously identified WNK chloride-binding motif converted WNK4 effects on SPAK from inhibitory to stimulatory in mammalian cells. Disruption of this motif in WNKs 1, 3, and 4 had different effects on NCC, consistent with the three WNKs having different chloride sensitivities. Thus, potassium effects on NCC are graded within the physiological range, which explains how unique chloride-sensing properties of WNK4 enable it to mediate effects of potassium on NCC in vivo. Copyright © 2015 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Crystal Structure of the Potassium Importing KdpFABC Membrane Complex

PubMed Central

Huang, Ching-Shin; Pedersen, Bjørn Panyella; Stokes, David Lloyd

2017-01-01

Cellular potassium import systems play a fundamental role in osmoregulation, pH homeostasis and membrane potential in all domains of life. In bacteria, the kdp operon encodes a four subunit potassium pump that maintains intracellular homeostasis as well as cell shape and turgor under conditions where potassium is limiting1. This membrane complex, called KdpFABC, has one channel-like subunit (KdpA) belonging to the Superfamily of Potassium Transporters and another pump-like subunit (KdpB) belonging to the Superfamily of P-type ATPases. Although there is considerable structural and functional information about members from both superfamilies, the mechanism by which uphill potassium transport through KdpA is coupled with ATP hydrolysis by KdpB remains poorly understood. Here we report the 2.9 Å X-ray structure of the complete Escherichia coli KdpFABC complex with a potassium ion within the selectivity filter of KdpA as well as a water molecule at a canonical cation site in the transmembrane domain of KdpB. The structure also reveals two structural elements that appear to mediate the coupling between these two subunits. Specifically, a protein-embedded tunnel runs between these potassium and water sites and a helix controlling the cytoplasmic gate of KdpA is linked to the phosphorylation domain of KdpB. Based on these observations, we propose an unprecedented mechanism that repurposes protein channel architecture for active transport across biomembranes. PMID:28636601

The large-conductance calcium-activated potassium channel holds the key to the conundrum of familial hypokalemic periodic paralysis

PubMed Central

Kim, Sung-Jo; Kang, Sun-Yang; Yi, Jin Woong; Kim, Seung-Min

2014-01-01

Purpose Familial hypokalemic periodic paralysis (HOKPP) is an autosomal dominant channelopathy characterized by episodic attacks of muscle weakness and hypokalemia. Mutations in the calcium channel gene, CACNA1S, or the sodium channel gene, SCN4A, have been found to be responsible for HOKPP; however, the mechanism that causes hypokalemia remains to be determined. The aim of this study was to improve the understanding of this mechanism by investigating the expression of calcium-activated potassium (KCa) channel genes in HOKPP patients. Methods We measured the intracellular calcium concentration with fura-2-acetoxymethyl ester in skeletal muscle cells of HOKPP patients and healthy individuals. We examined the mRNA and protein expression of KCa channel genes (KCNMA1, KCNN1, KCNN2, KCNN3, and KCNN4) in both cell types. Results Patient cells exhibited higher cytosolic calcium levels than normal cells. Quantitative reverse transcription polymerase chain reaction analysis showed that the mRNA levels of the KCa channel genes did not significantly differ between patient and normal cells. However, western blot analysis showed that protein levels of the KCNMA1 gene, which encodes KCa1.1 channels (also called big potassium channels), were significantly lower in the membrane fraction and higher in the cytosolic fraction of patient cells than normal cells. When patient cells were exposed to 50 mM potassium buffer, which was used to induce depolarization, the altered subcellular distribution of BK channels remained unchanged. Conclusion These findings suggest a novel mechanism for the development of hypokalemia and paralysis in HOKPP and demonstrate a connection between disease-associated mutations in calcium/sodium channels and pathogenic changes in nonmutant potassium channels. PMID:25379045

Dietary potassium: a key mediator of the cardiovascular response to dietary sodium chloride.

PubMed

Kanbay, Mehmet; Bayram, Yeter; Solak, Yalcin; Sanders, Paul W

2013-01-01

Potassium and sodium share a yin/yang relationship in the regulation of blood pressure (BP). BP is directly associated with the total body sodium and negatively correlated with the total body potassium. Epidemiologic, experimental, and clinical studies have shown that potassium is a significant regulator of BP and further improves cardiovascular outcomes. Hypertensive cardiovascular damage, stroke, and stroke-related death are accelerated by salt intake but might be curbed by increasing dietary potassium intake. The antihypertensive effect of potassium supplementation appears to occur through several mechanisms that include regulation of vascular sensitivity to catecholamines, promotion of natriuresis, limiting plasma renin activity, and improving endothelial function. In the absence of chronic kidney disease, the combined evidence suggests that a diet rich in potassium content serves a vasculoprotective function, particularly in the setting of salt-sensitive hypertension and prehypertension. Copyright © 2013 American Society of Hypertension. All rights reserved.

The heart and potassium: a banana republic.

PubMed

Khan, Ehsan; Spiers, Christine; Khan, Maria

2013-03-01

The importance of potassium in maintaining stable cardiac function is a clinically understood phenomenon. Physiologically the importance of potassium in cardiac function is described by the large number of different kinds of potassium ions channels found in the heart compared to channels and membrane transport mechanisms for other ions such as sodium and calcium. Potassium is important in physiological homeostatic control of cardiac function, but is also of relevance to the diseased state, as potassium-related effects may stabilize or destabilize cardiac function. This article aims to provide a detailed understanding of potassium-mediated cardiac function. This will help the clinical practitioner evaluate how modulation of potassium ion channels by disease and pharmacological manipulation affect the cardiac patient, thus aiding in decision making when faced with clinical problems related to potassium.

Urocortin2 prolongs action potential duration and modulates potassium currents in guinea pig myocytes and HEK293 cells.

PubMed

Yang, Li-Zhen; Zhu, Yi-Chun

2015-07-05

We previously reported that activation of corticotropin releasing factor receptor type 2 by urocortin2 up-regulates both L-type Ca(2+) channels and intracellular Ca(2+) concentration in ventricular myocytes and plays an important role in cardiac contractility and arrhythmogenesis. This study goal was to further test the hypothesis that urocortin2 may modulate action potentials as well as rapidly and slowly activating delayed rectifier potassium currents. With whole cell patch-clamp techniques, action potentials and slowly activating delayed rectifier potassium currents were recorded in isolated guinea pig ventricular myocytes, respectively. And rapidly activating delayed rectifier potassium currents were tested in hERG-HEK293 cells. Urocortin2 produced a time- and concentration-dependent prolongation of action potential duration. The EC50 values of action potential duration and action potential duration at 90% of repolarization were 14.73 and 24.3nM respectively. The prolongation of action potential duration of urocortin2 was almost completely or partly abolished by H-89 (protein kinase A inhibitor) or KB-R7943 (Na(+)/Ca(2+) exchange inhibitor) pretreatment respectively. And urocortin2 caused reduction of rapidly activating delayed rectifier potassium currents in hERG-HEK293 cells. In addition, urocortin2 slowed the rate of slowly activating delayed rectifier potassium channel activation, and rightward shifted the threshold of slowly activating delayed rectifier potassium currents to more positive potentials. Urocortin2 prolonged action potential duration via activation of protein kinase A and Na(+)/ Ca(2+) exchange in isolated guinea pig ventricular myocytes in a time- and concentration- dependent manner. In hERG-HEK293 cells, urocortin2 reduced rapidly activating delayed rectifier potassium current density which may contribute to action potential duration prolongation. Copyright © 2015 Elsevier B.V. All rights reserved.

21 CFR 184.1625 - Potassium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium citrate. 184.1625 Section 184.1625 Food... Specific Substances Affirmed as GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing citric...

21 CFR 184.1625 - Potassium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium citrate. 184.1625 Section 184.1625 Food... Specific Substances Affirmed as GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing citric...

21 CFR 184.1625 - Potassium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium citrate. 184.1625 Section 184.1625 Food... Specific Substances Affirmed as GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing citric...

21 CFR 184.1625 - Potassium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium citrate. 184.1625 Section 184.1625 Food... Specific Substances Affirmed as GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing citric...

Molecular Basis of Cardiac Delayed Rectifier Potassium Channel Function and Pharmacology.

PubMed

Wu, Wei; Sanguinetti, Michael C

2016-06-01

Human cardiomyocytes express 3 distinct types of delayed rectifier potassium channels. Human ether-a-go-go-related gene (hERG) channels conduct the rapidly activating current IKr; KCNQ1/KCNE1 channels conduct the slowly activating current IKs; and Kv1.5 channels conduct an ultrarapid activating current IKur. Here the authors provide a general overview of the mechanistic and structural basis of ion selectivity, gating, and pharmacology of the 3 types of cardiac delayed rectifier potassium ion channels. Most blockers bind to S6 residues that line the central cavity of the channel, whereas activators interact with the channel at 4 symmetric binding sites outside the cavity. Copyright © 2016 Elsevier Inc. All rights reserved.

A ditopic fluorescent sensor for potassium fluoride.

PubMed

Koskela, Suvi J M; Fyles, Thomas M; James, Tony D

2005-02-21

The addition of potassium fluoride 'switches on' the fluorescence of sensors and while potassium chloride and bromide cause no fluorescence change; the fluorescence can be 'switched off' by removing the potassium cation from the benzocrown ether receptors of sensors and through the addition of [2.2.2]-cryptand and restored by the addition of the potassium cation as potassium chloride.

21 CFR 184.1077 - Potassium acid tartrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium acid tartrate. 184.1077 Section 184.1077... GRAS § 184.1077 Potassium acid tartrate. (a) Potassium acid tartrate (C4H5KO6, CAS Reg. No. 868-14-4) is the potassium acid salt of l−(+)−tartaric acid and is also called potassium bitartrate or cream of...

Genetics Home Reference: potassium-aggravated myotonia

MedlinePlus

... Facebook Twitter Home Health Conditions Potassium-aggravated myotonia Potassium-aggravated myotonia Printable PDF Open All Close All ... Javascript to view the expand/collapse boxes. Description Potassium-aggravated myotonia is a disorder that affects muscles ...

Can Diuretics Decrease Your Potassium Level?

MedlinePlus

... of low potassium? Can diuretics decrease your potassium level? Answers from Sheldon G. Sheps, M.D. Yes, ... your urine. This can lead to low potassium levels in your blood (hypokalemia). Signs and symptoms of ...

Clinical Trial of the Potassium Channel Activator Diazoxide for Major Depressive Disorder Halted Due to Intolerability.

PubMed

Kadriu, Bashkim; Yuan, Shiwen; Farmer, Cristan; Nugent, Allison C; Lener, Marc S; Niciu, Mark J; Park, Minkyung; Yazdian, Aaron; Ballard, Elizabeth D; Henn, Fritz A; Henter, Ioline D; Park, Lawrence T; Zarate, Carlos A

2018-06-01

Some glutamatergic modulators have demonstrated rapid and relatively sustained antidepressant properties in patients with major depressive disorder. Because the potassium channel activator diazoxide increases glutamate uptake via potassium channel activation, we hypothesized that it might exert antidepressant effects by increasing the removal of glutamate from the synaptic cleft, thereby reducing excessive glutamate transmission. This randomized, double-blind, placebo-controlled, crossover, single-site inpatient clinical study was conducted at the National Institute of Mental Health to assess the efficacy and safety of a 3-week course of diazoxide (200-400 mg daily, twice a day) versus a 3-week course of placebo in 6 participants with treatment-refractory major depressive disorder. The primary clinical outcome measure was change in Montgomery-Asberg Depression Rating Scale score from baseline to posttreatment. Quantitative insulin sensitivity check index, as well as concomitant imaging measures (electroencephalography, proton magnetic resonance spectroscopy, magnetoencephalography), were used as potential surrogate markers of target (KATP channel) engagement. The study was halted due to severe adverse effects. Given the small sample size, statistical evaluation of the effect of diazoxide on Montgomery-Asberg Depression Rating Scale scores or the imaging measures was not pursued. Visual inspection of the quantitative insulin sensitivity check index test revealed no evidence of target engagement. Although the results are negative, they are an important addition to the literature in this rapidly changing field.

Prerelease disease treatment with potassium permanganate for Fall Chinook salmon smolts

USGS Publications Warehouse

Smith, Stanley D.; Gould, Rowan W.; Zaugg, Wally S.; Harrell, Lee W.; Mahnken, Conrad V.W.

1995-01-01

Standard potassium permanganate treatment (2 mg KMnO4/L freshwater for 1 h on three consecutive days) was applied to presmolts (parr) and smolts of fall chinook salmon (Oncorhynchus tshawytscha). Smoltification was determined by gill Na+,K+-ATPase activity. Treatments were conducted 73, 59, 45, 31, 16, and 2 d prior to full-strength seawater entry in aquaria. Potassium permanganate did not affect either growth or survival in seawater over 25 d. We observed a delayed rise in gill Na+,K+-ATPase activity in fish treated 16 d prior to seawater entry.

Potassium dependent rescue of a myopathy with core-like structures in mouse

PubMed Central

Hanson, M Gartz; Wilde, Jonathan J; Moreno, Rosa L; Minic, Angela D; Niswander, Lee

2015-01-01

Myopathies decrease muscle functionality. Mutations in ryanodine receptor 1 (RyR1) are often associated with myopathies with microscopic core-like structures in the muscle fiber. In this study, we identify a mouse RyR1 model in which heterozygous animals display clinical and pathological hallmarks of myopathy with core-like structures. The RyR1 mutation decreases sensitivity to activated calcium release and myoplasmic calcium levels, subsequently affecting mitochondrial calcium and ATP production. Mutant muscle shows a persistent potassium leak and disrupted expression of regulators of potassium homeostasis. Inhibition of KATP channels or increasing interstitial potassium by diet or FDA-approved drugs can reverse the muscle weakness, fatigue-like physiology and pathology. We identify regulators of potassium homeostasis as biomarkers of disease that may reveal therapeutic targets in human patients with myopathy of central core disease (CCD). Altogether, our results suggest that amelioration of potassium leaks through potassium homeostasis mechanisms may minimize muscle damage of myopathies due to certain RyR1 mutations. DOI: http://dx.doi.org/10.7554/eLife.02923.001 PMID:25564733

Role of the activation gate in determining the extracellular potassium dependency of block of HERG by trapped drugs.

PubMed

Pareja, Kristeen; Chu, Elaine; Dodyk, Katrina; Richter, Kristofer; Miller, Alan

2013-01-01

Drug induced long QT syndrome (diLQTS) results primarily from block of the cardiac potassium channel HERG (human-ether-a-go-go related gene). In some cases long QT syndrome can result in the lethal arrhythmia torsade de pointes, an arrhythmia characterized by a rapid heart rate and severely compromised cardiac output. Many patients requiring medication present with serum potassium abnormalities due to a variety of conditions including gastrointestinal dysfunction, renal and endocrine disorders, diuretic use, and aging. Extracellular potassium influences HERG channel inactivation and can alter block of HERG by some drugs. However, block of HERG by a number of drugs is not sensitive to extracellular potassium. In this study, we show that block of WT HERG by bepridil and terfenadine, two drugs previously shown to be trapped inside the HERG channel after the channel closes, is insensitive to extracellular potassium over the range of 0 mM to 20 mM. We also show that bepridil block of the HERG mutant D540K, a mutant channel that is unable to trap drugs, is dependent on extracellular potassium, correlates with the permeant ion, and is independent of HERG inactivation. These results suggest that the lack of extracellular potassium dependency of block of HERG by some drugs may in part be related to the ability of these drugs to be trapped inside the channel after the channel closes.

Potassium and water coadsorption on TiO 2(110): OH-induced anchoring of potassium and the generation of single-site catalysts

DOE PAGES

Grinter, David C.; R. Remesal, Elena; Luo, Si; ...

2016-09-15

Potassium deposition on TiO 2(110) results in reduction of the substrate and formation of loosely bound potassium species that can move easily on the oxide surface to promote catalytic activity. The results of density functional calculations predict a large adsorption energy (~3.2 eV) with a small barrier (~0.25 eV) for diffusion on the oxide surface. In scanning tunneling microscopy images, the adsorbed alkali atoms lose their mobility when in contact with surface OH groups. Furthermore, K adatoms facilitate the dissociation of water on the titania surface. Lastly, the K–(OH) species generated are good sites for the binding of gold clustersmore » on the TiO 2(110) surface, producing Au/K/TiO 2(110) systems with high activity for the water–gas shift.« less

The role of aromatic side chain residues in micelle binding by pancreatic colipase. Fluorescence studies of the porcine and equine proteins.

PubMed Central

McIntyre, J C; Hundley, P; Behnke, W D

1987-01-01

Fluorescence techniques have been employed to study the interaction of porcine and equine colipase with pure taurodeoxycholate and mixed micelles. Nitrotyrosine-55 of porcine colipase is obtained by modification with tetranitromethane (low excess, in the presence of taurodeoxycholate) of the protein followed by gel filtration and ion-exchange chromatography. Verification of the residue modified was obtained by h.p.l.c. peptide purification and sequence analysis. Reduction and quantitative reaction with dansyl chloride yields a fluorescent derivative that is twice as active in conjunction with lipase as is native colipase and that exhibits a strong emission band at 550 nm. Addition of micellar concentrations of taurodeoxycholate causes a 4.3-fold increase in the emission maximum as well as a 70 nm blue shift to 480 nm. Inclusion of oleic acid to form a mixed micelle reduces these spectral effects. Scatchard analysis of the data yield a Kd of 6.8 X 10(-4) M and a single colipase-binding site for taurodeoxycholate micelles. The data, by analogy to a phospholipase system, are consistent with a direct insertion of dansyl-NH-tyrosine-55 into the micelle. The presence of a single tryptophan residue (Trp-52) in equine colipase provides an intrinsic fluorescent probe for studying protein-micelle interaction. The emission maximum of horse colipase at 345 nm indicates a solvent-accessible tryptophan residue which becomes less so on binding of micelles. A blue shift of 8 nm and a 2-fold increase in amplitude is indicative of a more hydrophobic environment for tryptophan induced by taurodeoxycholate micelles. There is also a decrease in KSV for acrylamide quenching in the presence of micelles, which further supports a loss of solvent accessibility. The most dramatic pH effects are observed with KI quenching, and may indicate the presence of negative charges near Trp-52. PMID:3663193

Role of Circadian Rhythms in Potassium Homeostasis

PubMed Central

Gumz, Michelle L.; Rabinowitz, Lawrence

2013-01-01

It has been known for decades that urinary potassium excretion varies with a circadian pattern. In this review, we consider the historical evidence for this phenomenon and present an overview of recent developments in the field. Extensive evidence from the latter part of the last century clearly demonstrates that circadian potassium excretion does not depend on endogenous aldosterone. Of note is the recent discovery that the expression of several renal potassium transporters varies with a circadian pattern that appears to be consistent with substantial clinical data regarding daily fluctuations in urinary potassium levels. We propose the circadian clock mechanism as a key regulator of renal potassium transporters, and consequently renal potassium excretion. Further investigation into the mechanism of regulation of renal potassium transport by the circadian clock is warranted in order to increase our understanding of the clinical relevance of circadian rhythms to potassium homeostasis. PMID:23953800

Pathophysiology of Intense Physical Conditioning in a Hot Climate. I. MECHANISMS OF POTASSIUM DEPLETION

PubMed Central

Knochel, James P.; Dotin, Larry N.; Hamburger, Richard J.

1972-01-01

Serial estimations of exchangeable 42K showed that six volunteer subjects undergoing intensive physical conditioning in a hot climate sustained a mean deficit of 517 mEq. This deficit occurred despite a daily potassium intake of 100 mEq. Simultaneous values for lean body mass rose suggesting that potassium deficiency was not the result of catabolism. Although sweating was the major avenue by which the deficit occurred, daily excretion of potassium into the urine when each subject was maximally deficient ranged from 46 to 75 mEq and thus was inappropriately high for potassium-depleted subjects. Despite high intakes of sodium and excretion of corresponding quantities into the urine, Na/K ratios in sweat were low thus indicating unsuppressed activity of aldosterone on sweat glands. Moreover, excretion and secretion of aldosterone and in many instances, plasma renin activity, appeared to be high with respect to sodium intake. These findings suggest that intense physical work in the heat stimulates higher production of aldosterone than would occur in nonexercising subjects on similar sodium intakes. Similar to the phenomenon of mineralocorticoid escape, such overproduction of aldosterone in the presence of conditions permitting excretion of sodium into the urine could facilitate continued excretion of potassium by the kidney despite serious potassium depletion. As a consequence, the kidney played a role in the genesis of potassium depletion in these subjects. In contrast to subjects undergoing conditioning in the summer months, potassium depletion did not occur in 16 subjects during identical training under cooler environmental conditions. Images PMID:5009112

Preliminary Studies of Acute Cadmium Administration Effects on the Calcium-Activated Potassium (SKCa and BKCa) Channels and Na+/K+-ATPase Activity in Isolated Aortic Rings of Rats.

PubMed

Vassallo, Dalton V; Almenara, Camila C P; Broseghini-Filho, Gilson Brás; Teixeira, Ariane Calazans; da Silva, David Chaves F; Angeli, Jhuli K; Padilha, Alessandra S

2018-06-01

Cadmium is an environmental pollutant closely linked with cardiovascular diseases that seems to involve endothelium dysfunction and reduced nitric oxide (NO) bioavailability. Knowing that NO causes dilatation through the activation of potassium channels and Na + /K + -ATPase, we aimed to determine whether acute cadmium administration (10 μM) alters the participation of K + channels, voltage-activated calcium channel, and Na + /K + -ATPase activity in vascular function of isolated aortic rings of rats. Cadmium did not modify the acetylcholine-induced relaxation. After L-NAME addition, the relaxation induced by acetylcholine was abolished in presence or absence of cadmium, suggesting that acutely, this metal did not change NO release. However, tetraethylammonium (a nonselective K + channels blocker) reduced acetylcholine-induced relaxation but this effect was lower in the preparations with cadmium, suggesting a decrease of K + channels function in acetylcholine response after cadmium incubation. Apamin (a selective blocker of small Ca 2+ -activated K + channels-SK Ca ), iberiotoxin (a selective blocker of large-conductance Ca 2+ -activated K + channels-BK Ca ), and verapamil (a blocker of calcium channel) reduced the endothelium-dependent relaxation only in the absence of cadmium. Finally, cadmium decreases Na + /K + -ATPase activity. Our results provide evidence that the cadmium acute incubation unaffected the calcium-activated potassium channels (SK Ca and BK Ca ) and voltage-calcium channels on the acetylcholine vasodilatation. In addition, acute cadmium incubation seems to reduce the Na + /K + -ATPase activity.

21 CFR 182.3637 - Potassium metabisulfite.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium metabisulfite. 182.3637 Section 182.3637...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3637 Potassium metabisulfite. (a) Product. Potassium metabisulfite. (b) [Reserved] (c) Limitations, restrictions, or explanation. This...

21 CFR 182.3616 - Potassium bisulfite.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium bisulfite. 182.3616 Section 182.3616 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD....3616 Potassium bisulfite. (a) Product. Potassium bisulfite. (b) [Reserved] (c) Limitations...

21 CFR 182.3637 - Potassium metabisulfite.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium metabisulfite. 182.3637 Section 182.3637 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD....3637 Potassium metabisulfite. (a) Product. Potassium metabisulfite. (b) [Reserved] (c) Limitations...

21 CFR 182.3637 - Potassium metabisulfite.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium metabisulfite. 182.3637 Section 182.3637 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD....3637 Potassium metabisulfite. (a) Product. Potassium metabisulfite. (b) [Reserved] (c) Limitations...

21 CFR 582.3637 - Potassium metabisulfite.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium metabisulfite. 582.3637 Section 582.3637 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3637 Potassium metabisulfite. (a) Product. Potassium metabisulfite. (b) [Reserved] (c) Limitations...

21 CFR 182.3616 - Potassium bisulfite.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium bisulfite. 182.3616 Section 182.3616 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD....3616 Potassium bisulfite. (a) Product. Potassium bisulfite. (b) [Reserved] (c) Limitations...

21 CFR 582.3616 - Potassium bisulfite.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium bisulfite. 582.3616 Section 582.3616 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3616 Potassium bisulfite. (a) Product. Potassium bisulfite. (b) [Reserved] (c) Limitations...

21 CFR 182.3616 - Potassium bisulfite.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium bisulfite. 182.3616 Section 182.3616 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD....3616 Potassium bisulfite. (a) Product. Potassium bisulfite. (b) [Reserved] (c) Limitations...

21 CFR 182.3637 - Potassium metabisulfite.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium metabisulfite. 182.3637 Section 182.3637 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD....3637 Potassium metabisulfite. (a) Product. Potassium metabisulfite. (b) [Reserved] (c) Limitations...

21 CFR 582.3637 - Potassium metabisulfite.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium metabisulfite. 582.3637 Section 582.3637 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3637 Potassium metabisulfite. (a) Product. Potassium metabisulfite. (b) [Reserved] (c) Limitations...

