Chronic exposure to trichloroethylene: lipid and acyl group composition in gerbil cerebral cortex and hippocampus.

Inhalation exposure of Mongolian gerbils to trichloroethylene (50 and 150 ppm) for 12 months caused only small changes in the lipid composition of their cerebral cortex and hippocampus. Total protein content and lipid class distribution were almost unaffected. However, the cholesterol to phospholipid ratio decreased in the cortex of animals exposed to trichloroethylene. This might be due to changes in the relative proportions of different membranes or cellular types. The finding of most interest was among the long-chain polyunsaturated fatty acids where changed ratios were found between long-chain derivatives of the linoleic and the linolenic acid series and a decrease in two minor fatty acids, 20:5 (n-3) and 22:5 (n-3). We think it is likely that such changes occur as a result of peroxidation of polyunsaturated fatty acids or in order to withstand the fluidizing properties of trichloroethylene.