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Metalothioneiny u drobných volně žijících savců jako bioindikátor znečištění životního prostředí
Křivská, D. ; Šestáková, Ivana
Metalothioneiny (MT) jsou cysteinem bohaté nízkomolekulární proteiny, schopné vázat esenciální i toxické kovy. Jejich syntéza je indukována přítomností zejména kadmia a zinku, ale také dalších kovů jako Pb, Ni, Hg, Ag a i jinými faktory (např. stres, kortikoidy) 1. Pro práce věnující se studiu biologických funkcí metalothioneinů jako homeostáze, prevence oxidačního stresu, detoxifikace či studie vlivu znečištění životního prostředí na různé živočichy je důležitý celkový obsah metalothioneinů v jednotlivých tkáních 2. U vodních organismů, zejména Mytilus galloprovincialis 3 a Ruditapes decussatus 4 je obsah MT užíván jako bioindikátor znečištění mořské vody a je proto snaha mít obdobnou možnost pro zjišťování kontaminace půdy a životního prostředí.
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Determination of Metallothioneins in the Liver of Small Terrestrial Mammals, Living at Hazardous Element Contaminated Sites
Křivská, D. ; Šestáková, Ivana
Animals living in the contaminated areas are exposed to elevated concentrations of risk elements. Pfibramsko is one of most contaminated sites in Czech Republic. This area is loaded with sources of geological and metallurgical industry influence resulting in extremely high Pb, Cd, and Zn contents in soil. We analyzed eighteen subjects trapped on selected locations around Kovohute Pribram, belonging to the species Apodemus sylvaticus and Microtus arvalis. By differential pulse voltammetry and modified Brdicka reaction were measured concentrations metallothionein (MT) in their livers. Differences of concentrations between measured MT contents were found between species and among places of trapping.
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Isolation and Characterization of Protoplasts and their Utilization for Model Membrane
Nováková, Kateřina ; Navrátil, Tomáš ; Šestáková, Ivana ; Langmaier, Jan ; Heyrovský, Michael ; Zámečníková, B. ; Vodičková, H.
Protoplasts are prepared form plant cells by removing their cell walls, which are usually destroyed mechanically or by enzymes. Protoplasts exhibit the spherical shape after removing of their cell walls. They can be isolated from a range of plant tissues: leaves, stems, roots, anthers, and even pollen. Plasmatic membranes surrounding protoplasts can be used as a source of model membranes. Therefore, some parts of plasmatic membranes or subcellular organelle membranes, which contain specific transport systems, can be isolated and integrated to model phospholipid membranes. State of such model membranes can be characterized by electrochemical impedance spectrometry (EIS) and the transported species can be determined with the use of voltammetric methods.
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Characterization of Liposomes Used as Model System of Biological Membranes by Glassy Carbon Electrode
Parisová, Martina ; Navrátil, Tomáš ; Šestáková, Ivana ; Barek, J.
This contribution deals with study and characterization of liposomes. These vesicles may serve as model membranes used for study of transporting processes of heavy metal ions across the real phospholipid membranes (PLMs). 1,2-dioleoyl-sn-glycero-3-phosphocholine was used for the formation of large unilamellar vesicles (LUV). These vesicles were prepared by hydration method. Interactions of cadmium ions with LUV in solution have been characterized using voltammetry, where glassy carbon electrode was used as the working electrode. Size and presence of liposomes in sample was proved by dynamic light scattering and free cadmium ions in samples were determined by differential pulse voltammetry.
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