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Effects of Organotins on Rat Brain Astrocytes in Culture
Author(s) -
RichterLandsberg Christiane,
Besser Andreas
Publication year - 1994
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1994.63062202.x
Subject(s) - vimentin , glial fibrillary acidic protein , cytotoxicity , in vivo , western blot , astrocyte , chemistry , microbiology and biotechnology , cell culture , intermediate filament , staining , in vitro , immunofluorescence , intracellular , neuroglia , biochemistry , biology , cell , cytoskeleton , immunohistochemistry , antibody , central nervous system , immunology , neuroscience , genetics , gene
The interaction of triethyltin (TET) and trimethyltin (TMT) with rat brain astrocytes in vitro was investigated. Both compounds are highly neurotoxic after in vivo application, cause neurobehavioral changes, and elicit neuronal and glial responses in the CNS. In this study, 5‐week‐old cultures were exposed to TMT or TET (0.1–2.5 µ M ) for 24 h. A concentration‐dependent cytotoxicity was observed for both agents by vital dye uptake assay using neutral red (NR). The order of potency for half‐maximal cytotoxicity (NR‐50) was TET (0.7 µ M )> TMT (2.5 µ M ), in agreement with results found after in vivo administration. TET and TMT caused similar morphological changes: large holes extending through the plasma membrane appeared initially in the flattened cell bodies, cytoplasmic extensions were retracted, and long cellular processes formed. Later, the cell bodies rounded up and had only a few extremely long and thin processes. Indirect immunofluorescence staining using anti‐vimentin and anti‐glial fibrillary acidic protein (GFAP) antibodies revealed that the orderly array of the intermediate filament system was severely disturbed. At lower concentrations, an increased bundling was observed, and at higher concentrations the disassembly of the intracellular framework was seen, and cellular staining appeared rather diffuse. Western blot analysis of cellular extracts was carried out to determine the protein levels of GFAP and vimentin. In this culture system, TET and TMT caused an almost two‐fold increase in the levels of GFAP at concentrations around and below NR‐50, indicating that astrocytes react to organotics independently of neuronal signals. Concomitantly, TET (0.7 µ M ) and TMT (2.5 µ M ) led to a 63% decrease in the activity of ecto‐5′‐nucleotidase, which in addition to its enzymatic function, represents a transmembrane cell surface protein and has been implicated in cellular adhesion and cell communication processes. Thus, triorganotins directly affect astrocytes in culture and alter their functional stage even in the absence of neurons.