Mitochondria are exposed to reactive nitrogen species under physiological conditions and even more under several pathologic states. In order to reveal the mechanism of these processes we studied the effects of peroxynitrite on isolated beef heart mitochondria in vitro. Peroxynitrite has the potential to nitrate protein tyrosine moieties, break the peptide bond, and eventually release the membrane proteins into the solution. All these effects were found in our experiments. Mitochondrial proteins were resolved by 2D electrophoresis and the protein nitration was detected by immunochemical methods and by nano LC-MS/MS. Mass spectrometry confirmed nitration of ATP synthase subunit beta, pyruvate dehydrogenase E1 component subunit beta, citrate synthase and acetyl-CoA acetyltransferase. Immunoblot detection using chemiluminiscence showed possible nitration of other proteins such as cytochrome b-c1 complex subunit 1, NADH dehydrogenase [ubiquinone] iron-sulfur protein 2, elongation factor Tu, NADH dehydrogenase [ubiquinone] flavoprotein 2, heat shock protein beta-1 and NADH dehydrogenase [ubiquinone] iron-sulfur protein 8. ATP synthase beta subunit was nitrated both in membrane and in fraction prepared by osmotic lysis. The high sensitivity of proteins to nitration by peroxynitrite is of potential biological importance, as these enzymes are involved in various pathways associated with energy production in the heart.

• MeSH
• dusík metabolismus   MeSH
• kyselina peroxydusitá farmakologie   MeSH
• mitochondriální proteiny účinky léků   metabolismus   MeSH
• proteomika * MeSH
• skot MeSH
• srdeční mitochondrie účinky léků   enzymologie   metabolismus   MeSH
• techniky in vitro MeSH
• tyrosin analogy a deriváty   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Isolated beef heart mitochondria have been exposed to tert-butyl hydroperoxide (tBHP) and peroxynitrite (PeN) in order to model the effects of reactive oxygen and nitrogen species on mitochondria in vivo. The formation of malondialdehyde (MDA), protein carbonyls, lipofuscin-like pigments (LFP), and nitrotyrosine was studied during incubations with various concentrations of oxidants for up to 24 h. The oxidants differed in their ability to oxidize particular substrates. Fatty acids were more sensitive to the low concentrations of tBHP, whereas higher concentrations of PeN consumed MDA. Oxidation of proteins producing carbonyls had different kinetics and also a probable mechanism with tBHP or PeN. Diverse proteins were affected by tBHP or PeN. In both cases, prolonged incubation led to the appearance of proteins with molecular weights lower than 29 kDa bearing carbonyl groups that might have been caused by protein fragmentation. PeN induced nitration of protein tyrosines that was more intensive in the soluble proteins than in the insoluble ones. LFP, the end products of lipid peroxidation, were formed more readily by PeN. On the other hand, fluorometric and chromatographic techniques have confirmed destruction of LFP by higher PeN concentrations. This is a unique feature that has not been described so far for any oxidant.

• MeSH
• kyselina peroxydusitá MeSH
• reaktivní formy dusíku metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• skot MeSH
• srdeční mitochondrie metabolismus   MeSH
• terc-butylhydroperoxid MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

Postnatal heart development is characterized by critical periods of heart remodeling. In order to characterize the changes in the lipophilic fraction induced by free radicals, fatty acids and their oxidized products, lipofuscin-like pigments (LFP), were investigated. Fatty acids were analyzed by gas chromatography and LFP were studied by fluorescence techniques. A fluorophore characterized by spectral methods was further resolved by HPLC. Major changes in the composition of fatty acids occurred immediately after birth and then during maturation. Fluorescence of LFP changed markedly on postnatal days 1, 4, 8, and 14, and differed from the adult animals. LFP comprise several fluorophores that were present since fetal state till adulthood. No new major fluorophores were formed during development, just the abundances of individual fluorophores have been modulated which produced changes in the shape of the spectral arrays. HPLC resolved the fluorophore with excitation maximum at 360 nm and emission maximum at 410 nm. New chromatographically distinct species appeared immediately on postnatal day 1, and then on days 30 and 60. Consumption of polyunsaturated fatty acids immediately after birth and subsequent formation of LFP suggests that oxidative stress is involved in normal heart development.

