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.

• Klíčová slova
• Galleria mellonella, In vivo, Potassium nitrate, Toxicity,
• MeSH
• aldehyddehydrogenasa metabolismus   MeSH
• aminohydrolasy metabolismus   MeSH
• dusičnany metabolismus   farmakologie   toxicita   MeSH
• glutathiontransferasa metabolismus   MeSH
• glyceraldehyd-3-fosfátdehydrogenasa (NADP+) metabolismus   MeSH
• hemocyty účinky léků   metabolismus   MeSH
• hmyzí proteiny metabolismus   MeSH
• katalasa metabolismus   MeSH
• larva účinky léků   metabolismus   MeSH
• mitochondriální proteiny metabolismus   MeSH
• můry metabolismus   MeSH
• oxidace-redukce účinky léků   MeSH
• proteom metabolismus   MeSH
• proteomika MeSH
• sloučeniny draslíku farmakologie   toxicita   MeSH
• superoxiddismutasa metabolismus   MeSH
• testy akutní toxicity metody   MeSH
• triózafosfátizomeráza metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aldehyddehydrogenasa MeSH
• aliphatic nitrilase MeSH Prohlížeč
• aminohydrolasy MeSH
• dusičnany MeSH
• glutathiontransferasa MeSH
• glyceraldehyd-3-fosfátdehydrogenasa (NADP+) MeSH
• hmyzí proteiny MeSH
• katalasa MeSH
• mitochondriální proteiny MeSH
• potassium nitrate MeSH Prohlížeč
• proteom MeSH
• sloučeniny draslíku MeSH
• superoxiddismutasa MeSH
• triózafosfátizomeráza MeSH

This study deals with the effects of the agents that dissipate the individual components of the proton motive force (short-chain fatty acids, nigericin, and valinomycin) upon the methyl viologen-coupled nitrate reductase activity in intact cells. Substitution of butyrate or acetate for chloride in Tris-buffered assay media resulted in a marked inhibition at pH 7. In a Tris--chloride buffer of neutral pH, the reaction was almost fully inhibitable by nigericin. Alkalinisation increased the IC(50) value for nigericin and decreased the maximal inhibition attained. Both types of inhibitions could be reversed by the permeabilisation of cells or by the addition of nitrite, and that caused by nigericin disappeared at high extracellular concentrations of potassium. These data indicate that nitrate transport step relies heavily on the pH gradient at neutral pH. Since the affinity of cells for nitrate was strongly diminished by imposing an inside-positive potassium (or lithium) diffusion potential at alkaline external pH, a potential dependent step may be of significance in the transporter cycle under these conditions. Experiments with sodium-depleted media provided no hints for Na(+) as a possible H(+) substitute.

• MeSH
• biologický transport účinky léků   MeSH
• draslík metabolismus   MeSH
• dusičnany metabolismus   MeSH
• ionofory farmakologie   MeSH
• koncentrace vodíkových iontů MeSH
• nigericin farmakologie   MeSH
• nitrátreduktasa MeSH
• nitrátreduktasy antagonisté a inhibitory   MeSH
• Paracoccus denitrificans účinky léků   metabolismus   MeSH
• paraquat chemie   MeSH
• protonmotorická síla účinky léků   fyziologie   MeSH
• sodík metabolismus   MeSH
• valinomycin farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• draslík MeSH
• dusičnany MeSH
• ionofory MeSH
• nigericin MeSH
• nitrátreduktasa MeSH
• nitrátreduktasy MeSH
• paraquat MeSH
• sodík MeSH
• valinomycin MeSH

When grown anaerobically on a succinate+nitrate (SN) medium, Paracoccus denitrificans forms the membrane-bound, cytoplasmically oriented, chlorate-reducing nitrate reductase Nar, while the periplasmic enzyme Nap is expressed during aerobic growth on butyrate+oxygen (BO) medium. Preincubation of SN cells with chlorate produced a concentration-dependent decrease in nitrate utilization, which could be ascribed to Nar inactivation. Toluenization rendered Nar less sensitive to chlorate, but more sensitive to chlorite, suggesting that the latter compound may be the true inactivator. The Nap enzyme of BO cells was inactivated by both chlorate and chlorite at concentrations that were at least two orders of magnitude lower than those shown to affect Nar. Partial purification of Nap resulted in insensitivity to chlorate and diminished sensitivity to chlorite. Azide was specific for SN cells in protecting nitrate reductase against chlorate attack, the protective effect of nitrate being more pronounced in BO cells. The results are discussed in terms of different metabolic activation of chlorine oxoanions in both types of cells, and limited permeation of chlorite across the cell membrane.

