Glutathione metabolism in brain - Metabolic interaction between astrocytesand neurons in the defense against reactive oxygen species

The cells of the adult human brain consume approximate to 20% of the oxygen utilized by the body although the brain comprises only 2% of the body weig ht. Reactive oxygen species, which are produced continuously during oxidati ve metabolism, are generated at high rates within the brain. Therefore, the defense against the toxic effects of reactive oxygen species is an essenti al task within the brain. An important component of the cellular detoxifica tion of reactive oxygen species is the antioxidant glutathione. The main fo cus of this short review is recent results on glutathione metabolism of bra in astrocytes and neurons in culture. These two types of cell prefer differ ent extracellular precursors for glutathione. Glutathione is involved in th e disposal of exogenous peroxides by astrocytes and neurons. In coculture a strocytes protect neurons against the toxicity of reactive oxygen species. One mechanism of this interaction is the supply by astrocytes of glutathion e precursors to neurons.