USE OF ASTROCYTES FOR IN-VITRO NEUROTOXICITY TESTING

The use of primary cultures of astrocytes as indicators of toxic poten tial was assessed using 20 selected compounds. Multiple endpoints were used to evaluate astrocyte reactions. Trypan blue dye exclusion and t otal cellular protein content of the cells were used as general indice s. EC,, values from the trypan blue experiments could be used to rank toxicity of compounds in a manner that correlates well with known toxi city for compounds that have specific astrocyte toxicities. Neurone sp ecific neurotoxicants had no measurable effects on astrocytes indicati ng that this system differentiates gliotoxicity from neurotoxicity. Pr otein content, and content of the astrocyte specific glial fibrillary acidic protein (GFAp), were seen to increase at lower doses of gliotox ic compounds. This phenomenon appears to be similar to reactive gliosi s in vivo, as assessed by immunostaining, and is an extremely sensitiv e indication of cellular damage. Support studies using astrocyte uptak e of 2-deoxy glucose showed a similar pattern of activation in the cel ls as protein increases. This has been confirmed using the nonisotopic technique of MTT reduction.