Potassium Loading Research Articles

Alkali Potassium Induced HCl/CO2 Selectivity Enhancement and Chlorination Reaction Inhibition for Catalytic Oxidation of Chloroaromatics

Industrial combustion of chloroaromatics is likely to generate unintentional biphenyls (PCBs), polychlorinated dibenzo- p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs). This process involves a surface-mediated reaction and can be accelerated in the presence of a catalyst. In the past decade, the effect of surface nature of applied catalysts on the conversion of chloroaromatics to PCBs/PCDD/PCDF has been well explored. However, studies on how the flue gas interferent components affect such a conversion process remain insufficient. In this article, a critical flue gas interferent component, alkali potassium, was investigated to reveal its effect on the chloroaromatics oxidation at a typical solid acid-base catalyst, Mn xCe1- xO2/HZSM-5. The loading of alkali potassium was found to improve the Lewis acidity of the catalyst (by increasing the amounts of surface Mn4+ after calcination), which thus promoted the CO2 selectivity for catalytic chlorobenzene (CB) oxidation. The KOH with a high hydrophilicity has favored the adsorption/activation of H2O molecules that provided sufficient hydroxyl groups and possibly induced a hydrolysis process to promote the formation of HCl. The K ion also served as a potential sink for chorine ions immobilization (via forming KCl). Both of these inhibited the formation of phenyl polychloride byproducts, thereby blocking the conversion of CB to chlorophenol and then PCDDs/PCDFs, and potentially ensuring a durable operation and less secondary pollution for the catalytic chloroaromatics combustion in industry.

The Nedd8 Co‐E3 DCNL4 is regulated by dietary potassium in renal intercalated cells and promotes WNK kinase degradation via the KLHL3/CUL3 complex

WNK kinases regulate NaCl and K+ transport in the distal nephron. The abundance of these kinases is controlled by the KLHL3/CUL3 complex, a cullin‐RING E3 ligase (CRL) that ubiquitylates the WNKs, marking them for degradation. Little is known about the mechanisms that physiologically regulate KLHL3/CUL3 complex activity. Mammalian DCN‐like (DCNL) proteins are a family of five evolutionarily conserved “co‐E3s” that promote CRL activation via neddylation. Since DCNL proteins are required for CRL activation in vitro, we hypothesized that specific DCNLs might be localized to the distal nephron to downregulate WNK kinases via the KLHL3/CUL3 complex. A kidney RNAseq database (Lee JW JASN 2015) detected DCNL4 transcripts in microdissected distal nephron segments, particularly the connecting tubule and cortical collecting duct. In immunohistochemistry and immunofluorescence studies, DCNL4‐specific antibodies detected a strong cytoplasmic signal in distal nephron intercalated cells (ICs). Notably, the signal was absent in the distal convoluted tubule and loop of Henle, the classical sites of WNK pathway activity. Recently, we showed that the abundance of the “long” kinase active form of WNK1 (L‐WNK1) is increased in ICs during dietary potassium loading. Consistent with this finding, dietary potassium loading (5% K+ with mixed citrate chloride and carbonate x10d) increased the abundance of the L‐WNK1 effector kinase SPAK in ICs, and decreased the abundance of DCNL4 by 53% by immunoblotting. Conversely, 10d of dietary K+ restriction upregulated DCNL4 in ICs and reciprocally decreased the abundance of L‐WNK1. In 293 cells, dicer substrate RNA‐mediated knockdown of DCNL4 increased endogenous steady state L‐WNK1 abundance, while overexpression of DCNL4 in the presence of KLHL3 and CUL3 enhanced L‐WNK1 degradation. These data support a model in which DCNL4 functions as an IC‐specific brake that downregulates L‐WNK1 and SPAK activity during hypokalemia, a process that is released during dietary potassium loading to activate IC‐mediated K‐secretion, possibly via basolateral NKCC1 cotransporters and apical BK channels. Thus, these findings suggest a novel physiological role for a specific DCNL protein in the regulation of potassium homeostasis.Support or Funding InformationNIH R01DK098145, R01DK038470, P30DK079307This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Dietary Approach to Recurrent or Chronic Hyperkalaemia in Patients with Decreased Kidney Function.

