High dietary sodium and low potassium intake is associated with high blood pressure (BP). The current study aimed to determine if the sodium-to-potassium ratio is more strongly associated with low (130-139/80-89 mm Hg) and high (≥140/90 mm Hg) BP thresholds among US adults than either sodium or potassium alone. A total of 30,776 patients aged ≥20 years with complete blood pressure participated in the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2018. Demographic information and health characteristics were compared between men and women using the chi-square test for categorical variables and independent samples t-test for continuous variables. Logistic regression was performed to investigate the association of the odds ratios (OR) of different levels of sodium, potassium, and sodium-to-potassium ratio. After multivariable adjustment (age, gender, Body mass index, Smoking, education, Race, Alcohol, total energy intake, and physical activity), no relationship has been observed between high versus low sodium-to-potassium ratio and BP threshold of 130-139/80-89 mm Hg (odds ratio [OR]: 1.02, 95% confidence interval [CI]: 0.92-1.12). Higher sodium-to-potassium ratio (OR=1.24; CI: 1.11-1.38) and dietary intake of potassium (OR=0.66; CI: 0.55-0.80) showed significant association in reducing the BP threshold of ≥140/90 mm Hg. In dose-response analysis, higher BP ≥140/90 mm Hg was inversely associated with higher potassium intake. Furthermore, the sodium-to-potassium ratio showed higher odds in predicting the BP of patients aged ≤60 years, underweight, nonsmokers, and non-alcohol users. The study confirms an inverse association between higher potassium intake and higher BP threshold. The Doses-response analyses showed sodium-to-potassium ratio is a better predictor of BP thresholds than sodium or potassium alone.

• Klíčová slova
• Blood pressure, NHANES, gender difference, potassium intake, sodium intake, sodium to potassium ratio,
• MeSH
• dospělí MeSH
• draslík dietní MeSH
• draslík MeSH
• hypertenze * epidemiologie   MeSH
• krevní tlak fyziologie   MeSH
• lidé MeSH
• rizikové faktory MeSH
• sodík * MeSH
• výživa - přehledy MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• draslík dietní MeSH
• draslík MeSH
• sodík * MeSH

ATP-sensitive potassium channels have been an intensively studied type of protein complexes incorporated in the cell membrane for several decades. Their unique function makes them special, as they create a connection between the metabolic state and membrane voltage of the cell. This position of a bridge involved in many cellular cascades allow them to participate in various processes at often surprising positions in nearly all organ systems of the body, from the pancreas, heart muscle or retina, to the central nervous system. This review summarizes the most important roles of ATP-sensitive potassium channels focusing on their possible clinical use within particular organ systems.

• Klíčová slova
• ATP-sensitive potassium channels, Alzheimerʻs disease, Alzheimer‘s disease, Arrhythmia, Cantú syndrome, Parkinsonʻs disease, Parkinson’s disease, Vasodilation, arrhythmia, diabetes, ischemic preconditioning, leptin, mitochondria,
• MeSH
• draslíkové kanály * MeSH
• KATP kanály * MeSH
• mitochondrie MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• draslíkové kanály * MeSH
• KATP kanály * MeSH

Extracellular potassium concentration might modify electrophysiological properties in the border zone of ischemic myocardium. We evaluated the depolarization and repolarization characteristics across the ischemic-normal border under [K+] variation. Sixty-four-lead epicardial mapping was performed in 26 rats ([K+] 2.3-6.4 mM) in a model of acute ischemia/reperfusion. The animals with [K+] < 4.7 mM (low-normal potassium) had an ischemic zone with ST-segment elevation and activation delay, a border zone with ST-segment elevation and no activation delay, and a normal zone without electrophysiological abnormalities. The animals with [K+] >4.7 mM (normal-high potassium) had only the ischemic and normal zones and no transitional area. Activation-repolarization intervals and local conduction velocities were inversely associated with [K+] in linear regression analysis with adjustment for the zone of myocardium. The reperfusion extrasystolic burden (ESB) was greater in the low-normal as compared to normal-high potassium animals. Ventricular tachycardia/fibrillation incidence did not differ between the groups. In patch-clamp experiments, hypoxia shortened action potential duration at 5.4 mM but not at 1.3 mM of [K+]. IK(ATP) current was lower at 1.3 mM than at 5.4 mM of [K+]. We conclude that the border zone formation in low-normal [K+] was associated with attenuation of IK(ATP) response to hypoxia and increased reperfusion ESB.

