Author/Editor		Filipič, Metka; Žegura, Bojana; Sedmak, Bojan; Horvat-Žnidaršič, Irena; Milutinovič, Aleksandra; Šuput, Dušan
Title		Subchronic exposure of rats to subletal dose of microcystin-YR induces DNA damage in multiple organs
Translated title		Podaljšana izpostavljenost podgan neletalnim odmerkom mikrocistina-LR povzroči poškodbe DNA v različnih organih
Type		članek
Source		Radiol Oncol
Vol. and No.		Letnik 41, št. 1
Publication year		2007
Volume		str. 15-22
Language		eng
Abstract		Background. Microcystins (MCs) are cyclic heptapeptides that are considered to be liver specific toxins. They are potent tumour promoters and recent studies indicate that they are also genotoxic. In this study we measured DNA damage in lymphocytes, liver, kidney (cortex and medulla), lung, spleen and brain cells of male Fisher F344 rats that were exposed to sublethal dose (every second day 10 Ug/kg b.w.; i.p) of microeysrin-YR (MCYR) for one month. Methods. At the end of exposure the animals were sacrificed, the lymphocytes were isolated from blood taken from jugular vein, liver cells were obtained by perfusion with collagenase A and the cells from other organs were isolated by incubating small tissue pieces with eollagenase A. The DNA damage in isolated cells was measured with the single cells gel electrophoresis (SCGE) also called the comet assay. Results. A significant increase of the % tail DNA in MCYR-exposed animals compared to the nonexposed control ones was observed in brain (2.5 fold), liver (2.1 fold), kidney medulla (1.9 fold), kidney cortex (1.8 fold) and lung (1.7 fold) cells, while the DNA from lymphocytes and spleen cells was not affected. Conclusion. This study demonstrated that subehronic exposure to sublethal doses of MCs can induce systemicgenotoxicity in mammals, and it affects not only the liver but also other vital organs.
Summary		Izhodišča. Mikrocistini (MC) so obročasti hepatapeptidi, za katere velja, da so specifični jetrni strupi. So učinkoviti promoterji tumorjev, novejše raziskave pa kažejo, da so tudi genotoksični. V tej raziskavi smo merili poškodovanost DNA limfocitov, jetrnih, ledvičnih (skorje in sredice), pljučnih, vraničnih in možganskih celic samcev podgan Fisher F344, ki so bill en mesec izpostavljene neletalnim odmerkom mikrocistina-YR (MCYR) (vsak drugi dan 10 mikro g/kg t.m.; i.p). Metode. Po končani izpostavljenosti smo živali žrtvovali. Limfocite smo izolirali iz krvi, odvzete iz podjezične vene, jetrne celice smo izolirali s perfuzijo s kolagenazo A, celice ostalih organov pa smo izolirali z inkubiranjem drobnih koščkov tkiv s kolagenaso A. Poškodovanost DNA izoliranih celic smo merili z elektroforezo posamezne celice, ki jo imenujemo tudi test komet. Rezultati. Pri živalih, ki so bile izpostavljene MCYR, smo ob primerjavi s kontrolnimi živalmi ugotovili značilno povečanje % DNA v repih kometov celic možganov (2,5 krat), jeter (2,1 krat), sredice ledvic (1,9 krat), ledvične skorje (1,8 krat) in pljuč (1,7 krat). DNA limfocitov in celic vranice ni bila poškodovana. Zaključki. Raziskava je pokazala, da podaljšana izpostavljenost neletalnim odmerkom mikrocistinov pri sesalcih lahko povzroči sistemski genotoksični odziv, ki prizadene ne le jetra, ampak tudi druge organe.
Descriptors		DNA DAMAGE BACTERIAL TOXINS CYANOBACTERIA RATS, INBRED F344