LIPID-COMPOSITION IN SCRAPIE-INFECTED MOUSE-BRAIN - PRION INFECTION INCREASES THE LEVELS OF DOLICHYL-PHOSPHATE AND UBIQUINONE

The neutral and phospholipid composition of mouse brain infected with scrapie prions was investigated, During the later stages of this disea se, the level of dolichol decreased by 30% whereas the level of dolich yl phosphate increased by 30%, In terminally ill mice, there was also a 2.5-fold increase in both total ubiquinone and its reduced form, Fur thermore, alpha-tocopherol was elevated at this stage by 50%, In contr ast, no changes were observed in phospholipid amount, in phospholipid composition, and in phosphatidylethanotamine plasmalogen content durin g the entire disease process, The fatty acid and aldehyde composition of individual phospholipids remained unaltered as well, No modificatio ns could be detected in cholesterol content. Thus, the majority of mem brane lipids in scrapie-infected mouse brain are modified in neither q uantity nor structure, but specific changes occur to a few polyisopren oid lipids, This specificity indicates that, although prions accumulat e in lysosomes, the infection process is not associated with a general membrane destruction caused by lysosomal enzyme leakage.