• MeSH
• chlorečnany metabolismus   farmakologie   MeSH
• chloridy metabolismus   farmakologie   MeSH
• dusičnany metabolismus   MeSH
• inhibitory enzymů metabolismus   farmakologie   MeSH
• kyselina jantarová metabolismus   MeSH
• nitrátreduktasa antagonisté a inhibitory   metabolismus   MeSH
• oxidace-redukce MeSH
• Paracoccus denitrificans enzymologie   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chlorečnany MeSH
• chloridy MeSH
• chlorite MeSH Prohlížeč
• dusičnany MeSH
• inhibitory enzymů MeSH
• kyselina jantarová MeSH
• nitrátreduktasa MeSH

The effects of potassium nitrate were investigated on ovarian activity, especially on ovarian activity, especially on follicle ripening and ovulation, conception rate and progesterone levels in the milk of cows with cloprostenol-induced oestrus (Oestrophan Spofa) at a rate of 500 micrograms i.m. Potassium nitrate was administered at an amount of 150 g per head/day, and this amount increased by 50 g every other fortnight to the total rate of 300 g per head/day. In a group of 11 cows exposed to potassium nitrate load, clinical examination of ovaries on day 8 after oestrus revealed the presence of CL in seven cows (63.6%), persisting follicles in two cows, and two cows did not have any CL or follicles (Tab. I). After the first insemination three cows got in calf (27.3%), and after all inseminations it was 10 cows in total (90.9%) on average in 24.4 days after cloprostenol administration, with SP 96.7 days and insemination index 1.7. No ovulation disorders were found in the control group. All five cows got in calf after the first insemination in three days after cloprostenol administration with SP 61.5 days and insemination index 1.0 (Tab. II). The progesterone levels in milk were 22.3 and 21.1 ng/ml before the second administration of cloprostenol, 2.7 and 2.1 ng/ml in oestrus and at the time of A.I., and 16.6 in eight days after insemination in cows exposed to nitrate load, and finally 21.7 ng/ml in the control group (Tab. III). Ovulation disorders were easily detectable by a clinical check of ovaries on day 8 after oestrus.(ABSTRACT TRUNCATED AT 250 WORDS)

• MeSH
• cloprostenol farmakologie   MeSH
• dusičnany farmakologie   MeSH
• lidé MeSH
• ovarium účinky léků   MeSH
• ovulace účinky léků   MeSH
• progesteron metabolismus   MeSH
• sloučeniny draslíku farmakologie   MeSH
• těhotenství u zvířat účinky léků   MeSH
• těhotenství MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• cloprostenol MeSH
• dusičnany MeSH
• potassium nitrate MeSH Prohlížeč
• progesteron MeSH
• sloučeniny draslíku MeSH

To reduce the risk of salt-induced hypertension, medical authorities have emphasized dietary guidelines promoting high intakes of potassium and low intakes of salt that provide molar ratios of potassium to salt of ≥1:1. However, during the past several decades, relatively few people have changed their eating habits sufficiently to reach the recommended dietary goals for salt and potassium. Thus, new strategies that reduce the risk of salt-induced hypertension without requiring major changes in dietary habits would be of considerable medical interest. In the current studies in a widely used model of salt-induced hypertension, the Dahl salt-sensitive rat, we found that supplemental dietary sodium nitrate confers substantial protection from initiation of salt-induced hypertension when the molar ratio of added nitrate to added salt is only ≈1:170. Provision of a low molar ratio of added nitrate to added salt of ≈1:110 by supplementing the diet with beetroot also conferred substantial protection against salt-induced increases in blood pressure. The results suggest that on a molar basis and a weight basis, dietary nitrate may be ≈100× more potent than dietary potassium with respect to providing substantial resistance to the pressor effects of increased salt intake. Given that leafy green and root vegetables contain large amounts of inorganic nitrate, these findings raise the possibility that fortification of salty food products with small amounts of a nitrate-rich vegetable concentrate may provide a simple method for reducing risk for salt-induced hypertension.

