INACTIVATION OF GLUTATHIONE-PEROXIDASE BY BENZALDEHYDE

Chronic benzaldehyde exposure is known to cause central nervous system (CNS) disturbances. Previous studies have shown that benzaldehyde cau ses the formation of reactive oxygen species (ROS) in rat synaptosomal fractions, Benzaldehyde has also been implicated in ROS formation in the CNS of rats treated with toluene. We have found that benzaldehyde effectively inactivates the antioxidant enzyme glutathione peroxidase (K-i similar or equal to 15 mu M), but has no effect on the other anti oxidant enzymes tested: catalase, superoxide dismutase, and glutathion e reductase, This effect has been found to be specific to benzaldehyde since other structurally related and unrelated aldehydes tested were found to be devoid of inactivating capacity toward glutathione peroxid ase. Since glutathione peroxidase is the main enzyme responsible for r emoval of hydrogen peroxide and organic hydroperoxides in brain, its i nactivation by benzaldehyde may be a main contributor to the observed ROS formation and the observed neurotoxicity caused by either benzalde hyde or toluene exposure. (C) 1996 Academic Press, Inc.