Effects of trichloroethylene inhalation on proteins of the gerbil brain

Inhalation exposure of adult Mongolian gerbils to 320 ppm of trichloroethylene (TCE) during 8 weeks causes a decrease of soluble proteins per wet weight in frontal cerebral cortex, cerebellar anterior part of the hemispheres and in the posterior part of vermis, as well as in hippocampus, although the levels of S 100, a glial cytoplasmic protein, showed an overgoing increase back to control levels, or a significant increase. In the sensory-motor cortex, an overgoing increase of soluble proteins, as well as of the S 100, were observed during the exposure period. One of the major soluble polypeptides (m.w. 50,000--52,000) of cerebral cortex, the cerebellar hemispheres and the brain stem, decreased at the end of the exposure period. Possible candidates for such a polypeptide are among others the subunit of microtubular protein or a subunit of (Na+K+)-ATPase. The results show that inhalation of TCE effect various brain areas differently. The observed biochemical changes could be interpreted as an adaptation and in some brain areas neuronal cells seem to be more sensitive than glial cells to TCE.