Primary metabolites Dotaz Zobrazit nápovědu
Liquid chromatography-tandem mass spectrometry has become the most convenient method to identify and quantify low molecular weight metabolites from various sources. Metabolomics studies of hepatocytes hold promise for the identification of the mechanisms of toxicant-related disease processes. In this chapter, we present a rapid and sensitive liquid chromatography-tandem mass spectrometry method for the quantification of intracellular concentrations of nine homocysteine-based metabolites, namely homocysteine, methionine, cysteine, dimethylglycine, cystathionine, S-adenosylmethionine, S-adenosylhomocysteine, choline, and betaine. The method is specifically designed for the analysis of cultured primary hepatocytes.
Úvod: Cyklosporin A je účinné imunosupresivum používané při transplantacích včetně transplantace ledvin. Jedním z jeho nežádoucích účinků je ovlivnění denní variability krevního tlaku, a to jeho signifikantním zvýšením v nočních hodinách. Klíčovým faktorem u pacientů po transplantaci ledvin je dobrá kompenzace krevního tlaku, přičemž k ověření může být užitečným nástrojem jeho 24hodinové ambulantní monitorování (ABPM). Cílem studie bylo porovnat vztah mezi koncentrací CsA a jeho metabolitů v krvi a lymfocytech a poklesem krevního tlaku v noci (tzv. „dipping“). Metoda: Soubor zahrnoval 31 pacientů (16 mužů, 15 žen) s průměrným věkem 54 ± 12 roků a průměrnou hmotností 75 ± 16 kg. Koncentrace CsA a jeho primárních metabolitů (AM1, AM9 a AM4N) v krvi a lymfocytech před užitím byly stanoveny metodou LC-MS/MS. ABPM bylo prováděno přístrojem Spacelabs 90207-Q, celkem 3× v 1ročních intervalech. Pacienti byli rozděleni podle nočního poklesu krevního tlaku do 2 skupin – „dipper“ (26 měření) a „non-dipper“ (pokles < 10 %, 25 měření). Ke statistické analýze byl použit program GraphPad Prism 5.00 pro Windows. Výsledky: V průběhu celé studie dosahoval průměrný krevní tlak v denních hodinách hodnot 128 ± 11/75 ± 10 mmHg, během nočních hodin 124 ± 15/70 ± 11 mmHg. Průměrné koncentrace CsA se v krvi pohybovaly v rozmezí 90,5 ± 40,1 μg/l ve skupině „dipper“ a 97,3 ± 44,5 μg/l ve skupině „non-dipper“, v lymfocytech 11,4 ± 4,0 μg/l („dipper“) a 11,8 ± 5,0 μg/l („non-dipper“). Jediný statisticky významný rozdíl (p = 0.0339) mezi skupinami byl nalezen u metabolitu AM4N, jehož koncentrace v lymfocytech byla ve skupině „non-dipper“ více než 4násobná („dipper“ 0,4 ± 0,8 μg/l, „non-dipper“ 1,7 ± 2,6 μg/l). Závěr: 400% nárůst lipofilního metabolitu AM4N v lymfocytech v odběru před užitím může být u pacientů po transplantaci ledvin jak příčinou, tak markerem pro výskyt „non-dippingu“.
Background: Cyclosporine A (CsA) is a potent immunosuppressive agent used after organ transplantation, including renal transplantation. CsA has also been shown to affect blood pressure (BP) diurnal variation by significantly increasing night-time blood pressure. Tight blood pressure control is a key objective in renal transplant patients, and for this purpose ABPM might be a useful tool. The aim of the study was to compare the relationship between blood and lymphocyte concentrations of CsA and its metabolites in patients with “dipping” or “non-dipping” status. Methods: Thirty-one stable renal transplant patients (16 men, 15 women) were included in this study. The mean patient age was 54 ± 12 years and the mean weight 75 ± 16 kg. Trough (C0) concentrations of CsA and its three metabolites, AM1, AM9, and AM4N, were estimated in blood and lymphocytes using the LC-MS/MS method. All patients underwent ABPM. The patients were divided into two groups: “dippers” (26 measurements) and “non-dippers” (with a nocturnal blood pressure fall < 10%, 25 measurements). GraphPad Prism version 5.00 for Windows was used for statistical analysis. A value of p < 0.05 was considered statistically significant. Results: The mean BP was 128 ± 11/75 ± 10 mm Hg and 124 ± 15/70 ± 11 mm Hg during daytime and during sleep, respectively. The mean cyclosporine trough level was 90.5 ± 40.1 μg/L (“dippers) and 97.3 ± 44.5 μg/L (“non-dippers”) in blood, and 11.4 ± 4.0 μg/L (“dippers”) and 11.8 ± 5.0 μg/L (“non-dippers”) in lymphocytes. Only one statistically significant difference (p = 0.0339) of AM4N concentrations in lymphocytes was found between “dippers” (0.4 ± 0.8 μg/L) and “non-dippers” (1.7 ± 2.6 μg/L). Conclusions: A 400% increase of lipophilic metabolite AM4N in lymphocytes in C0 can be the cause and/or predictor of “non-dipping” status in renal transplant patients.
