Tissue ischemia is connected with the production of free radicals (FR). This study was designed to directly measure of the amount of FR in rat brains related to a photothrombotic ischemic event shortly after establishing the lesion. A model of left hemisphere photothrombosis ischemia was used in the experiment. Brains of animals from the experimental group were removed and placed in liquid N(2) for 60 min after the green laser exposure, the control group brains, exposed to the photosensitive dye Rose Bengal (RB), were placed in liquid N(2) for 80 min after RB application, naive control brains were also briefly stored in liquid N(2). Spectroscopy of electron paramagnetic (spin) resonance was used to directly measure FR (hydroxyl (OH(.)) and nitroxyl (NO(.)). Compared to naive controls, both the ischemia and RB groups had significantly higher levels of OH(.), however, there were no differences between them. Comparison of hemispheres, i.e., with and without ischemia, in the experimental group did not show any significant difference in OH(.). NO(.) were elevated in the ischemia and RB groups compare to naive controls. Higher levels of NO(.) were found in hemispheres with ischemia compared to unexposed hemispheres. Increases in OH(.) were probably associated with the action of RB itself in this model of ischemia. Increases in NO(.) were closely related to the pathogenesis of photothrombotic ischemia and could be related to the activity of nitric oxide synthases.
- MeSH
- elektronová paramagnetická rezonance MeSH
- hydroxylový radikál metabolismus MeSH
- ischemie mozku metabolismus MeSH
- modely nemocí na zvířatech MeSH
- mozková kůra krevní zásobení MeSH
- oxidy dusíku metabolismus MeSH
- potkani Wistar MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Nitrogen oxides (NOx) are the components of fossil flue gas that give rise to the greatest environmental concerns. This study evaluated the ability of the green algae Chlorella to acclimate to high level of NOx and the potential utilization of Chlorella strains in biological NOx removal (DeNOx) from industrial flue gases. Fifteen Chlorella strains were subject to high-level of nitrite (HN, 176.5 mmolL(-1) nitrite) to simulate exposure to high NOx. These strains were subsequently divided into four groups with respect to their ability to tolerate nitrite (excellent, good, fair, and poor). One strain from each group was selected to evaluate their photosynthetic response to HN condition, and the nitrite adaptability of the four Chlorella strains were further identified by using chlorophyll fluorescence. The outcome of our experiments shows that, although high concentrations of nitrite overall negatively affect growth and photosynthesis of Chlorella strains, the degree of nitrite tolerance is a strain-specific feature. Some Chlorella strains have an appreciably higher ability to acclimate to high-level of nitrite. Acclimation is achieved through a three-step process of restrict, acclimate, and thriving. Notably, Chlorella sp. C2 was found to have a high tolerance and to rapidly acclimate to high concentrations of nitrite; it is therefore a promising candidate for microalgae-based biological NOx removal.
- MeSH
- aklimatizace účinky léků MeSH
- biodegradace MeSH
- Chlorella účinky léků genetika fyziologie MeSH
- chlorofyl metabolismus MeSH
- druhová specificita MeSH
- dusitany metabolismus MeSH
- fluorescence MeSH
- fotosyntéza účinky léků MeSH
- látky znečišťující vzduch metabolismus MeSH
- oxidy dusíku metabolismus MeSH
- plyny metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
The activation of Ca(2+)-dependent Cl(-) channels during norepinephrine-induced contraction of vascular smooth muscle was suggested to depolarize cell membrane and to increase Ca(2+) entry. Hypertension and ageing are associated with altered Ca(2+) handling including possible activation of Ca(2+)-dependent Cl(-) channels. Our study was aimed to determine Ca(2+)-dependent Cl(-) channels contribution to norepinephrine-induced contraction during hypertension and ageing. Norepinephrine-induced concentration-response curves of femoral arteries from 6- and 12-month-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats were recorded using wire myograph. Pretreatment with Ca(2+)-dependent Cl- channel inhibitor indanyloxyacetic acid 94 [R(+)-IAA-94](IAA) attenuated norepinephrine-induced contraction in all groups, but relatively more in WKY than SHR arteries. The attenuation of norepinephrine-induced contraction after Ca(2+)-dependent Cl(-) channels blockade was partially reduced in 12-month-old WKY rats, but substantially diminished in 12-month-old SHR. IAA effect was enhanced after NO synthase inhibition but decreased by ageing. In 20-month-old WKY rats norepinephrine-induced contraction was not affected by IAA but was almost abolished after cyclooxygenase inhibition by indomethacin or niflumic acid. In conclusion, contribution of Ca(2+)-dependent Cl(-) channels to norepinephrine-induced contraction diminished with age, hypertension development, and/or NO synthesis inhibition. Ca(2+)-dependent Cl(-) channels are important for maintenance of normal vascular tone while their inactivation/closing might be a pathological mechanism.
- MeSH
- arteria femoralis účinky léků metabolismus fyziologie MeSH
- chloridové kanály metabolismus MeSH
- endoteliny metabolismus MeSH
- hypertenze metabolismus MeSH
- krevní tlak účinky léků fyziologie MeSH
- krysa rodu rattus MeSH
- noradrenalin farmakologie MeSH
- oxidy dusíku metabolismus MeSH
- potkani inbrední SHR MeSH
- potkani inbrední WKY MeSH
- stárnutí účinky léků metabolismus MeSH
- svaly hladké cévní účinky léků metabolismus fyziologie MeSH
- vápník metabolismus MeSH
- vazokonstrikce účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
An epileptic seizure and postictal period in addition to well-known features are also characterized by massive consumption of energy. This is thought to lead to oxidative stress and increased generation of free radicals, which is reflected by increased levels of oxidative products. Our previous work described the neuroprotective effects of melatonin in preventing cognitive worsening after a single epileptic seizure. This work was aimed on direct measurement of free radicals in brain tissue using the EPR method 1, 15 and 60 minutes after seizure. The measurement was performed in adult male Wistar rats at the mentioned intervals after a single tonic-clonic seizure induced by flurothyl. In comparison to control animals there was a significant increase in hydroxyl and nitroxyl radicals 60 minutes after the seizure. The levels of hydroxyl radicals were significantly lower in animals that received melatonin 60 minutes before seizure induction compared to animals without preventive treatment. Therefore, melatonin affected the generation of the measured free radicals differently. An important finding was the delayed increase in free radicals after a single seizure in the later phases of recovery.
