Unknown

It was examined the associations of increased glial fibrillary acidic protein (GFAP) levels and hypertrophie changes with susceptibility to toxic insult in C6 rat glioma cells. The cells were treated with serial pulses of dibutyryl-cAMP (dBcAMP) (each 48 hr) which increased levels of GFAP approximately twofold and the surface to volume ratio by approximately 1.7 times after the third pulse. This treatment reduced cell number by 22% and increased total protein by 10%. The cells were then exposed to different toxic substances [tin chloride, lead tetraacetate, chloroquine, cadmium chloride, aluminium chloride, mercuric chloride, acrylamide, triethyltin bromide, ethylenediaminetetraacetatic acid (EDTA)] and toxicity to the cells measured by the neutral red (NR) assay. With the exceptions of aluminium chloride and EDTA, 50% effective concentration (EC(50)) values for the toxic substances were increased up to 10,000 times (for cadmium chloride).