Antioxidant defence Dotaz Zobrazit nápovědu
Východisko. Stopové prvky - zinok, meď a selén - sú súčasťou antioxidačných enzýmov superoxiddizmutázy (SOD) a glutationperoxidázy (GHPx). Pri obličkových chorobách môžu zmeny metabolizmu stopových prvkov ovplyvniť rovnováhu v antioxidačnom obrannom systéme a prispievať k uplatneniu toxického účinku reaktívnych kyslíkových molekúl. Metódy a výsledky. Autori vyšetrili u 53 detí s chronickými nefropatiami (34 s chronickou glomerulonefritídou, 11 s chronickou renálnou insuficienciou a 8 detí v chronickom dialyzačnom programe) zinok a selén v krvi aj v moči, a antioxidačné enzýmy SOD a GHPx v erytrocytoch. Najnižšiu aktivitu SOD (737 ± 219 U/g Hb, p < 0,01) a koncentrácie zinku v sére (12,9 ± 3,2, p < 0,05) našli u detí v terminálnej urémii. GHPx bola pri porovnaní so skupinou zdravých detí zvýšená vo všetkých skupinách chorých. U dialyzovaných detí bola aktivita GHPx najvyššia (p < 0,01) a korelovala s koncentráciami selénu v moči (r = -0,86, p < 0,05). Aktivita SOD bola závislá na sérových koncentráciách medi (r = 0,78, p < 0,05). Najvyššia renálna exkrécia zinku a selénu bola u chorých s glomerulonef- ritídou (p < 0,05). Závery. Výsledky podporujú hypotézu o kauzálnom vzťahu medzi stopovými prvkami a antioxidačnými enzýmami.
Background. Trace elements - zinc, copper and selenium are part of antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GHPx). In renal diseases changes in the trace element metabolism may influence the equilibrium in the antioxidant defence system and enhance the toxic effect of reactive oxygen molecules. Methods and Results. The authors examined in 53 children with chronic neprophathies (34 with chronic glomerulonephritis, 11 with chronic renal failure and 8 children included in a chronic dialyzation programme) zinc and selenium in blood and urine and antioxidant enzymes SOD and GHPx in red blood cells. The lowest SOD activity (737 ± 219 U/g Hb, p < 0.01) and serum zinc concentration (12.9 ± 3.2, p < 0.05) were found in children in the terminal stage of uraemia, GHPx was as compared with the group of healthy children elevated in all groups of sick children. In dialysed children GHPx was highest (p < 0.01) and correlated with urinary selenium concentrations (r = -0.86, p < 0.05). The SOD activity depended on the serum copper concentrations (r = 0.78, p < 0.05). The highest renal zinc and selenium excretion was recorded in patients with glomerulonephritis (p < 0.05). Conclusions. The results support the hypothesis on a causal relationship between trace elements and antioxidant enzymes.
- MeSH
- chronické selhání ledvin metabolismus MeSH
- dítě MeSH
- glutathionperoxidasa MeSH
- lidé MeSH
- měď krev metabolismus moč MeSH
- selen krev metabolismus moč MeSH
- stopové prvky metabolismus MeSH
- superoxiddismutasa MeSH
- zinek krev metabolismus moč MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- Publikační typ
- přehledy MeSH
Cytokinins modulate a number of important developmental processes, including the last phase of leaf development, known as senescence, which is associated with chlorophyll breakdown, photosynthetic apparatus disintegration and oxidative damage. There is ample evidence that cytokinins can slow down all these senescence-accompanying changes. Here, we review relationships between the various mechanisms of action of these regulatory molecules. We highlight their connection to photosynthesis, the pivotal process that generates assimilates, however may also lead to oxidative damage. Thus, we also focus on cytokinin induction of protective responses against oxidative damage. Activation of antioxidative enzymes in senescing tissues is described as well as changes in the levels of naturally occurring antioxidative compounds, such as phenolic acids and flavonoids, in plant explants. The main goal of this review is to show how the biological activities of cytokinins may be related to their chemical structure. New links between molecular aspects of natural cytokinins and their synthetic derivatives with antisenescent properties are described. Structural motifs in cytokinin molecules that may explain why these molecules play such a significant regulatory role are outlined.