21 CFR 582.3616 - Potassium bisulfite.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium bisulfite. 582.3616 Section 582.3616 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3616 Potassium bisulfite. (a) Product. Potassium bisulfite. (b) [Reserved] (c) Limitations...

21 CFR 582.3637 - Potassium metabisulfite.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium metabisulfite. 582.3637 Section 582.3637 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3637 Potassium metabisulfite. (a) Product. Potassium metabisulfite. (b) [Reserved] (c) Limitations...

21 CFR 582.3616 - Potassium bisulfite.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium bisulfite. 582.3616 Section 582.3616 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3616 Potassium bisulfite. (a) Product. Potassium bisulfite. (b) [Reserved] (c) Limitations...

21 CFR 582.3637 - Potassium metabisulfite.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium metabisulfite. 582.3637 Section 582.3637 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3637 Potassium metabisulfite. (a) Product. Potassium metabisulfite. (b) [Reserved] (c) Limitations...

21 CFR 582.3637 - Potassium metabisulfite.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium metabisulfite. 582.3637 Section 582.3637 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3637 Potassium metabisulfite. (a) Product. Potassium metabisulfite. (b) [Reserved] (c) Limitations...

21 CFR 182.3616 - Potassium bisulfite.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium bisulfite. 182.3616 Section 182.3616...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3616 Potassium bisulfite. (a) Product. Potassium bisulfite. (b) [Reserved] (c) Limitations, restrictions, or explanation. This substance is...

21 CFR 182.3637 - Potassium metabisulfite.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium metabisulfite. 182.3637 Section 182.3637 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD....3637 Potassium metabisulfite. (a) Product. Potassium metabisulfite. (b) [Reserved] (c) Limitations...

21 CFR 582.3616 - Potassium bisulfite.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium bisulfite. 582.3616 Section 582.3616 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3616 Potassium bisulfite. (a) Product. Potassium bisulfite. (b) [Reserved] (c) Limitations...

21 CFR 582.3616 - Potassium bisulfite.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium bisulfite. 582.3616 Section 582.3616 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3616 Potassium bisulfite. (a) Product. Potassium bisulfite. (b) [Reserved] (c) Limitations...

Small-Conductance Ca2+-Activated Potassium Channels Negatively Regulate Aldosterone Secretion in Human Adrenocortical Cells.

PubMed

Yang, Tingting; Zhang, Hai-Liang; Liang, Qingnan; Shi, Yingtang; Mei, Yan-Ai; Barrett, Paula Q; Hu, Changlong

2016-09-01

Aldosterone, which plays a key role in maintaining water and electrolyte balance, is produced by zona glomerulosa cells of the adrenal cortex. Autonomous overproduction of aldosterone from zona glomerulosa cells causes primary hyperaldosteronism. Recent clinical studies have highlighted the pathological role of the KCNJ5 potassium channel in primary hyperaldosteronism. Our objective was to determine whether small-conductance Ca(2+)-activated potassium (SK) channels may also regulate aldosterone secretion in human adrenocortical cells. We found that apamin, the prototypic inhibitor of SK channels, decreased membrane voltage, raised intracellular Ca(2+) and dose dependently increased aldosterone secretion from human adrenocortical H295R cells. By contrast, 1-Ethyl-2-benzimidazolinone, an agonist of SK channels, antagonized apamin's action and decreased aldosterone secretion. Commensurate with an increase in aldosterone production, apamin increased mRNA expression of steroidogenic acute regulatory protein and aldosterone synthase that control the early and late rate-limiting steps in aldosterone biosynthesis, respectively. In addition, apamin increased angiotensin II-stimulated aldosterone secretion, whereas 1-Ethyl-2-benzimidazolinone suppressed both angiotensin II- and high K(+)-stimulated production of aldosterone in H295R cells. These findings were supported by apamin-modulation of basal and angiotensin II-stimulated aldosterone secretion from acutely prepared slices of human adrenals. We conclude that SK channel activity negatively regulates aldosterone secretion in human adrenocortical cells. Genetic association studies are necessary to determine whether mutations in SK channel subtype 2 genes may also drive aldosterone excess in primary hyperaldosteronism. © 2016 American Heart Association, Inc.

Systematic review and meta-analysis of randomised controlled trials on the effects of potassium supplements on serum potassium and creatinine.

PubMed

Cappuccio, Francesco P; Buchanan, Laura A; Ji, Chen; Siani, Alfonso; Miller, Michelle A

2016-08-26

High potassium intake could prevent stroke, but supplementation is considered hazardous. We assessed the effect of oral potassium supplementation on serum or plasma potassium levels and renal function. We updated a systematic review of the effects of potassium supplementation in randomised clinical trials carried out worldwide, published in 2013, extending it to July 2015. We followed the PRISMA guidelines. Any individual taking part in a potassium supplementation randomised clinical trial. Studies included met the following criteria: randomised clinical trials, potassium supplement given and circulating potassium levels reported. Oral potassium supplementation. Serum or plasma potassium and serum or plasma creatinine. A total of 20 trials (21 independent groups) were included (1216 participants from 12 different countries). All but 2 were controlled (placebo n=16, control n=2). Of these trials, 15 were crossover, 4 had a parallel group and 1 was sequential. The duration of supplementation varied from 2 to 24 weeks and the amount of potassium given from 22 to 140 mmol/day. In the pooled analysis, potassium supplementation caused a small but significant increase in circulating potassium levels (weighted mean difference (WMD) 0.14 mmol/L, 95% CI 0.09 to 0.19, p<1×10(-5)), not associated with dose or duration of treatment. The average increase in urinary potassium excretion was 45.75 mmol/24 hours, 95% CI 38.81 to 53.69, p<1×10(-5). Potassium supplementation did not cause any change in circulating creatinine levels (WMD 0.30 µmol/L, 95% CI -1.19 to 1.78, p=0.70). In short-term studies of relatively healthy persons, a moderate oral potassium supplement resulted in a small increase in circulating potassium levels and no change in renal function. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Potassium Intake, Bioavailability, Hypertension, and Glucose Control

PubMed Central

Stone, Michael S.; Martyn, Lisa; Weaver, Connie M.

2016-01-01

Potassium is an essential nutrient. It is the most abundant cation in intracellular fluid where it plays a key role in maintaining cell function. The gradient of potassium across the cell membrane determines cellular membrane potential, which is maintained in large part by the ubiquitous ion channel the sodium-potassium (Na+-K+) ATPase pump. Approximately 90% of potassium consumed (60–100 mEq) is lost in the urine, with the other 10% excreted in the stool, and a very small amount lost in sweat. Little is known about the bioavailability of potassium, especially from dietary sources. Less is understood on how bioavailability may affect health outcomes. Hypertension (HTN) is the leading cause of cardiovascular disease (CVD) and a major financial burden ($50.6 billion) to the US public health system, and has a significant impact on all-cause morbidity and mortality worldwide. The relationship between increased potassium supplementation and a decrease in HTN is relatively well understood, but the effect of increased potassium intake from dietary sources on blood pressure overall is less clear. In addition, treatment options for hypertensive individuals (e.g., thiazide diuretics) may further compound chronic disease risk via impairments in potassium utilization and glucose control. Understanding potassium bioavailability from various sources may help to reveal how specific compounds and tissues influence potassium movement, and further the understanding of its role in health. PMID:27455317

Potassium Intake, Bioavailability, Hypertension, and Glucose Control.

PubMed

Stone, Michael S; Martyn, Lisa; Weaver, Connie M

2016-07-22

Potassium is an essential nutrient. It is the most abundant cation in intracellular fluid where it plays a key role in maintaining cell function. The gradient of potassium across the cell membrane determines cellular membrane potential, which is maintained in large part by the ubiquitous ion channel the sodium-potassium (Na+-K+) ATPase pump. Approximately 90% of potassium consumed (60-100 mEq) is lost in the urine, with the other 10% excreted in the stool, and a very small amount lost in sweat. Little is known about the bioavailability of potassium, especially from dietary sources. Less is understood on how bioavailability may affect health outcomes. Hypertension (HTN) is the leading cause of cardiovascular disease (CVD) and a major financial burden ($50.6 billion) to the US public health system, and has a significant impact on all-cause morbidity and mortality worldwide. The relationship between increased potassium supplementation and a decrease in HTN is relatively well understood, but the effect of increased potassium intake from dietary sources on blood pressure overall is less clear. In addition, treatment options for hypertensive individuals (e.g., thiazide diuretics) may further compound chronic disease risk via impairments in potassium utilization and glucose control. Understanding potassium bioavailability from various sources may help to reveal how specific compounds and tissues influence potassium movement, and further the understanding of its role in health.

21 CFR 182.3616 - Potassium bisulfite.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium bisulfite. 182.3616 Section 182.3616 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Potassium bisulfite. (a) Product. Potassium bisulfite. (b) [Reserved] (c) Limitations, restrictions, or...

21 CFR 582.5628 - Potassium glycerophosphate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium glycerophosphate. 582.5628 Section 582.5628 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Dietary Supplements 1 § 582.5628 Potassium glycerophosphate. (a) Product. Potassium glycerophosphate. (b...

21 CFR 582.5628 - Potassium glycerophosphate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium glycerophosphate. 582.5628 Section 582.5628 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Dietary Supplements 1 § 582.5628 Potassium glycerophosphate. (a) Product. Potassium glycerophosphate. (b...

21 CFR 582.5628 - Potassium glycerophosphate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium glycerophosphate. 582.5628 Section 582.5628 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Dietary Supplements 1 § 582.5628 Potassium glycerophosphate. (a) Product. Potassium glycerophosphate. (b...

21 CFR 582.5628 - Potassium glycerophosphate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium glycerophosphate. 582.5628 Section 582.5628 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Dietary Supplements 1 § 582.5628 Potassium glycerophosphate. (a) Product. Potassium glycerophosphate. (b...

21 CFR 582.5628 - Potassium glycerophosphate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium glycerophosphate. 582.5628 Section 582.5628 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Dietary Supplements 1 § 582.5628 Potassium glycerophosphate. (a) Product. Potassium glycerophosphate. (b...

21 CFR 862.1600 - Potassium test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Potassium test system. 862.1600 Section 862.1600....1600 Potassium test system. (a) Identification. A potassium test system is a device intended to measure potassium in serum, plasma, and urine. Measurements obtained by this device are used to monitor electrolyte...

21 CFR 862.1600 - Potassium test system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Potassium test system. 862.1600 Section 862.1600....1600 Potassium test system. (a) Identification. A potassium test system is a device intended to measure potassium in serum, plasma, and urine. Measurements obtained by this device are used to monitor electrolyte...

21 CFR 862.1600 - Potassium test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Potassium test system. 862.1600 Section 862.1600....1600 Potassium test system. (a) Identification. A potassium test system is a device intended to measure potassium in serum, plasma, and urine. Measurements obtained by this device are used to monitor electrolyte...

21 CFR 862.1600 - Potassium test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Potassium test system. 862.1600 Section 862.1600....1600 Potassium test system. (a) Identification. A potassium test system is a device intended to measure potassium in serum, plasma, and urine. Measurements obtained by this device are used to monitor electrolyte...

21 CFR 862.1600 - Potassium test system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Potassium test system. 862.1600 Section 862.1600....1600 Potassium test system. (a) Identification. A potassium test system is a device intended to measure potassium in serum, plasma, and urine. Measurements obtained by this device are used to monitor electrolyte...

21 CFR 582.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium bicarbonate. 582.1613 Section 582.1613 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1613 Potassium bicarbonate. (a) Product. Potassium bicarbonate. (b) Conditions of use. This...

21 CFR 582.7610 - Potassium alginate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium alginate. 582.7610 Section 582.7610 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium alginate. (a) Product. Potassium alginate. (b) Conditions of use. This substance is generally...

21 CFR 582.1619 - Potassium carbonate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium carbonate. 582.1619 Section 582.1619 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1619 Potassium carbonate. (a) Product. Potassium carbonate. (b) Conditions of use. This...

21 CFR 582.1643 - Potassium sulfate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium sulfate. 582.1643 Section 582.1643 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1643 Potassium sulfate. (a) Product. Potassium sulfate. (b) Conditions of use. This...

21 CFR 582.6625 - Potassium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.3640 - Potassium sorbate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium sorbate. 582.3640 Section 582.3640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3640 Potassium sorbate. (a) Product. Potassium sorbate. (b) Conditions of use. This substance is...

21 CFR 582.1619 - Potassium carbonate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium carbonate. 582.1619 Section 582.1619 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1619 Potassium carbonate. (a) Product. Potassium carbonate. (b) Conditions of use. This...

21 CFR 182.3640 - Potassium sorbate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium sorbate. 182.3640 Section 182.3640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Potassium sorbate. (a) Product. Potassium sorbate. (b) Conditions of use. This substance is generally...

21 CFR 582.3640 - Potassium sorbate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium sorbate. 582.3640 Section 582.3640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3640 Potassium sorbate. (a) Product. Potassium sorbate. (b) Conditions of use. This substance is...

21 CFR 582.1631 - Potassium hydroxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

21 CFR 582.1631 - Potassium hydroxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

21 CFR 582.1619 - Potassium carbonate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium carbonate. 582.1619 Section 582.1619 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1619 Potassium carbonate. (a) Product. Potassium carbonate. (b) Conditions of use. This...

21 CFR 582.1619 - Potassium carbonate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium carbonate. 582.1619 Section 582.1619 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1619 Potassium carbonate. (a) Product. Potassium carbonate. (b) Conditions of use. This...

21 CFR 582.1631 - Potassium hydroxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

21 CFR 582.3640 - Potassium sorbate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium sorbate. 582.3640 Section 582.3640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3640 Potassium sorbate. (a) Product. Potassium sorbate. (b) Conditions of use. This substance is...

21 CFR 582.1625 - Potassium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This...

21 CFR 582.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium bicarbonate. 582.1613 Section 582.1613 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1613 Potassium bicarbonate. (a) Product. Potassium bicarbonate. (b) Conditions of use. This...

21 CFR 582.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium bicarbonate. 582.1613 Section 582.1613 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1613 Potassium bicarbonate. (a) Product. Potassium bicarbonate. (b) Conditions of use. This...

21 CFR 182.3640 - Potassium sorbate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium sorbate. 182.3640 Section 182.3640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Potassium sorbate. (a) Product. Potassium sorbate. (b) Conditions of use. This substance is generally...

21 CFR 582.1625 - Potassium citrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This...

21 CFR 182.3640 - Potassium sorbate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium sorbate. 182.3640 Section 182.3640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Potassium sorbate. (a) Product. Potassium sorbate. (b) Conditions of use. This substance is generally...

21 CFR 582.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium bicarbonate. 582.1613 Section 582.1613 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1613 Potassium bicarbonate. (a) Product. Potassium bicarbonate. (b) Conditions of use. This...

21 CFR 582.1625 - Potassium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This...

21 CFR 582.7610 - Potassium alginate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium alginate. 582.7610 Section 582.7610 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium alginate. (a) Product. Potassium alginate. (b) Conditions of use. This substance is generally...

21 CFR 582.1643 - Potassium sulfate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium sulfate. 582.1643 Section 582.1643 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1643 Potassium sulfate. (a) Product. Potassium sulfate. (b) Conditions of use. This...

21 CFR 582.1625 - Potassium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This...

21 CFR 182.3640 - Potassium sorbate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium sorbate. 182.3640 Section 182.3640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Potassium sorbate. (a) Product. Potassium sorbate. (b) Conditions of use. This substance is generally...

21 CFR 582.6625 - Potassium citrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.6625 - Potassium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.1631 - Potassium hydroxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

21 CFR 582.1631 - Potassium hydroxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

21 CFR 582.6625 - Potassium citrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.1643 - Potassium sulfate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium sulfate. 582.1643 Section 582.1643 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1643 Potassium sulfate. (a) Product. Potassium sulfate. (b) Conditions of use. This...

21 CFR 582.3640 - Potassium sorbate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium sorbate. 582.3640 Section 582.3640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3640 Potassium sorbate. (a) Product. Potassium sorbate. (b) Conditions of use. This substance is...

21 CFR 182.3640 - Potassium sorbate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium sorbate. 182.3640 Section 182.3640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3640 Potassium sorbate. (a) Product. Potassium...

21 CFR 582.1613 - Potassium bicarbonate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium bicarbonate. 582.1613 Section 582.1613 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1613 Potassium bicarbonate. (a) Product. Potassium bicarbonate. (b) Conditions of use. This...

21 CFR 582.1625 - Potassium citrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This...

21 CFR 582.1619 - Potassium carbonate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium carbonate. 582.1619 Section 582.1619 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1619 Potassium carbonate. (a) Product. Potassium carbonate. (b) Conditions of use. This...

21 CFR 582.6625 - Potassium citrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.7610 - Potassium alginate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium alginate. 582.7610 Section 582.7610 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium alginate. (a) Product. Potassium alginate. (b) Conditions of use. This substance is generally...

21 CFR 582.3640 - Potassium sorbate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium sorbate. 582.3640 Section 582.3640 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3640 Potassium sorbate. (a) Product. Potassium sorbate. (b) Conditions of use. This substance is...

21 CFR 582.1643 - Potassium sulfate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium sulfate. 582.1643 Section 582.1643 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1643 Potassium sulfate. (a) Product. Potassium sulfate. (b) Conditions of use. This...

21 CFR 582.1643 - Potassium sulfate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium sulfate. 582.1643 Section 582.1643 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1643 Potassium sulfate. (a) Product. Potassium sulfate. (b) Conditions of use. This...

Potassium in hypertension and cardiovascular disease.

PubMed

Castro, Hector; Raij, Leopoldo

2013-05-01

The increased prevalence of hypertension and cardiovascular disease in industrialized societies undoubtedly is associated with the modern high-sodium/low-potassium diet. Extensive experimental and clinical data strongly link potassium intake to cardiovascular outcome. Most studies suggest that the sodium-to-potassium intake ratio is a better predictor of cardiovascular outcome than either nutrient individually. A high-sodium/low-potassium environment results in significant abnormalities in central hemodynamics, leading to potential target organ damage. Altered renal sodium handling, impaired endothelium-dependent vasodilatation, and increased oxidative stress are important mediators of this effect. It remains of paramount importance to reinforce consumption of a low-sodium/high-potassium diet as a critical strategy for prevention and treatment of hypertension and cardiovascular disease. Published by Elsevier Inc.

The effects of magnesium on potassium transport in ferret red cells.

PubMed Central

Flatman, P W

1988-01-01

1. The magnesium dependence of net and isotopic (using 86Rb as tracer) potassium transport was measured in fed ferret red cells. Bumetanide (0.1 mM) was used to dissect total flux into two components: bumetanide sensitive and bumetanide resistant. 2. Increasing the external magnesium concentration from zero (added) to 2 mM stimulated bumetanide-sensitive uptake by 16% but inhibited the bumetanide-resistant component by about 20%. 3. Ionophore A23187 was used to control internal magnesium concentration. A23187 was usually present in the cells during measurement of isotopic fluxes but was washed away before measurement of net fluxes. The magnesium-buffering characteristics of fed ferret red cells were assessed during these experiments. The cytoplasm acts as a high-capacity, low-affinity magnesium buffer over most of the range. Some high-affinity binding was seen in the presence of A23187 and 2 mM-EDTA. 4. A23187 itself slightly inhibits bumetanide-sensitive potassium transport. 5. Bumetanide-sensitive potassium transport is strongly dependent on the concentration of internal ionized magnesium. Transport is 35% maximal at 10(-7) M and increases up to the maximal rate at 1.3 mM. Further increase in ionized magnesium concentration to 3.5 mM has no additional effect. The curve relating activity to magnesium concentration is steepest at the physiological magnesium concentration. The effects of changing magnesium concentration are fully reversible. 6. Reduction of internal ionized magnesium concentration to 10(-7) M with A23187 and EDTA approximately doubles bumetanide-resistant potassium transport. 7. Bumetanide-sensitive fluxes occur via the sodium-potassium-chloride co-transport system under the conditions used. Results described in this paper thus suggest that internal magnesium may be an important physiological controller of sodium-potassium-chloride co-transport activity. PMID:3137332

A biophysical model examining the role of low-voltage-activated potassium currents in shaping the responses of vestibular ganglion neurons.

PubMed

Hight, Ariel E; Kalluri, Radha

2016-08-01

The vestibular nerve is characterized by two broad groups of neurons that differ in the timing of their interspike intervals; some fire at highly regular intervals, whereas others fire at highly irregular intervals. Heterogeneity in ion channel properties has been proposed as shaping these firing patterns (Highstein SM, Politoff AL. Brain Res 150: 182-187, 1978; Smith CE, Goldberg JM. Biol Cybern 54: 41-51, 1986). Kalluri et al. (J Neurophysiol 104: 2034-2051, 2010) proposed that regularity is controlled by the density of low-voltage-activated potassium currents (IKL). To examine the impact of IKL on spike timing regularity, we implemented a single-compartment model with three conductances known to be present in the vestibular ganglion: transient sodium (gNa), low-voltage-activated potassium (gKL), and high-voltage-activated potassium (gKH). Consistent with in vitro observations, removing gKL depolarized resting potential, increased input resistance and membrane time constant, and converted current step-evoked firing patterns from transient (1 spike at current onset) to sustained (many spikes). Modeled neurons were driven with a time-varying synaptic conductance that captured the random arrival times and amplitudes of glutamate-driven synaptic events. In the presence of gKL, spiking occurred only in response to large events with fast onsets. Models without gKL exhibited greater integration by responding to the superposition of rapidly arriving events. Three synaptic conductance were modeled, each with different kinetics to represent a variety of different synaptic processes. In response to all three types of synaptic conductance, models containing gKL produced spike trains with irregular interspike intervals. Only models lacking gKL when driven by rapidly arriving small excitatory postsynaptic currents were capable of generating regular spiking. Copyright © 2016 the American Physiological Society.

Inhibitory Effect of Vascular Endothelial Growth Factor on the Slowly Activating Delayed Rectifier Potassium Current in Guinea Pig Ventricular Myocytes.

PubMed

Lin, Zhenhao; Xing, Wenlu; Gao, Chuanyu; Wang, Xianpei; Qi, Datun; Dai, Guoyou; Zhao, Wen; Yan, Ganxin

2018-01-26

Vascular endothelial growth factor (VEGF) exerts a number of beneficial effects on ischemic myocardium via its angiogenic properties. However, little is known about whether VEGF has a direct effect on the electrical properties of cardiomyocytes. In the present study, we investigated the effects of different concentrations of VEGF on delayed rectifier potassium currents (I K ) in guinea pig ventricular myocytes and their effects on action potential (AP) parameters. I K and AP were recorded by the whole-cell patch clamp method in ventricular myocytes. Cells were superfused with control solution or solution containing VEGF at different concentrations for 10 minutes before recording. Some ventricular myocytes were pretreated with a phosphatidylinositol 3-kinase inhibitor for 1 hour before the addition of VEGF. We found that VEGF inhibited the slowly activating delayed rectifier potassium current (I K s ) in a concentration-dependent manner (18.13±1.04 versus 12.73±0.34, n=5, P =0.001; 12.73±0.34 versus 9.05±1.20, n=5, P =0.036) and prolonged AP duration (894.5±36.92 versus 746.3±33.71, n=5, P =0.021). Wortmannin, a phosphatidylinositol 3-kinase inhibitor, eliminated these VEGF-induced effects. VEGF had no significant effect on the rapidly activating delayed rectifier potassium current (I K r ), resting membrane potential, AP amplitude, or maximal velocity of depolarization. VEGF inhibited I K s in a concentration-dependent manner through a phosphatidylinositol 3-kinase-mediated signaling pathway, leading to AP prolongation. The results indicate a promising therapeutic potential of VEGF in prevention of ventricular tachyarrhythmias under conditions of high sympathetic activity and ischemia. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

21 CFR 582.5634 - Potassium iodide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium iodide. 582.5634 Section 582.5634 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5634 Potassium iodide. (a) Product. Potassium iodide. (b) Tolerance. 0.01 percent. (c...

21 CFR 172.730 - Potassium bromate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium bromate. 172.730 Section 172.730 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Other Specific Usage Additives § 172.730 Potassium bromate. The food additive potassium bromate may be...

21 CFR 172.160 - Potassium nitrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium nitrate. 172.160 Section 172.160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Food Preservatives § 172.160 Potassium nitrate. The food additive potassium nitrate may be safely used...

21 CFR 582.5634 - Potassium iodide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium iodide. 582.5634 Section 582.5634 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5634 Potassium iodide. (a) Product. Potassium iodide. (b) Tolerance. 0.01 percent. (c...

21 CFR 172.160 - Potassium nitrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium nitrate. 172.160 Section 172.160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Food Preservatives § 172.160 Potassium nitrate. The food additive potassium nitrate may be safely used...

