CONICET | Buscador de Institutos y Recursos Humanos

Abstract Some species of cyanobacteria produce toxins classified according their mode of action into hepatotoxins. Most of hepatotoxins (all cyclic heptapeptides) are microcystins and at least of 50 congeners of microcystins are known, and several of these may be produced during a bloom. Microcystis LR (Myc-LR) the first microcystin identified, the most toxic and common of this hepatotoxins is a potent inhibitor of serine and threonine protein phosphatases type 1 and 2A Acute illnesses and deaths in both human and non human animals following exposures to microcystins contaminated water sources have been reported worldwide. In instances of acute toxicity, liver damage and death occur due to a fatal hepatic congestion and hypovolemic shock. However chronic toxicity could become an important form of exposure due to the use of marginal water supplies or due to the presence of these toxins in the tap water. In the limited number of studies done evidence of hepatic damage has include single cell necrosis, fibrosis and tumor promotion. The propose of this study was to determinate, in a murine model, if the hepatic damage produced by chronic exposure to Myc-LR can be reversed when the exposition ends. The histopathologic analysis of the livers dissected from the mice injected with doses of 25 µg/Kg each two days during one month showed a disrupted lobular architecture and loss of hepatic cells without evidence for apoptotic process and the development of citoplasmatic lipid vacuolas. The recovery of damage was evident at cytological level but the lobular arquitecture recuperation was limited. These results are indicating that an intense process of cell reparation induced by microcystins occur when the exposition ends

enviar mensaje