• Klíčová slova
• diet, hypertension, nitric oxide, rats, sodium,
• MeSH
• Beta vulgaris * MeSH
• chlorid sodný toxicita   MeSH
• dieta metody   MeSH
• dusičnany aplikace a dávkování   MeSH
• hypertenze chemicky indukované   patofyziologie   prevence a kontrola   MeSH
• krevní tlak fyziologie   MeSH
• krysa rodu Rattus MeSH
• modely nemocí na zvířatech MeSH
• potkani inbrední Dahl MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• chlorid sodný MeSH
• dusičnany MeSH

On average, black individuals are widely believed to be more sensitive than white individuals to blood pressure (BP) effects of changes in salt intake. However, few studies have directly compared the BP effects of changing salt intake in black versus white individuals. In this narrative review, we analyze those studies and note that when potassium intake substantially exceeds the recently recommended US dietary goal of 87 mmol/day, black adults do not appear more sensitive than white adults to BP effects of short-term or long-term increases in salt intake (from an intake ≤50 mmol/day up to 150 mmol/day or more). However, with lower potassium intakes, racial differences in salt sensitivity are observed. Mechanistic studies suggest that racial differences in salt sensitivity are related to differences in vascular resistance responses to changes in salt intake mediated by vasodilator and vasoconstrictor pathways. With respect to cause and prevention of racial disparities in salt sensitivity, it is noteworthy that 1) on average, black individuals consume less potassium than white individuals and 2) consuming supplemental potassium bicarbonate, or potassium rich foods can prevent racial disparities in salt sensitivity. However, the new US dietary guidelines reduced the dietary potassium goal well below the amount associated with preventing racial disparities in salt sensitivity. These observations should motivate research on the impact of the new dietary potassium guidelines on racial disparities in salt sensitivity, the risks and benefits of potassium-containing salt substitutes or supplements, and methods for increasing consumption of foods rich in nutrients that protect against salt-induced hypertension.

• Klíčová slova
• hypertension, nitrate, race, salt-sensitive, sodium,
• MeSH
• běloši MeSH
• černoši MeSH
• draslík dietní * MeSH
• hypertenze patofyziologie   MeSH
• krevní tlak fyziologie   MeSH
• lidé MeSH
• rizikové faktory MeSH
• sodík dietní * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• draslík dietní * MeSH
• sodík dietní * MeSH

EDTA and EGTA when used in conjunction with AgNO3 enhanced the antibacterial action of the latter significantly, so that strains of Klebsiella pneumoniae and Staphylococcus aureus resistant to 70 micrograms/ml of AgNO3 were observed to became sensitive to 10 micrograms/ml of this compound. The synergistic effect of EDTA appears to be due to a mechanism other than the removal of lipopolysaccharide from outer membrane, as its effect could be observed in even non-LPS containing gram positive S. aureus cells. Penicillamine, another potent chelator had an opposite effect so that it decreased the toxicity of silver ions.

• MeSH
• antibakteriální látky aplikace a dávkování   MeSH
• antibiotická rezistence MeSH
• chelátory aplikace a dávkování   farmakologie   MeSH
• dusičnan stříbrný aplikace a dávkování   farmakologie   MeSH
• EDTA aplikace a dávkování   farmakologie   MeSH
• EGTA aplikace a dávkování   farmakologie   MeSH
• Klebsiella pneumoniae účinky léků   MeSH
• penicilamin aplikace a dávkování   farmakologie   MeSH
• Staphylococcus aureus účinky léků   MeSH
• synergismus léků MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• chelátory MeSH
• dusičnan stříbrný MeSH
• EDTA MeSH
• EGTA MeSH
• penicilamin MeSH

