Changes in ascorbate, glutathione and α-tocopherol concentrations in the brain regions during normal development and moderate hypoglycemia in rats

• Postnatal changes in antioxidant concentrations in the brain regions are unknown.
• Ascorbate, glutathione and α-tocopherol were studied in 7, 14 and 60 day old rats.
• The effect of acute hypoglycemia on the three antioxidants also was determined.
• All three antioxidants were 100–600% higher during development than at adulthood.
• Hypoglycemia led to less antioxidant decrease in developing brain than adult brain.

Ascorbate, glutathione and α-tocopherol are the major low molecular weight antioxidants in the brain. The simultaneous changes in these compounds during normal development, and under a pro-oxidant condition are poorly understood. Ascorbate, glutathione and α-tocopherol concentrations in the olfactory bulb, cerebral cortex, hippocampus, striatum, hypothalamus, midbrain, cerebellum, pons and medulla oblongata were determined in postnatal day (P) 7, P14 and P60 male rats. A separate group of P14 and P60 rats were subjected to acute hypoglycemia, a pro-oxidant condition, prior to tissue collection. The concentrations of all three antioxidants were 100–600% higher in the brain regions at P7 and P14, relative to P60. The neuron-rich anterior brain regions (cerebral cortex and hippocampus) had higher concentrations of all three antioxidants than the myelin-rich posterior regions (pons and medulla oblongata) at P14 and P60. Hypoglycemia had a differential effect on the antioxidants. Glutathione was decreased at both P14 and P60. However, the decrease was localized at P14 and global at P60. Hypoglycemia had no effect on ascorbate and α-tocopherol at either age. Higher antioxidant concentrations in the developing brain may reflect the risk of oxidant stress during the early postnatal period and explain the relative resistance to oxidant-mediated injury at this age.