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Biosensors Apr 2022The solid contact ion-selective electrode (ISE) is a promising skin-interfaced monitoring system for sweat ions. Despite a growing number of on-body usages of ISE with...
The solid contact ion-selective electrode (ISE) is a promising skin-interfaced monitoring system for sweat ions. Despite a growing number of on-body usages of ISE with fancy new materials and device fabrications, there are very few reports attempting to validate ISE results with a gold standard technique. For this purpose, this work uses inductively coupled plasma-optical emission spectrometry (ICP-OES) as a reference technique to conduct a direct evaluation of the sweat sodium and potassium ion levels obtained by ISE in an off-body approach. Eight healthy male subjects were recruited to collect exercise-induced sweat. It was found that sweat sodium and potassium ions present a rather wide concentration range. The sweat sodium concentration did not vary greatly in an exercise period of half an hour, while the sweat potassium concentration typically decreased with exercise. Mineral drink intake had no clear impact on the sweat sodium level, but increased the sweat potassium level. A paired -test and mean absolute relative difference (MARD) analysis, a method typically used for evaluating the performance of glucometers, was employed to compare the results of ISE and ICP-OES. The statistical analysis validated the feasibility of ISE for measuring sweat ions, although better accuracy is required. Our data suggests that overweight subjects are likely to possess a higher sweat sodium level.
Topics: Humans; Ion-Selective Electrodes; Ions; Male; Potassium; Sodium; Sweat
PubMed: 35448288
DOI: 10.3390/bios12040229 -
International Journal of Molecular... Feb 2019As the main cation in plant cells, potassium plays an essential role in adaptive responses, especially through its involvement in osmotic pressure and membrane potential... (Review)
Review
As the main cation in plant cells, potassium plays an essential role in adaptive responses, especially through its involvement in osmotic pressure and membrane potential adjustments. K homeostasis must, therefore, be finely controlled. As a result of different abiotic stresses, especially those resulting from global warming, K⁺ fluxes and plant distribution of this ion are disturbed. The hormone abscisic acid (ABA) is a key player in responses to these climate stresses. It triggers signaling cascades that ultimately lead to modulation of the activities of K⁺ channels and transporters. After a brief overview of transcriptional changes induced by abiotic stresses, this review deals with the post-translational molecular mechanisms in different plant organs, in Arabidopsis and species of agronomical interest, triggering changes in K⁺ uptake from the soil, K⁺ transport and accumulation throughout the plant, and stomatal regulation. These modifications involve phosphorylation/dephosphorylation mechanisms, modifications of targeting, and interactions with regulatory partner proteins. Interestingly, many signaling pathways are common to K⁺ and Cl/NO3 counter-ion transport systems. These cross-talks are also addressed.
Topics: Biological Transport; Gene Expression Regulation, Plant; Ion Transport; Ions; Osmotic Pressure; Plant Physiological Phenomena; Plants; Potassium; Protein Processing, Post-Translational; Salt Stress; Signal Transduction; Stress, Physiological
PubMed: 30736441
DOI: 10.3390/ijms20030715 -
International Journal of Molecular... Mar 2021Packed red blood cells (pRBCs), the most commonly transfused blood product, are exposed to environmental disruptions during storage in blood banks. In this study,...
Packed red blood cells (pRBCs), the most commonly transfused blood product, are exposed to environmental disruptions during storage in blood banks. In this study, temporal sequence of changes in the ion exchange in pRBCs was analyzed. Standard techniques commonly used in electrolyte measurements were implemented. The relationship between ion exchange and red blood cells (RBCs) morphology was assessed with use of atomic force microscopy with reference to morphological parameters. Variations observed in the Na, K, Cl, H, HCO, and lactate ions concentration show a complete picture of singly-charged ion changes in pRBCs during storage. Correlation between the rate of ion changes and blood group type, regarding the limitations of our research, suggested, that group 0 is the most sensitive to the time-dependent ionic changes. Additionally, the impact of irreversible changes in ion exchange on the RBCs membrane was observed in nanoscale. Results demonstrate that the level of ion leakage that leads to destructive alterations in biochemical and morphological properties of pRBCs depend on the storage timepoint.
