Author/Editor		Horvat-Žnidaršič, Irena
Title		Citotoksično in genotoksično delovanje makrocistina YR
Type		monografija
Place		Ljubljana
Publisher		Medicinska fakulteta
Publication year		2001
Volume		str. 111
Language		slo
Abstract		Microcystins are heptapeptides produced by cyanobacteria. The cause of death in acute lethal intoxication is intrahepatic bleeding, and liver is considered as the primary target organ for microcystins. The aim of the present study was to get an insight into the mechanisms of toxic effects of subchronic application of microcystin YR in relatively low sublethal doses, comparable to doses that could be ingested by a population when and where microcystins gain access to the drinking water. Our first hypothesis was that such application of microcystins would lead to a degeneration of liver and other internal organs, especially the kidney. For this purpose the concentrations of serum markers of liver and kidney degeneration were measured, and standard histopathologic techniques were used to assess the morphological changes in the liver and the kidney. Imunohistologic methods, epiflurescence methods and leser scanning confocal microscopy were used in order to demonstrate the effects of microcystins on basal lamina, intermediary filaments, cytoskeleton and cell nuclei. The hypotheses that microcystins and genetoxic and induce apoptosis were tested by use of Comet and TUNEL tests. Subchronic application of sublethal doses of microcystin YR increases the concentration of unspecific markers of tissue injury in the serum of experimental animals. Increased serum concentration of urate, haematuria, proteinuria, and glucosuria suggest kidney damage. Histopathological examination reveals only minor morphological changes in liver parenchyma. Moderate or weak cell degeneration, widening of sinusoidal spaces and hyperemia were the most prominent observations. Kidney damage was more pronounced and wide-spread. The cortex was most severely damaged. Bowman capsules were enlarged, and the capillary plexuses were affected as well. Epithelial cells of the proximal tubules were enlarged and filled with proteins or protein-like material. (Abstract truncated at 2000 characters).
Descriptors		CYANOBACTERIA BACTERIAL TOXINS MUTAGENICITY TESTS KIDNEY LIVER RATS HEMATURIA PROTEINURIA IMMUNOHISTOCHEMISTRY URINALYSIS GLYCOSURIA DNA DAMAGE APOPTOSIS MICROSCOPY, CONFOCAL DISEASE MODELS, ANIMAL