• Klíčová slova
• action potential duration, border zone, epicardial mapping, myocardial ischemia, potassium, potassium ionic currents,
• MeSH
• akční potenciály * fyziologie   MeSH
• draslík * krev   metabolismus   MeSH
• ischemická choroba srdeční * patofyziologie   krev   metabolismus   MeSH
• krysa rodu Rattus MeSH
• potkani Wistar MeSH
• reperfuzní poškození myokardu krev   patofyziologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• draslík * MeSH

Heart failure therapy involves the use of a number drugs that significantly affect potassium levels. While diuretics decrease potassium levels, others (angiotensin converting enzyme inhibitors, AT2 receptor blockers, sacubitril/valsartan, spironolactone) increase. Patients also have several comorbidities that can significantly reduce renal function and thus affect the resulting potassium level. Decreased or elevated potassium levels can be very dangerous for the patient and therefore need to be monitored. In recent years, the results of several studies have been published that have focused on potassium levels and mortality and have shown that the optimal potassium levels in patients with heart failure should be between 4-5 mmol/L.

• Klíčová slova
• SGLT2, heart failure, mortality, optimal level of kalemia, potassium,
• MeSH
• aminobutyráty terapeutické užití   MeSH
• antagonisté receptorů pro angiotenzin * terapeutické užití   MeSH
• bifenylové sloučeniny terapeutické užití   MeSH
• diuretika terapeutické užití   MeSH
• draslík terapeutické užití   MeSH
• fixní kombinace léků MeSH
• lidé MeSH
• srdeční selhání * MeSH
• tepový objem fyziologie   MeSH
• tetrazoly terapeutické užití   MeSH
• valsartan terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aminobutyráty MeSH
• antagonisté receptorů pro angiotenzin * MeSH
• bifenylové sloučeniny MeSH
• diuretika MeSH
• draslík MeSH
• fixní kombinace léků MeSH
• sacubitril MeSH Prohlížeč
• tetrazoly MeSH
• valsartan MeSH

Yeasts usually have one or two high-affinity potassium transporters. Two complete and one interrupted gene encoding three types of putative potassium uptake system exist in Candida albicans SC5314. As high intracellular potassium is essential for many yeast cell functions, the existence of three transporters with differing transport mechanisms (Trk uniporter, Hak cation-proton symporter, Acu ATPase) may help pathogenic C. albicans cells to acquire the necessary potassium in various organs and tissues of the host. When expressed in Saccharomyces cerevisiae lacking their own potassium uptake systems, all three putative transporters were able to provide cells with the ability to grow with low amounts of potassium over a broad range of external pH. Only CaTrk1 was properly recognized and secreted to the plasma membrane. Nevertheless, even the small number of CaHak1 and mainly CaAcu1 molecules which reached the plasma membrane resulted in an improved growth of cells in low potassium concentrations, suggesting a high affinity and capacity of the transporters. A single-point mutation restored the complete CaACU1 gene, and the resulting protein not only provided cells with the necessary potassium but also improved their tolerance to toxic lithium. In contrast to its known homologues, CaAcu1 did not seem to transport sodium.

• Klíčová slova
• Acu1 ATPase, Candida, Hak1 transporter, Trk1 transporter, cation homeostasis, potassium uptake,
• MeSH
• Candida albicans genetika   metabolismus   MeSH
• draslík metabolismus   MeSH
• koncentrace vodíkových iontů MeSH
• kultivační média chemie   MeSH
• membránové transportní proteiny genetika   metabolismus   MeSH
• proteiny přenášející kationty nedostatek   MeSH
• rekombinantní proteiny genetika   metabolismus   MeSH
• Saccharomyces cerevisiae - proteiny MeSH
• Saccharomyces cerevisiae genetika   růst a vývoj   metabolismus   MeSH
• testy genetické komplementace MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• draslík MeSH
• kultivační média MeSH
• membránové transportní proteiny MeSH
• proteiny přenášející kationty MeSH
• rekombinantní proteiny MeSH
• Saccharomyces cerevisiae - proteiny MeSH
• Trk1 protein, Candida albicans MeSH Prohlížeč
• TRK1 protein, S cerevisiae MeSH Prohlížeč
• TRK2 protein, S cerevisiae MeSH Prohlížeč

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 K2CO3, KHCO3 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.