- MeSH
- ambulantní monitorování krevního tlaku * metody využití MeSH
- antihypertenziva škodlivé účinky terapeutické užití MeSH
- cirkadiánní rytmus imunologie účinky léků MeSH
- cyklosporin * škodlivé účinky terapeutické užití MeSH
- hodnotící studie jako téma MeSH
- hypertenze * diagnóza etiologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- metabolismus imunologie účinky léků MeSH
- statistika jako téma MeSH
- transplantace ledvin škodlivé účinky MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
The environmental fate of airborne nanoparticles and their toxicity to plants is not yet fully understood. Pot-grown barley plants with second leaves developed were therefore exposed to CdO nanoparticles (CdONPs) of ecologically relevant size (7-60 nm) and concentration (2.03 ± 0.45 × 10(5) particles cm(-3)) in air for 3 weeks. An experiment was designed to test the effects of different treatments when only leaves (T1); leaves and soil substrate (T2); and leaves, soil, and water supply were exposed to nanoparticles (T3). A fourth, control group of plants was left without treatment (T0). Although CdONPs were directly absorbed by leaves from the air, a part of leaf-allocated Cd was also transported from roots by transpiration flow. Chromatographic assays revealed that CdONPs had a significant effect on total content of primary metabolites (amino acids and saccharides) but no significant effect on total content of secondary metabolites (phenolic compounds, Krebs cycle acids, and fatty acids). In addition, the compositions of individual metabolite classes were affected by CdONP treatment. For example, tryptophan and phenylalanine were the most affected amino acids in both analysed organs, while ferulic acid and isovitexin constituted the polyphenols most affected in leaves. Even though CdONP treatment had no effect on total fatty acids content, there were significant changes in the composition of saturated and unsaturated fatty acids in both the roots and leaves of treated plants. Although the results indicate the most pronounced effect in T3 plants as compared to T1 and T2 plants, even just leaf exposure to CdONPs has the potential to induce changes in plant metabolism.
- MeSH
- aminokyseliny metabolismus MeSH
- apigenin metabolismus MeSH
- fenoly metabolismus MeSH
- ječmen (rod) účinky léků metabolismus MeSH
- kořeny rostlin účinky léků metabolismus MeSH
- kyseliny kumarové metabolismus MeSH
- látky znečišťující půdu toxicita MeSH
- látky znečišťující vodu toxicita MeSH
- listy rostlin účinky léků metabolismus MeSH
- nanočástice toxicita MeSH
- oxidy toxicita MeSH
- sekundární metabolismus účinky léků MeSH
- sloučeniny kadmia toxicita MeSH
- Publikační typ
- časopisecké články MeSH
N-Benzylphenethylamines are novel psychedelic substances increasingly used for research, diagnostic, or recreational purposes. To date, only a few metabolism studies have been conducted for N-2-methoxybenzylated compounds (NBOMes). Thus, the available 2,5-dimethoxy-4-(2-((2-methoxybenzyl)amino)ethyl)benzonitrile (25CN-NBOMe) metabolism data are limited. Herein, we investigated the metabolic profile of 25CN-NBOMe in vivo in rats and in vitro in Cunninghamella elegans (C. elegans) mycelium and human liver microsomes. Phase I and phase II metabolites were first detected in an untargeted screening, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) identification of the most abundant metabolites by comparison with in-house synthesized reference materials. The major metabolic pathways described within this study (mono- and bis-O-demethylation, hydroxylation at different positions, and combinations thereof, followed by the glucuronidation, sulfation, and/or N-acetylation of primary metabolites) generally correspond to the results of previously reported metabolism of several other NBOMes. The cyano functional group was either hydrolyzed to the respective amide or carboxylic acid or remained untouched. Differences between species should be taken into account in studies of the metabolism of novel substances.