21 CFR 172.160 - Potassium nitrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium nitrate. 172.160 Section 172.160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Food Preservatives § 172.160 Potassium nitrate. The food additive potassium nitrate may be safely used...

High Temperature Stability of Potassium Beta Alumina

NASA Technical Reports Server (NTRS)

Williams, R. M.; Kisor, A.; Ryan, M. A.

1996-01-01

None. From Objectives section: Evaluate the stability of potassium beta alumina under potassium AMTEC operating conditions. Evaluate the stability regime in which potassium beta alumina can be fabricated.

Structurally diverse natural products that cause potassium leakage trigger multicellularity in Bacillus subtilis.

PubMed

López, Daniel; Fischbach, Michael A; Chu, Frances; Losick, Richard; Kolter, Roberto

2009-01-06

We report a previously undescribed quorum-sensing mechanism for triggering multicellularity in Bacillus subtilis. B. subtilis forms communities of cells known as biofilms in response to an unknown signal. We discovered that biofilm formation is stimulated by a variety of small molecules produced by bacteria--including the B. subtilis nonribosomal peptide surfactin--that share the ability to induce potassium leakage. Natural products that do not cause potassium leakage failed to induce multicellularity. Small-molecule-induced multicellularity was prevented by the addition of potassium, but not sodium or lithium. Evidence is presented that potassium leakage stimulates the activity of a membrane protein kinase, KinC, which governs the expression of genes involved in biofilm formation. We propose that KinC responds to lowered intracellular potassium concentration and that this is a quorum-sensing mechanism that enables B. subtilis to respond to related and unrelated bacteria.

21 CFR 201.72 - Potassium labeling.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Potassium labeling. 201.72 Section 201.72 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.72 Potassium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the potassium content...

21 CFR 201.72 - Potassium labeling.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Potassium labeling. 201.72 Section 201.72 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.72 Potassium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the potassium content...

21 CFR 201.72 - Potassium labeling.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Potassium labeling. 201.72 Section 201.72 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.72 Potassium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the potassium content...

Agreement of arterial sodium and arterial potassium levels with venous sodium and venous potassium in patients admitted to intensive care unit.

PubMed

Nanda, Sunil Kumar; Ray, Lopamudra; Dinakaran, Asha

2015-02-01

Electrolyte abnormalities are one of the common causes of morbidity and mortality in critically ill patients. The turnaround time for electrolyte reporting should be as low as possible. Electrolytes are measured conventionally in serum obtained from venous blood by electrolyte analyser which takes 20 to 30 min. Point of care analysers are now available where in electrolytes can be measured in arterial blood within 5 min. This study was done to study the agreement of arterial sodium and arterial potassium with venous sodium and venous potassium levels. Venous sodium and venous potassium levels and arterial sodium and arterial potassium levels were analysed on 206 patient samples admitted to Intensive Care Unit (ICU). The venous values were compared with the arterial values for correlation. Venous sodium was compared with arterial sodium by spearman correlation. Venous potassium was compared with arterial potassium by pearson correlation. The mean value of arterial sodium was 134 and venous sodium was 137. The mean value of arterial potassium was 3.6 and venous potassium was 4.1. The correlation coefficient obtained for sodium was 0.787 and correlation coefficient obtained for potassium was 0.701. There was positive correlation of arterial sodium and arterial potassium with venous sodium and venous potassium indicating agreement between the parameters. Arterial sodium and arterial potassium can be used instead of venous sodium and venous potassium levels in management of critically ill patients.

21 CFR 184.1077 - Potassium acid tartrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium acid tartrate. 184.1077 Section 184.1077... Listing of Specific Substances Affirmed as GRAS § 184.1077 Potassium acid tartrate. (a) Potassium acid tartrate (C4H5KO6, CAS Reg. No. 868-14-4) is the potassium acid salt of l−(+)−tartaric acid and is also...

21 CFR 184.1077 - Potassium acid tartrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium acid tartrate. 184.1077 Section 184.1077... Listing of Specific Substances Affirmed as GRAS § 184.1077 Potassium acid tartrate. (a) Potassium acid tartrate (C4H5KO6, CAS Reg. No. 868-14-4) is the potassium acid salt of l−(+)−tartaric acid and is also...

Recipe for potassium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Izutani, Natsuko

2012-11-12

I investigate favorable conditions for producing potassium (K). Observations show [K/Fe] > 0 at low metallicities, while zero-metal supernova models show low [K/Fe] (< 0). Theoretically, it is natural that the odd-Z element, potassium decreases with lower metallicity, and thus, the observation should imply new and unknown sites for potassium. In this proceedings, I calculate proton-rich nucleosynthesis with three parameters, the initial Y{sub e} (from 0.51 to 0.60), the initial density {rho}{sub max} (10{sup 7}, 10{sup 8}, and 10{sup 9} [g/cm{sup 3}]), and the e-fold time {tau} for the density (0.01, 0.1, and 1.0 [sec]). Among 90 models I havemore » calculated, only 26 models show [K/Fe] > 0, and they all have {rho}{sub max} = 10{sup 9}[g/cm{sup 3}]. I discuss parameter dependence of [K/Fe].« less

Docetaxel modulates the delayed rectifier potassium current (IK) and ATP-sensitive potassium current (IKATP) in human breast cancer cells.

PubMed

Sun, Tao; Song, Zhi-Guo; Jiang, Da-Qing; Nie, Hong-Guang; Han, Dong-Yun

2015-04-01

Ion channel expression and activity may be affected during tumor development and cancer growth. Activation of potassium (K(+)) channels in human breast cancer cells is reported to be involved in cell cycle progression. In this study, we investigated the effects of docetaxel on the delayed rectifier potassium current (I K) and the ATP-sensitive potassium current (I KATP) in two human breast cancer cell lines, MCF-7 and MDA-MB-435S, using the whole-cell patch-clamp technique. Our results show that docetaxel inhibited the I K and I KATP in both cell lines in a dose-dependent manner. Compared with the control at a potential of +60 mV, treatment with docetaxel at doses of 0.1, 1, 5, and 10 µM significantly decreased the I K in MCF-7 cells by 16.1 ± 3.5, 30.2 ± 5.2, 42.5 ± 4.3, and 46.4 ± 9% (n = 5, P < 0.05), respectively and also decreased the I KATP at +50 mV. Similar results were observed in MDA-MB-435S cells. The G-V curves showed no significant changes after treatment of either MCF-7 or MDA-MB-435S cells with 10 μM docetaxel. The datas indicate that the possible mechanisms of I K and I KATP inhibition by docetaxel may be responsible for its effect on the proliferation of human breast cancer cells.

21 CFR 172.160 - Potassium nitrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium nitrate. 172.160 Section 172.160 Food... ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Food Preservatives § 172.160 Potassium nitrate. The food additive potassium nitrate may be safely used as a curing agent in the processing of cod...

21 CFR 172.160 - Potassium nitrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium nitrate. 172.160 Section 172.160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Preservatives § 172.160 Potassium nitrate. The food additive potassium nitrate may be safely used as a curing...

Clofilium inhibits Slick and Slack potassium channels.

PubMed

de Los Angeles Tejada, Maria; Stolpe, Kathleen; Meinild, Anne-Kristine; Klaerke, Dan A

2012-01-01

Slick and Slack high-conductance potassium channels have been recently discovered, and are found in the central nervous system and in the heart. Both channels are activated by Na(+) and Cl(-), and Slick channels are also inhibited by adenosine triphospate (ATP). An important role of setting the resting membrane potential and controlling the basal excitability of neurons has been suggested for these channels. In addition, no specific blockers for these channels are known up to the present. With the purpose of studying the pharmacological characteristics of Slick and Slack channels, the effects of exposure to the antiarrhythmic compound clofilium were evaluated. Clofilium was able to modulate the activity of Slick and Slack channels effectively, with a stronger effect on Slack than Slick channels. In order to evaluate the pharmacological behavior of Slick and Slack channels further, 38 commonly used potassium channel blockers were tested. Screening of these compounds did not reveal any modulators of Slick and Slack channels, except for clofilium. The present study provides a first approach towards elucidating the pharmacological characteristics of Slick and Slack channels and could be the basis for future studies aimed at developing potent and specific blockers and activators for these channels.

Protective effect of dietary potassium against vascular injury in salt-sensitive hypertension.

PubMed

Kido, Makiko; Ando, Katsuyuki; Onozato, Maristela L; Tojo, Akihiro; Yoshikawa, Masahiro; Ogita, Teruhiko; Fujita, Toshiro

2008-02-01

Hypertensive cardiovascular damage is accelerated by salt loading but counteracted by dietary potassium supplementation. We suggested recently that antioxidant actions of potassium contribute to protection against salt-induced cardiac dysfunction. Therefore, we examined whether potassium supplementation ameliorated cuff-induced vascular injury in salt-sensitive hypertension via suppression of oxidative stress. Four-week-old Dahl salt-sensitive rats were fed a normal-salt (0.3% NaCl), high-salt (8% NaCl), or high-salt plus high-potassium (8% KCl) diet for 5 weeks, and some of the rats fed a high-salt diet were also given antioxidants. One week after the start of the treatments, a silicone cuff was implanted around the femoral artery. Examination revealed increased cuff-induced neointimal proliferation with adventitial macrophage infiltration in arteries from salt-loaded Dahl salt-sensitive rats compared with that in arteries from non-salt-loaded animals (intima/media ratio: 0.471+/-0.070 versus 0.302+/-0.037; P<0.05), associated with regional superoxide overproduction and reduced nicotinamide-adenine dinucleotide phosphate oxidase activation and mRNA overexpression. On the other hand, simultaneous potassium supplementation attenuated salt-induced neointimal hyperplasia (intima/media ratio: 0.205+/-0.012; P<0.001), adventitial macrophage infiltration, superoxide overproduction, and reduced nicotinamide-adenine dinucleotide phosphate oxidase activation and overexpression. Antioxidants, which decrease vascular oxidative stress, also reduced neointima formation induced by salt excess. In conclusion, high-potassium diets seems to have a protective effect against the development of vascular damage induced by salt loading mediated, at least in part, through suppression of the production of reactive oxygen species probably generated by reduced nicotinamide-adenine dinucleotide phosphate oxidase.

21 CFR 184.1804 - Sodium potassium tartrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium potassium tartrate. 184.1804 Section 184... Listing of Specific Substances Affirmed as GRAS § 184.1804 Sodium potassium tartrate. (a) Sodium potassium tartrate (C4H4KNaO6·4H2O, CAS Reg. No. 304-59-6) is the sodium potassium salt of l−(+)−tartaric acid and is...

21 CFR 184.1804 - Sodium potassium tartrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium potassium tartrate. 184.1804 Section 184... as GRAS § 184.1804 Sodium potassium tartrate. (a) Sodium potassium tartrate (C4H4KNaO6·4H2O, CAS Reg. No. 304-59-6) is the sodium potassium salt of l−(+)−tartaric acid and is also called the Rochelle...

21 CFR 184.1804 - Sodium potassium tartrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium potassium tartrate. 184.1804 Section 184... Listing of Specific Substances Affirmed as GRAS § 184.1804 Sodium potassium tartrate. (a) Sodium potassium tartrate (C4H4KNaO6·4H2O, CAS Reg. No. 304-59-6) is the sodium potassium salt of l−(+)−tartaric acid and is...

21 CFR 184.1804 - Sodium potassium tartrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium potassium tartrate. 184.1804 Section 184... Listing of Specific Substances Affirmed as GRAS § 184.1804 Sodium potassium tartrate. (a) Sodium potassium tartrate (C4H4KNaO6·4H2O, CAS Reg. No. 304-59-6) is the sodium potassium salt of l−(+)−tartaric acid and is...

Potassium test

MedlinePlus

High levels of potassium ( hyperkalemia ) may be due to: Addison disease (rare) Blood transfusion Certain medicines Crushed tissue injury Hyperkalemic periodic paralysis Hypoaldosteronism (very rare) ...

Daily potassium intake and sodium-to-potassium ratio in the reduction of blood pressure: a meta-analysis of randomized controlled trials.

PubMed

Binia, Aristea; Jaeger, Jonathan; Hu, Youyou; Singh, Anurag; Zimmermann, Diane

2015-08-01

To evaluate the efficacy of daily potassium intake on decreasing blood pressure in non-medicated normotensive or hypertensive patients, and to determine the relationship between potassium intake, sodium-to-potassium ratio and reduction in blood pressure. Mixed-effect meta-analyses and meta-regression models. Medline and the references of previous meta-analyses. Randomized controlled trials with potassium supplementation, with blood pressure as the primary outcome, in non-medicated patients. Fifteen randomized controlled trials of potassium supplementation in patients without antihypertensive medication were selected for the meta-analyses (917 patients). Potassium supplementation resulted in reduction of SBP by 4.7 mmHg [95% confidence interval (CI) 2.4-7.0] and DBP by 3.5 mmHg (95% CI 1.3-5.7) in all patients. The effect was found to be greater in hypertensive patients, with a reduction of SBP by 6.8 mmHg (95% CI 4.3-9.3) and DBP by 4.6 mmHg (95% CI 1.8-7.5). Meta-regression analysis showed that both increased daily potassium excretion and decreased sodium-to-potassium ratio were associated with blood pressure reduction (P < 0.05). Increased total daily potassium urinary excretion from 60 to 100 mmol/day and decrease of sodium-to-potassium ratio were shown to be necessary to explain the estimated effect. Potassium supplementation is associated with reduction of blood pressure in patients who are not on antihypertensive medication, and the effect is significant in hypertensive patients. The reduction in blood pressure significantly correlates with decreased daily urinary sodium-to-potassium ratio and increased urinary potassium. Patients with elevated blood pressure may benefit from increased potassium intake along with controlled or decreased sodium intake.

Probing the Energy Landscape of Activation Gating of the Bacterial Potassium Channel KcsA

PubMed Central

Linder, Tobias; de Groot, Bert L.; Stary-Weinzinger, Anna

2013-01-01

The bacterial potassium channel KcsA, which has been crystallized in several conformations, offers an ideal model to investigate activation gating of ion channels. In this study, essential dynamics simulations are applied to obtain insights into the transition pathways and the energy profile of KcsA pore gating. In agreement with previous hypotheses, our simulations reveal a two phasic activation gating process. In the first phase, local structural rearrangements in TM2 are observed leading to an intermediate channel conformation, followed by large structural rearrangements leading to full opening of KcsA. Conformational changes of a highly conserved phenylalanine, F114, at the bundle crossing region are crucial for the transition from a closed to an intermediate state. 3.9 µs umbrella sampling calculations reveal that there are two well-defined energy barriers dividing closed, intermediate, and open channel states. In agreement with mutational studies, the closed state was found to be energetically more favorable compared to the open state. Further, the simulations provide new insights into the dynamical coupling effects of F103 between the activation gate and the selectivity filter. Investigations on individual subunits support cooperativity of subunits during activation gating. PMID:23658510

Potassium-doped n-type bilayer graphene

NASA Astrophysics Data System (ADS)

Yamada, Takatoshi; Okigawa, Yuki; Hasegawa, Masataka

2018-01-01

Potassium-doped n-type bilayer graphene was obtained. Chemical vapor deposited bilayer and single layer graphene on copper (Cu) foils were used. After etching of Cu foils, graphene was dipped in potassium hydroxide aqueous solutions to dope potassium. Graphene on silicon oxide was characterized by X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), and Raman spectroscopy. Both XPS and EDX spectra indicated potassium incorporation into the bilayer graphene via intercalation between the graphene sheets. The downward shift of the 2D peak position of bilayer graphene after the potassium hydroxide (KOH) treatment was confirmed in Raman spectra, indicating that the KOH-treated bilayer graphene was doped with electrons. Electrical properties were measured using Hall bar structures. The Dirac points of bilayer graphene were shifted from positive to negative by the KOH treatment, indicating that the KOH-treated bilayer graphene was n-type conduction. For single layer graphene after the KOH treatment, although electron doping was confirmed from Raman spectra, the peak of potassium in the X-ray photoelectron spectroscopy (XPS) spectrum was not detected. The Dirac points of single layer graphene with and without the KOH treatment showed positive.

Drug-induced abnormalities of potassium metabolism.

PubMed

Kokot, Franciszek; Hyla-Klekot, Lidia

2008-01-01

Pharmacotherapy has progressed rapidly over the last 20 years with the result that general practioners more and more often use drugs which may influence potassium metabolism at the kidney or gastrointestinal level, or the transmembrane transport of potassium at the cellular level. Potassium abnormalities may result in life-theatening clinical conditions. Hypokalemia is most frequently caused by renal loss of this electrolyte (thiazide, thiazide-like and loop diuretics, glucocorticoids) and the gastrointestinal tract (laxatives, diarrhea, vomiting, external fistula), and may be the result of an increased intracellular potassium influx induced by sympathicomimetics used mostly by patients with asthma, or by insulin overdosage in diabetic subjects. The leading symptoms of hypokalemia are skeletal and smooth muscle weakness and cardiac arrhythmias. Hyperkalemia may be caused by acute or end-stage renal failure, impaired tubular excretion of potassium (blockers of the renin-angiotensin-aldosterone system, nonsteroidal anti-inflammatory drugs, cyclosporine, antifungal drugs, potassium sparing diuretics), acidemia, and severe cellular injury (tumor lysis syndrome). Hyperkalemia may be the cause of severe injury of both skeletal and smooth muscle cells. The specific treatment counteracting hyperkalemia is a bolus injection of calcium salts and, when necessary, hemodialysis.

Race, Serum Potassium, and Associations With ESRD and Mortality.

PubMed

Chen, Yan; Sang, Yingying; Ballew, Shoshana H; Tin, Adrienne; Chang, Alex R; Matsushita, Kunihiro; Coresh, Josef; Kalantar-Zadeh, Kamyar; Molnar, Miklos Z; Grams, Morgan E

2017-08-01

Recent studies suggest that potassium levels may differ by race. The basis for these differences and whether associations between potassium levels and adverse outcomes differ by race are unknown. Observational study. Associations between race and potassium level and the interaction of race and potassium level with outcomes were investigated in the Racial and Cardiovascular Risk Anomalies in Chronic Kidney Disease (RCAV) Study, a cohort of US veterans (N=2,662,462). Associations between African ancestry and potassium level were investigated in African Americans in the Atherosclerosis Risk in Communities (ARIC) Study (N=3,450). Race (African American vs non-African American and percent African ancestry) for cross-sectional analysis; serum potassium level for longitudinal analysis. Potassium level for cross-sectional analysis; mortality and end-stage renal disease for longitudinal analysis. The RCAV cohort was 18% African American (N=470,985). Potassium levels on average were 0.162mmol/L lower in African Americans compared with non-African Americans, with differences persisting after adjustment for demographics, comorbid conditions, and potassium-altering medication use. In the ARIC Study, higher African ancestry was related to lower potassium levels (-0.027mmol/L per each 10% African ancestry). In both race groups, higher and lower potassium levels were associated with mortality. Compared to potassium level of 4.2mmol/L, mortality risk associated with lower potassium levels was lower in African Americans versus non-African Americans, whereas mortality risk associated with higher levels was slightly greater. Risk relationships between potassium and end-stage renal disease were weaker, with no difference by race. No data for potassium intake. African Americans had slightly lower serum potassium levels than non-African Americans. Consistent associations between potassium levels and percent African ancestry may suggest a genetic component to these differences. Higher and

Role of 11beta-hydroxysteroid dehydrogenase 2 renal activity in potassium homeostasis in rats with chronic renal failure.

PubMed

Yeyati, N L; Altuna, M E; Damasco, M C; Mac Laughlin, M A

2010-01-01

Aldosterone concentrations vary in advanced chronic renal failure (CRF). The isozyme 11beta-hydroxysteroid dehydrogenase 2 (11beta-HSD2), which confers aldosterone specificity for mineralocorticoid receptors in distal tubules and collecting ducts, has been reported to be decreased or normal in patients with renal diseases. Our objective was to determine the role of aldosterone and 11beta-HSD2 renal microsome activity, normalized for glomerular filtration rate (GFR), in maintaining K+ homeostasis in 5/6 nephrectomized rats. Male Wistar rats weighing 180-220 g at the beginning of the study were used. Rats with experimental CRF obtained by 5/6 nephrectomy (N = 9) and sham rats (N = 10) were maintained for 4 months. Systolic blood pressure and plasma creatinine (Pcr) concentration were measured at the end of the experiment. Sodium and potassium excretion and GFR were evaluated before and after spironolactone administration (10 mg.kg-1.day-1 for 7 days) and 11beta-HSD2 activity on renal microsomes was determined. Systolic blood pressure (means +/- SEM; Sham = 105 +/- 8 and CRF = 149 +/- 10 mmHg) and Pcr (Sham = 0.42 +/- 0.03 and CRF = 2.53 +/- 0.26 mg/dL) were higher (P < 0.05) while GFR (Sham = 1.46 +/- 0.26 and CRF = 0.61 +/- 0.06 mL/min) was lower (P < 0.05) in CRF, and plasma aldosterone (Pald) was the same in the two groups. Urinary sodium and potassium excretion was similar in the two groups under basal conditions but, after spironolactone treatment, only potassium excretion was decreased in CRF rats (sham = 0.95 +/- 0.090 (before) vs 0.89 +/- 0.09 microEq/min (after) and CRF = 1.05 +/- 0.05 (before) vs 0.37 +/- 0.07 microEq/min (after); P < 0.05). 11beta-HSD2 activity on renal microsomes was lower in CRF rats (sham = 0.807 +/- 0.09 and CRF = 0.217 +/- 0.07 nmol.min-1.mg protein-1; P < 0.05), although when normalized for mL GFR it was similar in both groups. We conclude that K+ homeostasis is maintained during CRF development despite normal Pald levels. This

Extracellular potassium changes in the rat neurohypophysis during activation of the magnocellular neurosecretory system.

PubMed Central

Leng, G; Shibuki, K

1987-01-01

1. Potassium-sensitive microelectrodes were used to measure extracellular [K+] in the isolated rat neurohypophysis maintained in vitro. Electrical stimulation of the neurohypophysial stalk (20 Hz 5 s) increased the inferred extracellular [K+] by 9.2 +/- 0.4 mM (mean +/- S.E. of mean; n = 21). 2. Veratridine (10 microM) enhanced the response to stalk stimulation, and at a higher concentration (50 microM) increased extracellular [K+] in the absence of stimulation. By contrast, tetrodotoxin (1 microM) blocked the [K+] increase completely and reversibly in each of five experiments, indicating that the increase was a consequence of action potential generation. 3. At the end of brief periods of stimulation, the raised extracellular [K+] returned to pre-stimulation levels within 30 s. In the presence of ouabain (100 microM), the recovery was slower: the half-decay time was extended by 150-300% in each of three experiments. 4. Replacement of calcium in the medium with cobalt, cadmium or magnesium reduced the amplitude of the [K+] increase by 26-30%, indicating that the [K+] increase was largely independent of events subsequent to evoked release of hormone and/or transmitters. 5. Potassium-sensitive microelectrodes were placed in the neurohypophysis of rats anaesthetized with urethane. Electrical stimulation of the pituitary stalk (50 Hz, 5 s) produced transient voltage increases of 7.6 +/- 0.9 mV (mean +/- S.E. of mean of seven experiments). These voltage increases were similar in magnitude to the response of the electrodes to the addition of 7.6 +/- 1.0 mM-K+ to rat plasma. 6. In seven lactating rats, the suckling of a litter of hungry pups evoked periodic reflex milk ejections, as detected by increases in intramammary pressure. Potassium-sensitive microelectrodes in the neurohypophysis recorded transient voltage increases prior to each milk ejection (0.4-5.5 mV). Each increase preceded an increase in intramammary pressure by 12-30 s. 7. Thus synchronized high

Equatorial potassium currents in lenses.

PubMed

Wind, B E; Walsh, S; Patterson, J W

1988-02-01

Earlier work with the vibrating probe demonstrated the existence of outward potassium currents at the equator and inward sodium currents at the optical poles of the lens. By adding microelectrodes to the system, it is possible to relate steady currents (J) to the potential difference (PD) measured with a microelectrode. By injecting an outward current (I), it is possible to determine resistances and also the PD at which the steady outward potassium current becomes zero (PDJ = 0). At this PD the concentration gradient for potassium efflux and the electrical gradient for potassium influx are balanced so that there is no net flow of potassium across the membranes associated with the production of J. The PDJ = 0 for 18 rat lenses was 86 mV and that for 12 frogs lenses was -95 mV. This agrees with the potassium equilibrium potential and provides strong evidence to support the view that the outward equatorial current, J, is a potassium current. With the injection of outward current, I, the PD becomes more negative, the outward equatorial current, J, decreases, and the inward current at the optical poles increases. This suggests that there are separate electrical loops for K+ and Na+ that are partially linked by the Na, K-pump. Using Ohm's law, it is possible to calculate the input resistance (R = delta PD/I), the resistance related to the production of J (RJ = delta PD/delta J), and the effect of the combined resistances (delta J/I). The driving force for J can be estimated (PDJ = 0-PD). The relationships among currents, voltages and resistance can be used to determine the characteristics of the membranes that are associated with the outward potassium current observed at the equator. The effects of graded deformation of the lens were determined. The effects were reversible. The sites of inward and outward currents were not altered. Following deformation, the equatorial current, J, increased, and the PD became less negative. The PDJ = 0 remains the same so the ratio of K

Dialysate Potassium and Mortality in a Prospective Hemodialysis Cohort.

