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EN
Cyanobacterial blooms, often observed in eutrophic water reservoirs, produce toxic metabolites known as cyanotoxins that affect animal health. There are five groups of cyanotoxins classified on the basis of their toxic action: hepatotoxins, neurotoxins, cytotoxins, dermatotoxins and irritant toxins. Microcystin (MC) is a very common and well described hepatotoxin produced by various genera, such as Microcystis, Anabaena, Planktothrix, Anabenopsis, Hapalosiphon and Nostoc. It acts as an inhibitor of serine/threonine protein phosphatase 1 (PP1) and 2A (PP2A), inducing hyperphosphorylation of cell proteins and a variety of toxic changes in hepatocytes often leading to liver insufficiency and death caused by hypovolemic shock. Since the reports on MC toxicity are on the increase this cyanotoxin should be treated as an important environmental factor affecting human and animal health. A brief overview of existing literature on the intake, mechanism of action, and hepatotoxic effects on mammalian animals is presented in this paper
EN
Heavy metal accumulation, physiological status and resistance against Zn and Pb were compared in lichens occurring in metalpolluted (Silesian Upland, S. Poland) and unpolluted (forest complex, NE Poland) areas. Sandy soil near Zn/Pb ore mine had significantly lower (5–35-times) metal content than dolomite-containing ground of mine tailing dump in polluted area (S. Poland). Metal contents in native lichens sampled from those sites followed the same pattern. Total Zn, Pb, Cd and Cu contents in native lichens recorded in two sites of Zn/Pb mining area varied broadly and were considerably higher than in lichens from a control unpolluted site. Independently of the sampling site, epiphytic lichens of higher surface to biovolume ratio (i.e. Candelariella Mull. Arg., Lepraria Ach.) accumulated much more metals (6.05 – 9.57 mg g–1 DW) than lichens of a lower ratio (e.g. 0.25 mg g–1DW in Peltigera didactyla (With.) J.R.Laundon or 0.29 mg g–1 DW in some Cladonia Hill ex Browne). In general, the studied lichens accumulated metals in the following order: Zn>Pb>Cd≥Cu, that was in agreement with the metal content in soils. However, Cladonia furcata (Huds.) Schrad. From tailing dump contained 2-fold more Pb than Zn. Internal Zn and Pb contents (non-exchangeable fraction) in the studied lichens ranged broadly from 17 to 90% of the total metal content. Phaeophytinisation quotients (PhQ), total chlorophyll contents and chl a/b ratios in the native lichens from polluted sites ranged 0.84 – 1.44; 0.514 – 4.858 mg g–1 DW and 2.09 – 5.56, respectively. Experimental exposure of selected species (Hypogymnia physodes (L.) Nyl., Hypocenomyce scalaris (Ach.) Choisy, Lepraria elobata Tonsberg, L. incana (L.) Ach., sampled from the both polluted and unpolluted sites, to high doses of Zn2+ and Pb2+ (0.36 or 0.72 mmol g–1 DW) revealed higher resistance of lichens from the Zn/Pb-polluted sites than con-specific lichens from the unpolluted one. The resistance of epiphytic species from the polluted area to high doses of Zn2+ and Pb2+ increased as follows: H. physodes
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