Topics: Blood Preservation; Carbonates; Erythrocyte Membrane; Erythrocytes; Humans; Ion Exchange; Ions; Lactic Acid; Microscopy, Atomic Force; Potassium; Sodium; Specimen Handling
PubMed: 33809183
DOI: 10.3390/ijms22062885 -
Nature Communications Jul 2022Sodium-Potassium Pump (Na/K-ATPase, NKA) is an ion pump that generates an electrochemical gradient of sodium and potassium ions across the plasma membrane by hydrolyzing...
Sodium-Potassium Pump (Na/K-ATPase, NKA) is an ion pump that generates an electrochemical gradient of sodium and potassium ions across the plasma membrane by hydrolyzing ATP. During each Post-Albers cycle, NKA exchanges three cytoplasmic sodium ions for two extracellular potassium ions through alternating changes between the E1 and E2 states. Hitherto, several steps remained unknown during the complete working cycle of NKA. Here, we report cryo-electron microscopy (cryo-EM) structures of recombinant human NKA (hNKA) in three distinct states at 2.7-3.2 Å resolution, representing the E1·3Na and E1·3Na·ATP states with cytosolic gates open and the basic E2·[2K] state, respectively. This work provides the insights into the cytoplasmic Na entrance pathway and the mechanism of cytoplasmic gate closure coupled with ATP hydrolysis, filling crucial gaps in the structural elucidation of the Post-Albers cycle of NKA.
Topics: Adenosine Triphosphate; Cryoelectron Microscopy; Humans; Ions; Potassium; Sodium; Sodium-Potassium-Exchanging ATPase
PubMed: 35803952
DOI: 10.1038/s41467-022-31602-y -
Chemical & Pharmaceutical Bulletin 2022To verify the interaction between sodium polystyrene sulfonate (SPS) and its concomitant drugs, we elucidated the capability of potassium ions and concomitant drugs to...
To verify the interaction between sodium polystyrene sulfonate (SPS) and its concomitant drugs, we elucidated the capability of potassium ions and concomitant drugs to adsorb onto SPS and the effect of their coexistence on the amount adsorbed. We identified 14 drugs used concomitantly with SPS from 2017-2019 in our investigation, and 5 drug preparations used in the clinical setting were used for the experiments. In the artificial intestinal juice, SPS adsorbed 39.05-69.77 mEq/g of potassium ions. Amlodipine besylate and nifedipine were well-adsorbed, while azosemide and febuxostat were did not adsorb well onto SPS. Our results and the results of a previous study suggest that additives in drug preparations affect the adsorption of drugs onto SPS. The adsorption kinetics onto SPS of drugs conformed to the pseudo-second order model. However, the adsorption of amlodipine besylate completely may not be fitted to the pseudo-second order model. The amount of amlodipine besylate adsorbed under the coexistence of potassium ions decreased compared to when potassium ions were absent. The amount of nifedipine and potassium ions adsorbed remained constant, regardless of whether potassium ions were present or not. These results might be due to the differences in their mechanisms of adsorption onto SPS and to the characteristics of the drugs. In a clinical setting, SPS is used concomitantly with various oral drugs. The interaction between SPS and its other concomitant drugs need to be elucidated more to obtain enough evidence for pharmacists to propose the appropriate prescription.
Topics: Adsorption; Nifedipine; Ions; Potassium; Gastrointestinal Tract; Amlodipine
PubMed: 36450586
DOI: 10.1248/cpb.c22-00542 -
Journal of Dairy Science Jul 1997Milk fever is a complex metabolic disorder that occurs at the onset of lactation. Clinical symptoms of this disease include inappetence, tetany, inhibition of urination... (Review)
Review
Milk fever is a complex metabolic disorder that occurs at the onset of lactation. Clinical symptoms of this disease include inappetence, tetany, inhibition of urination and defecation, lateral recumbency, and eventual coma and death if left untreated. The hallmark of this disease is severe hypocalcemia, which probably accounts for most of the clinical signs associated with a milk fever episode. Several factors have been consistently associated with increased incidence of milk fever, including parturition and initiation of lactation, advancing age, breed, and diet. Of the various methods used in attempts to control the disease, the most progress has been made in dietary management. Until recently, most attention has focused on manipulating the levels of dietary calcium to control milk fever incidence; results, however, have been inconsistent, except for those diets containing very low (8 to 10 g/d) concentrations of Ca. During the past decade, there has been renewed interest and research in the use of dietary anions (Cl- and SO4(2-) in controlling milk fever. An outgrowth of this research has been the surprising realization that dietary K is significant (perhaps more significant than Ca) in determining the susceptibility of dairy cows to milk fever. This knowledge has expanded the understanding of the pathogenesis of milk fever and has focused attention on research designed to study methods for neutralizing the detrimental effects of dietary K excess on periparturient animal health. This report discusses various practical strategies and potential research areas for managing the dietary forage components to minimize the effects of K on milk fever incidence.
