Author/Editor		Milutinović, Aleksandra
Title		Preučevanje kroničnih degenerativnih učinkov mikrocistinov LR in YR na jetra podgane
Type		monografija
Place		Ljubljana
Publisher		Medicinska fakulteta
Publication year		2003
Volume		str. 52
Language		slo
Abstract		Microcystins (MCs), such as microcystin LR (MC-LR) and microcystin YR (MCYR), comprise a family of more than 60 structurally related toxins produced by some strains of cyanobacteria. MCs are taken up into hepatocytes via a specific bile acid carrier. MCs selectively inhibit protein phosphatases 1 and 2A. The acute hyperphosphorylation state induced by large doses of MCs could induce the cytoskeletal damage, intrahepatic hemorrhage and massive necrosis and/or apoptosis of liver cells, while chronic hyperphosphorylation state induced by relatively low doses of MCs is assumed to promote tumour formation. The aim of the study was to evaluate if MC-LR and MC-YR, in chronic exposure of animals with relatively low doses, have the hepatotoxic and/or genotoxic effects. MC-LR and MC-YR were isolated from cyanobacterial bloom from Koseze pond in Ljubljana, Slovenia. Male adult Wistar rats were treated every second day for 8 months with MC-LR (n=5) and MC-YR (n=5) in relatively low doses (10 micro g MC-LR/kg and 10 micro g MCYR/kg i.p., respectively). Control groups were treated either with vehicle (n=5; ethanol and methanol 4:1 v/v) or with physiologic saline (n=4). Magnetic resonance imaging was performed at the beginning and at the end of eight months experimental period. The intensity of the T1- weighted magnetic resonance signal of the liver in the MCtreated groups was significantly increased. Magnetic resonance imaging also showed significantly enlarged liver volume in rats treated with MCs that was confirmed by postmortem volume measurements. Haematoxylin-eosin staining of the sections of livers of rats treated with MCs revealed only insignificant degenerative changes of liver parenchyma. In groups treated with MCs and in both control groups the basophilic, acidophilic, clear cell and fatty degenerative cell foci were found in liver parenchyma. (Abstract truncated at 2000 characters).
Descriptors		LIVER CYANOBACTERIA BACTERIAL TOXINS APOPTOSIS DNA FRAGMENTATION RATS, WISTAR DNA DAMAGE MAGNETIC RESONANCE IMAGING MICROFILAMENTS RHODAMINES BODY WEIGHT