PubMed

Ferrey, Antoney; You, Amy S; Kovesdy, Csaba P; Nakata, Tracy; Veliz, Mary; Nguyen, Danh V; Kalantar-Zadeh, Kamyar; Rhee, Connie M

2018-06-07

Studies examining the association of dialysate potassium concentration and mortality in hemodialysis patients show conflicting findings. We hypothesized that low dialysate potassium concentrations are associated with higher mortality, particularly in patients with high pre-dialysis serum potassium concentrations. We evaluated 624 hemodialysis patients from the prospective Malnutrition, Diet, and Racial Disparities in Kidney Disease study recruited from 16 outpatient dialysis facilities over 2011-2015 who underwent protocolized collection of dialysis treatment characteristics every 6 months. We examined the association of dialysate potassium concentration, categorized as 1, 2, and 3 mEq/L, with all-cause mortality risk in the -overall cohort, and stratified by pre-dialysis serum potassium (< 5 vs. ≥5 mEq/L) using case-mix adjusted Cox models. In baseline analyses, dialysate potassium concentrations of 1 mEq/L were associated with higher mortality, whereas concentrations of 3 mEq/L were associated with similar mortality in the overall cohort (reference: 2 mEq/L): adjusted hazard ratios (aHRs; 95% CI) 1.70 (1.01-2.88) and 0.95 (0.64-1.39), respectively. In analyses stratified by serum potassium, baseline dialysate potassium concentrations of 1 mEq/L were associated with higher mortality in patients with serum potassium ≥5 mEq/L but not in those with serum potassium < 5 mEq/L: aHRs (95% CI) 2.87 (1.51-5.46) and 0.74 (0.27-2.07), respectively (p interaction = 0.04). These findings were robust with incremental adjustment for serum potassium, potassium-binding resins, and potassium-modifying medications. Low (1 mEq/L) dialysate potassium -concentrations were associated with higher mortality, particularly in hemodialysis patients with high pre-dialysis serum potassium. Further studies are needed to identify therapeutic strategies that mitigate inter-dialytic serum potassium accumulation and subsequent high dialysate serum potassium gradients in this population. �

Simultaneous recovery of phosphorus and potassium as magnesium potassium phosphate from synthetic sewage sludge effluent.

PubMed

Nakao, Satoshi; Nishio, Takayuki; Kanjo, Yoshinori

2017-10-01

Bench-scale experiments were performed to investigate simultaneous recovery of phosphorus and potassium from synthetic sewage sludge effluent as crystals of magnesium potassium phosphate (MPP or struvite-(K), MgKPO 4 ·6H 2 O). The optimal pH of MPP formation was 11.5. A phosphorus level of at least 3 mM and K:P molar ratio over 3 were necessary to form MPP, which showed higher content rate of phosphorus and potassium in precipitate. MPP crystallization was confirmed by analysing the precipitates using a scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX) apparatus and an X-ray Diffractometer (XRD). Inhibition of MPP crystallization by iron and aluminium was confirmed by precipitation experiments and SEM-EDX analysis. Potassium ratio against magnesium in precipitate decreased for iron concentrations greater than over 0.2 mM and aluminium concentrations over 0.05 mM.

Analysis of the acute response of Galleria mellonella larvae to potassium nitrate.

PubMed

Maguire, Ronan; Kunc, Martin; Hyrsl, Pavel; Kavanagh, Kevin

2017-05-01

Potassium nitrate (E252) is widely used as a food preservative and has applications in the treatment of high blood pressure however high doses are carcinogenic. Larvae of Galleria mellonella were administered potassium nitrate to establish whether the acute effects in larvae correlated with those evident in mammals. Intra-haemocoel injection of potassium nitrate resulted in a significant increase in the density of circulating haemocytes and a small change in the relative proportions of haemocytes but haemocytes showed a reduced fungicidal ability. Potassium nitrate administration resulted in increased superoxide dismutase activity and in the abundance of a range of proteins associated with mitochondrial function (e.g. mitochondrial aldehyde dehydrogenase, putative mitochondrial Mn superoxide dismutase), metabolism (e.g. triosephosphate isomerase, glyceraldehyde 3 phosphate dehydrogenase) and nitrate metabolism (e.g. aliphatic nitrilase, glutathione S-transferase). A strong correlation exists between the toxicity of a range of food preservatives when tested in G. mellonella larvae and rats. In this work a correlation between the effect of potassium nitrate in larvae and mammals is shown and opens the way to the utilization of insects for studying the in vivo acute and chronic toxicity of xenobiotics. Copyright © 2017 Elsevier Inc. All rights reserved.

21 CFR 582.1804 - Sodium potassium tartrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium potassium tartrate. 582.1804 Section 582.1804 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1804 Sodium potassium tartrate. (a) Product. Sodium potassium tartrate. (b) Conditions of...

21 CFR 582.1804 - Sodium potassium tartrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium potassium tartrate. 582.1804 Section 582.1804 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1804 Sodium potassium tartrate. (a) Product. Sodium potassium tartrate. (b) Conditions of...

21 CFR 182.1129 - Aluminum potassium sulfate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Aluminum potassium sulfate. 182.1129 Section 182.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b...

21 CFR 582.1129 - Aluminum potassium sulfate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Aluminum potassium sulfate. 582.1129 Section 582.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b) Conditions of...

21 CFR 582.6804 - Sodium potassium tartrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium potassium tartrate. 582.6804 Section 582.6804 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....6804 Sodium potassium tartrate. (a) Product. Sodium potassium tartrate. (b) Conditions of use. This...

21 CFR 582.1129 - Aluminum potassium sulfate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Aluminum potassium sulfate. 582.1129 Section 582.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b) Conditions of...

21 CFR 582.1804 - Sodium potassium tartrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium potassium tartrate. 582.1804 Section 582.1804 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1804 Sodium potassium tartrate. (a) Product. Sodium potassium tartrate. (b) Conditions of...

21 CFR 182.1129 - Aluminum potassium sulfate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Aluminum potassium sulfate. 182.1129 Section 182.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b...

21 CFR 582.6804 - Sodium potassium tartrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium potassium tartrate. 582.6804 Section 582.6804 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....6804 Sodium potassium tartrate. (a) Product. Sodium potassium tartrate. (b) Conditions of use. This...

21 CFR 582.1129 - Aluminum potassium sulfate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Aluminum potassium sulfate. 582.1129 Section 582.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b) Conditions of...

21 CFR 582.1804 - Sodium potassium tartrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium potassium tartrate. 582.1804 Section 582.1804 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1804 Sodium potassium tartrate. (a) Product. Sodium potassium tartrate. (b) Conditions of...

21 CFR 582.6804 - Sodium potassium tartrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium potassium tartrate. 582.6804 Section 582.6804 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....6804 Sodium potassium tartrate. (a) Product. Sodium potassium tartrate. (b) Conditions of use. This...

21 CFR 182.1129 - Aluminum potassium sulfate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Aluminum potassium sulfate. 182.1129 Section 182.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b...

21 CFR 582.1804 - Sodium potassium tartrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium potassium tartrate. 582.1804 Section 582.1804 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1804 Sodium potassium tartrate. (a) Product. Sodium potassium tartrate. (b) Conditions of...

21 CFR 182.1129 - Aluminum potassium sulfate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Aluminum potassium sulfate. 182.1129 Section 182.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b...

21 CFR 582.6804 - Sodium potassium tartrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium potassium tartrate. 582.6804 Section 582.6804 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....6804 Sodium potassium tartrate. (a) Product. Sodium potassium tartrate. (b) Conditions of use. This...

21 CFR 582.1129 - Aluminum potassium sulfate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Aluminum potassium sulfate. 582.1129 Section 582.1129 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b) Conditions of...

21 CFR 182.1129 - Aluminum potassium sulfate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Aluminum potassium sulfate. 182.1129 Section 182...) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Multiple Purpose GRAS Food Substances § 182.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b) Conditions of use. This substance is generally...

21 CFR 582.6804 - Sodium potassium tartrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium potassium tartrate. 582.6804 Section 582.6804 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED....6804 Sodium potassium tartrate. (a) Product. Sodium potassium tartrate. (b) Conditions of use. This...

Vertebrate rod photoreceptors express both BK and IK calcium-activated potassium channels, but only BK channels are involved in receptor potential regulation.

PubMed

Pelucchi, Bruna; Grimaldi, Annalisa; Moriondo, Andrea

2008-01-01

In salamander rods, Ca(2+)-activated K(+) current (I(KCa)) provides an effective "clamp" of the dark membrane potential to its normal resting level. By a combination of electrophysiological, pharmacological, and immunohistochemical approaches, we show that salamander rods functionally express large-conductance Ca(2+)- and voltage-dependent potassium (BK) channel and intermediate-conductance Ca(2+)-dependent potassium (IK) channel, but not small-conductance Ca(2+)-dependent potassium channel (SK) subtypes. Application of 100 nM iberiotoxin and 100 nM clotrimazole reduced net I(KCa) to 36% and 63%, respectively, whereas the current was unaffected by application of 1 microM apamin. Consistently, anti- SK1, -SK2, and -SK3 antibodies were unable to stain rod photoreceptors, whereas both anti-BK and -SK4/ IK1 antibodies heavily stained the ellipsoid region of the inner segments of the rods. Moreover, by using current-clamp experiments, it was clearly seen that the strong clamping effect of the total I(KCa) was lost when IbTx, but not CLTZ, was applied to the bath. This behavior strongly suggests that of BK and IK channels, only the former are responsible for the clamping effect on the photoreceptor membrane potential.

Mapping Potassium

NASA Image and Video Library

2015-04-16

During the first year of NASA MESSENGER orbital mission, the spacecraft GRS instrument measured the elemental composition of Mercury surface materials. mong the most important discoveries from the GRS was the observation of higher abundances of the moderately volatile elements potassium, sodium, and chlorine than expected from previous scientific models and theories. Particularly high concentrations of these elements were observed at high northern latitudes, as illustrated in this potassium abundance map, which provides a view of the surface centered at 60° N latitude and 120° E longitude. This map was the first elemental map ever made of Mercury's surface and is to-date the only map to report absolute elemental concentrations, in comparison to element ratios. Prior to MESSENGER's arrival at Mercury, scientists expected that the planet would be depleted in moderately volatile elements, as is the case for our Moon. The unexpectedly high abundances observed with the GRS have forced a reevaluation of our understanding of the formation and evolution of Mercury. In addition, the K map provided the first evidence for distinct geochemical terranes on Mercury, as the high-potassium region was later found to also be distinct in its low Mg/Si, Ca/Si, S/Si, and high Na/Si and Cl/Si abundances. Instrument: Gamma-Ray Spectrometer (GRS) http://photojournal.jpl.nasa.gov/catalog/PIA19414

Delayed rectifier potassium channels are involved in SO2 derivative-induced hippocampal neuronal injury.

PubMed

Li, Guangke; Sang, Nan

2009-01-01

Recent studies implicate the possible neurotoxicity of SO(2), however, its mechanisms remain unclear. In the present study, we investigated SO(2) derivative-induced effect on delayed rectifier potassium channels (I(K)) and cellular death/apoptosis in primary cultured hippocampal neurons. The results demonstrate that SO(2) derivatives (NaHSO(3) and Na(2)SO(3), 3:1M/M) effectively augmented I(K) and promoted the activation of delayed rectifier potassium channels. Also, SO(2) derivatives increased neuronal death percentage and contributed to the formation of DNA ladder in concentration-dependent manners. Interestingly, the neuronal death and DNA ladder formation, caused by SO(2) derivatives, could be attenuated by the delayed rectifier potassium channel blocker (tetraethylammonium, TEA), but not by the transient outward potassium channel blocker (4-aminopyridine, 4-AP). It implies that stimulating delayed rectifier potassium channels were involved in SO(2) derivative-caused hippocampal neuronal insults, and blocking these channels might be one of the possibly clinical treatment for SO(2)-caused neuronal dysfunction.

21 CFR 582.1077 - Potassium acid tartrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium acid tartrate. 582.1077 Section 582.1077 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1077 Potassium acid tartrate. (a) Product. Potassium acid tartrate. (b) Conditions of use...

21 CFR 582.1077 - Potassium acid tartrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium acid tartrate. 582.1077 Section 582.1077 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1077 Potassium acid tartrate. (a) Product. Potassium acid tartrate. (b) Conditions of use...

21 CFR 582.1077 - Potassium acid tartrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium acid tartrate. 582.1077 Section 582.1077 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1077 Potassium acid tartrate. (a) Product. Potassium acid tartrate. (b) Conditions of use...

40 CFR 721.10553 - Potassium titanium oxide.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Potassium titanium oxide. 721.10553... Substances § 721.10553 Potassium titanium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as potassium titanium oxide (PMN P-06-149; CAS No. 12673-69...

40 CFR 721.10553 - Potassium titanium oxide.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Potassium titanium oxide. 721.10553... Substances § 721.10553 Potassium titanium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as potassium titanium oxide (PMN P-06-149; CAS No. 12673-69...

21 CFR 582.1077 - Potassium acid tartrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium acid tartrate. 582.1077 Section 582.1077 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1077 Potassium acid tartrate. (a) Product. Potassium acid tartrate. (b) Conditions of use...

Differential distribution of the sodium-activated potassium channels slick and slack in mouse brain.

PubMed

Rizzi, Sandra; Knaus, Hans-Günther; Schwarzer, Christoph

2016-07-01

The sodium-activated potassium channels Slick (Slo2.1, KCNT2) and Slack (Slo2.2, KCNT1) are high-conductance potassium channels of the Slo family. In neurons, Slick and Slack channels are involved in the generation of slow afterhyperpolarization, in the regulation of firing patterns, and in setting and stabilizing the resting membrane potential. The distribution and subcellular localization of Slick and Slack channels in the mouse brain have not yet been established in detail. The present study addresses this issue through in situ hybridization and immunohistochemistry. Both channels were widely distributed and exhibited distinct distribution patterns. However, in some brain regions, their expression overlapped. Intense Slick channel immunoreactivity was observed in processes, varicosities, and neuronal cell bodies of the olfactory bulb, granular zones of cortical regions, hippocampus, amygdala, lateral septal nuclei, certain hypothalamic and midbrain nuclei, and several regions of the brainstem. The Slack channel showed primarily a diffuse immunostaining pattern, and labeling of cell somata and processes was observed only occasionally. The highest Slack channel expression was detected in the olfactory bulb, lateral septal nuclei, basal ganglia, and distinct areas of the midbrain, brainstem, and cerebellar cortex. In addition, comparing our data obtained from mouse brain with a previously published study on rat brain revealed some differences in the expression and distribution of Slick and Slack channels in these species. J. Comp. Neurol. 524:2093-2116, 2016. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.

Differential distribution of the sodium‐activated potassium channels slick and slack in mouse brain

PubMed Central

Knaus, Hans‐Günther; Schwarzer, Christoph

2015-01-01

ABSTRACT The sodium‐activated potassium channels Slick (Slo2.1, KCNT2) and Slack (Slo2.2, KCNT1) are high‐conductance potassium channels of the Slo family. In neurons, Slick and Slack channels are involved in the generation of slow afterhyperpolarization, in the regulation of firing patterns, and in setting and stabilizing the resting membrane potential. The distribution and subcellular localization of Slick and Slack channels in the mouse brain have not yet been established in detail. The present study addresses this issue through in situ hybridization and immunohistochemistry. Both channels were widely distributed and exhibited distinct distribution patterns. However, in some brain regions, their expression overlapped. Intense Slick channel immunoreactivity was observed in processes, varicosities, and neuronal cell bodies of the olfactory bulb, granular zones of cortical regions, hippocampus, amygdala, lateral septal nuclei, certain hypothalamic and midbrain nuclei, and several regions of the brainstem. The Slack channel showed primarily a diffuse immunostaining pattern, and labeling of cell somata and processes was observed only occasionally. The highest Slack channel expression was detected in the olfactory bulb, lateral septal nuclei, basal ganglia, and distinct areas of the midbrain, brainstem, and cerebellar cortex. In addition, comparing our data obtained from mouse brain with a previously published study on rat brain revealed some differences in the expression and distribution of Slick and Slack channels in these species. J. Comp. Neurol. 524:2093–2116, 2016. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc. PMID:26587966

21 CFR 582.5622 - Potassium chloride.

Code of Federal Regulations, 2012 CFR

2012-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5622 Potassium chloride. (a) Product. Potassium chloride. (b) Conditions of use. This...

21 CFR 582.5622 - Potassium chloride.

Code of Federal Regulations, 2014 CFR

2014-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5622 Potassium chloride. (a) Product. Potassium chloride. (b) Conditions of use. This...

21 CFR 582.5622 - Potassium chloride.

Code of Federal Regulations, 2013 CFR

2013-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5622 Potassium chloride. (a) Product. Potassium chloride. (b) Conditions of use. This...

21 CFR 582.5622 - Potassium chloride.

Code of Federal Regulations, 2011 CFR

2011-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5622 Potassium chloride. (a) Product. Potassium chloride. (b) Conditions of use. This...

21 CFR 582.5622 - Potassium chloride.

Code of Federal Regulations, 2010 CFR

2010-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5622 Potassium chloride. (a) Product. Potassium chloride. (b) Conditions of use. This...

Potassium acetate and potassium lactate enhance the microbiological and physical properties of marinated catfish fillets

USDA-ARS?s Scientific Manuscript database

Sodium or potassium salts such as lactate and acetate can be used to inhibit the growth of spoilage bacteria and food-borne pathogens, and thereby prolong the shelf-life of refrigerated seafood. However, minimal information is available regarding the combined effects of potassium salts (acetate and ...

Butanolysis: Comparison of potassium hydroxide and potassium tert-butoxide as catalyst for biodiesel preparing from rapeseed oil.

PubMed

Musil, Martin; Skopal, Frantisek; Hájek, Martin; Vavra, Ales

2018-07-15

Biodiesel is a mixture of esters of fatty acids (most often palmitic, stearic and oleic) and lower alcohols (in our work butanol) produced by transesterification. It is a renewable source of energy, prepared from triacylglycerides, which are contained in vegetable oils and animal fats. This work focuses on alkaline catalyzed transesterification of rapeseed oil with butanol and comparison of two catalysts (potassium hydroxide and potassium tert-butoxide). In industry is usually transesterification of rapeseed oil carried out like reaction catalyzed by potassium hydroxide. Potassium hydroxide have high content of K 2 CO 3 , KHCO 3 and water. Moreover water is formed by neutralization of potassium hydroxide with free fatty acids contained in oil. In cause of tert-butoxide catalyzed reaction, it is not possible because tert-butoxide have not a OH - aniont, which is needed for water forming. The influence of various conditions (addition of water, temperature of separation, intensity of stirring and type of catalyst) on butanolysis process was studied for both catalysts. For both catalysts dependence of conversions on time were plotted. When tert-butoxide was used, satisfactory phase separation was not achieved. The only way was separation of hot crude reaction mixture without adding water. Ester formed by this method had high content of free glycerol and soaps, but reached higher conversion. The best results were obtained with KOH and subsequent separation of cold crude reaction mixture with the addition of water and slow stirring. The difference between reactions catalyzed by potassium hydroxide and potassium tert-butoxide was described. Copyright © 2018 Elsevier Ltd. All rights reserved.

Potassium Loss during Galvanotaxis of Slime Mold

PubMed Central

Anderson, John D.

1962-01-01

The posterior reticulated regions of the plasmodia of the slime mold, Physarum polycephalum, whose migration has been oriented by direct current (3.0 to 5.0 µa/mm2 in the agar substrate), contain 30 per cent less potassium than the advancing non-reticulated region. The anterior regions have the same potassium concentration as that of the controls, approximately 32 meq/kg wet weight. Differences in potassium concentration between anterior and posterior regions of control plasmodia, not oriented by electric current, are less than 5 per cent. Sodium, in contrast to potassium, is generally less concentrated in the anterior than in the posterior regions of electrically oriented plasmodia, but sodium concentrations are extremely variable. No significant difference in protein concentration was found between oriented and control plasmodia. Thirty-five per cent of the total potassium, but none of the sodium, is found in acidified ethanol precipitates from plasmodial homogenates. Potassium, but not sodium, appears to be closely associated with processes which differentiate anterior from posterior in an oriented plasmodium. PMID:13861244

DFT insight into the effect of potassium on the adsorption, activation and dissociation of CO2 over Fe-based catalysts.

PubMed

Nie, Xiaowa; Meng, Linlin; Wang, Haozhi; Chen, Yonggang; Guo, Xinwen; Song, Chunshan

2018-05-30

Catalytic conversion of CO2 including hydrogenation has attracted great attention as a method for chemical fixation of CO2 in combination with other techniques such as CO2 capture and storage. Potassium is a well-known promotor for many industrial catalytic processes such as in Fischer-Tropsch synthesis. In this work, we performed density functional theory (DFT) calculations to investigate the effect of potassium on the adsorption, activation, and dissociation of CO2 over Fe(100), Fe5C2(510) and Fe3O4(111) surfaces. The function of K was analyzed in terms of electronic interactions between co-adsorbed CO2 and K-surfaces which showed conspicuous promotion in the presence of K of the adsorption and activation of CO2. The adsorption strength of CO2 on these surfaces ranks as oct2-Fe3O4(111) > Fe(100) > Fe5C2(510). Generally, we observed a direct proportional correlation between the adsorption strength and the charges on the adsorbates. Adding K on the catalyst surface also reduces the kinetic barrier for CO2 dissociation. CO2 dissociation is more facile to occur on Fe(100) and Fe5C2(510) in the presence of K whereas the Fe3O4(111) surfaces impede CO2 dissociation regardless of the existence of K. Instead, a stable CO3- species is formed upon CO2 adsorption on Fe3O4(111) which will be directly hydrogenated when sufficient H* are available on the surface. Our results highlight the origin of the promotion effect of potassium and provide insight for the future design of K-promoted Fe-based catalysts for CO2 hydrogenation.

Potassium Blood Test: MedlinePlus Lab Test Information

MedlinePlus

... https://medlineplus.gov/labtests/potassiumbloodtest.html Potassium Blood Test To use the sharing features on this page, please enable JavaScript. What is a Potassium Blood Test? A potassium blood test measures the amount of ...

Role of potassium channels in chlorogenic acid-induced apoptotic volume decrease and cell cycle arrest in Candida albicans.

PubMed

Yun, JiEun; Lee, Dong Gun

2017-03-01

Chlorogenic acid (CRA) is an abundant phenolic compound in the human diet. CRA has a potent antifungal effect, inducing cell death in Candida albicans. However, there are no further studies to investigate the antifungal mechanism of CRA, associated with ion channels. To evaluate the inhibitory effects on CRA-induced cell death, C. albicans cells were pretreated with potassium and chloride channel blockers, separately. Flow cytometry was carried out to detect several hallmarks of apoptosis, such as cell cycle arrest, caspase activation, and DNA fragmentation, after staining of the cells with SYTOX green, FITC-VAD-FMK, and TUNEL. CRA caused excessive potassium efflux, and an apoptotic volume decrease (AVD) was observed. This change, in turn, induced cytosolic calcium uptake and cell cycle arrest in C. albicans. Moreover, CRA induced caspase activation and DNA fragmentation, which are considered apoptotic markers. In contrast, the potassium efflux and proapoptotic changes were inhibited when potassium channels were blocked, whereas there was no inhibitory effect when chloride channels were blocked. CRA induces potassium efflux, leading to AVD and G2/M cell cycle arrest in C. albicans. Therefore, potassium efflux via potassium channels regulates the CRA-induced apoptosis, stimulating several apoptotic processes. This study improves the understanding of the antifungal mechanism of CRA and its association with ion homeostasis, thereby pointing to a role of potassium channels in CRA-induced apoptosis. Copyright © 2016. Published by Elsevier B.V.

Lactococcin G is a potassium ion-conducting, two-component bacteriocin.

PubMed

Moll, G; Ubbink-Kok, T; Hildeng-Hauge, H; Nissen-Meyer, J; Nes, I F; Konings, W N; Driessen, A J

1996-02-01

Lactococcin G is a novel lactococcal bacteriocin whose activity depends on the complementary action of two peptides, termed alpha and beta. Peptide synthesis of the alpha and beta peptides yielded biologically active lactococcin G, which was used in mode-of-action studies on sensitive cells of Lactococcus lactis. Approximately equivalent amounts of both peptides were required for optimal bactericidal effect. No effect was observed with either the alpha or beta peptide in the absence of the complementary peptide. The combination of alpha and beta peptides (lactococcin G) dissipates the membrane potential (delta omega), and as a consequence cells release alpha-aminoisobutyrate, a non-metabolizable alanine analog that is accumulated through a proton motive-force dependent mechanism. In addition, the cellular ATP level is dramatically reduced, which results in a drastic decrease of the ATP-driven glutamate uptake. Lactococcin G does not form a proton-conducting pore, as it has no effect on the transmembrane pH gradient. Dissipation of the membrane potential by uncouplers causes a slow release of potassium (rubidium) ions. However, rapid release of potassium was observed in the presence of lactococcin G. These data suggest that the bactericidal effect of lactococcin G is due to the formation of potassium-selective channels by the alpha and beta peptides in the target bacterial membrane.

Suicidal ingestion of potassium permanganate crystals: a rare encounter.

PubMed

Karthik, Ravikanti; Veerendranath, Hari Prasad Kanakapura; Wali, Siddraj; Mohan, Murali N T; Kumar, Praveen A C; Trimurty, Gaganam

2014-01-01

Potassium permanganate poisoning is not common. Although Symptoms of potassium permanganate ingestion are gastrointestinal and Complications due to ingestion of potassium permanganate include cardiovascular depression, hepatic and renal damage, upper airway obstruction, bleeding tendency and methemoglobinemia. Gastric damage due to potassium permanganate has rarely been reported previously. We are reporting a 34-year old female patient who presented to our Emergency Department after suicidal ingestion of potassium permanganate crystals. After treatment, the patient was discharged home on the 8(th) day after admission. So we conclude that Emergency endoscopy has a significant role in diagnosis and management of potassium permanganate ingestion.

Suicidal Ingestion of Potassium Permanganate Crystals: A Rare Encounter

PubMed Central

Karthik, Ravikanti; Veerendranath, Hari Prasad Kanakapura; Wali, Siddraj; Mohan, Murali N T; Kumar, Praveen A. C.; Trimurty, Gaganam

2014-01-01

Potassium permanganate poisoning is not common. Although Symptoms of potassium permanganate ingestion are gastrointestinal and Complications due to ingestion of potassium permanganate include cardiovascular depression, hepatic and renal damage, upper airway obstruction, bleeding tendency and methemoglobinemia. Gastric damage due to potassium permanganate has rarely been reported previously. We are reporting a 34-year old female patient who presented to our Emergency Department after suicidal ingestion of potassium permanganate crystals. After treatment, the patient was discharged home on the 8th day after admission. So we conclude that Emergency endoscopy has a significant role in diagnosis and management of potassium permanganate ingestion. PMID:25948978

In vivo Expression of a Light-activatable Potassium Channel Using Unnatural Amino Acids

PubMed Central

Kang, Ji-Yong; Kawaguchi, Daichi; Coin, Irene; Xiang, Zheng; O’Leary, Dennis D. M.; Slesinger, Paul A.; Wang, Lei

2013-01-01

SUMMARY Optical control of protein function provides excellent spatial-temporal resolution for studying proteins in situ. Although light-sensitive exogenous proteins and ligands have been employed to manipulate neuronal activity, a method for optical control of neuronal proteins using unnatural amino acids (Uaa) in vivo is lacking. Here, we describe the genetic incorporation of a photoreactive Uaa into the pore of an inwardly-rectifying potassium channel Kir2.1. The Uaa occluded the pore, rendering the channel non-conducting, and upon brief light illumination, was released to permit outward K+ current. Expression of this photo-inducible inwardly rectifying potassium (PIRK) channel in rat hippocampal neurons created a light-activatable PIRK switch for suppressing neuronal firing. We also expressed PIRK channels in embryonic mouse neocortex in vivo and demonstrated a light-activated PIRK current in cortical neurons. The principles applied here to a potassium channel could be generally expanded to other proteins expressed in the brain to enable optical regulation. PMID:24139041

Hydrogen Sorption Properties of Potassium Alanate

NASA Astrophysics Data System (ADS)

Matysina, Z. A.; Zaginaichenko, S. Yu.; Schur, D. V.; Zolotarenko, Al. D.; Zolotarenko, An. D.; Gabdulin, M. T.

2018-06-01

Molecular kinetic representations were used to develop the statistical theory of phase transformations of thermal decomposition of KAlH4 potassium alanate with formation of a more complex K3AlH6 alanate and KH potassium hydride and subsequent dehydrogenation of the latter accompanied with free hydrogen, pure potassium and aluminum yield. Temperature dependence of the emitted free hydrogen was established. Isotherms and isopleths were built. The possibility of hysteresis effect manifestation was established. The results of calculations were compared to the experimental data.

Potassium in the atmosphere of Mercury

NASA Technical Reports Server (NTRS)

Potter, A. E.; Morgan, T. H.

1986-01-01

Spectral data are reported from a search for potassium in the Mercury atmosphere. The data were collected with instrumentation at Kitt Peak (7699 A) and at McDonald Observatory (7698.98 and 7664.86 A). The equivalent mean widths of the potassium emission lines observed are tabulated, along with the estimated abundances, which are compared with sodium abundances as determined by resonance lines. The average column abundance of potassium is projected to be 1 billion atoms/sq cm, about 1 percent the column abundance of sodium.

Multi-walled carbon nanotubes suppress potassium channel activities in PC12 cells

NASA Astrophysics Data System (ADS)

Xu, Haifei; Bai, Juan; Meng, Jie; Hao, Wei; Xu, Haiyan; Cao, Ji-Min

2009-07-01

The advancement in nanotechnology has produced technological and conceptual breakthroughs but the effects nanomaterials have on organisms at the cellular level are poorly understood. Here we report that carboxyl-terminated multi-walled carbon nanotubes (MWCNTs) act as antagonists of three types of potassium channels as assessed by whole-cell patch clamp electrophysiology on undifferentiated pheochromocytoma (PC12) cells. Our results showed that carboxyl-terminated MWCNTs suppress the current densities of Ito, IK and IK1 in a time-dependent and irreversible manner. The suppressions were most distinct 24 h after incubation with MWCNTs. However, MWCNTs did not significantly change the expression levels of reactive oxygen species (ROS) or intracellular free calcium and also did not alter the mitochondrial membrane potential (ΔΨm) in PC12 cells. These results suggest that oxidative stress was not involved in the MWCNTs suppression of Ito, IK and IK1 current densities. Nonetheless, the suppression of potassium currents by MWCNTs will impact on electrical signaling of excitable cells such as neurons and muscles.

Expression and distribution of Kv4 potassium channel subunits and potassium channel interacting proteins in subpopulations of interneurons in the basolateral amygdala.

PubMed

Dabrowska, J; Rainnie, D G

2010-12-15

The Kv4 potassium channel α subunits, Kv4.1, Kv4.2, and Kv4.3, determine some of the fundamental physiological properties of neurons in the CNS. Kv4 subunits are associated with auxiliary β-subunits, such as the potassium channel interacting proteins (KChIP1 - 4), which are thought to regulate the trafficking and gating of native Kv4 potassium channels. Intriguingly, KChIP1 is thought to show cell type-selective expression in GABA-ergic inhibitory interneurons, while other β-subunits (KChIP2-4) are associated with principal glutamatergic neurons. However, nothing is known about the expression of Kv4 family α- and β-subunits in specific interneurons populations in the BLA. Here, we have used immunofluorescence, co-immunoprecipitation, and Western Blotting to determine the relative expression of KChIP1 in the different interneuron subtypes within the BLA, and its co-localization with one or more of the Kv4 α subunits. We show that all three α-subunits of Kv4 potassium channel are found in rat BLA neurons, and that the immunoreactivity of KChIP1 closely resembles that of Kv4.3. Indeed, Kv4.3 showed almost complete co-localization with KChIP1 in the soma and dendrites of a distinct subpopulation of BLA neurons. Dual-immunofluorescence studies revealed this to be in BLA interneurons immunoreactive for parvalbumin, cholecystokin-8, and somatostatin. Finally, co-immunoprecipitation studies showed that KChIP1 was associated with all three Kv4 α subunits. Together our results suggest that KChIP1 is selectively expressed in BLA interneurons where it may function to regulate the activity of A-type potassium channels. Hence, KChIP1 might be considered as a cell type-specific regulator of GABAergic inhibitory circuits in the BLA. Copyright © 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

Influence of biochar application on potassium-solubilizing Bacillus mucilaginosus as potential biofertilizer.

PubMed

Liu, Sainan; Tang, Wenzhu; Yang, Fan; Meng, Jun; Chen, Wenfu; Li, Xianzhen

2017-01-02

Biochar can enhance soil fertility to increase agricultural productivity, whereas its improvement in soil microbial activity is still unclear. In this article, the influence of biochar on the cell growth and the potassium-solubilizing activity of Bacillus mucilaginosus AS1153 was examined. The impact on cell growth is related to the biochar-derived feedstocks and the particle size of biochar. Both intrinsic features and inner component fraction can promote the cell growth of B. mucilaginosus AS1153. The potassium-solubilizing activity was increased by 80% when B. mucilaginosus was incubated in conjunction with the biochar derived from corn stover. The survival time of B. mucilaginosus also was prolonged by adsorption in biochar. The experimental results suggested that the biochar containing B. mucilaginosus could be used as a potential biofertilizer to sustain crop production.

FORMULATION AND EVALUATION OF MICROSPHERES CONTAINING LOSARTAN POTASSIUM BY SPRAY-DRYING TECHNIQUE.

PubMed

Balwierz, Radoslaw; Jankowski, Andrzej; Jasinska, Agata; Marciniak, Dominik; Pluta, Janusz

2016-09-01

Despite numerous applications of microspheres, few works devoted to the preparation of microspheres containing cardiac medications have been published. This study presents the potential of receiving microspheres containing losartan potassium, based on a matrix containing Eudragit L30D55. The study focuses on the possibilities of controlled release of losartan potassium from microspheres in order to reduce the dosage frequency, and also provides information on the effect of the addition of excipients to the quality of the microspheres. Microspheres are monolithic, porous or smooth microparticles ranging from 1 to 500 microns in size. For the preparation of microspheres containing losartan potassium, the spray-drying method was used. The performed study confirmed that the spray-drying technology used to obtain microspheres meets the criteria of size and morphology of the microparticles. The assessment of the kinetics of losartan potassium release from the examined microspheres demonstrated that the release profile followed the first- and/or zero-order kinetics. The use of spray-drying techniques as well as Eudragit L30D55 polymer matrix to obtain the microspheres containing losartan potassium makes it possible to obtain a product with the required particle morphology and particle size ensuring the release of the active substance up to 12 h.

Dietary potassium intake and renal handling, and their impact on the cardiovascular health of normotensive afro-caribbeans.

PubMed

Cohall, D H; Scantlebury-Manning, T; Rafie, C; James, S; Hall, K

2014-01-01

Recent nutritional profiles of dietary intake have indicated a shift from the ancient diet to the Western diet. The ancient diet provided a high potassium and low sodium intake, which in turn leads to sodium conservation and potassium excretion. This change in the dietary intake is expected to affect potassium and sodium handling in the kidneys. Numerous studies have been done to emphasize the importance of sodium handling by the kidneys and its impact on cardiovascular health. This study will investigate potassium intake and handling, and its impact on the cardiovascular health of a sample of normotensive Afro-Caribbeans by the possible modulation of the renin angiotensin aldosterone system (RAAS). A sample of 51 normotensive Afro-Caribbean participants was recruited for the study. Participants were observed over a two-day period in which they were given a 24-hour ambulatory blood pressure monitor and a container to collect blood pressure data and a 24-hour urine sample. Anthropometric measurements were noted. Urinary electrolytes and supine plasma renin activity (PRA) were determined from the 24-hour urine collection and a blood sample. Dietary potassium intake was estimated based on dietary intake observations and calculated based on the urinary potassium excretion. SPSS version 19 was used to analyse the data to make inferences. The daily potassium intake was observed to be 2.95 g/day and measured intake from the urinary potassium was between 4.95 and 7.32 g/day. Urinary potassium excretion was 3.66 (± 1.40) g/day. The urinary potassium excretion in the Afro-Caribbean sample in Barbados was higher than the other population samples. The averaged PRA of the participants (supine) was 0.778 (± 1.072) ng/mL/hour. The averaged nocturnal systolic blood pressure dip of the participants was 5.97 (± 4.324) %. There was no significant correlation between urinary potassium excretion, blood pressure, nocturnal systolic blood pressure dip and PRA. The Afro

Calcium-activated potassium channels in insect pacemaker neurons as unexpected target site for the novel fumigant dimethyl disulfide.

PubMed

Gautier, Hélène; Auger, Jacques; Legros, Christian; Lapied, Bruno

2008-01-01

Dimethyl disulfide (DMDS), a plant-derived insecticide, is a promising fumigant as a substitute for methyl bromide. To further understand the mode of action of DMDS, we examined its effect on cockroach octopaminergic neurosecretory cells, called dorsal unpaired median (DUM) neurons, using whole-cell patch-clamp technique, calcium imaging and antisense oligonucleotide strategy. At low concentration (1 microM), DMDS modified spontaneous regular spike discharge into clear bursting activity associated with a decrease of the amplitude of the afterhyperpolarization. This effect led us to suspect alterations of calcium-activated potassium currents (IKCa) and [Ca(2+)](i) changes. We showed that DMDS reduced amplitudes of both peak transient and sustained components of the total potassium current. IKCa was confirmed as a target of DMDS by using iberiotoxin, cadmium chloride, and pSlo antisense oligonucleotide. In addition, we showed that DMDS induced [Ca(2+)](i) rise in Fura-2-loaded DUM neurons. Using calcium-free solution, and (R,S)-(3,4-dihydro-6,7-dimethoxy-isoquinoline-1-yl)-2-phenyl-N,N-di-[2-(2,3,4-trimethoxy-phenyl)ethyl]-acetamide (LOE 908) [an inhibitor of transient receptor potential (TRP)gamma], we demonstrated that TRPgamma initiated calcium influx. By contrast, omega-conotoxin GVIA (an inhibitor of N-type high-voltage-activated calcium channels), did not affect the DMDS-induced [Ca(2+)](i) rise. Finally, the participation of the calcium-induced calcium release mechanism was investigated using thapsigargin, caffeine, and ryanodine. Our study revealed that DMDS-induced elevation in [Ca(2+)](i) modulated IKCa in an unexpected bell-shaped manner via intracellular calcium. In conclusion, DMDS affects multiple targets, which could be an effective way to improve pest control efficacy of fumigation.

21 CFR 181.33 - Sodium nitrate and potassium nitrate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium nitrate and potassium nitrate. 181.33...-Sanctioned Food Ingredients § 181.33 Sodium nitrate and potassium nitrate. Sodium nitrate and potassium... nitrite, with or without sodium or potassium nitrite, in the production of cured red meat products and...

21 CFR 181.34 - Sodium nitrite and potassium nitrite.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium nitrite and potassium nitrite. 181.34...-Sanctioned Food Ingredients § 181.34 Sodium nitrite and potassium nitrite. Sodium nitrite and potassium... fixatives and preservative agents, with or without sodium or potassium nitrate, in the curing of red meat...

21 CFR 181.33 - Sodium nitrate and potassium nitrate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium nitrate and potassium nitrate. 181.33...-Sanctioned Food Ingredients § 181.33 Sodium nitrate and potassium nitrate. Sodium nitrate and potassium... nitrite, with or without sodium or potassium nitrite, in the production of cured red meat products and...

21 CFR 181.34 - Sodium nitrite and potassium nitrite.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium nitrite and potassium nitrite. 181.34...-Sanctioned Food Ingredients § 181.34 Sodium nitrite and potassium nitrite. Sodium nitrite and potassium... fixatives and preservative agents, with or without sodium or potassium nitrate, in the curing of red meat...

Recent advances in distal tubular potassium handling

PubMed Central

Rodan, Aylin R.; Cheng, Chih-Jen

2011-01-01

It is well known that sodium reabsorption and aldosterone play important roles in potassium secretion by the aldosterone-sensitive distal nephron. Sodium- and aldosterone-independent mechanisms also exist. This review focuses on some recent studies that provide novel insights into the sodium- and aldosterone-independent potassium secretion by the aldosterone-sensitive distal nephron. In addition, we discuss a study reporting on the regulation of the mammalian potassium kidney channel ROMK by intracellular and extracellular magnesium, which may be important in the pathogenesis of persistent hypokalemia in patients with concomitant potassium and magnesium deficiency. We also discuss outstanding questions and propose working models for future investigation. PMID:21270092

Potassium Iodide

MedlinePlus

... iodide you should take or give to your child depends on your age or your child's age. If potassium iodide is taken by a ... you should take yourself or give to your child. Ask your doctor, pharmacist, or public official if ...

Plasma Potassium Determines NCC Abundance in Adult Kidney-Specific γENaC Knockout.

PubMed

Boscardin, Emilie; Perrier, Romain; Sergi, Chloé; Maillard, Marc P; Loffing, Johannes; Loffing-Cueni, Dominique; Koesters, Robert; Rossier, Bernard C; Hummler, Edith

2018-03-01

The amiloride-sensitive epithelial sodium channel (ENaC) and the thiazide-sensitive sodium chloride cotransporter (NCC) are key regulators of sodium and potassium and colocalize in the late distal convoluted tubule of the kidney. Loss of the α ENaC subunit leads to a perinatal lethal phenotype characterized by sodium loss and hyperkalemia resembling the human syndrome pseudohypoaldosteronism type 1 (PHA-I). In adulthood, inducible nephron-specific deletion of α ENaC in mice mimics the lethal phenotype observed in neonates, and as in humans, this phenotype is prevented by a high sodium (HNa + )/low potassium (LK + ) rescue diet. Rescue reflects activation of NCC, which is suppressed at baseline by elevated plasma potassium concentration. In this study, we investigated the role of the γ ENaC subunit in the PHA-I phenotype. Nephron-specific γ ENaC knockout mice also presented with salt-wasting syndrome and severe hyperkalemia. Unlike mice lacking α ENaC or β ΕΝaC, an HNa + /LK + diet did not normalize plasma potassium (K + ) concentration or increase NCC activation. However, when K + was eliminated from the diet at the time that γ ENaC was deleted, plasma K + concentration and NCC activity remained normal, and progressive weight loss was prevented. Loss of the late distal convoluted tubule, as well as overall reduced β ENaC subunit expression, may be responsible for the more severe hyperkalemia. We conclude that plasma K + concentration becomes the determining and limiting factor in regulating NCC activity, regardless of Na + balance in γ ENaC-deficient mice. Copyright © 2018 by the American Society of Nephrology.

21 CFR 181.33 - Sodium nitrate and potassium nitrate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium nitrate and potassium nitrate. 181.33... nitrate and potassium nitrate. Sodium nitrate and potassium nitrate are subject to prior sanctions issued... potassium nitrite, in the production of cured red meat products and cured poultry products. [48 FR 1705, Jan...

21 CFR 181.34 - Sodium nitrite and potassium nitrite.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium nitrite and potassium nitrite. 181.34... nitrite and potassium nitrite. Sodium nitrite and potassium nitrite are subject to prior sanctions issued... without sodium or potassium nitrate, in the curing of red meat and poultry products. [48 FR 1705, Jan. 14...

40 CFR 721.10021 - Magnesium potassium titanium oxide.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Magnesium potassium titanium oxide... Specific Chemical Substances § 721.10021 Magnesium potassium titanium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as magnesium potassium...

40 CFR 721.10021 - Magnesium potassium titanium oxide.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Magnesium potassium titanium oxide... Specific Chemical Substances § 721.10021 Magnesium potassium titanium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as magnesium potassium...

40 CFR 721.10021 - Magnesium potassium titanium oxide.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Magnesium potassium titanium oxide... Specific Chemical Substances § 721.10021 Magnesium potassium titanium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as magnesium potassium...

40 CFR 721.10021 - Magnesium potassium titanium oxide.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Magnesium potassium titanium oxide... Specific Chemical Substances § 721.10021 Magnesium potassium titanium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as magnesium potassium...

The relationship between uric acid and potassium in normal subjects.

PubMed Central

Kennedy, A C; Boddy, K; King, P C; Brennan, J; Anderson, J A; Buchanan, W W

1978-01-01

The serum uric acid concentration in normal healthy subjects has been studied in relation to sex, height, weight, lean body mass measured from total body potassium and predicted from the Hume-Weyers formula (1971), total body potassium, plasma potassium and urea, and packed cell volume. The strongest correlation was found with sex, but height, weight, total body potassium, lean body mass (measured and predicted) also correlated significantly with serum uric acid concentration. However, when the sex variable was removed, the other factors lost their significant correlation. Finally, total red blood cell and plasma volumes were predicted (Hume and Goldberg, 1964) and from these an estimate of total plasma uric acid, total plasma potassium, and total red blood cell potassium obtained. Measured total body potassium was found to correlate well with total plasma potassium and total red blood cell potassium independent of sex. Total plasma uric acid correlated well with measured total body potassium when both sexes were considered and when separated into male and female groups the males retained a significant correlation as did the female group. PMID:686865

Low-Cost High-Energy Potassium Cathode

DOE PAGES

Xue, Leigang; Li, Yutao; Gao, Hongcai; ...

2017-01-26

Potassium has as rich an abundance as sodium in the earth, but the development of a K-ion battery is lagging behind because of the higher mass and larger ionic size of K + than that of Li + and Na +, which makes it difficult to identify a high-voltage and high-capacity intercalation cathode host. Here we propose a cyanoperovskite K xMnFe(CN) 6 (0 ≤ x ≤ 2) as a potassium cathode: high-spin Mn III/Mn II and low-spin Fe III/Fe II couples have similar energies and exhibit two close plateaus centered at 3.6 V; two active K + per formula unitmore » enable a theoretical specific capacity of 156 mAh g -1; Mn and Fe are the two most-desired transition metals for electrodes because they are cheap and environmental friendly. As a powder prepared by an inexpensive precipitation method, the cathode delivers a specific capacity of 142 mAh g -1. Lastly, the observed voltage, capacity, and its low cost make it competitive in large-scale electricity storage applications.« less

The role of dietary potassium in hypertension and diabetes.

PubMed

Ekmekcioglu, Cem; Elmadfa, Ibrahim; Meyer, Alexa L; Moeslinger, Thomas

2016-03-01

Potassium is an essential mineral which plays major roles for the resting membrane potential and the intracellular osmolarity. In addition, for several years, it has been known that potassium also affects endothelial and vascular smooth muscle functions and it has been repeatedly shown that an increase in potassium intake shifts blood pressure to a more preferable level. Meanwhile, the blood pressure lowering effects of potassium were presented in several intervention trials and summarized in a handful of meta-analyses. Furthermore, accumulating epidemiological evidence from, especially, the last decade relates low dietary potassium intake or serum potassium levels to an increased risk for insulin resistance or diabetes. However, intervention trials are required to confirm this association. So, in addition to reduction of sodium intake, increasing dietary potassium intake may positively affect blood pressure and possibly also glucose metabolism in many populations. This concise review not only summarizes the studies linking potassium to blood pressure and diabetes but also discusses potential mechanisms involved, like vascular smooth muscle relaxation and endothelium-dependent vasodilation or stimulation of insulin secretion in pancreatic β-cells, respectively.

Movement of Potassium Ions inside KcsA in the High Concentration Regime using a Molecular Dynamics Simulation

NASA Astrophysics Data System (ADS)

Kim, Myojeong; Jo, Byeong Chul; Yoon, Hyun Jung; Wu, Sangwook; Thangappan, Jayaraman; Eun, Changsun

2018-05-01

The selectivity and conduction specificity of the KcsA channel toward potassium ions is crucial to the activity of this protein and this channel is intricately associated with several osmotic regulation and neuronal signaling processes. Despite multi-ion characteristics, the selective conduction behavior of KcsA is controlled by the size and distance specific electrostatic interaction between the selected residues and the potassium ions. The mechanism describing the movement of potassium ions in the channel and the conformational changes to KcsA that facilitate ion movement were investigated by a molecular dynamics (MD) simulation. In this study, we analyze the movement of potassium ions and water molecules at various time intervals during a 90 ns molecular dynamics simulation in the high potassium ion concentration regime and in the absence of the voltage. Examination of specific (3.6, 17.3, 43.38 and 43.44 ns) simulation periods revealed that key residues in the selectivity filter of KcsA influence the movement of potassium ions in the channel.

40 CFR 721.10031 - Lithium potassium titanium oxide.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Lithium potassium titanium oxide. 721... Substances § 721.10031 Lithium potassium titanium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as lithium potassium titanium oxide (PMN P-02...

40 CFR 721.10031 - Lithium potassium titanium oxide.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Lithium potassium titanium oxide. 721... Substances § 721.10031 Lithium potassium titanium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as lithium potassium titanium oxide (PMN P-02...

40 CFR 721.10031 - Lithium potassium titanium oxide.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Lithium potassium titanium oxide. 721... Substances § 721.10031 Lithium potassium titanium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as lithium potassium titanium oxide (PMN P-02...

40 CFR 721.10031 - Lithium potassium titanium oxide.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Lithium potassium titanium oxide. 721... Substances § 721.10031 Lithium potassium titanium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as lithium potassium titanium oxide (PMN P-02...

40 CFR 721.10031 - Lithium potassium titanium oxide.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Lithium potassium titanium oxide. 721... Substances § 721.10031 Lithium potassium titanium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as lithium potassium titanium oxide (PMN P-02...

21 CFR 172.375 - Potassium iodide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be...

A Duo of Potassium-Responsive Histidine Kinases Govern the Multicellular Destiny of Bacillus subtilis.

PubMed

Grau, Roberto R; de Oña, Paula; Kunert, Maritta; Leñini, Cecilia; Gallegos-Monterrosa, Ramses; Mhatre, Eisha; Vileta, Darío; Donato, Verónica; Hölscher, Theresa; Boland, Wilhelm; Kuipers, Oscar P; Kovács, Ákos T

2015-07-07

Multicellular biofilm formation and surface motility are bacterial behaviors considered mutually exclusive. However, the basic decision to move over or stay attached to a surface is poorly understood. Here, we discover that in Bacillus subtilis, the key root biofilm-controlling transcription factor Spo0A~Pi (phosphorylated Spo0A) governs the flagellum-independent mechanism of social sliding motility. A Spo0A-deficient strain was totally unable to slide and colonize plant roots, evidencing the important role that sliding might play in natural settings. Microarray experiments plus subsequent genetic characterization showed that the machineries of sliding and biofilm formation share the same main components (i.e., surfactin, the hydrophobin BslA, exopolysaccharide, and de novo-formed fatty acids). Sliding proficiency was transduced by the Spo0A-phosphorelay histidine kinases KinB and KinC. We discovered that potassium, a previously known inhibitor of KinC-dependent biofilm formation, is the specific sliding-activating signal through a thus-far-unnoticed cytosolic domain of KinB, which resembles the selectivity filter sequence of potassium channels. The differential expression of the Spo0A~Pi reporter abrB gene and the different levels of the constitutively active form of Spo0A, Sad67, in Δspo0A cells grown in optimized media that simultaneously stimulate motile and sessile behaviors uncover the spatiotemporal response of KinB and KinC to potassium and the gradual increase in Spo0A~Pi that orchestrates the sequential activation of sliding, followed by sessile biofilm formation and finally sporulation in the same population. Overall, these results provide insights into how multicellular behaviors formerly believed to be antagonistic are coordinately activated in benefit of the bacterium and its interaction with the host. Alternation between motile and sessile behaviors is central to bacterial adaptation, survival, and colonization. However, how is the collective

Benefit and risk assessment of increasing potassium intake by replacement of sodium chloride with potassium chloride in industrial food products in Norway.

PubMed

Steffensen, Inger-Lise; Frølich, Wenche; Dahl, Knut Helkås; Iversen, Per Ole; Lyche, Jan Ludvig; Lillegaard, Inger Therese Laugsand; Alexander, Jan

2018-01-01

High sodium chloride (NaCl) intake is associated with health risks. NaCl may be replaced by potassium chloride (KCl) to decrease sodium intake. However, increased potassium may also have negative health effects. We conducted a benefit and risk assessment of increasing potassium by ratios of 30:70, 50:50, 70:30 (weight % K + : weight % Na + ) in children, adolescents and adults in Norway, using intake data from national food consumption surveys and available literature on potassium health effects. An intake of at least 3.5 g/day of potassium decreases risk of stroke and hypertension, and this level was used in the benefit assessment of the healthy population. Three g/day of potassium added to mean food intake is assumed safe, and these levels were used in the risk assessment. Not all persons reached the protective level of potassium, and increasing numbers exceeded the safe levels, in these scenarios. In addition, elderly above 85 years and infants below one year of age, as well as several patient groups and medication users, are particularly vulnerable to hyperkalemia. In conclusion, the number of Norwegians facing increased risk is far greater than the number likely to benefit from this replacement of sodium with potassium in industrially produced food. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lack of genotoxicity of potassium iodate in the alkaline comet assay and in the cytokinesis-block micronucleus test. Comparison to potassium bromate.

PubMed

Poul, J M; Huet, S; Godard, T; Sanders, P

2004-02-01

Iodine could be added to the diet of human population in the form of iodide or iodate but iodate had not been adequately tested for genotoxicity and carcinogenicity. In the present study, genotoxic effects of potassium iodate were evaluated in vitro using the alkaline comet assay and the cytokinesis-block micronucleus assay on CHO cells and compared to halogenate salt analogues potassium bromate and chlorate and also to their respective reduced forms (potassium iodide, bromide and chloride). The results showed that the comet assay failed to detect the presence of DNA damage after a treatment of cells by potassium iodate for concentrations up to 10 mM. This absence of primary DNA damage was confirmed in the cytokinesis-block micronucleus assay. In the same way, results showed that potassium chlorate as well as potassium iodide, bromide and chloride did not induced DNA damage in the alkaline comet assay for doses up to 10 mM. By contrast, potassium bromate exposure led to an increase in both DNA damage and frequency of micronucleated cells. The repair of bromate-induced DNA damage was incomplete 24 h after the end of treatment. These results seem to indicate that potassium bromate would induce DNA damage by several mechanisms besides oxidative stress.

21 CFR 582.5634 - Potassium iodide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5634 Potassium iodide. (a) Product. Potassium iodide. (b) Tolerance. 0.01 percent. (c... salt as a source of dietary iodine in accordance with good manufacturing or feeding practice. ...

21 CFR 582.5634 - Potassium iodide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5634 Potassium iodide. (a) Product. Potassium iodide. (b) Tolerance. 0.01 percent. (c... salt as a source of dietary iodine in accordance with good manufacturing or feeding practice. ...

21 CFR 582.5634 - Potassium iodide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5634 Potassium iodide. (a) Product. Potassium iodide. (b) Tolerance. 0.01 percent. (c... salt as a source of dietary iodine in accordance with good manufacturing or feeding practice. ...

21 CFR 172.375 - Potassium iodide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be safely used in accordance with the...

Preventive dietary potassium supplementation in young salt-sensitive Dahl rats attenuates development of salt hypertension by decreasing sympathetic vasoconstriction.

PubMed

Zicha, J; Dobešová, Z; Behuliak, M; Kuneš, J; Vaněčková, I

2011-05-01

Increased potassium intake attenuates the development of salt-dependent hypertension, but the detailed mechanisms of blood pressure (BP) reduction are still unclear. The aims of our study were (i) to elucidate these mechanisms, (ii) to compare preventive potassium effects in immature and adult animals and (iii) to evaluate the therapeutic effects of dietary potassium supplementation in rats with established salt hypertension.   Young (4-week-old) and adult (24-week-old) female salt-sensitive Dahl rats were fed a high-salt diet (5% NaCl) or a high-salt diet supplemented with 3% KCl for 5 weeks. The participation of vasoconstrictor (renin-angiotensin and sympathetic nervous systems) and vasodilator systems [prostanoids, Ca(2+) -activated K(+) channels, nitric oxide (NO)] was evaluated using a sequential blockade of these systems. Preventive potassium supplementation attenuated the development of severe salt hypertension in young rats, whereas it had no effects on BP in adult rats with moderate hypertension. Enhanced sympathetic vasoconstriction was responsible for salt hypertension in young rats and its attenuation for potassium-induced BP reduction. Conversely, neither salt hypertension nor its potassium-induced attenuation were associated with significant changes of the vasodilator systems studied. The relative deficiency of vasodilator action of NO and Ca(2+) -activated K(+) channels in salt hypertensive Dahl rats was not improved by potassium supplementation. The attenuation of enhanced sympathetic vasoconstriction is the principal mechanism of antihypertensive action exerted by preventive potassium supplementation in immature Dahl rats. Dietary potassium supplementation has no preventive effects on BP in adult salt-loaded animals or no therapeutic effects on established salt hypertension in young rats. © 2011 The Authors. Acta Physiologica © 2011 Scandinavian Physiological Society.

Magneto-optical trapping of potassium isotopes

NASA Astrophysics Data System (ADS)

Williamson, Robert Sylvester, III

1997-12-01

We have demonstrated a magneto-optical trap (scMOT) suitable for capturing radioactive potassium produced on- line with the UW-Madison 12MeV tandem electrostatic accelerator. To do this, we made and characterized the first scMOT for potassium, measured the potassium ultracold collision rate, and developed a numerical trap- loading rate model that makes useful quantitative predictions. We have created a cold beam of collimated potassium atoms using a pyramidal magneto-optical funnel and used it to load a long-lifetime scMOT operating at ultrahigh vacuum. We have also built a target that produces a beam of radioactive 37K and 38K and coupled it to the magneto-optical funnel and trap. Once a trap of radioactive 38K has been demonstrated, the primary goal of this project is to measure the beta-asymmetry parameter in the decay of 38K, performing a sensitive test of the Standard Model of weak interactions.

Multimegawatt potassium Rankine power for nuclear electric power

NASA Technical Reports Server (NTRS)

Rovang, Richard D.; Mills, Joseph C.; Baumeister, Ernie B.

1991-01-01

A cermet fueled potassium rankine power system concept has been developed for various power ranges and operating lifetimes. This concept utilizes a single primary lithium loop to transport thermal energy from the reactor to the boiler. Multiple, independent potassium loops are employed to achieve the required reliability of 99 percent. The potassium loops are two phase systems which expand heated potassium vapor through multistage turboalternators to produce a 10-kV dc electrical output. Condensation occurs by-way-of a shear-flow condenser, producing a 100 percent liquid potassium stream which is pumped back to the boiler. Waste heat is rejected by an advanced carbon-carbon radiator at approximately 1000 K. Overall system efficiencies of 19.3 percent to 20.5 percent were calculated depending on mission life and power level.

21 CFR 582.1077 - Potassium acid tartrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Additives § 582.1077 Potassium acid tartrate. (a) Product. Potassium acid tartrate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or...

21 CFR 582.1129 - Aluminum potassium sulfate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Additives § 582.1129 Aluminum potassium sulfate. (a) Product. Aluminum potassium sulfate. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or...

21 CFR 172.730 - Potassium bromate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Other Specific Usage Additives § 172.730 Potassium bromate. The food additive potassium bromate may be... intended for use in the malting of barley under conditions whereby the amount of the additive present in...

21 CFR 172.730 - Potassium bromate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Other Specific Usage Additives § 172.730 Potassium bromate. The food additive potassium bromate may be... intended for use in the malting of barley under conditions whereby the amount of the additive present in...

21 CFR 184.1639 - Potassium lactate.

Code of Federal Regulations, 2011 CFR

2011-04-01

.... No. 996-31-6) is the potassium salt of lactic acid. It is a hydroscopic, white, odorless solid and is prepared commercially by the neutralization of lactic acid with potassium hydroxide. (b) The ingredient... current good manufacturing practice. (d) Prior sanctions for this ingredient different from the uses...

21 CFR 184.1639 - Potassium lactate.

Code of Federal Regulations, 2012 CFR

2012-04-01

.... No. 996-31-6) is the potassium salt of lactic acid. It is a hydroscopic, white, odorless solid and is prepared commercially by the neutralization of lactic acid with potassium hydroxide. (b) The ingredient... current good manufacturing practice. (d) Prior sanctions for this ingredient different from the uses...

21 CFR 184.1639 - Potassium lactate.

Code of Federal Regulations, 2013 CFR

2013-04-01

.... No. 996-31-6) is the potassium salt of lactic acid. It is a hydroscopic, white, odorless solid and is prepared commercially by the neutralization of lactic acid with potassium hydroxide. (b) The ingredient... current good manufacturing practice. (d) Prior sanctions for this ingredient different from the uses...

21 CFR 184.1639 - Potassium lactate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... potassium salt of lactic acid. It is a hydroscopic, white, odorless solid and is prepared commercially by the neutralization of lactic acid with potassium hydroxide. (b) The ingredient must be of a purity.... (d) Prior sanctions for this ingredient different from the uses established in this section do not...

21 CFR 184.1639 - Potassium lactate.

Code of Federal Regulations, 2010 CFR

2010-04-01

.... No. 996-31-6) is the potassium salt of lactic acid. It is a hydroscopic, white, odorless solid and is prepared commercially by the neutralization of lactic acid with potassium hydroxide. (b) The ingredient... current good manufacturing practice. (d) Prior sanctions for this ingredient different from the uses...

Fischer–Tropsch Synthesis: XANES Spectra of Potassium in Promoted Precipitated Iron Catalysts as a Function of Time On-stream

DOE PAGES

Jacobs, Gary; Pendyala, Venkat Ramana Rao; Martinelli, Michela; ...

2017-06-06

XANES K-edge spectra of potassium promoter in precipitated Fe catalysts were acquired following activation by carburization in CO and as a function of time on-stream during the course of a Fischer–Tropsch synthesis run for a 100Fe:2K catalyst by withdrawing catalysts, sealed in wax product, for analysis. CO-activated and end-of-run spectra of the catalyst were also obtained for a 100Fe:5K catalyst. Peaks representing electronic transitions and multiple scattering were observed and resembled reference spectra for potassium carbonate or potassium formate. The shift in the multiple scattering peak to higher energy was consistent with sintering of potassium promoter during the course ofmore » the reaction test. The catalyst, however, retained its carbidic state, as demonstrated by XANES and EXAFS spectra at the iron K-edge, suggesting that sintering of potassium did not adversely affect the carburization rate, which is important for preventing iron carbides from oxidizing. This method serves as a starting point for developing better understanding of the chemical state and changes in structure occurring with alkali promoter.« less

Potassium acceptor doping of ZnO crystals

NASA Astrophysics Data System (ADS)

Parmar, Narendra S.; Corolewski, Caleb D.; McCluskey, Matthew D.; Lynn, K. G.

2015-05-01

ZnO bulk single crystals were doped with potassium by diffusion at 950°C. Positron annihilation spectroscopy confirms the filling of zinc vacancies and a different trapping center for positrons. Secondary ion mass spectroscopy measurements show the diffusion of potassium up to 10 μm with concentration ˜1 × 1016 cm-3. IR measurements show a local vibrational mode (LVM) at 3226 cm-1, at a temperature of 9 K, in a potassium doped sample that was subsequently hydrogenated. The LVM is attributed to an O-H bond-stretching mode adjacent to a potassium acceptor. When deuterium substitutes for hydrogen, a peak is observed at 2378 cm-1. The O-H peak is much broader than the O-D peak, perhaps due to an unusually low vibrational lifetime. The isotopic frequency ratio is similar to values found in other hydrogen complexes. Potassium doping increases the resistivity up to 3 orders of magnitude at room temperature. The doped sample has a donor level at 0.30 eV.

Potassium acceptor doping of ZnO crystals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parmar, Narendra S., E-mail: nparmar@wsu.edu; Lynn, K. G.; Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814

2015-05-15

ZnO bulk single crystals were doped with potassium by diffusion at 950°C. Positron annihilation spectroscopy confirms the filling of zinc vacancies and a different trapping center for positrons. Secondary ion mass spectroscopy measurements show the diffusion of potassium up to 10 μm with concentration ∼1 × 10{sup 16} cm{sup −3}. IR measurements show a local vibrational mode (LVM) at 3226 cm{sup −1}, at a temperature of 9 K, in a potassium doped sample that was subsequently hydrogenated. The LVM is attributed to an O–H bond-stretching mode adjacent to a potassium acceptor. When deuterium substitutes for hydrogen, a peak is observedmore » at 2378 cm{sup −1}. The O-H peak is much broader than the O-D peak, perhaps due to an unusually low vibrational lifetime. The isotopic frequency ratio is similar to values found in other hydrogen complexes. Potassium doping increases the resistivity up to 3 orders of magnitude at room temperature. The doped sample has a donor level at 0.30 eV.« less

Diagnostic value of potassium level in a spot urine sample as an index of 24-hour urinary potassium excretion in unselected patients hospitalized in a hypertension unit

PubMed Central

Symonides, Bartosz; Wojciechowska, Ewa; Gryglas, Adam; Gaciong, Zbigniew

2017-01-01

Background Primary hyperaldosteronism may be associated with elevated 24-hour urinary potassium excretion. We evaluated the diagnostic value of spot urine (SU) potassium as an index of 24-hour urinary potassium excretion. Methods We measured SU and 24-hour urinary collection potassium and creatinine in 382 patients. Correlations between SU and 24-hour collections were assessed for potassium levels and potassium/creatinine ratios. We used the PAHO formula to estimate 24-hour urinary potassium excretion based on SU potassium level. The agreement between estimated and measured 24-hour urinary potassium excretion was evaluated using the Bland-Altman method. To evaluate diagnostic performance of SU potassium, we calculated areas under the curve (AUC) for SU potassium/creatinine ratio and 24-hour urinary potassium excretion estimated using the PAHO formula. Results Strongest correlation between SU and 24-hour collection was found for potassium/creatinine ratio (r = 0.69, P<0.001). The PAHO formula underestimated 24-hour urinary potassium excretion by mean 8.3±18 mmol/d (95% limits of agreement -28 to +44 mmol/d). Diagnostic performance of SU potassium/creatinine ratio was borderline good only if 24-hour urinary potassium excretion was largely elevated (AUC 0.802 for 120 mmol K+/24 h) but poor with lower values (AUC 0.696 for 100 mmol K+/24 h, 0.636 for 80 mmol K+/24 h, 0.675 for 40 mmol K+/24 h). Diagnostic performance of 24-hour urinary potassium excretion estimated by the PAHO formula was excellent with values above 120 mmol/d and good with lower values (AUC 0.941 for 120 mmol K+/24 h, 0.819 for 100 mmol K+/24 h, 0.823 for 80 mmol K+/24 h, 0.836 for 40 mmol K+/24 h). Conclusions Spot urine potassium/creatinine ratio might be a marker of increased 24-hour urinary potassium excretion and a potentially useful screening test when reliable 24-hour urine collection is not available. The PAHO formula allowed estimation of the 24-hour urinary potassium excretion based on SU

A Simplified Extemporaneously Prepared Potassium Chloride Oral Solution.

PubMed

Tannous, Elias; Tal, Yana; Amarny, Kamal

2016-01-01

Although commercial preparations of oral potassium supplements are usually available, there are times when our Medical Center is faced with situations in which the oral solution of potassium chloride is not available. This solution is necessary for our pediatric outpatients who cannot swallow tablets and need an oral solution. Moreover, there are no studies available which describe an extemporaneously prepared potassium chloride oral solution on which we can rely for assigning a beyond-use date. The aim of this study was to formulate an extemporaneous pediatric oral solution of potassium chloride and to determine the physical and chemical stability of this preparation. We prepared 1 mMoL/mL by withdrawing 25 mL of potassium chloride 14.9%. Ora-Sweet SF was added to 50 mL in a metered flask. The solution was kept refrigerated (2°C to 8°C). Samples were withdrawn to measure potassium concentration, pH, and microbial overgrowth. The test was performed by our biochemical laboratory. The oral solution of potassium chloride 1 mMoL/mL stored at 2°C to 8°C maintained at least 91% of the initial concentration for 28 days. There were no notable changes in pH, and the solution remained physically stable with no visual microbial growth. The oral solution of potassium chloride 1 mMoL/mL prepared in Ora-Sweet and stored at 2°C to 8°C in amber glass bottles is expected to remain stable for 28 days. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

Implementation of a timed, electronic, assessment-driven potassium-replacement protocol.

PubMed

Zielenski, Christopher; Crabtree, Adam; Le, Tien; Marlatt, Alyse; Ng, Dana; Tran, Alan

2017-06-15

The adherence to and effectiveness and safety of a timed, electronic, assessment-driven potassium-replacement protocol (TARP) were compared with an electronic nurse-driven replacement protocol (NRP) are reported. A retrospective observational study was conducted in a community hospital evaluating protocol adherence, effectiveness, and safety for 2 potassium-replacement protocols. All adults on medical units with an order for potassium replacement per protocol during the 3-month trial periods were reviewed. All patients requiring potassium replacement per protocol were included in the analysis. Adherence to the protocol was assessed by evaluating the dose of potassium administered and performance of reassessments. Effectiveness of the protocol was assessed by evaluating the time to achieve target potassium levels. Safety was assessed by evaluating the route of administration and occurrence of hyperkalemia. A total of 300 patients treated using potassium-replacement protocols required potassium replacement during the study period, with 148 patients in the NRP group requiring 491 instances of potassium replacement. In the TARP group a total of 564 instances requiring potassium replacement corresponded to 152 patients. Of the 491 instances requiring replacement in the NRP group, the correct dose was administered and reassessment performed 117 times (23.8%). Overall adherence ( p < 0.05), correct dose given ( p < 0.05), average time from blood draw to potassium replacement ( p < 0.0001), use of oral replacement ( p < 0.05), and time to achieve target potassium level within 12 hours ( p < 0.05) were significantly improved in the TARP group. The TARP improved the effectiveness and safety of potassium-replacement therapy over the traditional NRP without negatively affecting timeliness of care. Copyright © 2017 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

21 CFR 172.375 - Potassium iodide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be..., will not result in daily ingestion of the additive so as to provide a total amount of iodine in excess...

21 CFR 172.375 - Potassium iodide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.375 Potassium iodide. The food additive potassium iodide may be..., will not result in daily ingestion of the additive so as to provide a total amount of iodine in excess...

21 CFR 172.730 - Potassium bromate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Other Specific Usage Additives § 172.730 Potassium bromate. The food additive potassium bromate may be safely used in the malting of barley... barley under conditions whereby the amount of the additive present in the malt from the treatment does...

Novel treatment strategies for smooth muscle disorders: Targeting Kv7 potassium channels.

PubMed

Haick, Jennifer M; Byron, Kenneth L

2016-09-01

Smooth muscle cells provide crucial contractile functions in visceral, vascular, and lung tissues. The contractile state of smooth muscle is largely determined by their electrical excitability, which is in turn influenced by the activity of potassium channels. The activity of potassium channels sustains smooth muscle cell membrane hyperpolarization, reducing cellular excitability and thereby promoting smooth muscle relaxation. Research over the past decade has indicated an important role for Kv7 (KCNQ) voltage-gated potassium channels in the regulation of the excitability of smooth muscle cells. Expression of multiple Kv7 channel subtypes has been demonstrated in smooth muscle cells from viscera (gastrointestinal, bladder, myometrial), from the systemic and pulmonary vasculature, and from the airways of the lung, from multiple species, including humans. A number of clinically used drugs, some of which were developed to target Kv7 channels in other tissues, have been found to exert robust effects on smooth muscle Kv7 channels. Functional studies have indicated that Kv7 channel activators and inhibitors have the ability to relax and contact smooth muscle preparations, respectively, suggesting a wide range of novel applications for the pharmacological tool set. This review summarizes recent findings regarding the physiological functions of Kv7 channels in smooth muscle, and highlights potential therapeutic applications based on pharmacological targeting of smooth muscle Kv7 channels throughout the body. Published by Elsevier Inc.

The amiodarone derivative KB130015 activates hERG1 potassium channels via a novel mechanism

PubMed Central

Gessner, Guido; Macianskiene, Regina; Starkus, John G.; Schönherr, Roland; Heinemann, Stefan H.

2010-01-01

Human ether à go-go related gene (hERG1) potassium channels underlie the repolarizing IKr current in the heart. Since they are targets of various drugs with cardiac side effects we tested whether the amiodarone derivative 2-methyl-3-(3,5-diiodo-4-carboxymethoxybenzyl)benzofuran (KB130015) blocks hERG1 channels like its parent compound. Using patch-clamp and two-electrode voltage-clamp techniques we found that KB130015 blocks native and recombinant hERG1 channels at high voltages, but it activates them at low voltages. The activating effect has an apparent EC50 value of 12 μM and is brought about by an about 4-fold acceleration of activation kinetics and a shift in voltage-dependent activation by −16 mV. Channel activation was not use-dependent and was independent of inactivation gating. KB130015 presumably binds to the hERG1 pore from the cytosolic side and functionally competes with hERG1 block by amiodarone, E4031 (N-[4-[[1-[2-(6-methyl-2-pyridinyl)ethyl] -4-piperidinyl] carbonyl] phenyl] methanesulfonamide dihydrochloride), and sertindole. Vice versa, amiodarone attenuates hERG1 activation by KB130015. Based on synergic channel activation by mallotoxin and KB130015 we conclude that the hERG1 pore contains at least two sites for activators that are functionally coupled among each other and to the cavity-blocker site. KB130015 and amiodarone may serve as lead structures for the identification of hERG1 pore-interacting drugs favoring channel activation vs. block. PMID:20097192

Age-dependent axonal expression of potassium channel proteins during development in mouse hippocampus.