• MeSH
• biologické pigmenty metabolismus   MeSH
• krysa rodu rattus MeSH
• lipofuscin metabolismus   MeSH
• mastné kyseliny metabolismus   MeSH
• novorozená zvířata MeSH
• oxidační stres fyziologie   MeSH
• peroxidace lipidů fyziologie   MeSH
• potkani Wistar MeSH
• srdce růst a vývoj   MeSH
• těhotenství MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Fluorescent pigments are the end-products of reactions involving free radical attack on biological molecules and can be formed, for example, in reactions between lipid peroxidation products, mainly unsaturated aldehydes, with free amino groups. Their characteristic emission maximum was found to be at 420-470 nm after being excited at 340-390 nm. The mechanism of their formation and chemical identity has been revealed in many in vitro studies, in which reactive aldehydes were incubated with amino group-containing molecules. Owing to their intrinsic fluorescent properties and molecular stability these products are easily measured by means of spectrofluorimetry and are used as biomarkers of oxidative stress caused by various triggers. It has been found that the fluorescent products are formed in excess in conditions linked with increased free radical production, such as atherosclerosis, Alzheimer's disease and multiple sclerosis. METHODS: We searched the literature using "MEDLINE" and "Web of Science" in order to get an overview of the state of knowledge about fluorescent products of free radicals, that is, their analysis from in vitro studies, animal and human studies and their use as markers of oxidative damage. CONCLUSIONS: Although their chemical structure may not have been elucidated, the fluorophores formed in this way have found application as markers of oxidative stress in many animal and human studies. In vitro experiments using model reactions have given some clues as to how certain fluorescent pigments arise during oxidative reactions in vivo. Advances in analytical techniques should lead the chemical characterization of pigments of different origin to completeness.

• MeSH
• biologické markery chemie   MeSH
• lidé MeSH
• lipofuscin chemie   MeSH
• nemoc * MeSH
• oxidační stres MeSH
• peroxidace lipidů * MeSH
• volné radikály chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Increased generation of reactive oxygen species results in the formation of fluorescent end-products of lipid peroxidation - lipofuscin-like pigments (LFP). LFP increased up to six-fold from the fetal value in the rat heart immediately after birth. In the experimental design of this study the fetuses were sampled 1 day before birth, and then the samples were collected on postnatal days 1, 4, 7, 10, 15, 30, and 60. Males and females were compared on day 30 and 60 when the difference between right and left ventricle was studied as well. Four LFP fluorophores were analyzed: F355/440, F310/470, F350/450, F315/450 (excitation/emission, nm). All fluorophores decreased on day 4 relative to day 1, subsequent transient increases ended in a significant decrease on day 60. However, the LFP levels on day 60 are still about threefold higher than those in fetuses. Differences between male and female hearts were observed on day 30. The corresponding male ventricles contained by one third higher concentration of LFP than the female counterparts. The increase in LFP concentration in male ventricles on day 30 was only transient, no difference between corresponding male and female ventricles was found on day 60. The most distinguished feature in the male heart was a sharp LFP decrease in the right ventricle on day 60.

• MeSH
• krysa rodu rattus MeSH
• lipofuscin metabolismus   MeSH
• myokard metabolismus   MeSH
• novorozená zvířata MeSH
• peroxidace lipidů MeSH
• potkani Wistar MeSH
• srdce účinky léků   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The effect of three-day fasting on cardiac ischemic tolerance was investigated in adult male Wistar rats. Anesthetized open-chest animals (pentobarbitone 60 mg/kg, i.p.) were subjected to 20-min left anterior descending coronary artery occlusion and 3-h reperfusion for infarct size determination. Ventricular arrhythmias were monitored during ischemia and at the beginning (3 min) of reperfusion. Myocardial concentrations of beta-hydroxybutyrate and acetoacetate were measured to assess mitochondrial redox state. Short-term fasting limited the infarct size (48.5+/-3.3 % of the area at risk) compared to controls (74.3+/-2.2 %) and reduced the total number of premature ventricular complexes (12.5+/-5.8) compared to controls (194.9+/-21.9) as well as the duration of ventricular tachycardia (0.6+/-0.4 s vs. 18.8+/-2.5 s) occurring at early reperfusion. Additionally, fasting increased the concentration of beta-hydroxybutyrate and beta-hydroxybutyrate/acetoacetate ratio (87.8+/-27.0) compared to controls (7.9+/-1.7), reflecting altered mitochondrial redox state. It is concluded that three-day fasting effectively protected rat hearts against major endpoints of acute I/R injury. Further studies are needed to find out whether these beneficial effects can be linked to altered mitochondrial redox state resulting from increased ketogenesis.