Whereas the adequate intake of potassium is relatively high in healthy adults, i.e., 4.7 g per day, a dietary potassium restriction of usually less than 3 g per day is recommended in the management of patients with reduced kidney function, especially those who tend to develop hyperkalaemia including patients who are treated with angiotensin pathway modulators. Most potassium-rich foods are considered heart-healthy nutrients with high fibre, high anti-oxidant vitamins and high alkali content such as fresh fruits and vegetables; hence, the main challenge of dietary potassium management is to maintain high fibre intake and a low net fixed-acid load, because constipation and metabolic acidosis are per se major risk factors for hyperkalaemia. To achieve a careful reduction of dietary potassium load without a decrease in alkali or fibre intake, we recommend the implementation of certain pragmatic dietary interventions as follows: Improving knowledge and education about the type of foods with excess potassium (per serving or per unit of weight); identifying foods that are needed for healthy nutrition in renal patients; classification of foods based on their potassium content normalized per unit of dietary fibre; education about the use of cooking procedures (such as boiling) in order to achieve effective potassium reduction before eating; and attention to hidden sources of potassium, in particular additives in preserved foods and low-sodium salt substitutes. The present paper aims to review dietary potassium handling and gives information about practical approaches to limit potassium load in chronic kidney disease patients at risk of hyperkalaemia.

Deactivation of Co-Based Fischer–Tropsch Catalyst by Aerosol Deposition of Potassium Salts

A 20%Co/0.5%Re/γAl2O3 Fischer–Tropsch catalyst was poisoned by four potassium salts (KNO3, K2SO4, KCl, and K2CO3) using the aerosol deposition technique, depositing up to 3500 ppm K as solid particles. Standard characterization techniques (H2 chemisorption, BET, TPR) showed no difference between treated samples and their unpoisoned counterpart. The Fischer–Tropsch activity was investigated at industrially relevant conditions (210 °C, H2:CO = 2:1, 20 bar). The catalytic activity was significantly reduced for samples exposed to potassium, and the loss of activity was more severe with higher potassium loadings, regardless of the potassium salt used. A possible dual deactivation effect by potassium and the counterion (chloride and sulfate) is observed with the samples poisoned by KCl and K2SO4. The selectivity toward heavier hydrocarbons (C5+) was slightly increased with increasing potassium loading, while the CH4 selectivity was reduced for all the treated samples. The results support the idea that potassium...

Sodium-Reduced Meat and Poultry Products Contain a Significant Amount of Potassium from Food Additives

BackgroundSodium-reduced packaged food products are increasingly available to consumers; however, it is not clear whether they are suitable for inclusion in a potassium-reduced diet. For individuals with impaired renal potassium excretion caused by chronic kidney disease and for those taking certain medications that interfere with the rennin-angiotensin aldosterone axis, the need to limit dietary potassium is important in view of the risk for development of hyperkalemia and fatal cardiac arrhythmias. ObjectiveThe primary objective of this study was to determine the impact of the reduction of sodium in packaged meat and poultry products (MPPs) on the content of potassium and phosphorus from food additives. DesignThis was a cross-sectional study comparing chemically analyzed MPPs (n=38, n=19 original, n=19 sodium-reduced), selected from the top three grocery chains in Canada, based on market share sales. All MPPs with a package label containing a reduced sodium content claim together with their non-sodium-reduced packaged MPP counterparts were selected for analysis. The protein, sodium, phosphorus, and potassium contents of sodium-reduced MPPs and the non-sodium-reduced (original) MPP counterparts were chemically analyzed according to the Association of Analytical Communities official methods 992.15 and 984.27 and compared by using a paired t test. The frequency of phosphorus and potassium additives appearing on the product labels' ingredient lists were compared between groups by using McNemar’s test. ResultsSodium-reduced MPPs (n=19) contained 44% more potassium (mg/100 g) than their non-sodium-reduced counterparts (n=19) (mean difference [95% CI): 184 [90-279]; P=0.001). The potassium content of sodium-reduced MPPs varied widely and ranged from 210 to 1,500 mg/100 g. Potassium-containing additives were found on the ingredient list in 63% of the sodium-reduced products and 26% of the non–sodium-reduced products (P=0.02). Sodium-reduced MPPs contained 38% less sodium (mg/100 g) than their non–sodium-reduced counterparts (mean difference [95% CI]: 486 [334-638]; P<0.001). The amounts of phosphorus and protein, as well as the frequency of phosphorus additives appearing on the product label ingredient list, did not significantly differ between the two groups. ConclusionsPotassium additives are frequently added to sodium-reduced MPPs in amounts that significantly contribute to the potassium load for patients with impaired renal handling of potassium caused by chronic kidney disease and certain medications. Patients requiring potassium restriction should be counseled to be cautious regarding the potassium content of sodium-reduced MPPs and encouraged to make food choices accordingly.

The Study of the Preparation of Catalysts for Carbonyl Sulfide Hydrolysis under Moderate Temperature

Multifunctional composite catalyst for carbonyl sulfide hydrolysis under moderate temperature was prepared by impregnation method. The hydrolysis and deoxidization ability of the prepared catalyst was investigated in a fixed bed reactor. It was found that deoxidization ability of the prepared catalyst was raised by the increase of the content of potassium loading catalyst and reaction temperature. And the concentration of H2S had no effect on deoxidization while COS improved the deoxidization ratio. And deoxidization rates were nearly scaled up with concentration of H2. The hydrolysis ability was decreased by the decrease of the surface basicity.

Potassium-regulated distal tubule WNK bodies are kidney-specific WNK1 dependent.

With-no-lysine (WNK) kinases coordinate volume and potassium homeostasis by regulating renal tubular electrolyte transport. In the distal convoluted tubule (DCT), potassium imbalance causes WNK signaling complexes to concentrate into large discrete foci, which we call "WNK bodies." Although these structures have been reported previously, the mechanisms that drive their assembly remain obscure. Here, we show that kidney-specific WNK1 (KS-WNK1), a truncated kinase-defective WNK1 isoform that is highly expressed in the DCT, is critical for WNK body formation. While morphologically distinct WNK bodies were evident in the distal tubules of mice subjected to dietary potassium loading and restriction, KS-WNK1 knockout mice were deficient in these structures under identical conditions. Combining in vivo observations in kidney with reconstitution studies in cell culture, we found that WNK bodies are dynamic membraneless foci that are distinct from conventional organelles, colocalize with the ribosomal protein L22, and cluster the WNK signaling pathway. The formation of WNK bodies requires an evolutionarily conserved cysteine-rich hydrophobic motif harbored within a unique N-terminal exon of KS-WNK1. We propose that WNK bodies are not pathological aggregates, but rather are KS-WNK1-dependent microdomains of the DCT cytosol that modulate WNK signaling during physiological shifts in potassium balance.

PP.28.29] THE ACUTE REDUCTION IN PLASMA POTASSIUM AND INCREASE IN RENIN LEVELS DURING AN ORAL GLUCOSE LOAD

PP.28.29] THE ACUTE REDUCTION IN PLASMA POTASSIUM AND INCREASE IN RENIN LEVELS DURING AN ORAL GLUCOSE LOAD

The renal response to potassium stress: integrating past with present.

The current review combines past findings with recent advances in our understanding of the homeostatic response to potassium imbalance. Following the ingestion of a dietary potassium load, a combination of extrarenal and renal mechanisms act to maintain extracellular K+ within a tight window. Through hormonal regulation and direct K+ sensing, the nephron is ideally suited to respond to wide shifts in external K+ balance. Current evidence indicates that dietary K+ loading triggers a coordinated kaliuretic response that appears to involve voltage-dependent changes in sodium transport across multiple nephron segments, including the proximal tubule, medullary loop of Henle, and distal tubule. Inhibition of sodium transport in these segments would accomplish the final goal of enhancing distal NaCl delivery, luminal flow, and K+ secretion in the aldosterone sensitive distal nephron (ASDN). Ongoing research seeks to define the relationship between potassium and volume homeostasis by elucidating pathways that couple renal K+ sensing and tubular function during the potassium stress response.

Use of 3D printing for biofuel production: efficient catalyst for sustainable biodiesel production from wastes

This work deals with the sustainable biodiesel production from low-cost renewable feedstock (waste and non-edible oils) using a heterogeneous catalyst constituted by potassium loaded on an amorphous aluminum silicate naturally occurring as volcanic material (pumice). The main challenge to biodiesel production from low-quality oils (used oils and greases) is the high percentage of free fatty acids (FFAs) and water in the feedstock that causes undesirable side reactions. The catalytic materials studied were tested in the transesterification reaction when using low-quality oils containing a high proportion of free fatty acids (FFAs) and water. Results indicated that the amount of acid and basic sites on the catalytic surface increases upon increasing potassium loading in the catalyst, displaying better performance for biodiesel production. Indeed, the modification of the aluminum silicate substrate upon potassium incorporation results in a catalytic material containing both acidic and basic sites, which are responsible for both triglycerides transesterification and FFA esterification reactions. The studied catalyst not only showed good performance in the biodiesel production reaction but also good tolerance to FFA and water contained in the feedstock for biodiesel production. The catalytic material was microstructured by 3D printing in order to design a catalytic stirring system with high mechanical strength, efficient and reusable. The use of 3D printing in biofuel production is a novelty that brings good solutions for catalyst production.

Green Synthesis of Veratraldehyde Using Potassium Promoted Lanthanum–Magnesium Mixed Oxide Catalyst

Veratraldehyde is an important chemical used in perfumery, agrochemical, and pharmaceutical industries. Current processes of manufacture of veratraldehyde use homogeneous catalysts, which make them highly polluting, creating problems of disposal of effluents and product purity. In the current work, veratraldehyde was synthesized from O-alkylation of vanillin with an environmentally benign reagent, dimethyl carbonate. A series of potassium loaded La2O3–MgO were prepared by the incipient wetness impregnation method, and their performance was evaluated vis-a-vis MgO, La2O3, La2O3–MgO, and a series of 1–4 wt % K/La2O3–MgO. All catalysts were characterized by different techniques, such as N2 adsorption/desorption, XRD, TGA-DSC, FT-IR, CO2-TPD, and SEM techniques. The effect of different loadings (1–4 wt %) of potassium on La2O3–MgO was studied, among which 2 wt % K/La2O3–MgO showed the best activity and selectivity due to high dispersion of potassium and high basicity in comparison with the rest. The activity ...

Diesel soot elimination over potassium-promoted Co3O4 nanowires monolithic catalysts under gravitation contact mode

Herein, we report the high catalytic activity of the potassium-promoted Co3O4 nanowires supported on the monolithic three-dimensional macroporous (3-DM) nickel foam substrate (xKCo-NW) for soot combustion. The 3-DM structure of Ni foam and the space among these nanowires can extremely improve the contact efficiency between soot and catalysts. Loading of potassium provides the new active sites for soot oxidation, improves catalyst-soot contact as a molten salt and increases the number of the surface adsorbed oxygen species. The 5KCo-NW catalyst loaded with 5% potassium shows the highest catalytic performance, as well as a high water resistance. There are two types of potassium species in the catalysts, most potassium species is in the form of separate phases, and few interacts with cobalt oxide. The interaction between potassium species and cobalt oxide stabilizes a part of potassium species, and the stabilized potassium species can promote the catalytic activity for the consecutive soot combustion cycle. Moreover, our results show that the chemisorbed NOx species on the 5KCo-NW catalyst are more active than the gaseous NO2 for soot oxidation. In the presence of O2, soot combustion is accelerated to react with the chemisorbed NOx species; whereas the formed nitrate/nitrite species are catalytically inert.

Understanding of potassium promoter effects on oxychlorination of ethylene by operando spatial-time resolved UV–vis–NIR spectrometry

Obtaining the comprehensive kinetics of elementary reaction steps in catalytic redox cycles remains a challenge. We report here an operando study by combined mass and UV–vis–NIR spectrometry to obtain kinetic data for reduction and oxidation steps in the catalytic cycle of ethylene oxychlorination on potassium-promoted CuCl2/Al2O3 catalysts and understand the catalytic consequences of potassium promotion for ethylene oxychlorination through a comprehensive kinetic analysis of the catalytic cycle. The results demonstrate that the Cu2+ and Cu1+ concentration, the number of active sites, and the activity of the active sites are highly dynamic, depending on the catalyst composition and the operating conditions. A pseudo-steady-state approach was applied to deconvolute the effect of promoters on the oxychlorination reaction into the effects on the individual reduction and oxidation steps, as well as their consequences in steady state in terms of the active site number and the site activity. It has been found that the rate of oxidation of Cu1+ by oxygen is much lower than the rate of reduction of Cu2+ by ethylene at relatively high Cu2+ content. This resulted in CuCl dominating at the surface and thus a low rate in the steady state on the neat CuCl2 catalyst. Potassium promotion increased the reducible Cu2+ content from 0.61mol/molCu of the neat CuCl2 catalyst to 0.8mol/molCu by reducing the interaction between Cu and the alumina support. Further increasing the potassium loading from 0.92 to 1.54wt.% decreases the reducible Cu2+ from about 0.8 to 0.7mol/molCu. Potassium promotion significantly increased the site activity of the Cu1+ oxidation, but decreased the site activity of the Cu2+ reduction by ethylene. The positive effect of potassium promotion is due to the increase in the number of Cu2+ active sites, which was more significant than the negative impact on turnover frequency (TOF); thus, potassium promotion increased the steady-state reaction rate. In addition, owing to the kinetic balance between the higher Cu1+ oxidation rate and the lower Cu2+ reduction rate, potassium promotion yielded an increased Cu oxidation state with Cu2+ dominating the steady-state catalyst surface. This led to remarkably improved stability of CuCl2 catalysts.

In Situ XRD Study on Promotional Effect of Potassium on Carburization of Spray‐dried Precipitated Fe2O3 Catalysts

AbstractA study of the promotional effect of potassium on the carburization behavior of a series of spray‐dried precipitated Fe2O3 catalysts (100 Fe, 100 Fe/0.52 K, 100 Fe/1.54 K, and 100 Fe/2.4 K) has been performed by using in situ XRD. The average crystallite size evolution for species such as α‐Fe2O3, Fe3O4, χ‐Fe5C2, and θ‐Fe3C were followed. The potassium promoter clearly inhibits the reduction of α‐Fe2O3 to Fe3O4, where the decreasing binding energy in the Fe 2p3/2, O 1s and K 2p3/2 spectra from X‐ray photoelectron spectroscopy (XPS) suggests an electron density increase in Fe and O upon potassium promotion, leading to the enhanced covalency in the Fe−O bond. In terms of crystallite size during carburization, an optimum potassium loading exists in catalyst 100 Fe/0.52 K, which shows the fastest reduction to Fe3O4 with minimum crystallite sizes of around 7 to 15 nm. Potassium has no clear effect in determining the final crystallite size of χ‐Fe5C2. An arch‐shaped curve in the evolution of crystallite size of the Fe3O4 intermediate was observed, which can be explained by the activation energy difference between the bidirectional steps of the outward oxygen diffusion and the inward carbon diffusion.

Toxicity detection in water containing heavy metal ions with a self-powered microbial fuel cell-based biosensor

In this work, a self-powered microbial fuel cell (MFC)-based biosensor was developed for detecting toxicity in water containing heavy metal ions. Experimental conditions containing concentration of potassium ferricyanide, load resistor and glucose concentration were optimized. Six heavy metal ions (2mg/L, Cu2+, Hg2+, Zn2+, Cd2+, Pb2+ and Cr3+) were tested by this biosensor and the inhibition ratios obtained were 12.56%, 13.99%, 8.81%, 9.29%, 5.59% and 1.95%, respectively. The inhibition ratios of 28.13% was also obtained for detecting the laboratory wastewater containing several heavy metal ions. The experimental results exhibited the feasibility and potential of the self-powered biosensor in detecting toxicities in water containing heavy metal ions.

Storage of Nitrous Oxide (NOx) in Diesel Engine Exhaust Gas using Alumina-Based Catalysts: Preparation, Characterization, and Testing