• Klíčová slova
• Biodiesel, Butanol, KOH, Rapeseed oil, Separation, Transesterification,
• MeSH
• biopaliva * MeSH
• butanoly * MeSH
• hydroxidy * MeSH
• katalýza MeSH
• kyseliny mastné mononenasycené MeSH
• olej z řepky MeSH
• oleje rostlin MeSH
• sloučeniny draslíku * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biopaliva * MeSH
• butanoly * MeSH
• hydroxidy * MeSH
• kyseliny mastné mononenasycené MeSH
• olej z řepky MeSH
• oleje rostlin MeSH
• potassium hydroxide MeSH Prohlížeč
• sloučeniny draslíku * MeSH
• tert-butoxide, potassium MeSH Prohlížeč

A high intracellular concentration of potassium (200-300 mmol/L) is essential for many yeast cell functions, such as the regulation of cell volume and pH, maintenance of membrane potential, and enzyme activation. Thus, cells use high-affinity specific transporters and expend a lot of energy to acquire the necessary amount of potassium from their environment. In Candida genomes, genes encoding 3 types of putative potassium uptake systems were identified: Trk uniporters, Hak symporters, and Acu ATPases. Tests of the tolerance and sensitivity of C. albicans, C. dubliniensis, C. glabrata, C. krusei, C. parapsilosis, and C. tropicalis to various concentrations of potassium showed significant differences among the species, and these differences were partly dependent on external pH. The species most tolerant to potassium-limiting conditions were C. albicans and C. krusei, while C. parapsilosis tolerated the highest KCl concentrations. Also, the morphology of cells changed with the amount of potassium available, with C. krusei and C. tropicalis being the most influenced. Taken together, our results confirm potassium uptake and accumulation as important factors for Candida cell growth and suggest that the sole (and thus probably indispensable) Trk1 potassium uptake system in C. krusei and C. glabrata may serve as a target for the development of new antifungal drugs.

• Klíčová slova
• Candida, homéostasie du potassium, morphologie, morphology, potassium homeostasis,
• MeSH
• Candida albicans růst a vývoj   patogenita   MeSH
• Candida glabrata růst a vývoj   patogenita   MeSH
• Candida tropicalis růst a vývoj   patogenita   MeSH
• Candida růst a vývoj   patogenita   MeSH
• draslík metabolismus   MeSH
• genom fungální MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• draslík MeSH

Candida krusei is a pathogenic yeast species that is phylogenetically outside both of the well-studied yeast groups, whole genome duplication and CUG. Like all other yeast species, it needs to accumulate high amounts of potassium cations, which are needed for proliferation and many other cell functions. A search in the sequenced genomes of nine C. krusei strains revealed the existence of two highly conserved genes encoding putative potassium uptake systems. Both of them belong to the TRK family, whose members have been found in all the sequenced genomes of species from the Saccharomycetales subclade. Analysis and comparison of the two C. krusei Trk sequences revealed all the typical features of yeast Trk proteins but also an unusual extension of the CkTrk2 hydrophilic N-terminus. The expression of both putative CkTRK genes in Saccharomyces cerevisiae lacking its own potassium importers showed that only CkTrk1 is able to complement the absence of S. cerevisiae's own transporters and provide cells with a sufficient amount of potassium. Interestingly, a portion of the CkTrk1 molecules were localized to the vacuolar membrane. The presence of CkTrk2 had no evident phenotype, due to the fact that this protein was not correctly targeted to the S. cerevisiae plasma membrane. Thus, CkTrk2 is the first studied yeast Trk protein to date that was not properly recognized and targeted to the plasma membrane upon heterologous expression in S. cerevisiae.