• MeSH
• acetoacetáty metabolismus   farmakologie   MeSH
• infarkt myokardu metabolismus   veterinární   MeSH
• komorová tachykardie komplikace   MeSH
• krysa rodu rattus MeSH
• kyselina 3-hydroxymáselná metabolismus   farmakologie   MeSH
• mitochondrie metabolismus   MeSH
• oxidace-redukce MeSH
• potkani Wistar MeSH
• reperfuzní poškození myokardu metabolismus   veterinární   MeSH
• srdeční arytmie patofyziologie   veterinární   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

This study was carried out to investigate the role of lead in the development of oxidative stress in the brain. We examined the rate of lipid peroxidation and we determined lipid fluorescence products (lipofuscin-like pigments - LFP) as a marker of lipid peroxidation after short in vitro incubation of rat brain homogenates with lead acetate (10(-2), 10(-4), 10(-6) M lead acetate, 2 h). Simultaneously we examined by the same method in vivo indices of oxidative stress in brains of mice exposed for 12 weeks to 0.2% lead acetate in drinking water. The results show that the concentration of LFP in rat brain homogenates increased significantly after 2 h incubation with 10(-2) M lead acetate as compared to controls (P<0.0001). This effect was not observed in lower doses of lead acetate (10(-4) and 10(-6) M). After the long-term exposure of mice to 0.2% lead acetate, pronounced accumulation of lead and significantly increased concentration of LFP (P<0.004) in the brains of exposed animals as compared to controls were observed. The evidence for the formation of specific fluorophores originating from oxidative damage was shown also in qualitative changes in 3D spectral arrays and synchronous spectra. The presented results proved the influence of lead on the activation of radical reactions in the brain after short in vitro exposure of rat brain as well as within long-term in vivo exposure in mice using lipofuscin-like pigments as an indicator of oxidative stress.

• MeSH
• aplikace orální MeSH
• biologické markery metabolismus   MeSH
• časové faktory MeSH
• fluorescenční spektrometrie MeSH
• inbrední kmeny myší MeSH
• krysa rodu rattus MeSH
• lipofuscin metabolismus   MeSH
• mozek účinky léků   metabolismus   MeSH
• myši MeSH
• olovo farmakokinetika   toxicita   MeSH
• oxidační stres účinky léků   MeSH
• peroxidace lipidů účinky léků   MeSH
• pitná voda MeSH
• potkani Wistar MeSH
• volné radikály metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• techniky in vitro MeSH

Oxidative stress, which is present in Alzheimer's disease (AD), results in the formation of various end-products of free radical reactions with proteins and lipids. At present there are no reliable diagnostic biomarkers of AD in the blood. Therefore, specific products of lipid peroxidation in the blood of AD patients were investigated. Lipophilic extracts of erythrocytes in the group of patients with AD (n = 44) and age-matched controls (n = 16) were studied. The end-products of lipid peroxidation, so called lipofuscin-like pigments (LFP), were analysed by fluorescence spectroscopy. It was found that the level of these products is significantly increased in erythrocytes of AD patients compared to controls. LFP were further separated by means of HPLC into individual fractions to study their composition in AD and controls. The specific fraction of LFP in AD patients, which was isolated, might represent a disease-specific product in the blood.

• MeSH
• Alzheimerova nemoc diagnóza   metabolismus   MeSH
• biologické markery metabolismus   MeSH
• erytrocyty metabolismus   MeSH
• fluorescenční spektrometrie MeSH
• lidé MeSH
• lipofuscin metabolismus   MeSH
• oxidační stres fyziologie   MeSH
• peroxidace lipidů fyziologie   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Publikace obsahuje soubor testových otázek z chemie, který je určen pro budoucí studenty lékařství i studenty různých bakalářských směrů na 2. lékařské fakultě Univerzity Karlovy v Praze.

• MeSH
• chemie MeSH

• Konspekt
• Chemie. Mineralogické vědy
• NLK Obory
• chemie, klinická chemie
• NLK Publikační typ
• otázky a odpovědi
• testy

The aim of the study was to characterize a) the lipofuscin-like pigment (LFP) accumulation (an indicator of ROS production) in the rat heart during early postnatal period and b) possible antioxidative role of selenium. Experimental animals received Na2SeO3 in drinking water during gravidity and up to day 15 post partum. Two fluorophores of LFP in the hearts of 1-, 4-, 7- and 15-day-old rats were evaluated by fluorescent analysis. The highest level of heart/body weight ratio in control rats was observed on day 4, in the Se-supplemented rats on day 7. Cardiac LFP content in controls increased from postnatal day 4, in the hearts of Se-supplemented rats the LFP content increased already from day 1. As compared with the Se-supplemented group the LFP content of control hearts was significantly higher on day 1 but significantly lower on day 4. LFP concentration in control hearts decreased from postnatal day 1 to 4; this decrease was followed by significant increase until day 7 and decrease to day 15. LFP concentration in the Se-supplemented hearts was the highest on postnatal day 7; it differed from controls on day 1 and 4. Significant changes of LFP suggest an important role of ROS during critical ontogenetic period.

• MeSH
• financování organizované MeSH
• krysa rodu rattus MeSH
• lipofuscin metabolismus   MeSH
• myokard metabolismus   MeSH
• potkani Wistar MeSH
• potravní doplňky MeSH
• selen aplikace a dávkování   farmakologie   MeSH
• srdce růst a vývoj   účinky léků   MeSH
• tělesná hmotnost účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH