Selenium is an essential trace element important for many physiological processes, especially for the functions of immune and reproductive systems, metabolism of thyroid hormones, as well as antioxidant defense. Selenium deficiency is usually manifested by an increased incidence of retention of placenta, metritis, mastitis, aborts, lowering fertility and increased susceptibility to infections. In calves, lambs and kids, the selenium deficiency demonstrates by WMD (white muscle disease), in foals and donkey foals, it is associated with incidence of WMD and yellow fat disease, and in pigs it causes VESD (vitamin E/selenium deficiency) syndrome. The prevention of these health disorders can be achieved by an adequate selenium supplementation to the diet. The review summarizes the survey of knowledge on selenium, its biological significance in the organism, the impact of its deficiency in mammalian livestock (comparison of ruminants vs. non-ruminants, herbivore vs. omnivore) and possibilities of its peroral administration. The databases employed were as follows: Web of Science, PubMed, MEDLINE and Google Scholar.

• Klíčová slova
• antioxidant, donkeys, horses, metallomics, oxidative stress, ruminants, selenium,
• MeSH
• lidé MeSH
• potravní doplňky MeSH
• savci metabolismus   MeSH
• selen nedostatek   metabolismus   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• selen MeSH

This paper reviews the current understanding of the toxicity of selenium (Se) to terrestrial mammalian and aquatic organisms. Adverse biological effects occur in the case of Se deficiencies, associated with this element having essential biological functions and a narrow window between essentiality and toxicity. Several inorganic species of Se (-2, 0, +4, and +6) and organic species (monomethylated and dimethylated) have been reported in aquatic systems. The toxicity of Se in any given sample depends not only on its speciation and concentration, but also on the concomitant presence of other compounds that may have synergistic or antagonistic effects, affecting the target organism as well, usually spanning 2 or 3 orders of magnitude for inorganic Se species. In aquatic ecosystems, indirect toxic effects, linked to the trophic transfer of excess Se, are usually of much more concern than direct Se toxicity. Studies on the toxicity of selenium nanoparticles indicate the greater toxicity of chemically generated selenium nanoparticles relative to selenium oxyanions for fish and fish embryos while oxyanions of selenium have been found to be more highly toxic to rats as compared to nano-Se. Studies on polymer coated Cd/Se quantum dots suggest significant differences in toxicity of weathered vs. non-weathered QD's as well as a significant role for cadmium with respect to toxicity.

• Klíčová slova
• Biological selenium, Metals, Nanoparticles, Organisms, Quantum dots, Toxicity,
• MeSH
• ekosystém MeSH
• krysa rodu Rattus MeSH
• kvantové tečky toxicita   MeSH
• látky znečišťující životní prostředí toxicita   MeSH
• lidé MeSH
• organoselenové sloučeniny toxicita   MeSH
• skot MeSH
• sloučeniny kadmia toxicita   MeSH
• sloučeniny selenu toxicita   MeSH
• synergismus léků MeSH
• vodní organismy účinky léků   růst a vývoj   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• cadmium selenide MeSH Prohlížeč
• látky znečišťující životní prostředí MeSH
• organoselenové sloučeniny MeSH
• sloučeniny kadmia MeSH
• sloučeniny selenu MeSH

Renal retention of selenium after administration of trimethylselenonium iodide (TMSeI) was studied in vivo in male and female rats during sexual maturation. The selenium level in the kidneys was found to be significantly higher in male rats than in females during the first hour after intravenous (i.v.) administration of TMSeI. The sex-linked difference, manifested already in 21-day old animals, increased markedly during the following four weeks of postnatal life. It was shown that this process may be accelerated by previously increased selenium intake. The sex-linked difference in renal retention of selenium was observed after administration of TMSeI in a wide range of doses: 0.002-10.0 mumol per animal. The size of the applied dose did not affect significantly the kinetic patterns of selenium in the kidneys during the first hour after i.v. injection. The results suggest the existence of a sex-dependent mechanism in the kidneys which may control the rate of excretion of trimethylselenonium ions in urine both under conditions of normal selenium intake and selenium intoxication.

• MeSH
• injekce intravenózní MeSH
• krysa rodu Rattus MeSH
• ledviny účinky léků   metabolismus   MeSH
• pohlavní dimorfismus MeSH
• potkani Wistar MeSH
• selen metabolismus   moč   MeSH
• sloučeniny selenu aplikace a dávkování   farmakologie   MeSH
• stárnutí MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• selen MeSH
• sloučeniny selenu MeSH
• trimethylselenonium MeSH Prohlížeč

Utilization of selenium was examined in slow-growing laying-type chickens (SG) and in fast-growing broiler hybrids (FG) fed ad libitum on a diet with 265 microg of selenium/kg, including 128 microg of selenium added as sodium selenite. To 40 d of age, coefficients of selenium retention increased (P < 0.05) daily in the SG and FG groups by 0.76 and 0.61%, respectively. From 40 to 100 d, the regression coefficients were not significant. Coefficients of selenium retention and retention per unit of body gain were higher in SG chickens. The influence of age on selenium content in BW gain of birds was evident (P < 0.01). From 5 to 40 d, allometric coefficients were 1.444 and 1.070 for SG and FG, respectively, and from d 40 to 100 the corresponding values were 1.282 and 1.081, respectively.

