alpha-Tocopherol and ubiquinones in rat brain subjected to decapitation ischemia.

Levels of alpha-tocopherol (alpha-Toc), reduced ubiquinones (QH2) and oxidized ubiquinones (Q) were assayed in rat forebrain subjected to decapitation ischemia. Post-decapitation levels of alpha-Toc decreased by 16% at 3 min and 20% at 15 min. Increases in Q9H2 (83%) and in Q10H2 (107%) were observed immediately following decapitation; thereafter their levels began to decrease and approached to the pre-ischemic values at 15 min. In contrast, Q9 and Q10 tended to increase continuously during ischemia. The data indicate that complete ischemia results in distinct changes in the cerebral content of lipid-soluble antioxidants. The decrease of alpha-Toc may make the brain prone to peroxidative attack when cerebral tissue is subsequently reoxygenated.