Topics: Animals; Calcium; Cations; Cattle; Diet; Female; Parturient Paresis; Potassium; Pregnancy
PubMed: 9241589
DOI: 10.3168/jds.S0022-0302(97)76056-9 -
Biochemistry. Biokhimiia Aug 2022The conclusions made in the three papers published in Function by Juhaszova et al. [Function, 3, 2022, zqab065, zqac001, zqac018], can be seen as a breakthrough in... (Review)
Review
The conclusions made in the three papers published in Function by Juhaszova et al. [Function, 3, 2022, zqab065, zqac001, zqac018], can be seen as a breakthrough in bioenergetics and mitochondrial medicine. For more than half a century, it has been believed that mitochondrial energetics is solely protonic and is based on the generation of electrochemical potential of hydrogen ions across the inner mitochondrial membrane upon oxidation of respiratory substrates, resulting in the generation of ATP via reverse transport of protons through the ATP synthase complex. Juhaszova et al. demonstrated that ATP synthase transfers not only protons, but also potassium ions, with the generation of ATP. This mechanism seems logical, given the fact that in eukaryotic cells, the concentration of potassium ions is several million times higher than the concentration of protons. The transport of K+ through the ATP synthase was enhanced by the activators of mitochondrial ATP-dependent K+ channel (K/ATP), leading to the conclusion that ATP synthase is the material essence of K/ATP. Beside ATP generation, the transport of osmotically active K+ to the mitochondrial matrix is accompanied by water entry to the matrix, leading to an increase in the matrix volume and activation of mitochondrial respiration with the corresponding increase in the ATP synthesis, which suggests an advantage of such transport for energy production. The driving force for K+ transport into the mitochondria is the membrane potential; an excess of K+ is exported from the matrix by the hypothetical K+/H+ exchangers. Inhibitory factor 1 (IF1) plays an important role in the activation of K/ATP by increasing the chemo-mechanical efficiency of ATP synthase, which may be a positive factor in the protective anti-ischemic signaling.
Topics: Adenosine Triphosphate; Mitochondria; Potassium; Potassium Channels; Protons; Water
PubMed: 36171650
DOI: 10.1134/S0006297922080016 -
Biophysical Journal Jul 2020The Na/K-ATPase is a chemical molecular machine responsible for the movement of Na and K ions across the cell membrane. These ions are moved against their... (Review)
Review
The Na/K-ATPase is a chemical molecular machine responsible for the movement of Na and K ions across the cell membrane. These ions are moved against their electrochemical gradients, so the protein uses the free energy of ATP hydrolysis to transport them. In fact, the Na/K-ATPase is the single largest consumer of energy in most cells. In each pump cycle, the protein sequentially exports 3Na out of the cell, then imports 2K into the cell at an approximate rate of 200 cycles/s. In each half cycle of the transport process, there is a state in which ions are stably trapped within the permeation pathway of the protein by internal and external gates in their closed states. These gates are required to open alternately; otherwise, passive ion diffusion would be a wasteful end of the cell's energy. Once one of these gates open, ions diffuse from their binding sites to the accessible milieu, which involves moving through part of the electrical field across the membrane. Consequently, ions generate transient electrical currents first discovered more than 30 years ago. They have been studied in a variety of preparations, including native and heterologous expression systems. Here, we review three decades' worth of work using these transient electrical signals to understand the kinetic transitions of the movement of Na and K ions through the Na/K-ATPase and propose the significance that this work might have to the understanding of the dysfunction of human pump orthologs responsible for some newly discovered neurological pathologies.