• MeSH
• kur domácí genetika   růst a vývoj   metabolismus   MeSH
• selen metabolismus   MeSH
• stárnutí metabolismus   MeSH
• stravovací zvyklosti MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• selen MeSH

The serum selenium levels in 367 healthy adult (25-64 yr) Central Bohemia residents, 176 men and 191 women, were determined using atomic absorption spectrometry. An extremely wide range of values was found in the whole population sample (< 20-296 micrograms/L) as well as in each sex or age category studied. The mean selenium concentration and 95% confidence interval calculated after logarithmic transformation of the data were 74 micrograms/L (71-77) for the whole population sample, 72 micrograms/L (67-76) for men, and 76 micrograms/L (72-81) for women. About 10% of the residents exhibited serum selenium level below 45 micrograms/L. There was no significant correlation between serum selenium and sex, age, or smoking status of participants. However, the lowest average level was found in the group of heavy smoking women: 66 micrograms/L. The selenium status of the Central Bohemia population seems to be below European average. Groups of residents having a very low nutritional selenium intake may be expected to occur in this population.

• MeSH
• dospělí MeSH
• kouření MeSH
• lidé středního věku MeSH
• lidé MeSH
• rizikové faktory MeSH
• selen krev   MeSH
• sexuální faktory MeSH
• spektrofotometrie ultrafialová MeSH
• stárnutí krev   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Československo MeSH
• Názvy látek
• selen MeSH

We studied organ concentration, excretion and excreted forms of selenium in young and adult rats after a single s.c. injection of a sublethal dose of 75Se-selenite. In the young about a 10-fold higher concentration of 75Se in blood, liver, kidneys and In the young, about a 10-fold higher concentration of 75Se in blood, liver, kidneys and heart was found at all the experimental intervals studied (1-7 days). The highest 75Se concentration in the young was in the liver while in the adults it was found in the kidneys. The spectrum of radioselenium metabolites in the urine was the same in both groups. However, the main product excreted by young rats was 75Se-glutathione selenotrisulphide and an unidentified neutral substance while it was the trimethylselenonium ion in the adults. Ontogenetic differences in selenium metabolism could be one of the factors underlying the differences in the response of the young and the adult rats to toxic doses of selenite.

• MeSH
• inbrední kmeny potkanů MeSH
• krysa rodu Rattus MeSH
• kyselina seleničitá MeSH
• radioizotopy selenu MeSH
• selen farmakokinetika   toxicita   MeSH
• stárnutí MeSH
• tkáňová distribuce MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyselina seleničitá MeSH
• radioizotopy selenu MeSH
• selen MeSH

Several mineralization methods for the determination of selenium using hydride generation optical emission spectrometry with inductively coupled plasma in biological samples (whole egg powder and pork liver) were compared using the analysis of means (ANOM) method. This statistical tool is suitable for graphical representation of testing on simple comparative experiments. The results yielded by ANOM are identical with those obtained with the commonly used analysis of variance (ANOVA) method; however, the graphical output of ANOM is more illustrative in comparison to ANOVA. Both methods indicated a significant discrepancy between the results obtained using muffle furnace ashing mineralization and the results provided by other mineralization methods. This is probably due to the loss of volatile selenium compounds during the decomposition of organic matter.

• MeSH
• analýza potravin metody   MeSH
• červené maso analýza   MeSH
• prasata MeSH
• selen analýza   MeSH
• spektrální analýza MeSH
• vejce analýza   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• selen MeSH

BACKGROUND AND OBJECTIVE: Microbial selenium (Se) supplementation is an essential area of biotechnological research due to differences in the bioavailability and toxicity of different forms of selenium. To date, research has focused mainly on the use of selenized yeast. However, in recent years, scientific interest has also increased in other microorganisms, such as lactic acid bacteria (LAB), which have several unique properties that can affect the quality and bioavailability of selenium. LAB, unlike yeast, can also act as probiotics, which may bring additional health benefits related to improving the intestinal microbiota and supporting the health of the gastrointestinal tract. METHODS: This study investigates the in vitro bioaccessibility and bioavailability of Se from two lactic acid bacterial strains, Streptococcus thermophilus CCDM 144 and Enterococcus faecium CCDM 922 A. We evaluated Se accumulation, speciation, and stability during simulated gastrointestinal digestion and Se permeation through a Caco-2 cell monolayer model. RESULTS: Both strains accumulated Se, metabolizing it predominantly into selenium nanoparticles (SeNPs, 64-77 % of total Se), with only a minor fraction (<5 % of total Se) of organic Se species. Experiments revealed that while organic Se species had high bioavailability (up to 90 %), their bioaccessibility during digestion was very low (<0.1 % of total Se). In contrast, SeNPs showed high bioaccessibility (∼90 %) and moderate transport efficiency through the intestinal model (16-19 % after 4 hours). CONCLUSION: These results highlight the potential of SeNPs produced by lactic acid bacteria as a bioaccessible form of Se for dietary supplementation. Further research is required to explore the behavior of SeNPs within the human body to fully understand how they can be used safely and effectively in nutrition or other applications.

• Klíčová slova
• Caco-2 cells, Enterococcus, Se species stability, Streptococcus, selenium nanoparticles,
• MeSH
• biologická dostupnost * MeSH
• biologické modely MeSH
• Caco-2 buňky MeSH
• funkce střevní bariéry MeSH
• Lactobacillales metabolismus   MeSH
• lidé MeSH
• permeabilita MeSH
• selen * metabolismus   MeSH
• Streptococcus thermophilus metabolismus   MeSH
• trávení MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• selen * MeSH

Selenium is a trace element that is essential for living organism. Its beneficial effect is, however, expressed in a very narrow dosage range: the high and low doses of selenium are connected with pathological manifestations. The toxicity depends on the chemical form of selenium, state of organism, interactions with heavy metals and on the stage of ontogenetic development. Whereas one dose of sodium selenite (20 micromol/kg b.w.) is lethal in adult rats, suckling rats are entirely resistant. However, within one week after administration of the same dose, cataract of eye lens developed. The highest incidence of cataract was observed in 10-day-old animals and it decreased until day 20. From postnatal day 20 to day 40 the rats were resistant to both the lethal and cataractogenic effects of selenium. The incidence of cataract may be suppressed by premature weaning, lower hydration of suckling, change of water soluble/water insoluble lens protein ratio, thyroxine treatment, and by interaction with mercury. By means of its oxidative and reduction properties, selenium is involved in the maintenance of the cell redox homeostasis. Typical example is its possible cardioprotective effect: selenium decreased number of arrhythmias, reduced infarct size and improved the contractile recovery after ischemia/reperfusion injury. Selenium supplementation may thus increase cardiac tolerance to ischemic damage.

• MeSH
• infarkt myokardu patologie   prevence a kontrola   MeSH
• kardiotonika farmakologie   terapeutické užití   MeSH
• katarakta metabolismus   patologie   MeSH
• lidé MeSH
• oční čočka účinky léků   patologie   MeSH
• oxidace-redukce MeSH
• reperfuzní poškození myokardu patofyziologie   prevence a kontrola   MeSH
• sloučeniny selenu farmakologie   toxicita   MeSH
• srdeční arytmie patologie   prevence a kontrola   MeSH
• věkové faktory MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• kardiotonika MeSH
• sloučeniny selenu MeSH

The goal of the experiment was to monitor the changes in the selenium concentration in goat milk during short-term oral supplementation of three different forms of selenium. The experiment involved 24 lactating goats of white shorthaired breed. Group C was the control; group S received selenium in the form of selenium-enriched yeast, group L in the form of lactate, and group B in the form of proteinate. Individual selenium preparations were administered individually orally in 250 microg Se dose per animal for 20 days. After the beginning of selenium supplementation, the selenium concentration in milk during the first 5 days grew gradually in group S. Between days 7 and 20 of Se supplementation, the mean Se concentrations in milk in groups were 12.53 +/- 3.69 microg l(-1) (C), 25.90 +/- 6.30 microg l(-1) (S), 13.14 +/- 3.54 microg l(-1) (L), 11.70 +/- 3.69 microg l(-1) (B). Differences between group S and other groups (C, B, L) were highly significant (p < 0.0001). Based on our results, selenium in the form of lactate and proteinate was excreted into the milk similarly, but selenium in the form of yeast, which contains high amount of selenomethionine, was excreted by milk in the highest amounts.

• MeSH
• časové faktory MeSH
• kozy MeSH
• kvasinky MeSH
• kyselina mléčná metabolismus   farmakologie   MeSH
• laktace účinky léků   MeSH
• mléko metabolismus   MeSH
• potravní doplňky * MeSH
• selen metabolismus   farmakologie   MeSH
• selenomethionin metabolismus   farmakologie   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kyselina mléčná MeSH
• selen MeSH
• selenomethionin MeSH