Dados da Tese de Doutorado
Author: Raquel Moraes Soares.
Title: Aspects of the biodistribution and effects of microcystins (cyanobacteria hepatotoxins) in mammals..
Year: 2005. Full text (in Portuguese)
Abstract
The most commonly reported cyanobacteria toxicosis is caused by microcystins, cyanotoxins described as potent and specific inhibitors of protein phosphatases, especially PP1 and PP2A in liver. The general objective of this study was to contribute to elucidation of MCYSTs accumulation and redistribution processes in animals and human beings, as well as analyzing the effects of these toxins on liver and lung of mice through experiments using sub-lethal doses intraperitoneally injected. The results showed that sub-lethal doses of microcystins damaged the physiology of liver and lung in young and adult animals. However, adult animal livers showed signs of recovery, observed by the increase in protein phosphatases activity as well as the return of glutathione concentration to the control levels. In mice lungs, MCYSTs caused alveolar collapse and an acute inflammatory process since the first hours, being characterized by PMN cells infiltration and intersticial edema. The inflammation probably caused to the observed increase in resistive and viscoelastic pressures and in elastances as well, indicating damage to the respiratory process. The results of studies with serum indicated that microcystins can remain in the organism for a long period. These toxins were detected over 2 months in serum of renal patients who were exposed to water containing MCYSTs during hemodialysis treatment at HUCFF-UFRJ. Therefore, this study contributed to demonstrate that it is always worthed to stand out the importance of monitoring and control of cyanobacteria blooms in recreational and source waters, once this a critical issue to the public health.
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