Oxidative Stress and the CNS

Re^2: Symposium 783

Bernhard H.J. Juurlink
juurlink@duke.usask.ca

Dr, Rice,
One thing that puzzles me is why neurons which have a poor ability to reduce oxidized-ascorbate (because of their relatively oxidized cytosol) should have an order of magnitude more ascorbate than astrocytes which have a very good ability to reduce oxidized-ascorbate. Is there any evidence for ascorbate metabolic coupling between neurons and astrocytes with oxidized-ascorbate transferred from neurons to astrocytes and reduced-ascorbate transferred from astrocytes to neuron? It is known that the glucose transporters transport oxidized-ascorbate and there would be a concentration gradient differential tending to move oxidized-ascorbate out of the neuron to the extracellular space and from there to the astrocyte. What about the movement of reduced-ascorbate in the other direction?

Why should there be so much ascorbate in neurons? Does it have a function other than reducing oxidized-tocopherol? What would this be? BJ

Mon Dec 14