- Publikační typ
- časopisecké články MeSH
Cytotoxicity of de novo purine synthesis (DNPS) metabolites is critical to the pathogenesis of three known and one putative autosomal recessive disorder affecting DNPS. These rare disorders are caused by biallelic mutations in the DNPS genes phosphoribosylformylglycineamidine synthase (PFAS), phosphoribosylaminoimidazolecarboxylase/phosphoribosylaminoimidazolesuccinocarboxamide synthase (PAICS), adenylosuccinate lyase (ADSL), and aminoimidazole carboxamide ribonucleotide transformylase/inosine monophosphate cyclohydrolase (ATIC) and are clinically characterized by developmental abnormalities, psychomotor retardation, and nonspecific neurological impairment. At a biochemical level, loss of function of specific mutated enzymes results in elevated levels of DNPS ribosides in body fluids. The main pathogenic effect is attributed to the accumulation of DNPS ribosides, which are postulated to be toxic to the organism. Therefore, we decided to characterize the uptake and flux of several DNPS metabolites in HeLa cells and the impact of DNPS metabolites to viability of cancer cell lines and primary skin fibroblasts. We treated cells with DNPS metabolites and followed their flux in purine synthesis and degradation. In this study, we show for the first time the transport of formylglycinamide ribotide (FGAR), aminoimidazole ribotide (AIR), succinylaminoimidazolecarboxamide ribotide (SAICAR), and aminoimidazolecarboxamide ribotide (AICAR) into cells and their flux in DNPS and the degradation pathway. We found diminished cell viability mostly in the presence of FGAR and AIR. Our results suggest that direct cellular toxicity of DNPS metabolites may not be the primary pathogenetic mechanism in these disorders.
- Publikační typ
- časopisecké články MeSH
End-stage kidney disease is preferably treated by kidney transplantation. The suboptimal function of the allograft often results in misbalances in kidney-controlled processes and requires long-term monitoring of allograft function and viability. As the kidneys are organs with a very high metabolomic rate, a metabolomics approach is suitable to describe systematic changes in post-transplant patients and has great potential for monitoring allograft function, which has not been described yet. In this study, we used blood plasma samples from 55 patients after primary kidney transplantation identically treated with immunosuppressants with follow-up 50 months in the mean after surgery and evaluated relative levels of basal plasma metabolites detectable by NMR spectroscopy. We were looking for the correlations between circulating metabolites levels and allograft performance and allograft rejection features. Our results imply a quantitative relationship between restricted renal function, insufficient hydroxylation of phenylalanine to tyrosine, lowered renal glutamine utilization, shifted nitrogen balance, and other alterations that are not related exclusively to the metabolism of the kidney. No link between allograft function and energy metabolism can be concluded, as no changes were found for glucose, glycolytic intermediates, and 3-hydroxybutyrate as a ketone body representative. The observed changes are to be seen as a superposition of changes in the comprehensive inter-organ metabolic exchange, when the restricted function of one organ may induce compensatory effects or cause secondary alterations. Particular differences in plasma metabolite levels in patients with acute cellular and antibody-mediated allograft rejection were considered rather to be related to the loss of kidney function than to the molecular mechanism of graft rejection since they largely follow the alterations observed by restricted allograft function. In the end, we showed using a simple mathematical model, multilinear regression, that the basal plasmatic metabolites correlated with allograft function expressed by the level of glomerular filtration rate (with creatinine: p-value = 4.0 × 10-26 and r = 0.94, without creatinine: p-value = 3.2 × 10-22 and r = 0.91) make the noninvasive estimation of the allograft function feasible.
- Publikační typ
- časopisecké články MeSH