PubMed

Prüss, Harald; Grosse, Gisela; Brunk, Irene; Veh, Rüdiger W; Ahnert-Hilger, Gudrun

2010-03-01

The development of the hippocampal network requires neuronal activity, which is shaped by the differential expression and sorting of a variety of potassium channels. Parallel to their maturation, hippocampal neurons undergo a distinct development of their ion channel profile. The age-dependent dimension of ion channel occurrence is of utmost importance as it is interdependently linked to network formation. However, data regarding the exact temporal expression of potassium channels during postnatal hippocampal development are scarce. We therefore studied the expression of several voltage-gated potassium channel proteins during hippocampal development in vivo and in primary cultures, focusing on channels that were sorted to the axonal compartment. The Kv1.1, Kv1.2, Kv1.4, and Kv3.4 proteins showed a considerable temporal variation of axonal localization among neuronal subpopulations. It is possible, therefore, that hippocampal neurons possess cell type-specific mechanisms for channel compartmentalization. Thus, age-dependent axonal sorting of the potassium channel proteins offers a new approach to functionally distinguish classes of hippocampal neurons and may extend our understanding of hippocampal circuitry and memory processing.

Identification of potential novel interaction partners of the sodium-activated potassium channels Slick and Slack in mouse brain.

PubMed

Rizzi, Sandra; Schwarzer, Christoph; Kremser, Leopold; Lindner, Herbert H; Knaus, Hans-Günther

2015-12-01

The sodium-activated potassium channels Slick (Slo2.1, KCNT2) and Slack (Slo2.2, KCNT1) are paralogous channels of the Slo family of high-conductance potassium channels. Slick and Slack channels are widely distributed in the mammalian CNS and they play a role in slow afterhyperpolarization, generation of depolarizing afterpotentials and in setting and stabilizing the resting potential. In the present study we used a combined approach of (co)-immunoprecipitation studies, Western blot analysis, double immunofluorescence and mass spectrometric sequencing in order to investigate protein-protein interactions of the Slick and Slack channels. The data strongly suggest that Slick and Slack channels co-assemble into identical cellular complexes. Double immunofluorescence experiments revealed that Slick and Slack channels co-localize in distinct mouse brain regions. Moreover, we identified the small cytoplasmic protein beta-synuclein and the transmembrane protein 263 (TMEM 263) as novel interaction partners of both, native Slick and Slack channels. In addition, the inactive dipeptidyl-peptidase (DPP 10) and the synapse associated protein 102 (SAP 102) were identified as constituents of the native Slick and Slack channel complexes in the mouse brain. This study presents new insights into protein-protein interactions of native Slick and Slack channels in the mouse brain.

Identification of the functional binding pocket for compounds targeting small-conductance Ca2+-activated potassium channels

PubMed Central

Zhang, Miao; Pascal, John M.; Schumann, Marcel; Armen, Roger S.; Zhang, Ji-fang

2012-01-01

Small- and intermediate-conductance Ca2+-activated potassium channels, activated by Ca2+-bound calmodulin, play an important role in regulating membrane excitability. These channels are also linked to clinical abnormalities. A tremendous amount of effort has been devoted to developing small molecule compounds targeting these channels. However, these compounds often suffer from low potency and lack of selectivity, hindering their potentials for clinical use. A key contributing factor is the lack of knowledge of the binding site(s) for these compounds. Here we demonstrate by X-ray crystallography that the binding pocket for the compounds of the 1-EBIO class is located at the calmodulin-channel interface. We show that, based on structure data and molecular docking, mutations of the channel can effectively change the potency of these compounds. Our results provide insight into the molecular nature of the binding pocket and its contribution to the potency and selectivity of the compounds of the 1-EBIO class. PMID:22929778

40 CFR 721.5970 - Phosphated polyarylphenol ethoxylate, potassium salt.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., potassium salt. 721.5970 Section 721.5970 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5970 Phosphated polyarylphenol ethoxylate, potassium salt. (a) Chemical... as phosphated polyarylphenol ethoxylate, potassium salt (PMN P-93-1222) is subject to reporting under...

40 CFR 721.5970 - Phosphated polyarylphenol ethoxylate, potassium salt.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., potassium salt. 721.5970 Section 721.5970 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5970 Phosphated polyarylphenol ethoxylate, potassium salt. (a) Chemical... as phosphated polyarylphenol ethoxylate, potassium salt (PMN P-93-1222) is subject to reporting under...

40 CFR 721.5970 - Phosphated polyarylphenol ethoxylate, potassium salt.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., potassium salt. 721.5970 Section 721.5970 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5970 Phosphated polyarylphenol ethoxylate, potassium salt. (a) Chemical... as phosphated polyarylphenol ethoxylate, potassium salt (PMN P-93-1222) is subject to reporting under...

40 CFR 721.5970 - Phosphated polyarylphenol ethoxylate, potassium salt.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., potassium salt. 721.5970 Section 721.5970 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5970 Phosphated polyarylphenol ethoxylate, potassium salt. (a) Chemical... as phosphated polyarylphenol ethoxylate, potassium salt (PMN P-93-1222) is subject to reporting under...

40 CFR 721.5970 - Phosphated polyarylphenol ethoxylate, potassium salt.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., potassium salt. 721.5970 Section 721.5970 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.5970 Phosphated polyarylphenol ethoxylate, potassium salt. (a) Chemical... as phosphated polyarylphenol ethoxylate, potassium salt (PMN P-93-1222) is subject to reporting under...

Prolonged oral administration of potassium upon aldosterone biosynthesis by rat glomerulosa tissue in vitro.

PubMed

Regöly-Mérei, J; Sólyom, J

1975-01-01

Steroid production rate of adrenals derived from rats drinking a 0.3 M KC1 + 5% glucose solution for 7 days was compared to that of control rats drinking a 5% glucose solution in order to investigate the effect of potassium loading upon the early and late step of aldosterone biosynthesis. Following potassium loading the quartered adrenals produced more aldosterone but less corticosterone as compared to the control. Potassium loading resulted in an increased aldosterone production rate by capsular adrenals (z. glomerulosa) provided that the corticosterone concentration in the incubation medium was elevated either by incubating it together with the decapsulated adrenal or adding exogenous corticosterone (4--16 mug/ml) to the medium. The corticosterone to aldosterone converting capacity of capsular adrenals is markedly higher in the potassium-loaded rats than in the controls. In the first 15 minutes of incubation the corticosterone production rate of the two groups was equal, aldosterone production rate by capsular adrenals of potassium-loaded rats, being higher than that of control animals. Corticosterone output of capsular adrenals from potassium-loaded rats decreased more rapidly in course of the incubation than it did in control tissue. These results suggest that the increase in aldosterone secretion in vivo following potassium loading is due to the stimulation of conversion of corticosterone to aldosterone in the glomerulosa cells. However, the endogenous corticosterone production during the incubation of glomerulosa cells from pottasium-loaded rats decreases so rapidly that the cells are not capable of producing more aldosterone than the control ones in spite of activated 18-hydroxylase.

Control of resting membrane potential by delayed rectifier potassium currents in ferret airway smooth muscle cells.

PubMed Central

Fleischmann, B K; Washabau, R J; Kotlikoff, M I

1993-01-01

1. In order to determine the physiological role of specific potassium currents in airway smooth muscle, potassium currents were measured in freshly dissociated ferret trachealis cells using the nystatin-permeabilized, whole-cell method, at 35 degrees C. 2. The magnitude of the outward currents was markedly increased as bath temperature was increased from 22 to 35 degrees C. This increase was primarily due to the increase in maximum potassium conductance (gK,max), although there was also a small leftward shift in the relationship between gK and voltage at higher temperatures. The maximum conductance and the kinetics of current activation and inactivation were also temperature dependent. At 35 degrees C, gating of the current was steeply voltage dependent between -40 and 0 mV. Current activation was well fitted by fourth-order kinetics; the mean time constants of activation (30 mV clamp step) were 1.09 +/- 0.17 and 1.96 +/- 0.27 ms at 35 and 22 degrees C, respectively. 3. Outward currents using the nystatin method were qualitatively similar to delayed rectifier currents recorded in dialysed cells with high calcium buffering capacity solutions. 4-Aminopyridine (4-AP; 2 mM), a specific blocker of delayed rectifier potassium channels in this tissue, inhibited over 80% of the outward current evoked by voltage-clamp steps to between -10 and +20 mV (n = 6). Less than 5% of the outward current was blocked over the same voltage range by charybdotoxin (100 nM; n = 15), a specific antagonist of large-conductance, calcium-activated potassium channels in this tissue. 4. The degree to which delayed rectifier and calcium-activated potassium conductances control resting membrane potential was examined in current-clamp experiments. The resting membrane potential of current clamped cells was -33.6 +/- 1.0 mV (n = 62). Application of 4-AP (2 mM) resulted in a 14.4 +/- 1.0 mV depolarization (n = 8) and an increase in input resistance. Charybdotoxin (100 nM) had no effect on resting

75 FR 16509 - Certain Potassium Phosphate Salts From China

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-01

...)] Certain Potassium Phosphate Salts From China AGENCY: United States International Trade Commission. ACTION... retarded, by reason of subsidized and less-than-fair-value imports from China of certain potassium... ``phosphate salts''). Certain Potassium Phosphate Salts from the People's Republic of China: Preliminary...

Urine Potassium Excretion, Kidney Failure, and Mortality in CKD.

PubMed

Leonberg-Yoo, Amanda K; Tighiouart, Hocine; Levey, Andrew S; Beck, Gerald J; Sarnak, Mark J

2017-03-01

Low urine potassium excretion, as a surrogate for dietary potassium intake, is associated with higher risk for hypertension and cardiovascular disease in a general population. Few studies have investigated the relationship of urine potassium with clinical outcomes in chronic kidney disease (CKD). Longitudinal cohort study. The MDRD (Modification of Diet in Renal Disease) Study was a randomized controlled trial (N = 840) conducted in 1989 to 1993 to examine the effects of blood pressure control and dietary protein restriction on kidney disease progression in adults aged 18 to 70 years with CKD stages 2 to 4. This post hoc analysis included 812 participants. The primary predictor variable was 24-hour urine potassium excretion, measured at baseline and at multiple time points (presented as time-updated average urine potassium excretion). Kidney failure, defined as initiation of dialysis therapy or transplantation, was determined from US Renal Data System data. All-cause mortality was assessed using the National Death Index. Median follow-up for kidney failure was 6.1 (IQR, 3.5-11.7) years, with 9 events/100 patient-years. Median all-cause mortality follow-up was 19.2 (IQR, 10.8-20.6) years, with 3 deaths/100 patient-years. Baseline mean urine potassium excretion was 2.39±0.89 (SD) g/d. Each 1-SD higher baseline urine potassium level was associated with an adjusted HR of 0.95 (95% CI, 0.87-1.04) for kidney failure and 0.83 (95% CI, 0.74-0.94) for all-cause mortality. Results were consistent using time-updated average urine potassium measurements. Analyses were performed using urine potassium excretion as a surrogate for dietary potassium intake. Results are obtained from a primarily young, nondiabetic, and advanced CKD population and may not be generalizable to the general CKD population. Higher urine potassium excretion was associated with lower risk for all-cause mortality, but not kidney failure. Copyright © 2016 National Kidney Foundation, Inc. Published by

The role of sodium pump in the inhibition of smooth muscle responsiveness to agonists during potassium restoration

PubMed Central

Bose, D.; Innes, I. R.

1973-01-01

1. Isometric contractions of cat splenic capsular smooth muscle in response to noradrenaline and histamine were recorded. 2. Removal of potassium from the bathing medium did not change the resting tension or the responsiveness to noradrenaline. Restoration of potassium inhibited responses to noradrenaline or histamine only if the muscles were stimulated with an agonist while in the K-free medium. 3. This inhibition of responses to the agonists due to potassium was reversed rapidly by removing the ion or reversed slowly by prolonged exposure to the ion. The inhibition was also blocked by procedures or agents which block the sodium pump (ouabain, substitution of NaCl by LiCl), inhibit active processes (low ambient temperature) or prevent intracellular accumulation of sodium (substitution of choline for sodium). 4. It is proposed that under special circumstances such as when there is an increase in internal sodium concentration, the sodium pump is probably electrogenic and causes relaxation when activated by external potassium. In the normal muscle the pump is probably electrically neutral. PMID:4777707

Potassium carbonate poisoning

MedlinePlus

... dishwasher soaps Some forms of potash (material from wood ashes that is used in fertilizers) Some home ... several weeks after the potassium carbonate was swallowed. Death from complications may occur up to several months ...

ACE inhibitors and potassium foods--nurses' knowledge.

PubMed

Bertrand, Brenda; Livingston-Bowen, Carrie; Duffrin, Christopher; Mann, Amanda

2014-01-01

According to Joint Commission standards, patients should be educated about drug-nutrient interactions. Because nurses are well-suited to educating patients, this paper aims to assess their knowledge of ACE inhibitor drugs, nutrient interactions and high- and low-potassium foods. Licensed nurses from a teaching hospital in the US south eastern Atlantic region completed a self-administered questionnaire (n = 83). Means, standard deviations and 95 percent confidence intervals were calculated for continuous data and frequency and percentage distribution for discrete data. Student's t-test was used to evaluate responses by ACE inhibitor patient load and nursing education. Mean nurse knowledge of ACE inhibitors and potassium was 62 +/- 16 percent and identifying high- and low-potassium foods was 32 +/- 23 percent. Most identified five from 12 high-potassium foods and did not know the designation of six, one from 14 low-potassium foods and did not know the designation of 11. Knowledge scores and identifying high- and low-potassium foods were similar regardless of ACE inhibitor patient load and nursing education. ACE inhibitors are the fourth most commonly used drug class in the USA. Nurses are well positioned to recognize potential drug-nutrient interactions owing to changing or adding a drug, dose delivery method, dietary change or a patient's physical or clinical status that may indicate nutrient deficiency. The findings suggest that the nurses surveyed were proficient in identifying ACE inhibitors pharmacology, but that most were unable to identify foods that increase drug-nutrient interaction risk, and thus this is an area in which additional training might be beneficial. Case menus were used to portray real-life scenarios in which healthcare practitioners can provide patient education about ACE inhibitor drug and dietary potassium interactions.

Sodium cyanate-induced opening of calcium-activated potassium currents in hippocampal neuron-derived H19-7 cells.

PubMed

Huang, Chin-Wei; Huang, Chao-Ching; Huang, Mei-Han; Wu, Sheng-Nan; Hsieh, Yi-Jung

2005-03-29

We investigated the chemical toxic agent sodium cyanate (NaOCN) on the large conductance calcium-activated potassium channels (BK(Ca)) on hippocampal neuron-derived H19-7 cells. The whole-cell and cell-attach configuration of patch-clamp technique were applied to investigate the BK(Ca) currents in H19-7 cells in the presence of NaOCN (0.3 mM). NaOCN activated BK(Ca) channels on H19-7 cells. The single-channel conductance of BK(Ca) channels was 138+/-7pS. The presence of NaOCN (0.3 mM) caused an obvious increase in open probability of BK(Ca) channels. NaOCN did not exert effect on the slope of the activation curve and stimulated the activity of BK(Ca) channels in a voltage-dependent fashion in H19-7 cells. The presence of paxilline or EGTA significantly reduced the BK(Ca) amplitude, in comparison with the presence of NaOCN. These findings suggest that during NaOCN exposure, the activation of BK(Ca) channels in neurons could be one of the ionic mechanisms underlying the decreased neuronal excitability and neurological disorders.

Kinetics of caesium and potassium absorption by roots of three grass pastures and competitive effects of potassium on caesium uptake in Cynodon sp.

NASA Astrophysics Data System (ADS)

Ayub, J. Juri; Valverde, L. Rubio; Garcia-Sanchez, M. J.; Fernandez, J. A.; Velasco, R. H.

2008-08-01

Caesium uptake by plant roots has been normally associated with the uptake of potassium as the potassium transport systems present in plants have also the capacity to transport caesium. Three grass species (Eragrostis curvula, Cynodon sp and Distichlis spicata) growing in seminatural grassland of central Argentina were selected to study their capability to incorporate Cs+ (and K+) using electrophysiological techniques. Although the 137Cs soil inventory ranged between 328-730 Bq m-2 in this region, no 137Cs activity was detected in these plants. However, all the species, submitted previously to K+ starvation, showed the uptake of both Cs+ and K+ when micromolar concentrations of these cations were present in the medium. The uptake showed saturation kinetics for both cations that could be fitted to the Michelis-Menten model. KM values were smaller for K+ than for Cs+, indicating a higher affinity for the first cation. The presence of increasing K+ concentrations in the assay medium inhibited Cs+ uptake in Cynodon sp., as expected if both cations are transported by the same transport systems. This effect is due to the competition of both ions for the union sites of the high affinity potassium transporters. In field situation, where soil concentration of Cs+ is smaller than K+ concentration, is then expectable that caesium activity in plants is not detectable. Nevertheless, the studied plants would have the capacity to incorporate caesium if its availability in soil solution increases. In addition, studies of Cs/K interaction can help us to understand the variability in transfer factors.

Short-lived K2S Molecules in Superionic Potassium Sulfide

NASA Astrophysics Data System (ADS)

Okeya, Yusuke; Tsumuraya, Kazuo

2015-03-01

The first principles molecular dynamics method allows us to elucidate the formation of short-lived K2S molecular states in superionic potassium sulfide. The covalent and the Coulomb bonds exist between the ionized mobile potassiums and the ionized immobile sulfurs. Both the bonds induces indirect covalent and indirect Coulomb attractions between the di-interstitial potassiums on the mid-sulfurs, which forms the short-lived K2S molecular states. The covalent electron density also exists between short-lived potassium dimers. The three attractions reduce Haven's ratios of the potassiums in the conductor. The molecule formation indicates the electronic state of the conductor is intermediate between the ionic and covalent crystals. The absence of the long-lived potassium dimers implies a failure of the caterpillar diffusion model or the Frenkel-Kontorova chain model for the superionic diffusion of the potassiums in the sulfide. The incompletely ionized cations and anions reduce the Coulomb attractions between them which induces the sublattice melting of smaller size of the potassiums than the sulfurs.

21 CFR 526.1130 - Hetacillin potassium for intramammary infusion.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Hetacillin potassium for intramammary infusion... § 526.1130 Hetacillin potassium for intramammary infusion. (a) Specifications. Each 10 milliliter syringe contains hetacillin potassium equivalent of 62.5 milligrams of ampicillin. (b) Sponsor. See No...

21 CFR 526.1130 - Hetacillin potassium for intramammary infusion.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Hetacillin potassium for intramammary infusion... § 526.1130 Hetacillin potassium for intramammary infusion. (a) Specifications. Each 10 milliliter syringe contains hetacillin potassium equivalent of 62.5 milligrams of ampicillin. (b) Sponsor. See No...

21 CFR 526.1130 - Hetacillin potassium for intramammary infusion.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Hetacillin potassium for intramammary infusion... § 526.1130 Hetacillin potassium for intramammary infusion. (a) Specifications. Each 10 milliliter syringe contains hetacillin potassium equivalent of 62.5 milligrams of ampicillin. (b) Sponsor. See No...

Effects of Long-term Fertilization on Potassium Fixation Capacity in Brown Soil

NASA Astrophysics Data System (ADS)

Li, Na; Guo, Chunlei; Wang, Yue; Gao, Tianyi; Yang, Jinfeng; Han, Xiaori

2018-01-01

This study concentrated on the research of features of fixation. The objective of this study was to provide theoretical foundation of rational application of potassium fertilizer along with improving fertilizer availability ratio. A 32 years long-term experiment was conducted to evaluate the effects of fertilizer application on potassium changes and the factors affecting K fixation on brown soil by simulation in laboratory. When the concentration of exogenous potassium was in range of 400∼4000 mg·kg-1, potassium fixation capacity increased along with the rise of concentration of exogenous potassium, whereas K fixation rate reduced; Compared with no-potassium fertilizer, application of potassium fertilizer and organic fertilizer reduced soil potassium fixation capacity. Potassium rate and fixation-release of potassium character in soil should be taken into comprehensive consideration for rational fertilization to maintain or improve soil fertility for increasing potassium fertilizers efficiency in agriculture.

Dietary potassium intake and mortality in long-term hemodialysis patients.

PubMed

Noori, Nazanin; Kalantar-Zadeh, Kamyar; Kovesdy, Csaba P; Murali, Sameer B; Bross, Rachelle; Nissenson, Allen R; Kopple, Joel D

2010-08-01

Hyperkalemia has been associated with higher mortality in long-term hemodialysis (HD) patients. There are few data concerning the relationship between dietary potassium intake and outcome. The mortality predictability of dietary potassium intake from reported food items estimated using the Block Food Frequency Questionnaire (FFQ) at the start of the cohort was examined in a 5-year (2001-2006) cohort of 224 HD patients in Southern California using Cox proportional hazards regression. 224 long-term HD patients from 8 DaVita dialysis clinics. Dietary potassium intake ranking using the Block FFQ. 5-year survival. HD patients with higher potassium intake had greater dietary energy, protein, and phosphorus intakes and higher predialysis serum potassium and phosphorus levels. Greater dietary potassium intake was associated with significantly increased death HRs in unadjusted models and after incremental adjustments for case-mix, nutritional factors (including 3-month averaged predialysis serum creatinine, potassium, and phosphorus levels; body mass index; normalized protein nitrogen appearance; and energy, protein, and phosphorus intake) and inflammatory marker levels. HRs for death across the 3 higher quartiles of dietary potassium intake in the fully adjusted model (compared with the lowest quartile) were 1.4 (95% CI, 0.6-3.0), 2.2 (95% CI, 0.9-5.4), and 2.4 (95% CI, 1.1-7.5), respectively (P for trend = 0.03). Restricted cubic spline analyses confirmed the incremental mortality predictability of higher potassium intake. FFQs may underestimate individual potassium intake and should be used to rank dietary intake across the population. Higher dietary potassium intake is associated with increased death risk in long-term HD patients, even after adjustments for serum potassium level; dietary protein; energy, and phosphorus intake; and nutritional and inflammatory marker levels. The potential role of dietary potassium in the high mortality rate of HD patients warrants

Process for preparation of potassium-38

DOEpatents

Lambrecht, Richard M.; Wolf, Alfred P.

1981-01-01

A solution of potassium-38 suitable for use as a radiopharmaceutical and a method for its production. Argon is irradiated with protons having energies above the threshold for the .sup.40 Ar(p,3n).sup.38 K reaction. The resulting potassium-38 is dissolved in a sterile water and any contaminating chlorine-38 is removed.

High potassium level

MedlinePlus

... level is very high, or if you have danger signs, such as changes in an ECG . Emergency ... Seifter JL. Potassium disorders. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine . 25th ed. Philadelphia, PA: ...

A randomised controlled trial evaluating the effect of potassium supplementation on vascular function and the renin-angiotensin-aldosterone system.

PubMed

Graham, U M; McCance, D R; Young, I S; Mullan, K R

2014-05-01

There is limited evidence on the effect of potassium supplementation on the vasculature in patients at increased cardiovascular risk. Potassium increases aldosterone and there is a strong association of hyperaldosteronism with poor cardiac outcomes. We aimed to determine whether potassium supplementation has a significant medium-term effect on aldosterone levels and, if so, what the overall effect of this is on vascular function in patients at moderate cardiovascular disease risk. Forty patients at moderate cardiovascular disease risk were included in a randomised placebo-controlled crossover study. Patients were assigned to 64 mmol potassium chloride or placebo for 6 weeks. Vascular function was assessed using pulse-wave analysis including the detection of a change in augmentation index to salbutamol and nitroglycerine-induced vasodilation. There was no change in augmentation index with potassium vs placebo (25.2±1.4 vs. 26.0±1.3%, respectively). Potassium improved brachial systolic blood pressure (131.8±2.2 vs. 137.1±2.4 mm Hg; P=0.013), central systolic blood pressure (123.2±2.3 vs. 128.4±2.3 mm Hg; P=0.011) and central diastolic blood pressure (80.3±1.3 vs. 83.7±1.4 mm Hg; P=0.019). Plasma renin activity and serum aldosterone both increased with potassium (P=0.001 and P=0.048 respectively). We found that potassium supplementation had no effect on endothelial function or pulse-wave analysis. It lowered brachial systolic and central blood pressure. It was associated with increased plasma renin activity and serum aldosterone.

40 CFR 721.638 - Silyl amine, potassium salt (generic).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Silyl amine, potassium salt (generic... Substances § 721.638 Silyl amine, potassium salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as silyl amine, potassium salt...

40 CFR 721.638 - Silyl amine, potassium salt (generic).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Silyl amine, potassium salt (generic... Substances § 721.638 Silyl amine, potassium salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as silyl amine, potassium salt...

40 CFR 721.638 - Silyl amine, potassium salt (generic).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Silyl amine, potassium salt (generic... Substances § 721.638 Silyl amine, potassium salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as silyl amine, potassium salt...

40 CFR 721.638 - Silyl amine, potassium salt (generic).

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Silyl amine, potassium salt (generic... Substances § 721.638 Silyl amine, potassium salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as silyl amine, potassium salt...