- MeSH
- antioxidancia aplikace a dávkování MeSH
- epilepsie farmakoterapie metabolismus MeSH
- hydroxylový radikál metabolismus MeSH
- krysa rodu rattus MeSH
- látky tlumící činnost CNS aplikace a dávkování MeSH
- melatonin aplikace a dávkování MeSH
- oxidační stres účinky léků MeSH
- oxidy dusíku metabolismus MeSH
- potkani Wistar MeSH
- reaktivní formy kyslíku metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Cílem naší studie bylo zjistit, zda léčba tiotropiem ovlivní nitrační stres u nemocných s CHOPN. Jedná se o otevřenou studii. Koncentrace dusitanů a dusičnanů byly měřeny v kondenzátu vydechovaného vzduchu (KVV). Odběry KVV byly prováděny před zahájením léčby, po 4 a po 12ti týdnech léčby. Koncentrace dusitanů se po 4 ani po 12ti týdenní léčbě v porovnání s koncentrací před léčbou signifikantně nezměnily. Koncentrace dusičnanů byla po 12ti týdnech léčby tiotropiem signifikantně menší než před léčbou. Podávání tiotropia po dobu 12ti týdnů nemocným s CHOPN dokáže zmírnit nitrační stres (p=0,010).
The study aimed at determining whether tiotropium therapy influences nitrosative stress in patients with COPD. This is an open study. Nitrite and nitrate concentrations were measured in exhaled breath concentrate (EBC). EBC was collected before therapy initiation and after 4 and 12 weeks of treatment. Nitrite concentrations did not significantly change after 4 or 12 weeks of treatment when compared with concentrations prior to the therapy. After 12 weeks of tiotropium therapy, nitrate concentrations were significantly lower than those before the therapy. Twelve-week administration of tiotropium to COPD patients is able to decrease nitrosative stress (p = 0.010),
- MeSH
- chronická obstrukční plicní nemoc farmakoterapie MeSH
- dechové testy metody MeSH
- dusičnany analýza diagnostické užití MeSH
- dusitany analýza diagnostické užití MeSH
- lidé středního věku MeSH
- lidé MeSH
- oxidační stres účinky léků MeSH
- oxidy dusíku metabolismus škodlivé účinky MeSH
- senioři MeSH
- skopolaminové deriváty aplikace a dávkování farmakologie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- senioři MeSH
OBJECTIVES: The aim of the study was to demonstrate the ability to measure free radicals and singlet oxygen, using EPR methods, in the tail of anaesthetized rats. The advantage of this method lies in the potential for continuous evaluation of free radicals and singlet oxygen during nociceptive processes.
- MeSH
- antioxidancia farmakologie MeSH
- bolest metabolismus MeSH
- elektronová paramagnetická rezonance veterinární MeSH
- financování organizované MeSH
- hydroxylový radikál analýza metabolismus MeSH
- krysa rodu rattus MeSH
- měření bolesti metody přístrojové vybavení MeSH
- ocas metabolismus MeSH
- oxidy dusíku analýza metabolismus MeSH
- potkani Wistar MeSH
- práh bolesti fyziologie účinky léků MeSH
- singletový kyslík analýza metabolismus MeSH
- volné radikály analýza metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
Two classes of newly synthesized amphiphilic compounds, phenolic antioxidants ("phenolics") and N-oxides exert in vivo antioxidant effects on live S. cerevisiae cells. Both groups have low toxicity, phenolics being more toxic than N-oxides and compounds with a longer alkyl chain having higher toxicity than those with a shorter alkyl chain. Phenolic antioxidants protect yeast cells exposed to the superoxide producer paraquat and peroxyl generator tert-butylhydroperoxide better than N-oxides at 3-fold higher concentration. Both types of antioxidants enhance the survival of pro-oxidant-exposed cells of S. cerevisiae mutants deficient in cytosolic and/or mitochondrial superoxide dismutase and could be good compounds which mimic the role of superoxide dismutases. The results of measurement of antioxidant activity in an in vitro chemiluminescence test differ from the results obtained in vivo with S. cerevisiae superoxide dismutase mutants. In contrast to their action on live cells, phenolics are less effective than N-oxides in preventing lipid peroxidation of an emulsion of lipids isolated from S. cerevisiae membranes.
- MeSH
- antioxidancia farmakologie chemie metabolismus MeSH
- fenoly farmakologie chemie metabolismus MeSH
- financování organizované využití MeSH
- flavonoidy farmakologie chemie metabolismus MeSH
- oxidy dusíku farmakologie chemie metabolismus MeSH
- peroxidace lipidů účinky záření MeSH
- reaktivní formy kyslíku farmakologie chemie metabolismus MeSH
- Saccharomyces cerevisiae cytologie chemie růst a vývoj MeSH
- superoxiddismutasa farmakologie chemie metabolismus MeSH
- MeSH
- myši MeSH
- oxidy dusíku metabolismus MeSH
- thymus metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
