EFFECTS OF TRIMETHYLTIN (TMT) ON GLIAL AND NEURONAL CELLS IN AGGREGATE CULTURES - DEPENDENCE ON THE DEVELOPMENTAL STAGE

Long term effects of trimethyltin (TMT) applied at concentrations belo w the cytotoxic level were examined in three-dimensional cell cultures of fetal rat telencephalon using biochemical, immunochemical and morp hological criteria. It was found that in immature cultures low concent rations of TMT (10(-8) M) specifically induced a gliotic response in a strocytes, with increased immunoreactivity for glial fibrillary acidic protein, and a greater number of astrocytic processes. Significant ch anges in oligodendrocytic and neuronal parameters were found only at 1 0(-6) M of TMT. In differentiated cultures, distinct changes in cell t ype-specific parameters occurred at 10(-6) M of TMT (the lowest effect ive concentration). In addition, different patterns of responses were found for astrocytes and oligodendrocytes, as compared to immature cul tures. These results suggest that among neural cells, astroblasts are most sensitive to TMT, and that the glial responses to this neurotoxic ant are development-dependent. (C) 1995 Intox Press, Inc.