- MeSH
- antioxidancia chemie metabolismus MeSH
- cytokininy chemie metabolismus MeSH
- flavonoidy analýza MeSH
- fotosyntéza MeSH
- listy rostlin chemie růst a vývoj fyziologie MeSH
- molekulární struktura MeSH
- rostliny chemie MeSH
- vývoj rostlin MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Klíčová slova
- SELZINK PLUS (PRO.MED.CS PRAHA A.S.),
- MeSH
- antioxidancia aplikace a dávkování terapeutické užití MeSH
- lidé MeSH
- revmatické nemoci farmakoterapie patologie MeSH
- stopové prvky aplikace a dávkování terapeutické užití MeSH
- vitaminy aplikace a dávkování terapeutické užití MeSH
- volné radikály škodlivé účinky MeSH
- Check Tag
- lidé MeSH
- MeSH
- antioxidancia fyziologie MeSH
- buňky chemie imunologie MeSH
- finanční podpora výzkumu jako téma MeSH
- financování organizované MeSH
- lidé MeSH
- oxidační stres imunologie účinky léků MeSH
- plíce fyziologie chemie imunologie MeSH
- reaktivní formy kyslíku chemie imunologie škodlivé účinky MeSH
- tkáně fyziologie chemie imunologie MeSH
- Check Tag
- lidé MeSH
N-acetylcysteine (N-Acetyl L-cysteine, NAC) is a thiol compound derived from the addition of the acetyl group to cysteine amino acid. NAC has been used as an antioxidant, free radical scavenger, and chelating agent for reducing the deleterious effects on plants of biotic and abiotic environmental stresses. It can also relieve heavy metal (HM) toxicity, although its alleviating mechanism remains unknown. In this study, we compared HM-stressed (Cu, Hg, Cd and Pb, 100 μM each) wheat seedlings without NAC treatment and in combination with NAC (1 mM). In comparison to HMs alone, NAC treatment in combination with HMs (Cu, Cd, Hg and Pb, respectively) stimulated root growth (1.1-, 1.5-, 10.5- and 1.9-fold), and significantly increased fresh (1.3-, 1.5-, 4.3- and 1.4-fold) and dry (1.2-, 1.5-, 2.5- and 1.2-fold) mass. Combination treatment also led to significant reductions in HM concentrations (1.3-, 1.4-, 4- and 1.1-fold, respectively). GSH (1.1 - 1.8-fold), TBARS (1.4 - 2.7-fold) and H2O2 (1.6 - 1.8-fold) contents in treatment with HMs alone were significantly mitigated by the NAC combination. Some of the antioxidant enzyme activities increased or reduced by some HM treatments alone were stimulated by a combination of NAC with HMs, or remained unchanged or changed only insignificantly, supported by the phenolic pool of the plant. Ferulic, p-comaric and syringic acids were the major phenolic acids (PAs) in the roots in free, ester, glycoside and ester-bound forms, and their concentrations were increased by HM treatments alone, in comparison to the control seedlings, while PAs concentrations were relatively reduced by NAC in combination with HMs. These results indicate that NAC can alleviate HM toxicity and improve the growth of HM-stressed wheat seedlings by coordinated induction of the phenolic pool and the antioxidant defence system.
- MeSH
- acetylcystein farmakologie MeSH
- antioxidancia farmakologie MeSH
- hydroxybenzoáty metabolismus MeSH
- látky reagující s kyselinou thiobarbiturovou metabolismus MeSH
- látky znečišťující půdu toxicita MeSH
- oxidační stres účinky léků MeSH
- peroxid vodíku metabolismus MeSH
- pšenice účinky léků enzymologie růst a vývoj MeSH
- semenáček účinky léků enzymologie růst a vývoj MeSH
- těžké kovy toxicita MeSH
- Publikační typ
- časopisecké články MeSH
We investigated the effect of long-term exposure to CBZ on the antioxidant system in brain tissue of rainbow trout. Fish were exposed to sublethal concentrations of CBZ (1.0 microg/L, 0.2mg/L or 2.0mg/L) for 7, 21, and 42 days. Oxidative stress indices (LPO and CP) and activities of antioxidant enzymes (SOD, CAT, GPx and GR) in fish brain were measured. In addition, non-enzymatic antioxidant (GSH) was determined after 42 days exposure. Carbamazepine exposure at 0.2mg/L led to significant increases (p<0.05) of LPO and CP after 42 days and, at 2.0mg/L, after 21 days. Activities of the antioxidant enzymes SOD, CAT, and GPx in CBZ-treated groups slightly increased during the first period (7 days). However, activities of all measured antioxidant enzymes were significantly inhibited (p<0.05) at 0.2mg/L exposure after 42 days and after 21 days at 2.0mg/L. After 42 days, the content of GSH in fish brain was significantly lower (p<0.05) in groups exposed to CBZ at 0.2mg/L and 2.0mg/L than in other groups. Prolonged exposure to CBZ resulted in excess reactive oxygen species formation, finally resulting in oxidative damage to lipids and proteins and inhibited antioxidant capacities in fish brain. In short, a low level of oxidative stress could induce the adaptive responses of antioxidant enzymes, but long-term exposure to CBZ could lead to serious oxidative damage in fish brain.
- MeSH
- antioxidancia metabolismus MeSH
- časové faktory MeSH
- chemické látky znečišťující vodu toxicita MeSH
- glutathion metabolismus MeSH
- glutathionperoxidasa metabolismus MeSH
- glutathionreduktasa metabolismus MeSH
- karbamazepin toxicita MeSH
- karbonylace proteinů účinky léků MeSH
- katalasa metabolismus MeSH
- látky reagující s kyselinou thiobarbiturovou metabolismus MeSH
- mozek enzymologie účinky léků MeSH
- Oncorhynchus mykiss metabolismus MeSH
- oxidační stres účinky léků MeSH
- peroxidace lipidů účinky léků MeSH
- reaktivní formy kyslíku metabolismus MeSH
- rybí proteiny metabolismus MeSH
- superoxiddismutasa metabolismus MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
