Závěrečná zpráva o řešení grantu Agentury pro zdravotnický výzkum MZ ČR
nestr.
Přestože adukty s globinem jsou v preventivní medicíně široce využívány jako biomarkery dlouhodobé expozice reaktivním látkám, jejich další osud v organismu byl poprvé prozkoumán až v našem předchozím projektu. Prokázali jsme, že hydrolytickým štěpením globinových aduktů u potkanů vznikají adukty s aminokyselinami nebo s dipeptidy, vylučované močí. Nyní bude studováno vylučování těchto štěpných produktů u člověka. Budou vypracovány a do hygienické praxe v ČR zavedeny nové strategie biologického monitorování expozice průmyslovým škodlivinám ethylenoxidu a N,N-dimethylformamidu, kdy dosavadní odběry krve budou nahrazeny analýzou moče. Ze získaných údajů bude odvozen obecný matematicko-statistický model umožňující interpretovat nálezy štěpných produktů odvozených od dalších látek včetně karcinogenů, na něž se v projektu též zaměříme. Zavedení zcela nové kategorie biomarkerů specifických pro výchozí látky a vhodných pro hodnocení dlouhodobých expozic pomocí neinvazivního odběru vzorků bude významným přínosem pro prevenci poškození zdraví účinkem chemických látek v mezinárodním měřítku.; Although the adducts with globin have been widely used in preventive medicine as biomarkers of long-term exposures to reactive chemicals, we were the first to explore their subsequent fate in the organism. We found in rats that hydrolytic cleavage of the globin adducts produces amino acid or dipeptide adducts that are excreted in urine. In our current project we will investigate urinary excretion of these cleavage products in humans. First, we plan to develop and implement into public health practice new strategies of biomonitoring of industrial toxicants ethylene oxide and N,N-dimethylformamide, based on analysis of urine instead of blood. Obtained data will be used to create a general statistical model allowing to interpret urinary levels of cleavage products from other chemicals including carcinogens. Implementation of a novel promising category of biomarkers that combine specificity for the parent xenobiotic, monitoring of long-term exposures, and non-invasive sampling will significantly contribute to prevention of health damage due to exposures to chemicals.
- MeSH
- dehydratace MeSH
- hyponatremie etiologie MeSH
- intoxikace vodou * MeSH
- lidé MeSH
- voda fyziologie MeSH
- Check Tag
- lidé MeSH
Biomonitoring of human exposure to reactive electrophilic chemicals such as ethylene oxide (EO) has been commonly based on the determination of adducts with N-terminal valine in blood protein globin, but a systematic search has also been undertaken to find surrogate markers enabling non-invasive sampling. Recently, N-(2-hydroxyethyl)-L-valyl-L-leucine (HEVL) has been identified as an ultimate cleavage product of EO-adducted globin in the urine of occupationally exposed workers. Herein, full validation of the analytical procedure consisting of solid-phase extraction of HEVL from urine samples (2 mL) followed by high-performance liquid chromatography-electrospray ionization-high-resolution mass spectrometry determination using deuterium-labeled HEVL as an internal standard (IS) is described. Method limit of quantitation is 0.25 ng/mL, and its selectivity is excellent as demonstrated by the invariable ratio of the qualifier and quantifier ion intensities across diverse urine samples and synthetic standard. The linear calibration model was applicable over the whole concentration range tested (0.25-10 ng/mL). The method accuracy assessed as a recovery of HEVL using a spiking experiment was 98-100%. Within-day precision of the method ranged from 1.8% to 3.0%, while the results from consecutive analytical runs conducted within 1 week or within 10-150 weeks differed in the range of 2.2-9.7%. The stability study on urine samples (-20°C up to 3 years, freeze-and-thaw up to 10 cycles) as well as on aqueous solutions (5°C up to 4 months) indicated no relevant changes in HEVL concentration (≤4%) over the time tested. Analytical responses of both HEVL and IS correlated with urinary creatinine as an index of matrix composition, but this matrix effect was mostly eliminated using the HEVL/IS peak area ratio, attaining the IS-normalized relative matrix effect <3%. In conclusion, the method complied successfully with the bioanalytical method validation criteria, making it a reliable tool for HEVL determination in human biomonitoring.
- MeSH
- dipeptidy * MeSH
- ethylenoxid * MeSH
- globiny MeSH
- leucin MeSH
- lidé MeSH
- reprodukovatelnost výsledků MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
3. upravené a rozšířené vydání 411 stran : ilustrace (některé barevné) ; 25 cm
Vysokoškolská učebnice, která se zaměřuje na toxikologii.
- MeSH
- toxikologie MeSH
- Konspekt
- Farmacie. Farmakologie
- Učební osnovy. Vyučovací předměty. Učebnice
- NLK Obory
- toxikologie
- NLK Publikační typ
- učebnice vysokých škol
Novel aminonaphthylcysteine (ANC) adducts, formed via naphthylnitrenium ions and/or their metabolic precursors in the biotransformation of naphthylamines (NA) and nitronaphthalenes (NN), were identified and quantified in globin of rats dosed intraperitoneally with 0.16 mmol/kg b.w. of 1-NA, 1-NN, 2-NA and 2-NN. Using HPLC-ESI-MS2 analysis of the globin hydrolysates, S-(1-amino-2-naphthyl)cysteine (1A2NC) together with S-(4-amino-1-naphthyl)cysteine (4A1NC) were found in rats given 1-NA or 1-NN, and S-(2-amino-1-naphthyl)cysteine (2A1NC) in those given 2-NA or 2-NN. The highest level of ANC was produced by the most mutagenic and carcinogenic isomer 2-NA (35.8 ± 5.4 nmol/g globin). The ratio of ANC adduct levels for 1-NA, 1-NN, 2-NA and 2-NN was 1:2:100:3, respectively. Notably, the ratio of 1A2NC:4A1NC in globin of rats dosed with 1-NA and 1-NN differed significantly (2:98 versus 16:84 respectively), indicating differences in mechanism of the adduct formation. Moreover, aminonaphthylmercapturic acids, formed via conjugation of naphthylnitrenium ions and/or their metabolic precursors with glutathione, were identified in the rat urine. Their amounts excreted after dosing rats with 1-NA, 1-NN, 2-NA and 2-NN were in the ratio 1:100:40:2, respectively. For all four compounds tested, haemoglobin binding index for ANC was several-fold higher than that for the sulphinamide adducts, generated via nitrosoarene metabolites. Due to involvement of electrophilic intermediates in their formation, ANC adducts in globin may become toxicologically more relevant biomarkers of cumulative exposure to carcinogenic or non-carcinogenic arylamines and nitroarenes than the currently used sulphinamide adducts.
- MeSH
- 1-naftylamin aplikace a dávkování metabolismus toxicita MeSH
- 2-naftylamin aplikace a dávkování metabolismus toxicita MeSH
- acetylcystein analogy a deriváty moč MeSH
- biologické markery krev moč MeSH
- cystein MeSH
- globiny metabolismus MeSH
- injekce intraperitoneální MeSH
- naftaleny aplikace a dávkování krev toxicita MeSH
- potkani Wistar MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