This work investigated the nitrous oxide (NOx) storage process using alumina-based catalysts (K2 O/Al2 O3 , CaO/Al2 O3, and BaO/Al2 O3 ). The feed was a synthetic exhaust gas containing 1,000 ppm of nitrogen monoxide (NO), 1,000 ppm i-C4 H10 , and an 8% O2 and N2 balance. The catalyst was carried out at temperatures between 250–450°C and a contact time of 20 minutes. It was found that NOx was effectively adsorbed in the presence of oxygen. The NOx storage capacity of K2 O/Al2 O3 was higher than that of BaO/Al2 O3. The NOx storage capacity for K2 O/Al2 O3 decreased with increasing temperature and achieved a maximum at 250°C. Potassium loading higher than 15% in the catalyst negatively affected the morphological properties. The combination of Ba and K loading in the catalyst led to an improvement in the catalytic activity compared to its single metal catalysts. As a conclusion, mixed metal oxide was a potential catalyst for de-NOx process in meeting the stringent diesel engine exhaust emissions regulations. The catalysts were characterized by a number of techniques and measurements, such as X-ray diffraction (XRD), electron affinity (EA), a scanning electron microscope (SEM), Brunner-Emmett-Teller (BET) to measure surface area, and pore volume and pore size distribution assessments.

Carbon monoxide hydrogenation on potassium promoted Mo2N catalysts

The catalytic performance of Mo2N and K-Mo2N were assessed in hydrogenation of carbon monoxide in the reaction temperature range of 275–325°C, 7MPa and 60,000h−1. The nitrides were synthesized via temperature-programmed treatment of ammonium heptamolybdate (AHM) and K-AHM precursors under continuous NH3 flow. The influence of potassium loading (0.45–6.2wt.%) on the Mo nitride phase and its resultant effect on the catalytic properties were been investigated. The nitride catalysts were characterized in terms of BET/pore size, powder X-ray diffraction, DRIFTs, CO-TPD-mass, HR-TEM and XPS measurements. The formation of cubic γ-Mo2N and monoclinic K2MoO4 phases were confirmed by XRD and TEM. Platelet morphology with particle size in the range of 5–10nm was observed for γ-Mo2N. CO-TPD-mass results mainly revealed molecular CO sorption on Mo2N and K-Mo2N surface. The highest total oxygenate selectivity (44%, 300°C) was observed on 1.3K-Mo2N with a K/Moδ+ surface ratio of 0.06. This is associated with well distributed K in the matrix of γ-Mo2N. Distribution of K was reduced due to K2MoO4 formation at 3 and 6.2wt.%K loading. DRIFTs results clearly demonstrates greater hydrocarbon formation on unpromoted Mo2N due to (i) CO dissociative hydrogenation (ii) water-gas shift reaction. Further, addition of K to Mo2N significantly improved the oxygenate selectivity by promoting the molecular CO insertion into −CHx intermediate.

Catalytic decomposition of N2O over Mg-Co and Mg-Mn-Co composite oxides

Mg-Co and Mg-Mn-Co composite oxides with different compositions were prepared by sol-gel method for N2O catalytic decomposition in the presence of oxygen. Of Mg-Mn-Co catalysts, the one with higher activity was impregnated by K2CO3 solution to make K-modified catalyst. These catalysts were characterized by X-ray diffraction (XRD), nitrogen physisorption (BET), scanning electron microscopy (SEM), temperature-programmed reduction of hydrogen (H2-TPR), and temperature-programmed desorption of oxygen (O2-TPD). The effect of preparation parameters such as compositions and potassium loadings on their catalytic activity has been investigated. The results show that K-modified catalysts exhibit better activity and higher resistance towards water in contrast to un-modified catalyst due to the weakness of surface metal-oxygen bonds. Among these catalysts, 0.02K/MgMn0.2Co1.8O4 is the most active, over which 97% and 60% conversions of N2O can be reached at 400°C after continuous running for 50 h under the atmosphere of oxygen-alone and oxygen-steam together, respectively. When the steam is switched off, the catalytic activity of 0.02K/MgMn0.2Co1.8O4 can be restored to large extent, indicating the good water-resistance of K-modified catalyst.

Effect of Promoter Addition on Water Gas Shift Property over Structured-Type Iron Oxide Catalyst

This study deals with the development of a high performance catalyst for the water gas shift reaction (WGS) by doping a promoter (Cr, Mn, Co, Ni, Cu) and optimizing the potassium loading on a structured-type iron oxide catalyst. Doping a promoter was effective for enhancing the WGS activity over the iron oxide-type catalyst, except for the Mn- and Cu-doping. Especially, the Ni-doping catalyst displayed a better performance than the other catalysts. In addition, loading a potassium component was found to have a positive effect on suppression of methanation as well as a drastic enhancement of the WGS activity.

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

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.