• Klíčová slova
• Candida, Trk proteins, cation homeostasis, potassium uptake, yeast K+ transporters,
• MeSH
• Candida klasifikace   genetika   růst a vývoj   metabolismus   MeSH
• draslík metabolismus   MeSH
• fungální proteiny genetika   metabolismus   MeSH
• fylogeneze MeSH
• genetická variace MeSH
• genom fungální genetika   MeSH
• iontový transport MeSH
• proteiny přenášející kationty genetika   metabolismus   MeSH
• rekombinantní proteiny genetika   metabolismus   MeSH
• Saccharomyces cerevisiae klasifikace   genetika   růst a vývoj   metabolismus   MeSH
• Saccharomycetales klasifikace   genetika   MeSH
• testy genetické komplementace MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• draslík MeSH
• fungální proteiny MeSH
• proteiny přenášející kationty MeSH
• rekombinantní proteiny MeSH

Inward rectifier potassium currents (I Kir,x) belong to prominent ionic currents affecting both resting membrane voltage and action potential repolarization in cardiomyocytes. In existing integrative models of electrical activity of cardiac cells, they have been described as single current components. The proposed quantitative model complies with findings indicating that these channels are formed by various homomeric or heteromeric assemblies of channel subunits with specific functional properties. Each I Kir,x may be expressed as a total of independent currents via individual populations of identical channels, i.e., channels formed by the same combination of their subunits. Solution of the model equations simulated well recently observed unique manifestations of dual ethanol effect in rat ventricular and atrial cells. The model reflects reported occurrence of at least two binding sites for ethanol within I Kir,x channels related to slow allosteric conformation changes governing channel conductance and inducing current activation or inhibition. Our new model may considerably improve the existing models of cardiac cells by including the model equations proposed here in the particular case of the voltage-independent drug-channel interaction. Such improved integrative models may provide more precise and, thus, more physiologically relevant results.

• Klíčová slova
• Cardiomyocytes, Dual effect, Ethanol, I K1, Inward rectifier potassium currents, Quantitative model,
• MeSH
• akční potenciály * MeSH
• alosterická regulace MeSH
• draslíkové kanály dovnitř usměrňující chemie   metabolismus   MeSH
• ethanol farmakologie   MeSH
• kardiomyocyty účinky léků   metabolismus   fyziologie   MeSH
• krysa rodu Rattus MeSH
• modely kardiovaskulární MeSH
• multimerizace proteinu MeSH
• srdce - funkce komor MeSH
• srdeční komory cytologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• draslíkové kanály dovnitř usměrňující MeSH
• ethanol MeSH

The effect of potassium (K) concentration gradient on stable caesium (Cs) uptake by Calla palustris was studied under hydroponic conditions after eight-day exposure in a greenhouse experiment. The plants were exposed to two different concentrations of Cs (provided as 0.5 and 1 mM CsCl) and five different concentrations of K (provided as K2SO4 in 0.5, 1, 2, 5, and 10 mM). The results indicate negative dependence of Cs uptake on K concentrations for both Cs treatments. The application of K reduced the transfer of stable Cs from water to plant by about 44-72% for 0.5 mM CsCl and 56-74% for 1 mM CsCl. The highest efficiency of Cs removal from water was observed for plants in K+ deficient solutions (plants starving), with an efficiency 8.0% for plants cultivated in 0.5 mM CsCl and 9.4% for plants in 1 mM CsCl. An increasing concentration of K also supported translocation of Cs from roots to leaves. Higher translocation was observed for the treatments with lower level of Cs, where the concentration of Cs in leaves became higher than that in roots. The Cs uptake and translocations were affected not only by the external concentration of K, but also the external concentration of stable Cs. A high concentration of K in the environment protects the food chain from Cs uptake by plants, but lowers the efficiency of phytoremediation techniques.

• Klíčová slova
• Caesium, Calla palustris, Phytoremediation, Potassium, Uptake,
• MeSH
• biodegradace MeSH
• biologický transport účinky léků   fyziologie   MeSH
• Calla (rostlina) metabolismus   MeSH
• cesium analýza   metabolismus   MeSH
• chloridy analýza   metabolismus   MeSH
• draslík metabolismus   farmakologie   MeSH
• kořeny rostlin chemie   metabolismus   MeSH
• listy rostlin chemie   metabolismus   MeSH
• radioaktivní látky znečišťující půdu MeSH
• radioizotopy cesia analýza   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cesium chloride MeSH Prohlížeč
• cesium MeSH
• chloridy MeSH
• draslík MeSH
• radioaktivní látky znečišťující půdu MeSH
• radioizotopy cesia MeSH