Topics: Biophysics; Humans; Ions; Kinetics; Potassium; Sodium; Sodium-Potassium-Exchanging ATPase
PubMed: 32579966
DOI: 10.1016/j.bpj.2020.06.006 -
Anais Da Academia Brasileira de Ciencias 2018Vinasse is a byproduct of the process of distillation of sugarcane juice for the manufacture of sugar and alcohol. Because it is rich in nutrients, mainly potassium (K),...
Vinasse is a byproduct of the process of distillation of sugarcane juice for the manufacture of sugar and alcohol. Because it is rich in nutrients, mainly potassium (K), is used as fertilizer and applied via fertigation, without concerning for the fate of this compound in the soil. Thus, the objective of the study was to evaluate the interactions of the potassium ion (K+), applied via vinasse in a soil representative of the sugarcane zone of the State of Pernambuco using adsorption isotherms. The methodology was based on physical, chemical and soil mineralogical characterization, as well as equilibrium batch tests, where the experimental curves were fitted by Langmuir and Freundlich isotherm models. The results allowed to infer that the Freundlich model showed better fit of the curve in both forms: linear and non-linear (direct fit); the non-linear model was selected due to the values of coefficient of determination (R²). The interaction between potassium and soil occurred mainly with organic matter and the presence of soil kaolinite, because they showed negative ions on the external surface, thereby promoting potassium adsorption. Soil potassium adsorption capacity was higher for the first layer (0-20 cm) and decreased along the depth profile.
Topics: Adsorption; Fertilizers; Ions; Linear Models; Models, Chemical; Potassium; Reference Values; Saccharum; Soil
PubMed: 29044317
DOI: 10.1590/0001-3765201720160910 -
International Journal of Molecular... Nov 2023We have previously shown that an excess of deoxycorticosterone acetate and high sodium chloride intake (DOCA/salt) in one-renin gene mice induces a high urinary Na/K...
We have previously shown that an excess of deoxycorticosterone acetate and high sodium chloride intake (DOCA/salt) in one-renin gene mice induces a high urinary Na/K ratio, hypokalemia, and cardiac and renal hypertrophy in the absence of hypertension. Dietary potassium supplementation prevents DOCA/salt-induced pathological processes. In the present study, we further study whether DOCA/salt-treated mice progressively develop chronic inflammation and fibrosis in the kidney and whether dietary potassium supplementation can reduce the DOCA/salt-induced renal pathological process. Results showed that (1) long-term DOCA/salt-treated one-renin gene mice developed severe kidney injuries including tubular/vascular hypertrophy, mesangial/interstitial/perivascular fibrosis, inflammation (lymphocyte's immigration), proteinuria, and high serum creatinine in the absence of hypertension; (2) there were over-expressed mRNAs of plasminogen activator inhibitor-1 (PAI-1), fibronectin, collagen type I and III, interferon-inducible protein-10 (IP-10), monocyte chemotactic protein-1 (MCP1), transforming growth factor- (TGF-), tumor necrosis factor-alpha (TNF-), osteopontin, Nuclear factor kappa B (NF-κB)/P65, and intercellular adhesion molecule (ICAM)-1; and (3) dietary potassium supplementation normalized urinary Na/K ratio, hypokalemia, proteinuria, and serum creatinine, reduced renal hypertrophy, inflammations, and fibrosis, and down-regulated mRNA expression of fibronectin, Col-I and III, TGF-, TNF-, osteopontin, and ICAM without changes in the blood pressure. The results provide new evidence that potassium and sodium may modulate proinflammatory and fibrotic genes, leading to chronic renal lesions independent of blood pressure.
Topics: Mice; Animals; Blood Pressure; Sodium Chloride; Fibronectins; Osteopontin; Potassium, Dietary; Desoxycorticosterone Acetate; Chlorides; Renin; Hypokalemia; Tumor Necrosis Factor-alpha; Creatinine; Hypertension; Kidney; Sodium Chloride, Dietary; Glomerulonephritis; Inflammation; Dietary Supplements; Transforming Growth Factor beta; Proteinuria; Hypertrophy; Fibrosis; Acetates
PubMed: 38069178
DOI: 10.3390/ijms242316858