| genotoxicity of tetrodotoxin from puffer fish tested in root meristem cells of allium cepa l. | tetrodotoxin (ttx) extracted and purified from puffer fish arothron nigropunctatus was tested for genotoxicity employing the root meristem cells of allium cepa as the assay system. the genotoxicity endpoints investigated were mitotic index (mi), meta-anaphases with spindle aberrations, interphases with micronuclei (mnc) and sister chromatid exchanges (sce) in metaphase chromosomes. the results demonstrated that ttx inhibited mitosis at concentrations of > or = 30 microm as evident by the fall of ... | 1997 | 9237772 |