Meat of wild boar with an intial (137)Cs activity concentration of 103 Bq kg(-1) of fresh mass was treated by brining. Dry-salting reduced the (137)Cs activity only by about 12-18%. Subsequent brining was done by using both pure sodium chloride and a mixture of sodium chloride and potassium nitrate. After double-brine exchange, the (137)Cs activity concentration was reduced by at least 72%. The double-brine exchanges were done for two time intervals (the first each 24 h and the second each 7 days). There were no differences in the (137)Cs activity reduction for these two time intervals. From the technological point of view, the repeated exchange of the brine solution represents a relative easy method of (137)Cs activity reduction in contaminated pork meat.

• MeSH
• analýza potravin MeSH
• chlorid sodný chemie   MeSH
• dusičnany chemie   MeSH
• manipulace s potravinami metody   MeSH
• maso * účinky záření   MeSH
• osmolární koncentrace MeSH
• prasata * MeSH
• radioaktivní kontaminace potravin analýza   MeSH
• radioizotopy cesia analýza   chemie   MeSH
• roztoky MeSH
• sloučeniny draslíku chemie   MeSH
• soli chemie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• brine MeSH Prohlížeč
• chlorid sodný MeSH
• dusičnany MeSH
• potassium nitrate MeSH Prohlížeč
• radioizotopy cesia MeSH
• roztoky MeSH
• sloučeniny draslíku MeSH
• soli MeSH

• MeSH
• aktivní transport MeSH
• aminokyseliny metabolismus   MeSH
• biologický transport MeSH
• chloridy metabolismus   MeSH
• cykloheximid farmakologie   MeSH
• draslík farmakologie   MeSH
• dusičnany metabolismus   MeSH
• fosfáty metabolismus   MeSH
• glycin metabolismus   MeSH
• kyselina aspartová metabolismus   MeSH
• lysin metabolismus   MeSH
• Saccharomyces cerevisiae účinky léků   MeSH
• Saccharomyces účinky léků   metabolismus   MeSH
• sírany metabolismus   MeSH
• sodík farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aminokyseliny MeSH
• chloridy MeSH
• cykloheximid MeSH
• draslík MeSH
• dusičnany MeSH
• fosfáty MeSH
• glycin MeSH
• kyselina aspartová MeSH
• lysin MeSH
• sírany MeSH
• sodík MeSH

This paper describes the early stages of impregnation by the Golgi rapid method in sections and blocks of brain tissue. Aldehyde-fixed and potassium dichromate-treated sections of cerebral cortex were placed on glass slides and coverslipped. The dichromate solution was then replaced by a silver nitrate solution, and events taking place in the section were monitored and time-lapse recorded until the impregnation was interrupted and the sections subsequently prepared for electron microscopy. The tissue blocks, fixed and chromated in the same way, were placed into a silver nitrate solution for 30 min to 24 h and the progress of impregnation compared with the results obtained in the sections on the glass slides. Two basic modes of impregnation were observed, apparently in direct relation to the process of crystallization of silver chromate: crystals of silver chromate growing directly from the surface of the tissue into the nerve cell via its transected plasma membranes, and microcrystalline precipitate of silver chromate spreading into the nerve cell from nucleation centres dispersed in the tissue. The precipitate grows inside the cell as in a preformed channel until the cell has been filled. If the nucleation begins extracellularly, the precipitate extends into the narrow intercellular gaps. Electron microscopy showed that the crystalline precipitate consisted of multilamellar formations containing dense coalesced granules that did not cross plasma or endocellular membrane boundaries.

• MeSH
• barvení stříbrem metody   MeSH
• dusičnan stříbrný MeSH
• dvojchroman draselný MeSH
• elektronová mikroskopie MeSH
• krysa rodu Rattus MeSH
• krystalizace MeSH
• lidé MeSH
• mozek ultrastruktura   MeSH
• myši MeSH
• neurony ultrastruktura   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dusičnan stříbrný MeSH
• dvojchroman draselný MeSH