40 CFR 721.638 - Silyl amine, potassium salt (generic).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Silyl amine, potassium salt (generic... Substances § 721.638 Silyl amine, potassium salt (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as silyl amine, potassium salt...

Effects of allocryptopine on outward potassium current and slow delayed rectifier potassium current in rabbit myocardium.

PubMed

Fu, Yi-Cheng; Zhang, Yu; Tian, Liu-Yang; Li, Nan; Chen, Xi; Cai, Zhong-Qi; Zhu, Chao; Li, Yang

2016-05-01

Allocryptopine (ALL) is an effective alkaloid of Corydalis decumbens (Thunb.) Pers. Papaveraceae and has proved to be anti-arrhythmic. The purpose of our study is to investigate the effects of ALL on transmural repolarizing ionic ingredients of outward potassium current (I to) and slow delayed rectifier potassium current (I Ks). The monophasic action potential (MAP) technique was used to record the MAP duration of the epicardium (Epi), myocardium (M) and endocardium (Endo) of the rabbit heart and the whole cell patch clamp was used to record I to and I Ks in cardiomyocytes of Epi, M and Endo layers that were isolated from rabbit ventricles. The effects of ALL on MAP of Epi, M and Endo layers were disequilibrium. ALL could effectively reduce the transmural dispersion of repolarization (TDR) in rabbit transmural ventricular wall. ALL decreased the current densities of I to and I Ks in a voltage and concentration dependent way and narrowed the repolarizing differences among three layers. The analysis of gating kinetics showed ALL accelerated the channel activation of I to in M layers and partly inhibit the channel openings of I to in Epi, M and Endo cells. On the other hand, ALL mainly slowed channel deactivation of I Ks channel in Epi and Endo layers without affecting its activation. Our study gives partially explanation about the mechanisms of transmural inhibition of I to and I Ks channels by ALL in rabbit myocardium. These findings provide novel perspective regarding the anti-arrhythmogenesis application of ALL in clinical settings.

40 CFR 721.7375 - Potassium salt of polyolefin acid.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Potassium salt of polyolefin acid. 721... Substances § 721.7375 Potassium salt of polyolefin acid. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a potassium salt of polyolefin...

40 CFR 721.7375 - Potassium salt of polyolefin acid.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Potassium salt of polyolefin acid. 721... Substances § 721.7375 Potassium salt of polyolefin acid. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a potassium salt of polyolefin...

40 CFR 721.7375 - Potassium salt of polyolefin acid.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Potassium salt of polyolefin acid. 721... Substances § 721.7375 Potassium salt of polyolefin acid. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a potassium salt of polyolefin...

40 CFR 721.7375 - Potassium salt of polyolefin acid.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Potassium salt of polyolefin acid. 721... Substances § 721.7375 Potassium salt of polyolefin acid. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a potassium salt of polyolefin...

40 CFR 721.7375 - Potassium salt of polyolefin acid.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Potassium salt of polyolefin acid. 721... Substances § 721.7375 Potassium salt of polyolefin acid. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a potassium salt of polyolefin...

Interleukin-4 activates large-conductance, calciumactivated potassium (BKCa) channels in human airway smooth muscle cells

PubMed Central

Martin, Gilles; O’Connell, Robert J.; Pietrzykowski, Andrzej Z.; Treistman, Steven N.; Ethier, Michael F.; Madison, J. Mark

2014-01-01

Large-conductance, calcium-activated potassium (BKCa) channels are regulated by voltage and near-membrane calcium concentrations and are determinants of membrane potential and excitability in airway smooth muscle cells. Since the T helper–2 (Th2) cytokine, interleukin (IL)-4, is an important mediator of airway inflammation, we investigated whether IL-4 rapidly regulated BKCa activity in normal airway smooth muscle cells. On-cell voltage clamp recordings were made on subconfluent, cultured human bronchial smooth muscle cells (HBSMC). Interleukin-4 (50 ng ml−1), IL-13 (50 ng ml−1) or histamine (10 μm) was added to the bath during the recordings. Immunofluorescence studies with selective antibodies against the α and β1 subunits of BKCa were also performed. Both approaches demonstrated that HBSMC membranes contained large-conductance channels (>200 pS) with both calcium and voltage sensitivity, all of which is characteristic of the BKCa channel. Histamine caused a rapid increase in channel activity, as expected. A new finding was that perfusion with IL-4 stimulated rapid, large increases in BKCa channel activity (77.2 ± 63.3-fold increase, P < 0.05, n = 18). This large potentiation depended on the presence of external calcium. In contrast, IL-13 (50 ng ml−1) had little effect on BKCa channel activity, but inhibited the effect of IL-4. Thus, HBSMC contain functional BKCa channels whose activity is rapidly potentiated by the cytokine, IL-4, but not by IL-13.These findings are consistent with a model in which IL-4 rapidly increases near-membrane calcium concentrations to regulate BKCa activity. PMID:18403443

75 FR 23298 - Potassium Permanganate From China

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-03

... Permanganate From China AGENCY: United States International Trade Commission. ACTION: Institution of a five-year review concerning the antidumping duty order on potassium permanganate from China. SUMMARY: The... on potassium permanganate from China would be likely to lead to continuation or recurrence of...

75 FR 51112 - Potassium Permanganate From China

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-18

... Permanganate From China AGENCY: United States International Trade Commission. ACTION: Scheduling of an expedited five-year review concerning the antidumping duty order on potassium permanganate from China... of the antidumping duty order on potassium permanganate from China would be likely to lead to...

Potassium Supplementation Prevents Sodium Chloride Cotransporter Stimulation during Angiotensin II Hypertension

PubMed Central

Veiras, Luciana C.; Han, Jiyang; Ralph, Donna L.; McDonough, Alicia A.

2016-01-01

Ang II hypertension increases distal tubule Na-Cl cotransporter (NCC) abundance and phosphorylation (NCCp), as well as epithelial Na+ channel (ENaC) abundance and activating cleavage. Acutely raising plasma [K+] by infusion or ingestion provokes a rapid decrease in NCCp that drives a compensatory kaliuresis. The first aim tested whether acutely raising plasma [K+] with a single 3 hr 2% potassium meal would lower NCCp in Sprague Dawley rats after 14 days of AngII (400 ng/kg/min). The potassium-rich meal neither decreased NCCp nor increased K+ excretion. AngII infused rats exhibited lower plasma [K+] versus controls (3.6 ± 0.2 vs. 4.5 ± 0.1 mmol/L, p < 0.05) suggesting that Ang II mediated ENaC activation provokes K+ depletion. The second aim tested whether doubling dietary potassium intake from 1% (A1K) to 2% (A2K) would prevent K+ depletion during AngII infusion and, thus, prevent NCC accumulation. A2K fed rats exhibited normal plasma [K+] and 2-fold higher K+ excretion and plasma [aldosterone] versus A1K. In A1K rats, NCC, NCCpS71, and NCCpT53 abundance increased 1.5- to 3-fold versus controls (p< 0.05). The rise in NCC and NCCp abundance was prevented in the A2K rats, yet blood pressure did not significantly decrease. ENaC subunit abundance and cleavage increased 1.5- to 3-fold in both A1K and A2K; ROMK abundance was unaffected by Ang II or dietary K+. In summary, the accumulation and phosphorylation of NCC seen during chronic AngII infusion hypertension is likely secondary to potassium deficiency driven by ENaC stimulation. PMID:27600183

Potassium Supplementation Prevents Sodium Chloride Cotransporter Stimulation During Angiotensin II Hypertension.

PubMed

Veiras, Luciana C; Han, Jiyang; Ralph, Donna L; McDonough, Alicia A

2016-10-01

Angiotensin II (AngII) hypertension increases distal tubule Na-Cl cotransporter (NCC) abundance and phosphorylation (NCCp), as well as epithelial Na(+) channel abundance and activating cleavage. Acutely raising plasma [K(+)] by infusion or ingestion provokes a rapid decrease in NCCp that drives a compensatory kaliuresis. The first aim tested whether acutely raising plasma [K(+)] with a single 3-hour 2% potassium meal would lower NCCp in Sprague-Dawley rats after 14 days of AngII (400 ng/kg per minute). The potassium-rich meal neither decreased NCCp nor increased K(+) excretion. AngII-infused rats exhibited lower plasma [K(+)] versus controls (3.6±0.2 versus 4.5±0.1 mmol/L; P<0.05), suggesting that AngII-mediated epithelial Na(+) channel activation provokes K(+) depletion. The second aim tested whether doubling dietary potassium intake from 1% (A1K) to 2% (A2K) would prevent K(+) depletion during AngII infusion and, thus, prevent NCC accumulation. A2K-fed rats exhibited normal plasma [K(+)] and 2-fold higher K(+) excretion and plasma [aldosterone] versus A1K. In A1K rats, NCC, NCCpS71, and NCCpT53 abundance increased 1.5- to 3-fold versus controls (P<0.05). The rise in NCC and NCCp abundance was prevented in the A2K rats, yet blood pressure did not significantly decrease. Epithelial Na(+) channel subunit abundance and cleavage increased 1.5- to 3-fold in both A1K and A2K; ROMK (renal outer medulla K(+) channel abundance) abundance was unaffected by AngII or dietary K(+) In summary, the accumulation and phosphorylation of NCC seen during chronic AngII infusion hypertension is likely secondary to potassium deficiency driven by epithelial Na(+) channel stimulation. © 2016 American Heart Association, Inc.

40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt (PMN...

40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt (PMN...

40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt (PMN...

21 CFR 520.1696d - Penicillin V potassium tablets.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin V potassium tablets. 520.1696d Section... Penicillin V potassium tablets. (a) Specifications. Each tablet contains penicillin V potassium equivalent to 125 milligrams (200,000 units) or 250 milligrams (400,000 units) of penicillin V. (b) Sponsors. See...

21 CFR 520.1696d - Penicillin V potassium tablets.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Penicillin V potassium tablets. 520.1696d Section... Penicillin V potassium tablets. (a) Specifications. Each tablet contains penicillin V potassium equivalent to 125 milligrams (200,000 units) or 250 milligrams (400,000 units) of penicillin V. (b) Sponsors. See...

21 CFR 520.1696d - Penicillin V potassium tablets.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Penicillin V potassium tablets. 520.1696d Section... Penicillin V potassium tablets. (a) Specifications. Each tablet contains penicillin V potassium equivalent to 125 milligrams (200,000 units) or 250 milligrams (400,000 units) of penicillin V. (b) Sponsors. See...

40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt (PMN...

40 CFR 721.5425 - α-Olefin sulfonate, potassium salts.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false α-Olefin sulfonate, potassium salts... Substances § 721.5425 α-Olefin sulfonate, potassium salts. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as an α-olefin sulfonate, potassium salt (PMN...

Regulation of extrarenal potassium homeostasis by adrenal hormones in rats.

PubMed

Bia, M J; Tyler, K A; DeFronzo, R A

1982-06-01

The effect of chronic (7-10 days) adrenal insufficiency on extrarenal potassium tolerance was examined by infusing potassium into rats after acute nephrectomy. The increment in plasma potassium concentration was significantly higher in glucocorticoid-replaced adrenalectomized rats versus controls (max delta PK 3.59 +/-0.11 vs. 2.93 +/- 0.08 meq/liter; P less than 0.001). The impairment in extrarenal potassium tolerance in adrenalectomized rats could not be attributed to acidemia, hypotension, changes in plasma insulin or glucose concentration, or potassium retention prior to study. Acute replacement with aldosterone resulted in significant improvement in the rise in plasma potassium after KCl (max delta PK 3.18 +/- 0.06 meq/liter; P less than 0.005 compared with aldosterone-deficient adrenalectomized rats but higher than in controls, P less than 0.02). If given on a chronic basis, aldosterone replacement led to a complete correction of the defect (max delta PK = 2.89 +/- 0.08 meq/liter). Acute epinephrine replacement in adrenalectomized rats also returned potassium tolerance to normal (max delta PK = 3.02 +/- 0.10 meq/liter). The results demonstrate that extrarenal potassium tolerance is impaired in chronic adrenal insufficiency and suggest that both aldosterone and epinephrine deficiency may contribute to the defect, since replacement with either hormone returns potassium tolerance toward normal. Accordingly, both aldosterone and epinephrine have important extrarenal mechanisms of action.

Dietary sodium, dietary potassium, and systolic blood pressure in US adolescents.

PubMed

Chmielewski, Jennifer; Carmody, J Bryan

2017-09-01

Both high sodium and low potassium diets are associated with hypertension, but whether these risk factors are distinct or overlapping has not been thoroughly investigated. The authors evaluated the relationship between dietary sodium, potassium, and high systolic blood pressure among 4716 adolescents aged 12 to 14 years who participated in the National Health and Nutrition Examination Survey from 1999 to 2012. There was no association with blood pressure across most values of sodium or potassium intake. However, participants who reported sodium intake ≥7500 mg/d, potassium <700 mg/d, or sodium-potassium ratio ≥2.5 had increased odds for high systolic blood pressure (≥95th percentile for age, sex, and height). Although the high sodium and low potassium groups did not overlap, 49.2% of these adolescents also had a sodium-potassium ratio ≥2.5. In young adolescents, both excessive sodium and limited potassium are associated with high systolic blood pressure, but the balance between sodium and potassium intake may be more useful in explaining blood pressure in this population. © 2017 Wiley Periodicals, Inc.

Longitudinal effects of dietary sodium and potassium on blood pressure in adolescent girls.

PubMed

Buendia, Justin R; Bradlee, M Loring; Daniels, Stephen R; Singer, Martha R; Moore, Lynn L

2015-06-01

Identification of risk factors early in life for the development of high blood pressure is critical to the prevention of cardiovascular disease. To study prospectively the effect of dietary sodium, potassium, and the potassium to sodium ratio on adolescent blood pressure. The National Heart, Lung, and Blood Institute's Growth and Health Study is a prospective cohort study with sites in Richmond, California; Cincinnati, Ohio; and Washington, DC. Participants included 2185 black and white girls initially aged 9 to 10 years with complete data for early-adolescent to midadolescent diet and blood pressure who were followed up for 10 years. The first examination visits were from March 1987 through February 1988 and follow-up continued until February 1999. Longitudinal mixed models and analysis of covariance models were used to assess the effect of dietary sodium, potassium, and the potassium to sodium ratio on systolic and diastolic blood pressures throughout adolescence and after 10 years of follow-up, adjusting for race, height, activity, television/video time, energy intake, and other dietary factors. Mean dietary sodium and potassium intakes and the mean potassium to sodium ratio in individuals aged 9 to 17 years. To eliminate potential confounding by energy intake, energy-adjusted sodium and potassium residuals were estimated. Mean systolic and diastolic blood pressures throughout adolescence and at the end of follow-up (individuals aged 17-21 years). Sodium intakes were classified as less than 2500 mg/d (19.4% of participants), 2500 mg/d to less than 3000 mg/d (29.5%), 3000 mg/d to less than 4000 mg/d (41.4%), and 4000 mg/d or more (9.7%). Potassium intakes ranged from less than 1800 mg/d (36.0% of participants) to 1800 mg/d to less than 2100 mg/d (26.2%), 2100 mg/d to less than 2400 mg/d (18.8%), and 2400 mg/d or more (19.0%). There was no evidence that higher sodium intakes (3000 to <4000 mg/d and ≥4000 mg/d vs <2500 mg/d) had an adverse effect on adolescent

21 CFR 181.33 - Sodium nitrate and potassium nitrate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium nitrate and potassium nitrate. 181.33...-Sanctioned Food Ingredients § 181.33 Sodium nitrate and potassium nitrate. Sodium nitrate and potassium nitrate are subject to prior sanctions issued by the U.S. Department of Agriculture for use as sources of...

21 CFR 181.33 - Sodium nitrate and potassium nitrate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium nitrate and potassium nitrate. 181.33...-Sanctioned Food Ingredients § 181.33 Sodium nitrate and potassium nitrate. Sodium nitrate and potassium nitrate are subject to prior sanctions issued by the U.S. Department of Agriculture for use as sources of...

21 CFR 181.34 - Sodium nitrite and potassium nitrite.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium nitrite and potassium nitrite. 181.34...-Sanctioned Food Ingredients § 181.34 Sodium nitrite and potassium nitrite. Sodium nitrite and potassium nitrite are subject to prior sanctions issued by the U.S. Department of Agriculture for use as color...

21 CFR 181.34 - Sodium nitrite and potassium nitrite.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium nitrite and potassium nitrite. 181.34...-Sanctioned Food Ingredients § 181.34 Sodium nitrite and potassium nitrite. Sodium nitrite and potassium nitrite are subject to prior sanctions issued by the U.S. Department of Agriculture for use as color...

40 CFR Appendix A to Part 425 - Potassium Ferricyanide Titration Method

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Potassium Ferricyanide Titration..., App. A Appendix A to Part 425—Potassium Ferricyanide Titration Method Source The potassium... buffered sulfide solution is titrated with standard potassium ferricyanide solution in the presence of a...

40 CFR Appendix A to Part 425 - Potassium Ferricyanide Titration Method

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Potassium Ferricyanide Titration..., App. A Appendix A to Part 425—Potassium Ferricyanide Titration Method Source The potassium... buffered sulfide solution is titrated with standard potassium ferricyanide solution in the presence of a...

Compartmental shift of potassium--a result of sympathomimetic overdose.

PubMed

McCleave, D J; Phillips, P J; Vedig, A E

1978-04-01

A 17-year-old youth was admitted with a serum potassium concentration of 1.8 mmol/l after taking an overdose of pseudoephedrine and choline theophyllinate. Apart from tachycardia, tachypnoea and ankle clonus, examination was normal as was the initial electrocardiograph. The hypokalaemia resolved, but there was an overall positive potassium balance of only 13 mmol. This suggests that the sympathomimetics provoked a compartmental shift of potassium perhaps indirectly by inducing hyperglycaemia and hyperinsulinaemia, as well as directly. Other factors known to affect body potassium distribution were excluded. The fact that features commonly associated with hypokalaemia could not be demonstrated may be explained by a normal body potassium content. Severe hypokalaemia caused by a compartmental shift occurs with large doses of sympathomimetics as well as in periodic paralysis.

Urinary potassium excretion and risk of cardiovascular events.

PubMed

Kieneker, Lyanne M; Gansevoort, Ron T; de Boer, Rudolf A; Brouwers, Frank P; Feskens, Edith Jm; Geleijnse, Johanna M; Navis, Gerjan; Bakker, Stephan Jl; Joosten, Michel M

2016-05-01

Observational studies on dietary potassium and risk of cardiovascular disease (CVD) have reported weak-to-modest inverse associations. Long-term prospective studies with multiple 24-h urinary samples for accurate estimation of habitual potassium intake, however, are scarce. We examined the association between urinary potassium excretion and risk of blood pressure-related cardiovascular outcomes. We studied 7795 subjects free of cardiovascular events at baseline in the Prevention of Renal and Vascular End-stage Disease study, a prospective, observational cohort with oversampling of subjects with albuminuria at baseline. Main cardiovascular outcomes were CVD [including ischemic heart disease (IHD), stroke, and vascular interventions], IHD, stroke, and new-onset heart failure (HF). Potassium excretion was measured in two 24-h urine specimens at the start of the study (1997-1998) and midway through follow-up (2001-2003). Baseline median urinary potassium excretion was 70 mmol/24 h (IQR: 56-84 mmol/24 h). During a median follow-up of 10.5 y (IQR: 9.9-10.8 y), a total of 641 CVD, 465 IHD, 172 stroke, and 265 HF events occurred. After adjustment for age and sex, inverse associations were observed between potassium excretion and risk [HR per each 26-mmol/24-h (1-g/d) increase; 95% CI] of CVD (0.87; 0.78, 0.97) and IHD (0.86; 0.75, 0.97), as well as nonsignificant inverse associations for risk of stroke (0.85; 0.68, 1.06) and HF (0.94; 0.80, 1.10). After further adjustment for body mass index, smoking, alcohol consumption, education, and urinary sodium and magnesium excretion, urinary potassium excretion was not statistically significantly associated with risk (multivariable-adjusted HR per 1-g/d increment; 95% CI) of CVD (0.96; 0.85, 1.09), IHD (0.90; 0.81, 1.04), stroke (1.09; 0.86, 1.39), or HF (0.99; 0.83, 1.18). No associations were observed between the sodium-to-potassium excretion ratio and risk of CVD, IHD, stroke, or HF. In this cohort with oversampling of subjects

Expression of K2P5.1 potassium channels on CD4+ T lymphocytes correlates with disease activity in rheumatoid arthritis patients.

PubMed

Bittner, Stefan; Bobak, Nicole; Feuchtenberger, Martin; Herrmann, Alexander M; Göbel, Kerstin; Kinne, Raimund W; Hansen, Anker J; Budde, Thomas; Kleinschnitz, Christoph; Frey, Oliver; Tony, Hans-Peter; Wiendl, Heinz; Meuth, Sven G

2011-02-11

CD4+ T cells express K(2P)5.1 (TWIK-related acid-sensitive potassium channel 2 (TASK2); KCNK5), a member of the two-pore domain potassium channel family, which has been shown to influence T cell effector functions. Recently, it was shown that K(2P)5.1 is upregulated upon (autoimmune) T cell stimulation. The aim of this study was to correlate expression levels of K(2P)5.1 on T cells from patients with rheumatoid arthritis (RA) to disease activity in these patients. Expression levels of K(2P)5.1 were measured by RT-PCR in the peripheral blood of 58 patients with RA and correlated with disease activity parameters (C-reactive protein levels, erythrocyte sedimentation rates, disease activity score (DAS28) scores). Twenty patients undergoing therapy change were followed-up for six months. Additionally, synovial fluid and synovial biopsies were investigated for T lymphocytes expressing K(2P)5.1. K(2P)5.1 expression levels in CD4+ T cells show a strong correlation to DAS28 scores in RA patients. Similar correlations were found for serological inflammatory parameters (erythrocyte sedimentation rate, C-reactive protein). In addition, K(2P)5.1 expression levels of synovial fluid-derived T cells are higher compared to peripheral blood T cells. Prospective data in individual patients show a parallel behaviour of K(2P)5.1 expression to disease activity parameters during a longitudinal follow-up for six months. Disease activity in RA patients correlates strongly with K(2P)5.1 expression levels in CD4+ T lymphocytes in the peripheral blood in cross-sectional as well as in longitudinal observations. Further studies are needed to investigate the exact pathophysiological mechanisms and to evaluate the possible use of K(2P)5.1 as a potential biomarker for disease activity and differential diagnosis.

Map of Martian Potassium at Mid-Latitudes

NASA Image and Video Library

2003-03-13

This gamma ray spectrometer map of the mid-latitude region of Mars is based on gamma-rays from the element potassium. Potassium, having the chemical symbol K, is a naturally radioactive element and is a minor constituent of rocks on the surface of both Mars and Earth. The region of highest potassium content, shown in red, is concentrated in the northern part of Acidalia Planitia (centered near 55 degrees N, -30 degrees). Several areas of low potassium content, shown in blue, are distributed across the mid-latitudes, with two significant low concentrations, one associated with the Hellas Basin (centered near 35 degrees S, 70 degrees) and the other lying southeast of Elysium Mons (centered near 10 degrees N, 160 degrees). Contours of constant surface elevation are also shown. The long continuous line running from east to west marks the approximate separation of the younger lowlands in the north from the older highlands in the south. http://photojournal.jpl.nasa.gov/catalog/PIA04255

Evaluating Status Change of Soil Potassium from Path Model

PubMed Central

He, Wenming; Chen, Fang

2013-01-01

The purpose of this study is to determine critical environmental parameters of soil K availability and to quantify those contributors by using a proposed path model. In this study, plot experiments were designed into different treatments, and soil samples were collected and further analyzed in laboratory to investigate soil properties influence on soil potassium forms (water soluble K, exchangeable K, non-exchangeable K). Furthermore, path analysis based on proposed path model was carried out to evaluate the relationship between potassium forms and soil properties. Research findings were achieved as followings. Firstly, key direct factors were soil S, ratio of sodium-potassium (Na/K), the chemical index of alteration (CIA), Soil Organic Matter in soil solution (SOM), Na and total nitrogen in soil solution (TN), and key indirect factors were Carbonate (CO3), Mg, pH, Na, S, and SOM. Secondly, path model can effectively determine direction and quantities of potassium status changes between Exchangeable potassium (eK), Non-exchangeable potassium (neK) and water-soluble potassium (wsK) under influences of specific environmental parameters. In reversible equilibrium state of , K balance state was inclined to be moved into β and χ directions in treatments of potassium shortage. However in reversible equilibrium of , K balance state was inclined to be moved into θ and λ directions in treatments of water shortage. Results showed that the proposed path model was able to quantitatively disclose moving direction of K status and quantify its equilibrium threshold. It provided a theoretical and practical basis for scientific and effective fertilization in agricultural plants growth. PMID:24204659